PMCC PMCC

Search tips
Search criteria

Advanced
Results 1-25 (49)
 

Clipboard (0)
None
Journals
Year of Publication
Document Types
1.  Human antimicrobial peptide LL-37 is present in atherosclerotic plaques and induces death of vascular smooth muscle cells: a laboratory study 
Background
Death of smooth muscle cells in the atherosclerotic plaques makes the plaques more prone to rupture, which can initiate an acute ischemic event. The development of atherosclerosis includes the migration of immune cells e.g. monocytes/macrophages and T lymphocytes into the lesions. Immune cells can release antimicrobial peptides. One of these, human cathelicidin antimicrobial peptide hCAP-18, is cleaved by proteinase 3 generating a 4.5 kDa C-terminal fragment named LL-37, which has been shown to be cytotoxic. The aim of the study was to explore a potential role of LL-37 in the pathophysiology of atherosclerosis.
Methods
We investigated the presence of LL-37 in human atherosclerotic lesions obtained at autopsy using immunohistochemistry. The direct effects of LL-37 on cultured vascular smooth muscle cells and isolated neutrophil granulocytes were investigated with morphological, biochemical and flow cytometry analysis.
Results
The neointima of atherosclerotic plaques was found to contain LL-37-like immunoreactivity, mainly in macrophages. In cultured smooth muscle cells, LL-37 at 30 μg/ml caused cell shrinkage, membrane blebbing, nuclear condensation, DNA fragmentation and an increase in caspase-3 activity as studied by microscopy, ELISA and enzyme activity assay, respectively. Flow cytometry demonstrated that LL-37 in a subset of the cells caused a small but rapidly developing increase in membrane permeability to propidium iodide, followed by a gradual development of FITC-annexin V binding. Another cell population stained heavily with both propidium iodide and FITC-annexin V. Neutrophil granulocytes were resistant to these effects of LL-37.
Conclusion
This study shows that LL-37 is present in atherosclerotic lesions and that it induces death of vascular smooth muscle cells. In a subset of cells, the changes indicate the development of apoptosis triggered by an initial mild perturbation of plasma membrane integrity. The findings suggest a role for LL-37 as a mediator of immune cell-induced death of vascular smooth muscle cells in atherosclerosis.
doi:10.1186/1471-2261-6-49
PMCID: PMC1764755  PMID: 17181861
2.  Adherence to cardioprotective medications and mortality among patients with diabetes and ischemic heart disease 
Background
Patients with diabetes and ischemic heart disease (IHD) are at high risk for adverse cardiac outcomes. Clinical practice guidelines recommend multiple cardioprotective medications to reduce recurrent events. We evaluated the association between cardioprotective medication adherence and mortality among patients with diabetes and IHD.
Methods
In a retrospective cohort study of 3,998 patients with diabetes and IHD, we evaluated use of ACE inhibitors or angiotensin receptor blockers, β-blockers, and statin medications. Receipt of cardioprotective medications was based on filled prescriptions. Medication adherence was calculated as the proportion of days covered (PDC) for filled prescriptions. The primary outcome of interest was all-cause mortality.
Results
The majority of patients (92.8%) received at least 1 cardioprotective medication. Patients receiving any medications had lower unadjusted mortality rates compared to patients not receiving any medications (7.9% vs. 11.5%; p = 0.03). In multivariable analysis, receipt of any cardioprotective medication remained associated with lower all-cause mortality (OR 0.65; 95% CI 0.43–0.99). Among patients receiving cardioprotective medications, the majority (80.3%) were adherent (PDC ≥ 0.80). Adherent patients had lower unadjusted mortality rates (6.7% vs. 12.1%; p < 0.01). In multivariable analysis, medication adherence remained associated with lower all-cause mortality (OR 0.52; 95% CI 0.39–0.69) compared to non-adherence. In contrast, there was no mortality difference between patients receiving cardioprotective medications who were non-adherent compared to patients not receiving any medications (OR 1.01; 95% CI 0.64–1.61).
Conclusion
In conclusion, medication adherence is associated with improved outcomes among patients with diabetes and IHD. Quality improvement interventions are needed to increase medication adherence in order for patients to maximize the benefit of cardioprotective medications.
doi:10.1186/1471-2261-6-48
PMCID: PMC1762024  PMID: 17173679
3.  Cardiac involvement in Beagle-based canine X-linked muscular dystrophy in Japan (CXMDJ): electrocardiographic, echocardiographic, and morphologic studies 
Background
Cardiac mortality in Duchenne muscular dystrophy (DMD) has recently become important, because risk of respiratory failure has been reduced due to widespread use of the respirator. The cardiac involvement is characterized by distinctive electrocardiographic abnormalities or dilated cardiomyopathy, but the pathogenesis has remained obscure. In research on DMD, Golden retriever-based muscular dystrophy (GRMD) has attracted much attention as an animal model because it resembles DMD, but GRMD is very difficult to maintain because of their severe phenotypes. We therefore established a line of dogs with Beagle-based canine X-linked muscular dystrophy in Japan (CXMDJ) and examined the cardiac involvement.
Methods
The cardiac phenotypes of eight CXMDJ and four normal male dogs 2 to 21 months of age were evaluated using electrocardiography, echocardiography, and histopathological examinations.
Results
Increases in the heart rate and decreases in PQ interval compared to a normal littermate were detected in two littermate CXMDJ dogs at 15 months of age or older. Distinct deep Q-waves and increase in Q/R ratios in leads II, III, and aVF were detected by 6–7 months of age in all CXMDJ dogs. In the echocardiogram, one of eight of CXMDJ dogs showed a hyperechoic lesion in the left ventricular posterior wall at 5 months of age, but the rest had not by 6–7 months of age. The left ventricular function in the echocardiogram indicated no abnormality in all CXMDJ dogs by 6–7 months of age. Histopathology revealed myocardial fibrosis, especially in the left ventricular posterobasal wall, in three of eight CXMDJ dogs by 21 months of age.
