The α-adducin (ADD1) Gly460Trp polymorphism has been associated with hypertension and response to diuretic therapy, but controversy exists.
The present study was conducted to prospectively investigate the relationship between the ADD1 Gly460Trp polymorphism, diuretic use, and adverse cardiovascular outcomes among 5,979 hypertensive coronary artery disease patients, who participated in the INternational VErapamil SR-trandolapril STudy (INVEST) and provided genomic DNA. The primary outcome was defined as first occurrence of nonfatal stroke, nonfatal myocardial infarction, or all-cause death. Secondary outcomes were the components of the primary outcome. Ancestry informative markers were used to control for population stratification.
In Blacks, ADD1 variant carriers were at higher risk for a primary outcome event than wild-type homozygotes (adjusted hazard ratio (HR) 2.62; 95% confidence interval (CI) 1.23–5.58; p = .012), with a similar trend in Whites and Hispanics, albeit a smaller magnitude of effect (adjusted HR 1.43, 0.86–2.39 in Hispanics; 1.24, 0.90–1.71 in Whites). Secondary outcome analysis showed that the all-cause death was driving the differences in primary outcomes by genotype. There was no interaction between the ADD1 polymorphism and diuretic use for either primary outcome or secondary outcomes.
In hypertensive patients with coronary artery disease, black ADD1 variant carriers showed a 2.6-fold excess risk for a primary outcome event and an 8-fold increase risk of death. White and Hispanic ADD1 variant carriers showed an increased but nonsignificant excess risk. However, the effect of diuretic use on risk of cardiovascular outcomes did not vary by ADD1 carrier status.
pharmacogenetics; ADD1; diuretics; cardiovascular outcomes
Hypertension guidelines advocate treating systolic blood pressure (BP) to less than 130 mm Hg for patients with diabetes mellitus; however, data are lacking for the growing population who also have coronary artery disease (CAD).
To determine the association of systolic BP control achieved and adverse cardiovascular outcomes in a cohort of patients with diabetes and CAD.
Design, Setting, and Patients
Observational subgroup analysis of 6400 of the 22 576 participants in the International Verapamil SR-Trandolapril Study (INVEST). For this analysis, participants were at least 50 years old and had diabetes and CAD. Participants were recruited between September 1997 and December 2000 from 862 sites in 14 countries and were followed up through March 2003 with an extended follow-up through August 2008 through the National Death Index for US participants.
Patients received first-line treatment of either a calcium antagonist or β-blocker followed by angiotensin-converting enzyme inhibitor, a diuretic, or both to achieve systolic BP of less than 130 and diastolic BP of less than 85 mm Hg. Patients were categorized as having tight control if they could maintain their systolic BP at less than 130 mm Hg; usual control if it ranged from 130 mm Hg to less than 140 mm Hg; and uncontrolled if it was 140 mm Hg or higher.
Main Outcome Measures
Adverse cardiovascular outcomes, including the primary outcomes which was the first occurrence of all-cause death, nonfatal myocardial infarction, or nonfatal stroke.
During 16 893 patient-years of follow-up, 286 patients (12.7%) who maintained tight control, 249 (12.6%) who had usual control, and 431 (19.8%) who had uncontrolled systolic BP experienced a primary outcome event. Patients in the usual-control group had a cardiovascular event rate of 12.6% vs a 19.8% event rate for those in the uncontrolled group (adjusted hazard ratio [HR], 1.46; 95% confidence interval [CI], 1.25–1.71; P<.001). However, little difference existed between those with usual control and those with tight control. Their respective event rates were 12.6% vs 12.7% (adjusted HR, 1.11; 95% CI, 0.93–1.32; P=.24). The all-cause mortality rate was 11.0% in the tight-control group vs 10.2% in the usual-control group (adjusted HR, 1.20; 95% CI, 0.99–1.45; P=.06); however, when extended follow-up was included, risk of all-cause mortality was 22.8% in the tight control vs 21.8% in the usual control group (adjusted HR, 1.15; 95% CI, 1.01–1.32; P=.04).
Tight control of systolic BP among patients with diabetes and CAD was not associated with improved cardiovascular outcomes compared with usual control.
Our understanding of the growing population of very old patients (aged ≥80 years) with coronary artery disease and hypertension is limited, particularly the relationship between blood pressure and adverse outcomes.
This was a secondary analysis of the INternational VErapamil SR-Trandolapril STudy (INVEST), which involved 22,576 clinically stable hypertensive coronary artery disease patients aged ≥50 years. The patients were grouped by age in 10-year increments (aged ≥80, n = 2180; 70–<80, n = 6126; 60–<70, n = 7602; <60, n =6668). Patients were randomized to either verapamil SR- or atenolol-based treatment strategies, and primary outcome was first occurrence of all-cause death, nonfatal myocardial infarction, or nonfatal stroke.
At baseline, increasing age was associated with higher systolic blood pressure, lower diastolic blood pressure, and wider pulse pressure (P <.001). Treatment decreased systolic, diastolic, and pulse pressure for each age group. However, the very old retained the widest pulse pressure and the highest proportion (23.6%) with primary outcome. The adjusted hazard ratio for primary outcomes showed a J-shaped relationship among each age group with on-treatment systolic and diastolic pressures. The systolic pressure at the hazard ratio nadir increased with increasing age, highest for the very old (140 mm Hg). However, diastolic pressure at the hazard ratio nadir was only somewhat lower for the very old (70 mm Hg). Results were independent of treatment strategy.
Optimal management of hypertension in very old coronary artery disease patients may involve targeting specific systolic and diastolic blood pressures that are higher and somewhat lower, respectively, compared with other age groups.