Conclusion
Cardiac involvement in CXMDJ dogs is milder and has slower progression than that described in GRMD dogs. The distinct deep Q-waves have been ascribed to myocardial fibrosis in the posterobasal region of the left ventricle, but our data showed that they precede the lesion on echocardiogram and histopathology. These findings imply that studies of CXMDJ may reveal not only another causative mechanism of the deep Q-waves but also more information on the pathogenesis in the dystrophin-deficient heart.
doi:10.1186/1471-2261-6-47
PMCID: PMC1698931  PMID: 17140458
4.  Study protocol to investigate the effects of testosterone therapy as an adjunct to exercise rehabilitation in hypogonadal males with chronic heart failure 
Background
Testosterone deficiency is a common occurrence in men with chronic heart failure (CHF) and may underpin features of advanced disease, including reduced skeletal muscle mass and fatigue. It is positively correlated with cardiac output and exercise capacity in patients with CHF, whereas a significant improvement in both these parameters has been observed following testosterone replacement therapy. Testosterone therapy has also been shown to reduce circulating levels of inflammatory markers, (TNF-α, sICAM-1 and sVCAM-1) in patients with established coronary artery disease and testosterone deficiency. This pilot study will assess the feasibility of a combined exercise rehabilitation and adjunctive testosterone therapy intervention for evoking improvements in exercise capacity, circulating inflammatory markers, cardiac and skeletal muscle function, indices of psychological health status and quality of life in hypogonadal males with chronic heart failure.
Methods/design
Following ethical approval, 36 patients will be randomly allocated to one of two groups: testosterone or placebo therapy during exercise rehabilitation. A combined programme of moderate intensity aerobic exercise and resistance (strength) training will be used. The primary outcome measure is exercise capacity, assessed using an incremental shuttle walk test. Secondary outcome measures include measures of peak oxygen uptake, cardiac function, lower-limb skeletal muscle contractile function and oxygenation during exercise, circulating inflammatory markers, psychological health status and quality of life.
Discussion
Exercise rehabilitation can safely increase exercise capacity in stable CHF patients but there is a need for studies which are aimed at evaluating the long-term effects of physical training on functional status, morbidity and mortality. This pilot study will provide valuable preliminary data on the efficacy of testosterone therapy as an adjunct to exercise rehabilitation on a range of functional, physiological and health-related outcomes in this patient population. Preliminary data will be used in the design of a large-scale randomised controlled trial, aimed at informing clinical practice with respect to optimisation of exercise rehabilitation in this patient group.
doi:10.1186/1471-2261-6-46
PMCID: PMC1693568  PMID: 17137495
5.  Social and demographic predictors of no transport prior to premature cardiac death: United States 1999–2000 
Background
In the United States, over one-third of premature cardiac deaths occur outside of a hospital, without any transport prior to death. Transport prior to death is a strong, valid indicator of help-seeking behavior. We used national vital statistics data to examine social and demographic predictors of risk of no transport prior to cardiac death. We hypothesized that persons of lower social class, immigrants, non-metropolitan residents, racial/ethnic minorities, men, and younger decedents would be more likely to die prior to transport.
Methods
Our study population consisted of adult residents of the United States, aged 25 to 64 years, who died from heart disease during 1999–2000 (n = 242,406). We obtained transport status from the place of death variable on the death certificate. The independent effects of social and demographic predictor variables on the risk of a cardiac victim dying prior to transport vs. the risk of dying during or after transport to hospital were modeled using logistic regression.
Results
Results contradicted most of our a priori hypotheses. Persons of lower social class, immigrants, most non-metropolitan residents, and racial/ethnic minorities were all at lower risk of dying prior to transport. The greatest protective effect was found for racial/ethnic minority decedents compared with whites. The strongest adverse effect was found for marital status: the risk of dying with no transport was more than twice as high for those who were single (OR 2.35; 95% CI 2.29–2.40) or divorced (OR 2.29; 95% CI 2.24–2.34), compared with married decedents. Geographically, residents of the Western United States were at a 47% increased risk of dying prior to transport compared with residents of the metropolitan South.
Conclusion
Our results suggest that marital status, a broad marker of household structure, social networks, and social support, is more important than social class or race/ethnicity as a predictor of access to emergency medical services for persons who suffer an acute cardiac event. Future research should focus on ascertaining "event histories" for all acute cardiac events that occur in a community, with the goal of identifying the residents most susceptible to cardiac fatalities prior to medical intervention and transport.
doi:10.1186/1471-2261-6-45
PMCID: PMC1654180  PMID: 17107613
6.  Mitochondrial oxidative stress and nitrate tolerance – comparison of nitroglycerin and pentaerithrityl tetranitrate in Mn-SOD+/- mice 
Background
Chronic therapy with nitroglycerin (GTN) results in a rapid development of nitrate tolerance which is associated with an increased production of reactive oxygen species (ROS). According to recent studies, mitochondrial ROS formation and oxidative inactivation of the organic nitrate bioactivating enzyme mitochondrial aldehyde dehydrogenase (ALDH-2) play an important role for the development of nitrate and cross-tolerance.
Methods
Tolerance was induced by infusion of wild type (WT) and heterozygous manganese superoxide dismutase mice (Mn-SOD+/-) with ethanolic solution of GTN (12.5 μg/min/kg for 4 d). For comparison, the tolerance-free pentaerithrityl tetranitrate (PETN, 17.5 μg/min/kg for 4 d) was infused in DMSO. Vascular reactivity was measured by isometric tension studies of isolated aortic rings. ROS formation and aldehyde dehydrogenase (ALDH-2) activity was measured in isolated heart mitochondria.
Results
Chronic GTN infusion lead to impaired vascular responses to GTN and acetylcholine (ACh), increased the ROS formation in mitochondria and decreased ALDH-2 activity in Mn-SOD+/- mice. In contrast, PETN infusion did not increase mitochondrial ROS formation, did not decrease ALDH-2 activity and accordingly did not lead to tolerance and cross-tolerance in Mn-SOD+/- mice. PETN but not GTN increased heme oxygenase-1 mRNA in EA.hy 926 cells and bilirubin efficiently scavenged GTN-derived ROS.
Conclusion
Chronic GTN infusion stimulates mitochondrial ROS production which is an important mechanism leading to tolerance and cross-tolerance. The tetranitrate PETN is devoid of mitochondrial oxidative stress induction and according to the present animal study as well as numerous previous clinical studies can be used without limitations due to tolerance and cross-tolerance.
doi:10.1186/1471-2261-6-44
PMCID: PMC1654181  PMID: 17092343
7.  Effects of self-management intervention on health outcomes of patients with heart failure: a systematic review of randomized controlled trials 
Background
Heart failure is the most common cause of hospitalization among adults over 65. Over 60% of patients die within 10 years of first onset of symptoms. The objective of this study is to determine the effectiveness of self-management interventions on hospital readmission rates, mortality, and health-related quality of life in patients diagnosed with heart failure.
Methods
The study is a systematic review of randomized controlled trials. The following data sources were used: MEDLINE (1966-11/2005), EMBASE (1980-11/2005), CINAHL (1982-11/2005), the ACP Journal Club database (to 11/2005), the Cochrane Central Trial Registry and the Cochrane Database of Systematic Reviews (to 11/2005); article reference lists; and experts in the field. We included randomized controlled trials of self-management interventions that enrolled patients 18 years of age or older who were diagnosed with heart failure. The primary outcomes of interest were all-cause hospital readmissions, hospital readmissions due to heart failure, and mortality. Secondary outcomes were compliance with treatment and quality of life scores. Three reviewers independently assessed the quality of each study and abstracted the results. For each included study, we computed the pooled odds ratios (OR) for all-cause hospital readmission, hospital readmission due to heart failure, and death. We used a fixed effects model to quantitatively synthesize results. We were not able to pool effects on health-related quality of life and measures of compliance with treatment, but we summarized the findings from the relevant studies. We also summarized the reported cost savings.
Results
From 671 citations that were identified, 6 randomized trials with 857 patients were included in the review. Self-management decreased all-cause hospital readmissions (OR 0.59; 95% confidence interval (CI) 0.44 to 0.80, P = 0.001) and heart failure readmissions (OR 0.44; 95% CI 0.27 to 0.71, P = 0.001). The effect on mortality was not significant (OR = 0.93; 95% CI 0.57 to 1.51, P = 0.76). Adherence to prescribed medical advice improved, but there was no significant difference in functional capabilities, symptom status and quality of life. The reported savings ranged from $1300 to $7515 per patient per year.
Conclusion
Self-management programs targeted for patients with heart failure decrease overall hospital readmissions and readmissions for heart failure.
doi:10.1186/1471-2261-6-43
PMCID: PMC1660572  PMID: 17081306
8.  Smoking status and common carotid artery intima-medial thickness among middle-aged men and women based on ultrasound measurement: a cohort study 
Background
Cigarette smoking is an established causal factor for atherosclerosis. However, the smoking effect on different echogenic components of carotid arterial wall measured by ultrasound is not well elucidated.
Methods
Middle-aged men and women who had IMT measurement ≥ 0.7 mm at baseline and follow-up were included (N = 413, age 40–60 years at baseline in 1995). Intima-media thickness of common carotid artery (CCA-IMT) and its components (echogenic and echolucent layers) were measured at baseline and in the follow-up examination 3 years later. IMT and its components were compared across current, former and never smokers. Individual growth models were used to examine how smoking status was related to the baseline and progression of overall IMT and IMT components.
Results
For both men and women, current smoking was associated with thicker echogenic layer than never smokers; former smokers exhibited thinner echogenic layer than current smokers after adjustment for cigarette pack-years. Among women, current smoking was also associated with a thinned echolucent layer that resulted in a non-significant overall association of current smoking with IMT for women.
Conclusion
Cigarette smoking is associated with carotid artery morphological changes and the association is sex-dependent. The atherogenic effect of smoking appears to be partly reversible among former smokers. IMT measurement alone may not be adequate to detect carotid atherosclerosis associated with cigarette smoking among middle-age women.
doi:10.1186/1471-2261-6-42
PMCID: PMC1634872  PMID: 17067397
9.  The impact of diabetes on one-year health status outcomes following acute coronary syndromes 
Background
Diabetes is an important predictor of mortality patients with ACS. However, little is known about the association between diabetes and health status after ACS. The objective of this study was to examine the association between diabetes and patients' health status outcomes one year after an acute coronary syndrome (ACS).
Methods
This was a prospective cohort study of patients hospitalized with ACS. Patients were evaluated at baseline and one year with the Seattle Angina Questionnaire (SAQ). Socio-demographic and clinical characteristics were ascertained during index ACS hospitalization. One year SAQ Angina Frequency, Physical Limitation, and Health-Related Quality of Life (HRQoL) scales were the primary outcomes of the study.
Results
Of 1199 patients, 326 (37%) had diabetes. Patients with diabetes were more likely to present with unstable angina (52% vs. 40%; p < 0.001), less likely to present with STEMI (20% vs. 31%; p < 0.001), and less likely to undergo coronary angiography (68% vs. 82%; p < 0.001). In multivariable analyses, the presence of diabetes was associated with significantly more angina (OR 1.36; 95% CI 1.01–1.38), cardiac-related physical limitation (OR 1.94; 95% CI 1.57–3.24) and HRQoL deficits (OR 1.43; 95% CI 1.01–2.04) at one year.