Age; Blood pressure control; Coronary artery disease; Elderly; Epidemiology; Hypertension
G protein-coupled receptor kinases (GRKs) are important regulatory proteins for many G protein-coupled receptors, but little is known about GRK4 pharmacogenetics. We hypothesized three nonsynonymous GRK4 SNPs, R65L (rs2960306), A142V (rs1024323) and A486V (rs1801058) would be associated with blood pressure response to atenolol, but not hydrochlorothiazide, and would be associated with long term cardiovascular outcomes (all cause, death, nonfatal myocardial infarction, nonfatal stroke) in participants treated with an atenolol-based versus verapamil-SR-based antihypertensive strategy. GRK4 SNPs were genotyped in 768 hypertensive participants from the Pharmacogenomic Evaluation of Antihypertensive Responses (PEAR) trial. In Caucasians and African Americans, increasing copies of the variant 65L-142V haplotype were associated with significantly reduced atenolol-induced diastolic blood pressure lowering (−9.1 ± 6.8 vs −6.8 ± 7.1 vs −5.3 ± 6.4 mmHg in participants with 0, 1 and 2 copies of 65L-142V respectively; p=0.0088). 1460 participants with hypertension and coronary artery disease from the INternational VErapamil SR / Trandolapril STudy (INVEST) were genotyped and variant alleles of all three GRK4 SNPs were associated with increased risk for adverse cardiovascular outcomes in an additive fashion, with 486V homozygotes reaching statistical significance (Odds ratio 2.29 [1.48–3.55], p=0.0002). These effects on adverse cardiovascular outcomes were independent of antihypertensive treatment. These results suggest the presence of GRK4 variant alleles may be important determinants of blood pressure response to atenolol and risk for adverse cardiovascular events. The associations with GRK4 variant alleles were stronger in patients who were also ADRB1 389R-homozygotes, suggesting a potential interaction between these two genes.
hypertension; GRK4; atenolol; beta-blocker; outcomes; ADRB1; pharmacogenetics
Hypertensive diabetes individuals are at higher risk for cardiovascular events and progression to end stage renal disease. Several well conducted clinical trials indicate that aggressive treatment of hypertension in individual with diabetes reduces these complications. Combinations of two or more antihypertensive drugs are frequently required to reach the target blood pressure and to improve the cardiovascular and renal outcomes in these patients. There are physiological and clinical rationales for renin-angiotensin system blockade in hypertensive diabetics. Trandolapril/verapamil sustained released (SR) is a fixed-dose combination of trandolapril and a sustained release formulation of verapamil and indicated in treatment of hypertension in patients who require more than one drug to reach target blood pressure. The antihypertensive efficacy of trandolapril/verapamil SR has been evaluated extensively in large trials. In the INVEST trial, a verapamil SR-based treatment strategy that included trandolapril in most patients was effective in reducing the primary outcome in hypertensive patients with coronary artery disease. The new onset of diabetes was also significantly lower in the verapamil SR/trandolapril treatment group in comparison with those on the atenolol/hydroclorothiazide treatment group. The BErgamo NEphrologic DIabetes Complications Trial (BENEDICT) documented that in hypertensive diabetes and normoalbuminuria, trandolapril plus verapamil or trandolapril alone delayed the onset of microalbuminuria independent of their blood pressure-reducing effect. Thus, trandolapril/verapamil is an effective option for treatment of hypertensive diabetes patients requiring more than one agent to achieve target blood pressure.
diabetes mellitus; hypertension; trandolapril; verapamil SR
Background: Fixed-dose combination antihypertensive therapy has been recommended for patients with essential hypertension who are unresponsive to monotherapy or as a first-line treatment.
Objective: We investigated the effects of a fixed-dose combination of the phenylalkylamine-type calcium channel blocker verapamil slow release (SR)plus the angiotensin-converting enzyme inhibitor trandolapril on blood pressure (BP), serum lipid profile, urinary albumin excretion (UAE), left ventricular mass (LVM), and LVM index (LVMI), as well as the adverse events associated with this treatment.
Methods: Patients aged 30 to 65 years with mild to moderate essential hypertension were included in the study. All of the patients received capsules containing combination treatment with verapamil SR 180 mg plus trandolapril 2 mg orally, daily for 12 weeks. Mean arterial pressure (MAP), systolic BP (SBP), diastolic BP (DBP), and heart rate (HR) were measured at baseline and at 4, 8, and 12 weeks of treatment. Serum lipid profile, UAE, LVM, LVMI, and body mass index (BMI) were determined at baseline and at the end of the study period. All patients underwent electrocardiography and echocardiography at baseline and week 12. The primary end point of the study was to achieve an SBP/DBP ≤140/≤90 mm Hg (ie, normotensive) during week 12. All adverse events were assessed as mild, moderate, or severe at each visit. According to the response rate at week 12, patients were divided into 2 groups: those who became normotensive (responders) or those who remained hypertensive (SBP/DBP >140/>90 mm Hg; nonresponders).
Results: Forty-one patients (29 women, 12 men; mean [SD] age, 47.7 [7.8] years; mean [SD] BMI, 29.4 [3.5] kg/m2) were enrolled. The median durationof hypertension prior to enrollment was 5 months. Mean MAP, SBP, DBP, UAE, total cholesterol (TC), low-density lipoprotein cholesterol (LDL-C), LDL-C/highdensity lipoprotein cholesterol (HDL-C) ratio, LVM, LVMI, and BMI decreased significantly after 12 weeks of combination treatment; HR and triglyceride level did not change significantly. Treatment-related adverse events occurred in 31.7% of patients, and none were severe or caused any patient to withdraw from the study. The most common adverse events were cough, constipation, headache, and dryness in the throat. Microalbuminuria, which may be a marker of endothelial dysfunction, was found in 7 (17.1%) patients at baseline and regressed significantly after 12 weeks.