Conclusion
Diabetes is associated with more angina, worse physical limitation, and worse HRQoL one year after an ACS. Future studies should assess whether health status outcomes of patients with diabetes could be improved through more aggressive ACS treatment or post-discharge surveillance and angina management.
doi:10.1186/1471-2261-6-41
PMCID: PMC1635061  PMID: 17062160
10.  Amlodipine versus angiotensin II receptor blocker; control of blood pressure evaluation trial in diabetics (ADVANCED-J) 
Background
The coexistence of type 2 diabetes mellitus and hypertension increases the risk of cardiovascular diseases. The U.K. Prospective Diabetes Study has shown that blood pressure control as well as blood glucose control is efficient for prevention of complications in hypertensive patients with diabetes mellitus. However, some reports have shown that it is difficult to control the blood pressure and the concomitant use of a plurality of drugs is needed in hypertensive patients with diabetes mellitus. In recent years renin-angiotensin system depressants are increasingly used for the blood pressure control in diabetic patients. Particularly in Japan, angiotensin II (A II) antagonists are increasingly used. However, there is no definite evidence of the point of which is efficient for the control, the increase in dose of A II antagonist or the concomitant use of another drug, in hypertensive patients whose blood pressure levels are inadequately controlled with A II antagonist.
Methods/Design
Hypertensive patients of age 20 years or over with type 2 diabetes mellitus who have been treated by the single use of AII antagonist at usual doses for at least 8 weeks or patients who have been treated by the concomitant use of AII antagonist and an antihypertensive drug other than calcium channel blockers and ACE inhibitors at usual doses for at least 8 weeks are included.
Discussion
We designed a multi-center, prospective, randomized, open label, blinded-endpoint trial, ADVANCED-J, to compare the increases in dose of A II antagonist and the concomitant use of a Ca-channel blocker (amlodipine) and A II antagonist in hypertensive patients with diabetes mellitus, whose blood pressure levels were inadequately controlled with A II antagonist. This study is different from the usual previous studies in that home blood pressures are assessed as indicators of evaluation of blood pressure. The ADVANCED-J study may have much influence on selection of antihypertensive drugs for treatment in hypertensive patients with diabetes mellitus. It is expected to give an important hint for considering the validity of selection of antihypertensive drugs from the aspects not only of the antihypertensive effect but medical cost-effectiveness.
doi:10.1186/1471-2261-6-39
PMCID: PMC1615874  PMID: 17029631
11.  Estrogens, selective estrogen receptor modulators, and a selective estrogen receptor down-regulator inhibit endothelial production of tissue factor pathway inhibitor 1 
Background
Hormone therapy, oral contraceptives, and tamoxifen increase the risk of thrombotic disease. These compounds also reduce plasma content of tissue factor pathway inhibitor-1 (TFPI), which is the physiological inhibitor of the tissue factor pathway of coagulation. The current aim was to study if estrogens and estrogen receptor (ER) modulators may inhibit TFPI production in cultured endothelial cells and, if so, identify possible mechanisms involved.
Methods
Human endothelial cell cultures were treated with 17β-estradiol (E2), 17α-ethinylestradiol (EE2), tamoxifen, raloxifene, or fulvestrant. Protein levels of TFPI in cell media and cell lysates were measured by an enzyme-linked immunosorbent assay, and TFPI mRNA levels were assessed by quantitative PCR. Expression of ERα was analysed by immunostaining.
Results
All compounds (each in a concentration of 10 nM) reduced TFPI in cell medium, by 34% (E2), 21% (EE2), 16% (tamoxifen), and 28% (raloxifene), respectively, with identical inhibitory effects on cellular TFPI levels. Expression of TFPI mRNA was principally unchanged. Treatment with fulvestrant, which was also associated with down-regulation of secreted TFPI (9% with 10 nM and 26% with 1000 nM), abolished the TFPI-inhibiting effect of raloxifene, but not of the other compounds. Notably, the combination of 1000 nM fulvestrant and 10 nM raloxifene increased TFPI secretion, and, conversely, 10 nM of either tamoxifen or raloxifene seemed to partly (tamoxifen) or fully (raloxifene) counteract the inhibitory effect of 1000 nM fulvestrant. The cells did not express the regular nuclear 66 kDa ERα, but instead a 45 kDa ERα, which was not regulated by estrogens or ER modulators.
Conclusion
E2, EE2, tamoxifen, raloxifene, and fulvestrant inhibited endothelial production of TFPI by a mechanism apparently independent of TFPI transcription.
doi:10.1186/1471-2261-6-40
PMCID: PMC1609184  PMID: 17029634
12.  Homocysteine, vitamin B12 and folate levels in premature coronary artery disease 
Background
Hyperhomocysteinemia is known as an independent risk factor of atherosclerosis, but the probable role of hyperhomocysteinemia in premature Coronary Artery Disease (CAD) is not well studied. The aim of this study was to assess the role of hyperhomocysteinemia, folate and Vitamin B12 deficiency in the development of premature CAD.
Methods
We performed an analytical case-control study on 294 individuals under 45 years (225 males and 69 females) who were admitted for selective coronary angiography to two centers in Tehran.
Results
After considering the exclusion criteria, a total number of 225 individuals were enrolled of which 43.1% had CAD. The mean age of participants was 39.9 +/- 4.3 years (40.1 +/- 4.2 years in males and 39.4 +/- 4.8 years in females). Compared to the control group, the level of homocysteine measured in the plasma of the male participants was significantly high (14.9 +/- 1.2 versus 20.3 +/- 1.9 micromol/lit, P = 0.01). However there was no significant difference in homocysteine level of females with and without CAD (11.8 +/- 1.3 versus 11.5 ± 1.1 micromol/lit, P = 0.87). Mean plasma level of folic acid and vitamin B12 in the study group were 6.3 +/- 0.2 and 282.5 +/- 9.1 respectively. Based on these findings, 10.7% of the study group had folate deficiency while 26.6% had Vitamin B12 deficiency. Logistic regression analysis for evaluating independent CAD risk factors showed hyperhomocysteinemia as an independent risk factor for premature CAD in males (OR = 2.54 0.95% CI 1.23 to 5.22, P = 0.01). Study for the underlying causes of hyperhomocysteinemia showed that male gender and Vitamin B12 deficiency had significant influence on incidence of hyperhomocysteinemia.
Conclusion
We may conclude that hyperhomocysteinemia is an independent risk factor for CAD in young patients (bellow 45 years old) – especially in men -and vitamin B12 deficiency is a preventable cause of hyperhomocysteinemia.
doi:10.1186/1471-2261-6-38
PMCID: PMC1592513  PMID: 17002799
13.  Heritability and major gene effects on left ventricular mass in the Chinese population: a family study 
Background
Genetic components controlling for echocardiographically determined left ventricular (LV) mass are still unclear in the Chinese population.
Methods
We conducted a family study from the Chin-San community, Taiwan, and a total of 368 families, 1145 subjects, were recruited to undergo echocardiography to measure LV mass. Commingling analysis, familial correlation, and complex segregation analysis were applied to detect component distributions and the mode of inheritance.
Results
The two-component distribution model was the best-fitting model to describe the distribution of LV mass. The highest familial correlation coefficients were mother-son (0.379, P < .0001) and father-son (0.356, P < .0001). Genetic heritability (h2) of LV mass was estimated as 0.268 ± 0.061 (P < .0001); it decreased to 0.153 ± 0.052 (P = .0009) after systolic blood pressure adjustment. Major gene effects with polygenic components were the best-fitting model to explain the inheritance mode of LV mass. The estimated allele frequency of the gene was 0.089.
Conclusion
There were significant familial correlations, heritability and a major gene effect on LV mass in the population-based families.
doi:10.1186/1471-2261-6-37
PMCID: PMC1579230  PMID: 16945138
14.  Management of patients with uncontrolled arterial hypertension – the role of electronic compliance monitoring, 24-h ambulatory blood pressure monitoring and Candesartan/HCT 
Background
Incomplete drug regimen compliance (DRC) and white-coat hypertension are two of several possible causes of uncontrolled hypertension. Therefore the aim of the present study was to compare DRC in hypertensives treated with combination therapy whose blood pressures (BP) were controlled vers. uncontrolled after 4 weeks of self-monitored BP measurement. To observe the consequences in uncontrolled patients of switching one drug of the combination therapy to candesartan/HCTZ (16 mg/12.5 mg) with and without a compliance intervention program.
Methods
Self-and ambulatory-monitoring of BP were done with upper arm oscillometric devices. Patients' dosing histories were compiled electronically (MEMS(c), AARDEX). Patients with office blood pressure (OBP) >140/90 mmHg despite combination therapy were begun on MEMS monitoring and self BP measurement for 4 weeks of run-in. Of 62 such patients, 18 (29%) patients were normotensive according to self BP measurement and ambulatory BP measurement at 4 weeks (Group A); in the remaining 44 still uncontrolled patients, candesartan/HCTZ was substituted for one of the combination therapy drugs, with half these patients receiving passive compliance monitoring (B) and half a DRC intervention program (C). All groups were then followed for 8 weeks.
Results
DRC before week 4 was significantly higher in A than in the uncontrolled patients (B&C). DRC was stable during run-in A, but declined in B and C. DRC after week 4 was not different in the three groups and stayed constant over time. DRC during weekends was lower than during weekdays in all groups.
In group A no significant change in blood pressure was observed with all three methods of BP measurements. In groups B and C significant reductions of systolic and diastolic BP were observed for ABPM and SBPM. After the change to candesartan/HCTZ in B&C ambulatory 24-h-BP (ABPM) was normalized in 39% of patients.
Conclusion
Normalization of BP was associated with superior drug regimen compliance in previously uncontrolled patients treated with a combination drug regimen. Switching still-uncontrolled patients to candesartan/HCTZ significantly improved BP control and stabilized a declining DRC.
doi:10.1186/1471-2261-6-36
PMCID: PMC1590051  PMID: 16942618
15.  Endothelial dysfunction is associated with carotid plaque: a cross-sectional study from the population based Northern Manhattan Study 
Background
Impaired vascular function occurs early in atherogenesis. Brachial flow mediated dilatation (FMD) is a non-invasive measure of vascular function and may be an important marker of preclinical atherosclerosis. Data on the association between FMD and carotid plaque in multi-ethnic populations are limited. The objective of this study was to determine whether endothelial dysfunction is independently associated with carotid plaque in a community of northern Manhattan.
Methods
In the population-based Northern Manhattan Study (NOMAS), high-resolution B-mode ultrasound images of the brachial and carotid arteries were obtained in 643 stroke-free subjects (mean age 66 years; 55% women; 65% Caribbean-Hispanic, 17% African-American, 16% Caucasian). Brachial FMD was measured during reactive hyperemia. Maximum carotid plaque thickness (MCPT) was measured at the peak plaque prominence.
Results
The mean brachial FMD was 5.78 ± 3.83 %. Carotid plaque was present in 339 (53%) subjects. The mean MCPT was 1.68 ± 0.82 mm, and the 75th percentile was 2.0 mm. Reduced FMD was significantly associated with increased MCPT. After adjusting for demographics, vascular risk factors, and education, each percent of FMD decrease was associated with a significant 0.02 mm increase in MCPT (p = 0.028). In a dichotomous adjusted model, blunted FMD was associated with an increased risk of MCPT ≥ 2.0 mm (OR, 1.11 for every 1% decrease in FMD; 95% CI, 1.03–1.19).