Conclusions: In this study population, the fixed-dose combination of verapamil–trandolapril was an effective and well-tolerated antihypertensive therapy. This combination significantly reduced MAP, BP, TC, LDL-C, LDL-C/HDL-C ratio, UAE, LVM, and LVMI. Also, microalbuminuria decreased after this treatment. Verapamil–trandolapril may be useful in preventing microalbuminuria and left ventricular hypertrophy in patients with essential hypertension.
essential hypertension; combination therapy; trandolapril; verapamil
The INternational VErapamil SR-Trandolapril STudy (INVEST), a randomized trial of 22,576 predominantly elderly patients with an average 2.7-year follow-up, compared a calcium antagonist led strategy (verapamil SR plus trandolapril) with a β blocker led strategy (atenolol plus hydrochlorothiazide) for hypertension treatment and prevention of cardiovascular outcomes in coronary artery disease. patients.
Patients received individualized dose and drug titration following a flexible, multi-drug, guideline-based treatment algorithm, with the objective of achieving optimal blood pressure (BP) control individualized for comorbidities (e.g., diabetes). The primary outcome (PO) was first occurrence of death (all-cause), nonfatal myocardial infarction or nonfatal stroke.
The strategies resulted in significant and very similar BP reduction with approximately 70% of patients in both strategies achieving BP control (< 140/90 mm Hg). Increasing number of office visits with BP in control was associated with reduced risk of the PO. Overall, there was no difference in the PO comparing the strategies, however new onset diabetes occurred more frequently in those assigned the atenolol strategy. This report summarizes findings from INVEST and puts them in perspective with our current state of knowledge derived from other large hypertension treatment trials. INVEST findings support that 1) BP reduction is important for prevention of adverse cardiovascular morbidity and mortality; and 2) selection of antihypertensive agents should be based on patient comorbidities and other risk factors (e.g. risk for diabetes) and not necessarily that any one drug be given to all.
Coronary artery disease; hypertension; atenolol; verapamil SR; trandolapril; hydrochlorothiazide; INVEST; new onset diabetes
The G-protein coupled receptor kinases GRK2 and GRK5 are important regulators of beta-adrenergic signaling. This study characterized single nucleotide polymorphisms in the GRK2 gene (ADRBK1)and determined if these and a GRK5 Gln41Leu polymorphism affect the blood pressure (BP)response to atenolol or hydrochlorothiazide or adverse cardiovascular outcomes in hypertensives.
ADRBK1 regions were sequenced for 48 individuals. Putative functional SNPs were tested for mRNA expression differences in 96 lymphoblastoid cell line samples and 12 leukocyte samples from hypertensives. BP response to atenolol and hydrochlorothiazide by ADRBK1 SNPs and GRK5 Gln41Leuwas tested in 418patients from the Pharmacogenomic Evaluation of Antihypertensive Responses (PEAR) using linear regression. The influence of ADRBK1 SNPs and GRK5 Gln41Leuon death, myocardial infarction or stroke in treated hypertensive patients was evaluated in a case-control cohort (1:3) of the International Verapamil SR/Trandolapril Study GENEtic Substudy (INVEST GENES) using logistic regression models.
A novel ADRBK1 promoter SNP was not associated with differential GRK2 expression. GRK5 Leu41 decreased the risk for adverse cardiovascular outcomes independent of treatment strategy(adjusted odds ratio 0.535, 95% confidence interval 0.313 – 0.951, P = 0.0222)but was not associated with BP response to antihypertensive medication. An ADRBK1 SNP (rs1894111G>A) showed a signal for association with systolic and diastolic BP(SBP, DBP) response to hydrochlorothiazide in whites(DBP: −11.29±3.74 mmHg (G/A) vs. −4.26±4.79 mmHg (G/G), P = 0.0034 and SBP: −18.37±14.90 mmHg (G/A), −8.11±7.55 mmHg (G/G), P = 0.0191).
The GRK5 Leu41 allele protects from adverse cardiovascular outcomes in treated hypertensives.
GRK5; GRK2; ADRBK1; polymorphism; hypertension; beta-blocker; atenolol; diuretic; hydrochlorothiazide
The gene encoding the target of calcium channel blockers, the α1c-subunit of the L-type calcium channel (CACNA1C) has not been well characterized and only small pharmacogenetic studies testing this gene have been published to date.
Methods and Results
Resequencing of CACNA1C was performed followed by a nested case-control study of the INternational VErapamil SR/trandolapril STudy (INVEST) GENEtic Substudy (INVEST-GENES). Of 46 polymorphisms identified, eight were assessed in the INVEST-GENES. Rs1051375 was found to have a significant interaction with treatment strategy (p=0.0001). Rs1051375 A/A genotype was associated with a 46% reduction in the primary outcome among those randomized to verapamil SR treatment compared to atenolol treatment (OR 0.54 95% CI 0.32-0.92). In heterozygous A/G individuals, there was no difference in the occurrence of the primary outcome when randomized to verapamil SR versus atenolol treatment (OR 1.47 95% CI 0.86-2.53), while homozygous G/G individuals had a greater than 4-fold increased risk of the primary outcome with verapamil treatment compared to those randomized to atenolol treatment (OR 4.59 95% CI 1.67-12.67). We did not identify allelic expression imbalance or differences in mRNA expression in heart tissue by rs1051375 genotype.