Conclusion
Decreased brachial FMD is independently associated with carotid plaque. Non-invasive evaluation of endothelial dysfunction may be a useful marker of preclinical atherosclerosis and help to individualize cardiovascular risk assessment beyond traditional risk factors.
doi:10.1186/1471-2261-6-35
PMCID: PMC1560160  PMID: 16916467
16.  Funnel plots, performance variation and the Myocardial Infarction National Audit Project 2003–2004 
Background
Clinical governance requires health care professionals to improve standards of care and has resulted in comparison of clinical performance data. The Myocardial Infarction National Audit Project (a UK cardiology dataset) tabulates its performance. However funnel plots are the display method of choice for institutional comparison. We aimed to demonstrate that funnel plots may be derived from MINAP data and allow more meaningful interpretation of data.
Methods
We examined the attainment of National Service Framework standards for all hospitals (n = 230) and all patients (n = 99,133) in the MINAP database between 1st April 2003 and 31st March 2004. We generated funnel plots (with control limits at 3 sigma) of Door to Needle and Call to Needle thrombolysis times, and the use of aspirin, beta-blockers and statins post myocardial infarction.
Results
Only 87,427 patients fulfilled criteria for analysis of the use of secondary prevention drugs and 15,111 patients for analysis by Door to Needle and Call to Needle times (163 hospitals achieved the standards for Door to Needle times and 215 were within or above their control limits). One hundred and sixteen hospitals fell outside the 'within 25%' and 'more than 25%' standards for Call to Needle times, but 28 were below the lower control limits. Sixteen hospitals failed to reach the standards for aspirin usage post AMI and 24 remained below the lower control limits. Thirty hospitals were below the lower CL for beta-blocker usage and 49 outside the standard. Statin use was comparable.
Conclusion
Funnel plots may be applied to a complex dataset and allow visual comparison of data derived from multiple health-care units. Variation is readily identified permitting units to appraise their practices so that effective quality improvement may take place.
doi:10.1186/1471-2261-6-34
PMCID: PMC1555633  PMID: 16884535
17.  A new efficient trial design for assessing reliability of ankle-brachial index measures by three different observer groups 
Background
The usual method of assessing the variability of a measure such as the ankle brachial index (ABI) as a function of different observer groups is to obtain repeated measurements. Because the number of possible observer-subject combinations is impractically large, only a few small studies on inter- and intraobserver variability of ABI measures have been carried out to date. The present study proposes a new and efficient study design. This paper describes the study methodology.
Methods
Using a partially balanced incomplete block design, six angiologists, six primary-care physicians and six trained medical office assistants performed two ABI measurements each on six individuals from a group of 36 unselected subjects aged 65–70 years. Each test subject is measured by one observer from each of the three observer groups, and each observer measures exactly six of the 36 subjects in the group. Each possible combination of two observers occurs exactly once per patient and is not repeated on a second subject. The study involved four groups of 36 subjects (144), plus standbys.
Results
The 192 volunteers present at the study day were similar in terms of demographic characteristics and vascular risk factors: mean age 68.6 ± 1.7; mean BMI 29.1 ± 4.6; mean waist-hip ratio 0.92 ± 0.09; active smokers 12%; hypertension 60.9%; hypercholesterolemia 53.4%; diabetic 17.2%. A complete set of ABI measurements (three observers performing two Doppler measurements each) was obtained from 108 subjects. From all other subjects at least one ABI measurement was obtained. The mean ABI was 1.08 (± 0.13), 15 (7.9%) volunteers had an ABI <0.9, and none had an ABI >1.4, i.e. a ratio that may be associated with increased stiffening of the arterial walls.
Conclusion
This is the first large-scale study investigating the components of variability and thus reliability in ABI measurements. The advantage of the new study design introduced here is that only one sixth of the number of theoretically possible measurements is required to obtain information about measurement errors. Bland-Altman plots show that there are only small differences and no systematic bias between the observers from three occupational groups with different training backgrounds.
doi:10.1186/1471-2261-6-33
PMCID: PMC1560394  PMID: 16872534
18.  Edge restenosis: impact of low dose irradiation on cell proliferation and ICAM-1 expression 
Background
Low dose irradiation (LDI) of uninjured segments is the consequence of the suggestion of many authors to extend the irradiation area in vascular brachytherapy to minimize the edge effect. Atherosclerosis is a general disease and the uninjured segment close to the intervention area is often atherosclerotic as well, consisting of neointimal smooth muscle cells (SMC) and quiescent monocytes (MC). The current study imitates this complex situation in vitro and investigates the effect of LDI on proliferation of SMC and expression of intercellular adhesion molecule-1 (ICAM-1) in MC.
Methods
Plaque tissue from advanced primary stenosing lesions of human coronary arteries (9 patients, age: 61 ± 7 years) was extracted by local or extensive thrombendarterectomy. SMC were isolated and identified by positive reaction with smooth muscle α-actin. MC were isolated from buffy coat leukocytes using the MACS cell isolation kit. For identification of MC flow-cytometry analysis of FITC-conjugated CD68 and CD14 (FACScan) was applied. SMC and MC were irradiated using megavoltage photon irradiation (CLINAC2300 C/D, VARIAN, USA) of 6 mV at a focus-surface distance of 100 cm and a dose rate of 6 Gy min-1 with single doses of 1 Gy, 4 Gy, and 10 Gy. The effect on proliferation of SMC was analysed at day 10, 15, and 20. Secondly, total RNA of MC was isolated 1 h, 2 h, 3 h, and 4 h after irradiation and 5 μg of RNA was used in standard Northern blot analysis with ICAM-1 cDNA-probes.
Results
Both inhibitory and stimulatory effects were detected after irradiation of SMC with a dose of 1 Gy. At day 10 and 15 a significant antiproliferative effect was found; at day 20 after irradiation cell proliferation was significantly stimulated. Irradiation with 4 Gy and 10 Gy caused dose dependent inhibitory effects at day 10, 15, and 20. Expression of ICAM-1 in human MC was neihter inhibited nor stimulated by LDI.