Variation in CACNA1C is associated with treatment response among hypertensive patients with stable coronary artery disease. Our data suggest a genetically-defined group of patients that benefit most from calcium channel blocker therapy, a group that benefits most from β-blocker therapy, and a third group in which calcium channel blocker and β-blocker therapy are equivalent.
genetics; pharmacology; ion channels; calcium; pharmacogenetics
Our understanding of the growing population of revascularized patients with hypertension is limited. We retrospectively analyzed the International Verapamil SR-Trandolapril Study, which randomized coronary artery disease patients with hypertension to either verapamil SR- or atenolol-based treatment strategies, focusing on characteristics and outcomes of 6166 previously revascularized patients compared with 16 410 nonrevascularized patients. Revascularized patients had a history of coronary artery bypass grafting (45.2%), percutaneous coronary intervention (42.1%), or both (12.8%). Compared with nonrevascularized patients, revascularized patients at baseline demonstrated a higher prevalence of coronary artery disease risk factors and risk conditions (P<0.001). This higher prevalence was the principal cause of a higher incidence of primary outcome (death, nonfatal myocardial infarction, or nonfatal stroke) among revascularized patients (14.2% versus 8.5% for nonrevascularized patients; P<0.001). However, both patient groups demonstrated a relatively low incidence of subsequent revascularization (5.1% versus 1.5% respectively; P<0.0001). Associations between adjusted hazard ratio for primary outcome and follow-up blood pressure appeared “J shaped” for both patient groups. Because, as a group, revascularized patients with hypertension had worse outcomes compared with nonrevascularized patients, management of blood pressure to a specific target in future studies could result in improved outcomes.
hypertension; blood pressure; coronary artery disease; revascularization; coronary artery bypass grafting; percutaneous coronary intervention; epidemiology
Aspirin or dual antiplatelet therapy (DAPT) with aspirin and clopidogrel is standard therapy for patients at increased risk for cardiovascular events. However, the genetic determinants of variable response to aspirin (alone and in combination with clopidogrel) are not known.
Methods and Results
We measured ex-vivo platelet aggregation before and after DAPT in individuals (n=565) from the Pharmacogenomics of Antiplatelet Intervention (PAPI) Study and conducted a genome-wide association study (GWAS) of drug response. Significant findings were extended by examining genotype and cardiovascular outcomes in two independent aspirin-treated cohorts: 227 percutaneous coronary intervention (PCI) patients, and 1,000 patients of the International VErapamil SR/trandolapril Study (INVEST) GENEtic Substudy (INVEST-GENES). GWAS revealed a strong association between single nucleotide polymorphisms on chromosome 1q23 and post-DAPT platelet aggregation. Further genotyping revealed rs12041331 in the platelet endothelial aggregation receptor-1 (PEAR1) gene to be most strongly associated with DAPT response (P=7.66×10−9). In Caucasian and African American patients undergoing PCI, A-allele carriers of rs12041331 were more likely to experience a cardiovascular event or death compared to GG homozygotes (hazard ratio = 2.62, 95%CI 0.96-7.10, P=0.059 and hazard ratio = 3.97, 95%CI 1.10-14.31, P=0.035 respectively). In aspirin-treated INVEST-GENES patients, rs12041331 A-allele carriers had significantly increased risk of myocardial infarction compared to GG homozygotes (OR=2.03, 95%CI 1.01-4.09, P=0.048).
Common genetic variation in PEAR1 may be a determinant of platelet response and cardiovascular events in patients on aspirin, alone and in combination with clopidogrel.
Clinical Trial Registration Information
clinicaltrials.gov; Identifiers: NCT00799396 and NCT00370045
pharmacogenomics; platelets; percutaneous coronary intervention; PEAR1; CYP2C19
Due to time-dependent confounding by blood pressure and differential loss to follow-up, it is difficult to estimate the effectiveness of aggressive versus conventional antihypertensive combination therapies in non-randomized comparisons.
We utilized data from 22,576 hypertensive coronary artery disease patients, prospectively enrolled in the INternational VErapamil-Trandolapril STudy (INVEST). Our post-hoc analyses did not consider the randomized treatment strategies, but instead defined exposure time-dependently as aggressive treatment (≥3 concomitantly used antihypertensive medications) versus conventional treatment (≤2 concomitantly used antihypertensive medications). Study outcome was defined as time to first serious cardiovascular event (non-fatal myocardial infarction, non-fatal stroke, or all-cause death). We compared hazard ratio (HR) estimates for aggressive vs. conventional treatment from a Marginal Structural Cox Model (MSCM) to estimates from a standard Cox model. Both models included exposure to antihypertensive treatment at each follow-up visit, demographics, and baseline cardiovascular risk factors, including blood pressure. The MSCM further adjusted for systolic blood pressure at each follow-up visit, through inverse probability of treatment weights.
2,269 (10.1%) patients experienced a cardiovascular event over a total follow-up of 60,939 person-years. The HR for aggressive treatment estimated by the standard Cox model was 0.96 (95% confidence interval 0.87-1.07). The equivalent MSCM, which was able to account for changes in systolic blood pressure during follow-up, estimated a HR of 0.81 (95% CI 0.71-0.92).
Using a MSCM, aggressive treatment was associated with a lower risk for serious cardiovascular outcomes compared to conventional treatment. In contrast, a standard Cox model estimated similar risks for aggressive and conventional treatments.
Clinicaltrials.gov Identifier: NCT00133692
Blood pressure; Hypertension; Time-dependent confounding; Marginal structural models
The optimal blood pressure (BP) to prevent major adverse outcomes (death, myocardial infarction, and stroke) for patients with hypertension and coronary artery disease who have undergone previous revascularization is unknown but might be influenced by the type of revascularization procedure. We analyzed data from the INternational VErapamil SR-Trandolapril STudy, focusing on the relation between BP and the outcomes of 6,166 previously revascularized patients, using the 16,410 nonrevascularized patients as a reference group. The previous revascularization strategy consisted of coronary artery bypass grafting (CABG, 45.2%), percutaneous coronary intervention (PCI, 42.1%), or both (CABG+PCI, 12.8%). Patients who had undergone both CABG+PCI and CABG-only had a greater adverse outcome risk (adjusted hazard ratio 1.27% and 1.20%, 95% confidence interval 1.06 to 1.53 and 1.07 to 1.35, respectively). The risk was similar for PCI-only patients (adjusted hazard ratio 1.04, 95% confidence interval 0.92 to 1.19). The relations between the adjusted hazard ratio and on-treatment BP appeared J-shaped for each revascularization strategy, accentuated for PCI and diastolic BP (DBP), but excepting CABG only and DBP for which the relation was linear and positive. In conclusion, major adverse outcomes were more frequent in patients with coronary artery disease who had undergone previous CABG, with or without PCI, compared to those with previous PCI only. This likely reflected more severe vascular disease. The relation to systolic BP was J-shaped for each strategy. Among those patients with previous CABG only, the linear relation with DBP suggested that more complete revascularization might attenuate hypoperfusion at a low DBP. The management of BP might, therefore, require modification of targets according to the revascularization strategy to improve outcomes.
Hypertension is a common risk factor for peripheral arterial disease (PAD). Guidelines suggest treating PAD patients to a blood pressure <130/80 mm Hg; therefore, our objective was to explore whether attainment of this target blood pressure is associated with improved outcomes. We performed a post hoc analysis of the INternational VErapamil-SR/Trandolapril STudy, a randomized clinical trial, which included hypertensive patients with concomitant PAD and coronary artery disease. There were 2699 PAD patients followed for a mean of 2.7 years (60 970 patient-years). The primary outcome, all-cause death, nonfatal myocardial infarction, or nonfatal stroke, occurred in 16.3% of PAD patients versus 9.2% without PAD (adjusted hazard ratio: 1.26 [95% CI: 1.13 to 1.40]; P<0.0001). The primary outcome occurred least frequently among PAD patients treated to an average systolic blood pressure of 135 to 145 mm Hg and an average diastolic blood pressure of 60 to 90 mm Hg. PAD patients displayed a J-shape relationship with systolic blood pressure and the primary outcome, although individuals without PAD did not. PAD patients may require a different target blood pressure than those without PAD.
peripheral vascular disease; peripheral arterial disease; coronary artery disease; hypertension prognosis; calcium antagonist; β-blocker
OBJECTIVE--To compare the efficacy and tolerability of hydrochlorothiazide, sustained release verapamil, and their combination in patients with mild to moderate hypertension. DESIGN--Randomised multicentre trial of 48 weeks' duration with a double blind comparison of hydrochlorothiazide and verapamil followed by an open trial of combined treatment for patients not achieving the target diastolic blood pressure (less than 90 mm Hg) during treatment with a single drug. SETTING--Outpatient departments in 10 clinics and 10 private practices of general practitioners or internists. PATIENTS--369 Hypertensive patients with a diastolic blood pressure of 95-120 mm Hg during a placebo run in period of two weeks. INTERVENTIONS--Initial treatment consisted of 12.5 mg hydrochlorothiazide (n = 187) or 120 mg sustained release verapamil (n = 182) once daily (regimen I). If the target diastolic blood pressure of less than 90 mm Hg was not achieved within four weeks doses were increased to 25 mg hydrochlorothiazide or 240 mg verapamil once (regimen II) and twice daily (regimen III). Patients not achieving target blood pressure were given the combination of hydrochlorothiazide and verapamil--that is, 25 and 240 mg once (regimen IV) and twice daily (regimen V). MAIN OUTCOME MEASURE--Blood pressure determined with a device permitting automatic repeated measurements with printouts. RESULTS--After eight weeks of treatment with a single drug 76 out of 178 (43%) and 101 out of 175 (58%) patients achieved the target blood pressure with hydrochlorothiazide and verapamil, respectively. During follow up until 48 weeks patients treated with verapamil reached the target blood pressure more often and at lower doses and were less likely to switch to combination treatment than patients randomised to hydrochlorothiazide treatment. Adding verapamil to hydrochlorothiazide was more effective than the addition of hydrochlorothiazide to verapamil. At the end of the study 42 out of 169 (25%) and 73 out of 163 (45%) patients initially randomised to hydrochlorothiazide and verapamil, respectively, were at target blood pressure without combination treatment. After adding verapamil to hydrochlorothiazide or hydrochlorothiazide to verapamil an additional 58 (34%) and 29 (18%) patients reached the target blood pressure, respectively. Altogether 92 out of 332 (28%) patients failed to achieve target blood pressure with regimen V. There were four, 10, seven, and seven withdrawals due to possible adverse effects to treatment with hydrochlorothiazide, verapamil, combining verapamil with hydrochlorothiazide, and combining hydrochlorothiazide with verapamil, respectively. CONCLUSIONS--In doses currently used in antihypertensive treatment verapamil was more effective than hydrochlorothiazide as a single agent and in combination in mild to moderate hypertension, whereas withdrawal rates caused by side effects possibly related to treatment were similar.
Background and Purpose
Our understanding of factors influencing stroke risk among patients with coronary artery disease is incomplete. Accordingly, factors predicting stroke risk in hypertensive, clinically stable coronary artery disease patients were determined with data from the INternational VErapamil SR-trandolapril STudy (INVEST).
The effect of baseline characteristics and on-treatment blood pressure (BP) were analyzed to determine the risk of stroke (fatal or nonfatal) among the 22 576 patients enrolled. Cox proportional-hazards models (unadjusted, adjusted, and time dependent) were used to identify predictors of stroke among subgroups with these characteristics present at entry and on-treatment BP.
Excellent BP control (at 24 months, >70% <140/90 mm Hg) was achieved during 61 835 patient-years of follow-up, as 377 patients had a stroke (6.1 strokes/1000 patient-years) and 28% of those patients had a fatal stroke. Increased age, black race, US residency, and history of prior myocardial infarction, smoking, stroke/transient ischemic attack, arrhythmia, diabetes, and coronary bypass surgery were associated with an increased risk of stroke. Achieving a systolic BP <140 mm Hg and a diastolic BP <90 mm Hg was associated with a decreased risk of stroke. There was no statistically significant difference in stroke risk comparing the verapamil SR–based with the atenolol-based treatment strategy (adjusted hazard ratio=0.87; 95% CI, 0.71 to 1.06; P=0.17).