Conclusion
Thus, the stimulatory effect of LDI on SMC proliferation at day 20 days after irradiation may be the in vitro equivalent of a beginning edge effect. Extending the irradiation area in vascular brachytherapy in vivo may therefore merely postpone and not inhibit the edge effect. The data do not indicate that expression of ICAM-1 in quiescent MC is involved in the process.
doi:10.1186/1471-2261-6-32
PMCID: PMC1526455  PMID: 16827927
19.  An examination of factors influencing the choice of therapy for patients with coronary artery disease 
Background
A diverse range of factors influence clinicians' decisions regarding the allocation of patients to different treatments for coronary artery disease in routine cardiology clinics. These include demographic measures, risk factors, co-morbidities, measures of objective cardiac disease, symptom reports and functional limitations. This study examined which of these factors differentiated patients receiving angioplasty from medication; bypass surgery from medication; and bypass surgery from angioplasty.
Methods
Univariate and multivariate logistic regression analyses were conducted on patient data from 214 coronary artery disease patients who at the time of recruitment had been received a clinical assessment and were reviewed by their cardiologist in order to determine the form of treatment they were to undergo: 70 would receive/continue medication, 71 were to undergo angioplasty and 73 were to undergo bypass surgery.
Results
Analyses differentiating patients receiving angioplasty from medication produced 9 significant univariate predictors, of which 5 were also multivariately significant (left anterior descending artery disease, previous coronary interventions, age, hypertension and frequency of angina). The analyses differentiating patients receiving surgery from angioplasty produced 12 significant univariate predictors, of which 4 were multivariately significant (limitations in mobility range, circumflex artery disease, previous coronary interventions and educational level). The analyses differentiating patients receiving surgery from medication produced 14 significant univariate predictors, of which 4 were multivariately significant (left anterior descending artery disease, previous cerebral events, limitations in mobility range and circumflex artery disease).
Conclusion
Variables emphasised in clinical guidelines are clearly involved in coronary artery disease treatment decisions. However, variables beyond these may also be important factors when therapy decisions are undertaken thus their roles require further investigation.
doi:10.1186/1471-2261-6-31
PMCID: PMC1544353  PMID: 16820053
20.  Effects of an interactive CD-program on 6 months readmission rate in patients with heart failure – a randomised, controlled trial [NCT00311194] 
Background
Disease-management programmes including patient education have promoted improvement in outcome for patients with heart failure. However, there is sparse evidence concerning which component is essential for success, and very little is known regarding the validity of methods or material used for the education.
Methods
Effects of standard information to heart failure patients given prior to discharge from hospital were compared with additional education by an interactive program on all-cause readmission or death within 6 months. As a secondary endpoint, patients' general knowledge of heart failure and its treatment was tested after 2 months.
Results
Two hundred and thirty patients were randomised to standard information (S) or additional CD-ROM education (E). In (S) 52 % reached the endpoint vs. 49 % in (E). This difference was not significant. Of those who completed the questionnaire (37 %), patients in (E) achieved better knowledge and a marginally better outcome.
Conclusion
The lack of effect on the readmission rate could be due to an insufficient sample size but might also indicate that in pharmacologically well-treated patients there is little room for altering the course of the condition. As there was some indication that patients who knew more about their condition might fare better, the place for intensive education and support of heart failure patients has yet to be determined.
doi:10.1186/1471-2261-6-30
PMCID: PMC1526456  PMID: 16796760
21.  Evaluation of CXCL9 and CXCL10 as circulating biomarkers of human cardiac allograft rejection 
Background
Cardiac allograft rejection remains a significant clinical problem in the early phase after heart transplantation and requires frequent surveillance with endomyocardial biopsy. However, this is an invasive procedure, which is unpleasant for the patient and carries a certain risk. Therefore, a sensitive non-invasive biomarker of acute rejection would be desirable.
Methods
Endomyocardial tissue samples and serum were obtained in connection with clinical biopsies from twenty consecutive heart transplant patients followed for six months. A rejection episode was observed in 14 patients (11 men and 3 women) and biopsies obtained before, during and after the episode were identified. Endomyocardial RNA, from three patients, matching these three points in time were analysed with DNA microarray. Genes showing up-regulation during rejection followed by normalization after the rejection episode were evaluated further with real-time RT-PCR. Finally, ELISA was performed to investigate whether change in gene-regulation during graft rejection was reflected in altered concentrations of the encoded protein in serum.
Results
Three potential cardiac allograft rejection biomarker genes, chemokine (C-X-C motif) ligand 9 (CXCL9), chemokine (C-X-C motif) ligand 10 (CXCL10) and Natriuretic peptide precursor A (NPPA), from the DNA microarray analysis were selected for further evaluation. CXCL9 was significantly upregulated during rejection (p < 0.05) and CXCL10 displayed a similar pattern without reaching statistical significance. Serum levels of CXCL9 and CXCL10 were measured by ELISA in samples from 10 patients before, during and after cardiac rejection. There were no changes in CXCL9 and CXCL10 serum concentrations during cardiac rejection. Both chemokines displayed large individual variations in the selected samples, but the serum levels between the two chemokines correlated (p < 0.001).
Conclusion
We conclude, that despite a distinct up-regulation of CXCL9 mRNA in human hearts during cardiac allograft rejection, this was not reflected in the serum levels of the encoded protein. Thus, in contrast to previous suggestions, serum CXCL9 does not appear to be a promising serum biomarker for cardiac allograft rejection.
doi:10.1186/1471-2261-6-29
PMCID: PMC1569871  PMID: 16780603
22.  One year follow-up of patients with refractory angina pectoris treated with enhanced external counterpulsation 
Background
Enhanced external counterpulsation (EECP) is a non-invasive technique that has been shown to be effective in reducing both angina and myocardial ischemia in patients not responding to medical therapy and without revascularization alternatives. The aim of the present study was to assess the long-term outcome of EECP treatment at a Scandinavian centre, in relieving angina in patients with chronic refractory angina pectoris.