Among hypertensive patients with chronic coronary artery disease, stroke was an important complication associated with significant mortality. Black race, US residency, and conditions associated with increased vascular disease severity and arrhythmia predicted increased stroke risk, whereas achieving a BP <140/90 mm Hg on treatment predicted a reduced stroke risk.
atenolol; coronary artery disease; hydrochlorothiazide; hypertension; stroke; trandolapril; verapamil SR
STUDY OBJECTIVE--To compare responses of blood pressure to the calcium antagonist verapamil and the beta blocker metoprolol in black compared with white diabetics with hypertension and to monitor urinary albumin excretion in relation to fall in blood pressure. DESIGN--Double blind, placebo controlled, random order crossover trial with four week placebo run in period and two six week active phases separated by a two week placebo washout period. SETTING--Outpatient department of a general hospital in a multiethnic health department. Patients--Diabetic patients with hypertension. Four dropped out before randomisation; 25 black and 14 white patients completed the trial. INTERVENTIONS--Patients given slow release verapamil 120 mg or 240 mg twice daily with placebo or metoprolol 50 mg or 100 mg twice daily with placebo. Treatment for diabetes (diet alone or with oral hypoglycaemic drugs) remained unchanged. END POINT--Comparison of changes in blood pressure in the two groups taking both drugs. MEASUREMENTS AND MAIN RESULTS--Metoprolol had little effect on blood pressure in black patients (mean fall 4.0 mm Hg systolic (95% confidence interval -2.5 to 10.4 mm Hg), 4.3 mm Hg diastolic (-0.8 to 9.5)) but more effect in white patients (mean falls 13.4 mm Hg (0.1 to 26.7) and 10.6 mm Hg (4.5 to 16.7) respectively). Verapamil was more effective in both groups, with mean falls of 8.8 mm Hg (2.4 to 15.0) and 8.1 mm Hg (5.0 to 11.2) in black patients and 19.1 mm Hg (5.4 to 32.9) and 11.4 mm Hg (0.9 to 22.0) in white patients. Heart fate fell significantly in black patients taking metoprolol, which suggested compliance with treatment. Metabolic variables were unaltered by either treatment. Plasma renin activity was low in both groups after metoprolol treatment, but change in blood pressure could not be predicted from baseline plasma renin activity. Urinary albumin:creatinine ratio was independently related to baseline blood pressure but not significantly changed by treatment. CONCLUSIONS--beta Blockers alone are not effective in treating hypertension in black diabetics. Verapamil is effective but less so than in white patients. As yet no ideal monotherapy exists for hypertension in black patients.
Genetic variants of ACE are suspected risk factors in cardiovascular disease, but the alleles responsible for the variations remain unidentified. To search for regulatory polymorphisms, allelic angiotensin I–converting enzyme (ACE) mRNA expression was measured in 65 heart tissues, followed by genotype scanning of the ACE locus. Marked allelic expression imbalance (AEI) detected in five African-American subjects was associated with single-nucleotide polymorphisms (SNPs) (rs7213516, rs7214530, and rs4290) residing in conserved regions 2−3 kb upstream of ACE. Moreover, each of the SNPs affected transcription in reporter gene assays. SNPs rs4290 and rs7213516 were tested for associations with adverse cardiovascular outcomes in hypertensive patients with coronary disease (International Verapamil SR Trandolapril Study Genetic Substudy (INVEST-GENES), n = 1,032). Both SNPs were associated with adverse cardiovascular outcomes, largely attributable to nonfatal myocardial infarction in African Americans, showing an odds ratio of 6.16 (2.43−15.60) (P < 0.0001) for rs7213516. The high allele frequency in African Americans (16%) compared to Hispanics (4%) and Caucasians (<1%) suggests that these alleles contribute to variation between populations in cardiovascular risk and treatment outcomes.
Liver X receptor-α (LXRA) is a nuclear receptor that regulates genes important in cholesterol homeostasis and inflammation. Several single nucleotide polymorphisms (SNPs) in the LXRA gene have been previously associated with metabolic phenotypes (dyslipidemia and elevated BMI). Metabolic dysregulation is a major contributor to coronary disease; therefore, we assessed LXRA in INVEST-GENES, a genetic-substudy of a large clinical trial in patients with hypertension and coronary artery disease.
Seven tag SNPs in the LXRA gene region (NR1H3) were selected for study: rs11039149, rs12221497, rs2279238, rs7120118, rs326213, rs11039159 and rs10501321. 1059 subjects were genotyped from the INVEST-GENES case-control set (Verapamil-SR or Atenolol based treatment strategies), comprised of 297 cases frequency matched approximately 2.5:1 with event-free controls by sex and race. The primary outcome was defined as first occurrence of all-cause death, nonfatal MI, or nonfatal stroke. Adjusted odds ratios (OR) were calculated using logistic regression.
Three of the seven SNPs were associated with significant effects on the primary outcome in Non-Blacks. The variant G allele of rs11039149 and the variant A allele of rs12221497 were associated with reduced risk of experiencing the primary outcome (OR: 0.62, CI: 0.45-0.85, P=0.003 and OR: 0.60, CI: 0.39-0.91, P=0.016 respectively). The rs2279238 genotype was associated with a significant increase in risk for the primary outcome (OR: 1.42, CI: 1.03-1.95, P=0.03). Furthermore, there was a significant genotype-treatment strategy interaction for carriers of the variant T allele of rs2279238 (OR for Verapamil SR strategy compared to Atenolol: 2.86, CI: 1.50-5.46, P=0.0015). Diplotype analyses revealed that the SNPs are rarely co-inherited and support the directionally opposite effects of the SNPs on the primary outcome.
LXRA genotypes were associated with variable risk for cardiovascular outcomes and pharmacogenetic effect in INVEST-GENES. These novel findings suggest LXRA is a genetic/pharmacogenetic target that should be further explored.
LXRA; Nuclear Receptor; Pharmacogenetics; Polymorphisms; Cardiovascular Disease; Hypertension; Atenolol; Verapamil
Glomerular filtration rate (GFR) is a heritable trait, and hyperfiltration (GFR increment in remnant nephrons) may accelerate renal functional decline in chronic kidney disease (CKD). Mesangial and vascular smooth myocytes control GFR by contraction, dependent on voltage-gated Ca2+ influx, which is controlled by the regulatory β1-subunit (KCNMB1) of large-conductance heteromeric K+ (‘BK’) channels. KCNMB1 gain-of-function variant Glu65Lys results in generalized vasorelaxation and thus protection against systemic hypertension. Here we asked whether the Glu65Lys variant influences GFR, in the basal state or during progressive renal decline.
We explored Glu65Lys effects on GFR in three populations spanning two ethnicities and two diseases (hypertension and nephrosclerosis). GFR was either estimated (eGFR from serum creatinine) or directly measured (iothalamate clearance).
The 65Lys variant was relatively common, occurring on ∼5−10% of chromosomes in different biogeographic ancestry groups, and 65Lys carriers exhibited higher eGFR in two primary care populations: extreme BP values in Kaiser clinics (p = 0.029, accounting for ∼0.2% of trait variance), or treated hypertensives in VA clinics (p = 0.017, accounting for ∼0.9% of trait variance). In blacks with progressive renal disease (NIDDK AASK), 65Lys carriers displayed a steeper slope in GFR chronic decline (p = 0.030, accounting for ∼0.4% of trait variance), and Glu65Lys genotype also predicted time of onset of renal failure (log rank p = 0.019).
Common KCNMB1 gain-of-function variant Glu65Lys influences GFR, and 65Lys carriers exhibit not only elevated baseline GFR, but also more rapid GFR decline (and consequent development of renal failure) in CKD. The results suggest that profiling patients at Glu65Lys can assist in gauging renal prognosis as well as selection of rational therapy in hypertension with progressive renal disease.
Glomerular filtration rate; KCNMB1; Hypertensive nephrosclerosis; African-American Study of Kidney Disease and Hypertension
Levosimendan (Levo) increases sensitivity of troponin-C to calcium, thus increasing myocardial contractility. It is also a vascular K+-ATP channel agonist producing peripheral vasodilation. Previous research with levosimendan revealed an increase in cardiac output (CO) but not blood pressure (BP) in experimental verapamil poisoning. Levosimendan’s K+-channel agonist properties may augment verapamil’s vasodilatory effects. 4-Aminopyridine (4-AP) is a K+-channel antagonist. It has successfully reversed hypotension in experimental verapamil poisoning. We hypothesized that coadministration of these agents may improve BP and CO in verapamil poisoning. Anesthetized, ventilated, and canulated male Wistar rats were poisoned with verapamil. Animals received one of six treatments, which are as follows: (1) n-saline infusion (control), (2) Levo 6.25 μg/kg loading dose and 36 μg/kg/h infusion, (3) 4-AP 2 mg/kg loading dose and infusion (4-AP), (4) Levo+4-AP, (5) CaCl2 loading dose and infusion, and (6) Levo+CaCl2. Hemodynamic parameters were recorded for 60 min. Outcome measures were changes in CO, BP, and heart rate (HR) compared to control. All groups had similar pretoxicity and peak toxicity CO (50% of pretoxicity value), BP (50% or pretoxicity value), and HR. Control group CO, BP, and HR progressively dropped during the verapamil infusion. Levosimendan produced a statistically significant improvement in CO (75% of pretoxicity level) but not BP in comparison to control. 4-AP produced a significant improvement in CO (110% of pretoxicity) and BP (78% of pretoxicity). Levo+4-AP and Levo+CaCl2 groups improved CO (100% of pretoxicity) and BP (77% and 50% of pretoxicity, respectively), but there was no additive increase in CO or BP in animals compared to 4-AP or CaCl2 alone. Levosimendan moderately improved CO but not BP in verapamil poisoning. The hypotensive effects of levosimendan were not overcome by coadministration of either 4-AP or CaCl2. Levosimendan may not be an appropriate agent to use in the treatment of verapamil poisoning.
Poisoning; Overdose; Calcium channel blockers; Verapamil; Levosimendan; Aminopyridine; Rodent
Genetic variants that influence large conductance calcium-activated potassium channel (BKCa) function may alter arterial function and contribute to the known heritability of arterial stiffness and blood pressure. The β1-subunit (KCNMB1) of the BKCa channel includes two coding region polymorphisms. E65K, a gain-of-function polymorphism, is predicted to enhance BKCa channel opening and vasorelaxation, whereas V110L has no known effect. We and others have reported that E65K carriers have reduced blood pressure.
To test our hypothesis that E65K has a favorable effect on arterial function, we related arterial tonometry and brachial artery phenotypes to genotypes in 1,100 Framingham Offspring Study participants with available genotypes and phenotypes (53% women; mean age 61.5±9.4 years).
The minor allele frequency was 0.10 for E65K and 0.09 for V110L; both were in Hardy-Weinberg equilibrium (χ2 p > 0.05), and haplotype analysis found R2=0.01. E65K was associated with lower augmented pressure (7.4±3.3 vs. 9.0±3.8 mm Hg, p=0.01) and central pulse pressure (47.1±7.3 vs. 50.7±7.8 mm Hg, p=0.01) in multivariable analyses. No association was noted between E65K and mean arterial pressure, carotid-femoral pulse wave velocity or brachial artery diameter, flow velocity or volume flow. V110L was not associated with tonometry or brachial measures.