Methods
55 patients were treated with EECP. Canadian cardiovascular society (CCS) class, antianginal medication and adverse clinical events were collected prior to EECP, at the end of the treatment, and at six and 12 months after EECP treatment. Clinical signs and symptoms were recorded.
Results
EECP treatment significantly improved the CCS class in 79 ± 6% of the patients with chronic angina pectoris (p < 0.001). The reduction in CCS angina class was seen in patients with CCS class III and IV and persisted 12 months after EECP treatment. There was no significant relief in angina in patients with CCS class II prior to EECP treatment. 73 ± 7% of the patients with a reduction in CCS class after EECP treatment improved one CCS class, and 22 ± 7% of the patients improved two CCS classes. The improvement of two CCS classes could progress over a six months period and tended to be more prominent in patients with CCS class IV. In accordance with the reduction in CCS classes there was a significant decrease in the weekly nitroglycerin usage (p < 0.05).
Conclusion
The results from the present study show that EECP is a safe treatment for highly symptomatic patients with refractory angina. The beneficial effects were sustained during a 12-months follow-up period.
doi:10.1186/1471-2261-6-28
PMCID: PMC1513599  PMID: 16776842
23.  Loss of lag-response curvilinearity of indices of heart rate variability in congestive heart failure 
Background
Heart rate variability (HRV) is known to be impaired in patients with congestive heart failure (CHF). Time-domain analysis of ECG signals traditionally relies heavily on linear indices of an essentially non-linear phenomenon. Poincaré plots are commonly used to study non-linear behavior of physiologic signals. Lagged Poincaré plots incorporate autocovariance information and analysis of Poincaré plots for various lags can provide interesting insights into the autonomic control of the heart.
Methods
Using Poincaré plot analysis, we assessed whether the relation of the lag between heart beats and HRV is altered in CHF. We studied the influence of lag on estimates of Poincaré plot indices for various lengths of beat sequence in a public domain data set (PhysioNet) of 29 subjects with CHF and 54 subjects with normal sinus rhythm.
Results
A curvilinear association was observed between lag and Poincaré plot indices (SD1, SD2, SDLD and SD1/SD2 ratio) in normal subjects even for a small sequence of 50 beats (p value for quadratic term 3 × 10-5, 0.002, 3.5 × 10-5 and 0.0003, respectively). This curvilinearity was lost in patients with CHF even after exploring sequences up to 50,000 beats (p values for quadratic term > 0.5).
Conclusion
Since lagged Poincaré plots incorporate autocovariance information, these analyses provide insights into the autonomic control of heart rate that is influenced by the non-linearity of the signal. The differences in lag-response in CHF patients and normal subjects exist even in the face of the treatment received by the CHF patients.
doi:10.1186/1471-2261-6-27
PMCID: PMC1523370  PMID: 16768800
24.  Modular prevention of heart disease following acute coronary syndrome (ACS) [ISRCTN42984084] 
Background
Coronary heart disease (CHD) is a major cause of morbidity and mortality in Australia and it is recommended that all persons with unstable angina (UA) or myocardial infarction (MI) participate in secondary prevention as offered in cardiac rehabilitation (CR) programs. However, the majority of patients do not access standard CR and have higher baseline coronary risk and poorer knowledge of CHD than those persons due to commence CR. The objective of this study is to investigate whether a modular guided self-choice approach to secondary prevention improves coronary risk profile and knowledge in patients who do not access standard CR.
Methods/Design
This randomised controlled trial with one year follow-up will be conducted at a tertiary referral hospital. Participants eligible for but not accessing standard CR will be randomly allocated to either a modular or conventional care group. Modular care will involve participation in individualised modules that involve choice, goal-setting and coaching. Conventional care will involve ongoing heart disease management as directed by the participant's doctors. Both modular and conventional groups will be compared with a contemporary reference group of patients attending CR. Outcomes include measured modifiable risk factors, relative heart disease risk and knowledge of risk factors.
Discussion
We present the rationale and design of a randomised controlled trial testing a modular approachfor the secondary prevention of coronary heart disease following acute coronary syndrome.
doi:10.1186/1471-2261-6-26
PMCID: PMC1524985  PMID: 16762079
25.  Under- treatment and under diagnosis of hypertension: a serious problem in the United Arab Emirates 
Background
Hypertension, notably untreated or uncontrolled, is a major risk factor for cardiovascular diseases (CVD) morbidity and mortality. In countries in transition, little is known about the epidemiology of hypertension, and its biochemical correlates. This study was carried out in Al Ain, United Arab Emirates, to characterize self-reported (SR) normotensives and hypertensives in terms of actual hypertension status, demographic variables, CVD risk factors, treatment, and sequalae.
Methods
A sample, stratified by SR hypertensive status, of 349 SR hypertensives (Mean age ± SD; 50.8 ± 9.2 yrs; Male: 226) and 640 SR normotensives (42.9 ± 9.3 yrs, Male: 444) among nationals and expatriates was used. Hypertensives and normotensive subjects were recruited from various outpatient clinics and government organizations in Al-Ain city, United Arab Emirates (UAE) respectively. Anthropometric and demographic variables were measured by conventional methods.
Results
Both under-diagnosis of hypertension (33%) and under-treatment (76%) were common. Characteristics of undiagnosed hypertensives were intermediate between normotensives and SR hypertensives. Under-diagnosis of hypertension was more common among foreigners than among nationals. Risk factors for CVD were more prevalent among SR hypertensives. Obesity, lack of exercise and smoking were found as major risk factors for CVD among hypertensives in this population.
Conclusion
Hypertension, even severe, is commonly under-diagnosed and under-treated in the UAE. Preventive strategies, better diagnosis and proper treatment compliance should be emphasized to reduce incidence of CVD in this population.
doi:10.1186/1471-2261-6-24
PMCID: PMC1501045  PMID: 16753071

Results 1-25 (49)