A diminished augmented pressure in K-carriers suggests a reduced or delayed wave reflection and supports the hypothesis that E65K reduces arterial impedance mismatch in the arterial tree. Our findings in a middle-aged community-based cohort, if replicated, would support that E65K has a favorable effect on arterial function and pulsatile hemodynamic load.
KCNMB1; Single Nucleotide Polymorphism; Genetics; Vascular Tonometry
Single-nucleotide polymorphisms (SNPs) in NEDD4L may influence the ability of the NEDD4L protein to reduce epithelial sodium channel expression. A variant in NEDD4L, rs4149601, was associated with antihypertensive response and cardiovascular outcomes during treatment with thiazide diuretics and β-blockers in a Swedish population. We sought to further evaluate associations between NEDD4L polymorphisms, blood pressure response and cardiovascular outcomes with thiazide diuretics and β-blockers.
Four SNPs, rs4149601, rs292449, rs1008899 and rs75982813, were genotyped in 767 patients from the Pharmacogenomic Evaluation of Antihypertensive Responses (PEAR) clinical trial and association was assessed with blood pressure response to hydrochlorothiazide and atenolol. One SNP, rs4149601, was also genotyped in 1345 patients from the International Verapmil SR Trandolapril Study (INVEST), and association was examined with adverse cardiovascular outcomes relative to hydrochlorothiazide treatment.
Significant associations or trends were found between rs4149601, rs292449, rs75982813 and rs1008899 and decreases in blood pressure in whites on hydrochlorothiazide, and a significant association was observed with increasing copies of the GC rs4149601-rs292449 haplotype and greater blood pressure response to hydrochlorothiazide in whites (P = 0.0006 and 0.006, SBP and DBP, respectively). Significant associations were also seen with rs4149601 and an increased risk for adverse cardiovascular outcomes in whites not treated with hydrochlorothiazide [P = 0.022, odds ratio (95% confidence interval) = 10.65 (1.18–96.25)].
NEDD4L rs4149601, rs292449 and rs75982813 may be predictors for blood pressure response to hydrochlorothiazide in whites, and NEDD4L rs4149601 may be a predictor for adverse cardiovascular outcomes in whites not treated with hydrochlorothiazide.
epithelial sodium channel; hypertension; International Verapamil SR Trandolapril Study; neural precursor cell expressed developmentally down-regulated 4 like; Pharmacogenomic Evaluation of Antihypertensive Responses; pharmacogenetics
We sought to identify novel pharmacogenetic markers associated with cardiovascular outcomes in patients with hypertension on antihypertensive therapy. We genotyped a 1:4 case:control cohort (n=1345) on the Illumina HumanCVD Beadchip from the International Verapamil SR-Trandolapril Study, where participants were randomized to a β blocker strategy or a calcium channel blocker strategy. Genome-spanning SNP × treatment interaction analyses of non-synonymous SNPs were conducted in white and Hispanic race/ethnic groups. Top hits from whites were tested in Hispanics for consistency. A genetic risk score was constructed from the top three signals and tested in the Nordic Diltiazem study. SIGLEC12 rs16982743 and A1BG rs893184 had a significant interaction with treatment strategy for adverse cardiovascular outcomes (International Verapamil SR-Trandolapril Study whites and Hispanics combined interaction P=0.0038, and 0.0036, respectively). A genetic risk score including rs16982743, rs893184 and rs4525 in F5, was significantly associated with treatment-related adverse cardiovascular outcomes in whites and Hispanics from the International Verapamil SR-Trandolapril Study and in the Nordic Diltiazem study (meta-analysis interaction P=2.39×10−5). In patients with a genetic risk score of zero or 1, calcium channel blocker treatment was associated with lower risk (OR (95% CI) = 0.60 (0.42-0.86)), and in those with a genetic risk score of 2-3, calcium channel blocker treatment was associated with higher risk, OR (95% CI) = 1.31 (1.08-1.59)). These results suggest cardiovascular outcomes may differ based on SIGLEC12, A1BG, F5 genotypes and antihypertensive treatment strategy. These specific genetic associations and our risk score provide insight into a potential approach to personalized antihypertensive treatment selection.
Pharmacogenomics; Hypertension; antihypertensive agents; cardiovascular outcomes; genetic variation; beta-blockers, calcium channel blockers
To determine the relationship between resting heart rate (RHR) and adverse outcomes in coronary artery disease (CAD) patients treated for hypertension with different RHR-lowering strategies.
Methods and results
Time to adverse outcomes (death, non-fatal myocardial infarction, or non-fatal-stroke) and predictive values of base-line and follow-up RHR were assessed in INternational VErapamil-SR/trandolapril STudy (INVEST) patients randomized to either a verapamil-SR (Ve) or atenolol (At)-based strategy. Higher baseline and follow-up RHR were associated with increased adverse outcome risks, with a linear relationship for baseline RHR and J-shaped relationship for follow-up RHR. Although follow-up RHR was independently associated with adverse outcomes, it added less excess risk than baseline conditions such as heart failure and diabetes. The At strategy reduced RHR more than Ve (at 24 months, 69.2 vs. 72.8 beats/min; P < 0.001), yet adverse outcomes were similar [Ve 9.67% (rate 35/1000 patient-years) vs. At 9.88% (rate 36/1000 patient-years, confidence interval 0.90–1.06, P = 0.62)]. For the same RHR, men had a higher risk than women.
Among CAD patients with hypertension, RHR predicts adverse outcomes, and on-treatment RHR is more predictive than baseline RHR. A Ve strategy is less effective than an At strategy for lowering RHR but has a similar effect on adverse outcomes.
Coronary artery disease; Atenolol; Resting heart rate; Adverse outcomes; INVEST; Verapamil-SR