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1.  Peripheral arterial disease, prevalence and cumulative risk factor profile analysis 
The primary aim of the present study was to determine the cumulative effect of a set of peripheral artery disease (PAD) risk factors among age, gender and race/ethnicity groups in the United States.
We examined data from a nationally representative sample of the US population (National Health and Nutrition Examination Survey [NHANES], 1999–2004). A total of 7058 subjects 40 years or older that completed the interview, medical examination and had ankle–brachial index (ABI) measurements were included in this study.
The age- and sex-standardized prevalence of PAD was 4.6 % (standard error [SE] 0.3%).The highest prevalence of PAD was observed among elderly, non-Hispanic Blacks and women. In a multivariable age-, gender- and race/ethnicity-adjusted model hypertension, diabetes, chronic kidney disease, and smoking were retained as PAD risk factors (p ≤ 0.05 for each). The odds of PAD increased with each additional risk factor present from a non-significant 1.5-fold increase (O.R 1.5, 95% confidence interval [CI] 0.9–2.6) in the presence of one risk factor, to more than ten-fold (OR 10.2, 95% CI 6.4–16.3) in the presence of three or more risk factors. In stratified analysis, non-Hispanic Blacks (OR 14.7, 95% CI 2.1–104.1) and women (OR 18.6, 95% CI 7.1–48.7) were particularly sensitive to this cumulative effect.
In a large nationally representative sample, an aggregate set of risk factors that included diabetes mellitus, chronic kidney disease, hypertension and smoking significantly increase the likelihood of prevalent PAD. A cumulative risk factor analysis highlights important susceptibility differences among different population groups and provides additional evidence to redefine screening strategies in PAD.
PMCID: PMC4436703  PMID: 22739687
Peripheral arterial disease; risk assessment; traditional cardiovascular risk factors; NHANES
2.  Centrifugation Speed Affects Light Transmission Aggregometry 
Light transmission aggregometry (LTA) is considered the gold-standard for investigating platelet activity ex vivo. However, LTA protocols are not standardized and differences in LTA procedure are a potential source of variance in results. Centrifugation speed is an essential component of platelet preparation in LTA, has yet to be standardized, and may affect platelet aggregation results. We sought to investigate the effect of relative centrifugal force (RCF) intensity on LTA results.
Ten healthy controls had venous blood drawn and centrifuged at 150g, 200g, 300g, and 500g for 10 minutes. Cell counts in whole blood and PRP were measured using a hematology analyzer. LTA was performed using 1.0uM ADP and 0.4uM epinephrine as an agonist. Aggregation (%) was compared at 60, 120, 180, and 300 seconds (s) and at maximum aggregation.
Centrifugation speed was associated with decreasing platelet count (P<0.001) and decreasing MPV (P<0.001) in platelet rich plasma. Maximum aggregation decreased with increasing speeds for ADP 1.0uM (150g-89%, 200g-93%, 300g-71%, 500g-17%; P<0.001). Similar findings were noted at 120s (150g-69%, 200g-50%, 300g-35%, 500g-12%; P<0.001), 180s (150g-82%, 200g-74%, 300g-44%, 500g-13%; P<0.001), and 300s (150g-85%, 200g-88%, 300g-55%, 500g-14%; P<0.001). Consistently, platelet aggregation in response to epinephrine 0.4uM decreased significantly with increasing centrifuge RCF at 60s, 120s, 180s, 300s, and at maximum aggregation (P<0.05 for each comparison).
Our data demonstrate the importance of centrifugation speed in the interpretation of LTA results, supporting the need for standardization of centrifugation RCF in LTA protocols.
PMCID: PMC3209490  PMID: 21794095
Light transmission aggregometry; Methodology; Centrifuge; Platelets
4.  Aspirin Use, Dose, and Clinical Outcomes in Postmenopausal Women with Stable Cardiovascular Disease: The Women’s Health Initiative Observational Study 
Despite compelling evidence that aspirin reduces fatal and non-fatal vascular events among the overall population in various settings, women have frequently been underrepresented and their data underreported. We sought to evaluate the relationship between aspirin use, dose (81 or 325mg) and clinical outcomes among postmenopausal women with stable cardiovascular disease.
Women with cardiovascular disease (n=8928) enrolled in the Women’s Health Initiative Observational Study were used for this analysis. The primary outcome was the incidence of all-cause mortality and cardiovascular events (myocardial infarction, stroke and cardiovascular death).
Among 8928 women with stable cardiovascular disease, 4101 (46%) reported taking aspirin, of whom 30% were on 81 and 70% were on 325mg. At 6.5 years of follow-up, no significant association was noted for aspirin use and all-cause mortality or cardiovascular events. However, after multivariate adjustment, aspirin use was associated with a significantly lower all-cause (adjusted HR 0.86, [0.75-0.99], P=0.04) and cardiovascular related mortality (adjusted HR 0.75, [0.60-0.95], P=0.01) compared with no aspirin. Aspirin use was associated with a lower risk of cardiovascular events (adjusted HR 0.90, [0.78-1.04], P=0.14) which did not meet statistical significance. Compared with 325mg, use of 81mg was not significantly different for all-cause mortality, cardiovascular events or any individual endpoint.
After multivariate adjustment, aspirin use was associated with significantly lower risk of all-cause mortality, specifically cardiovascular mortality, among postmenopausal women with stable cardiovascular disease. No significant difference was noted between 81 and 325mg of aspirin. Overall, aspirin use was low in this cohort of women with stable cardiovascular disease.
PMCID: PMC2801891  PMID: 20031819
Aspirin; Dose; Women; Cardiovascular Disease; Observational Study
5.  Competency in Chest Radiography 
Accurate interpretation of chest radiographs (CXR) is essential as clinical decisions depend on readings.
We sought to evaluate CXR interpretation ability at different levels of training and to determine factors associated with successful interpretation.
Ten CXR were selected from the teaching file of the internal medicine (IM) department. Participants were asked to record the most important diagnosis, their certainty in that diagnosis, interest in a pulmonary career and adequacy of CXR training. Two investigators independently scored each CXR on a scale of 0 to 2.
Participants (n = 145) from a single teaching hospital were third year medical students (MS) (n = 25), IM interns (n = 44), IM residents (n = 45), fellows from the divisions of cardiology and pulmonary/critical care (n = 16), and radiology residents (n = 15).
The median overall score was 11 of 20. An increased level of training was associated with overall score (MS 8, intern 10, IM resident 13, fellow 15, radiology resident 18, P<.001). Overall certainty was significantly correlated with overall score (r = .613, P<.001). Internal medicine interns and residents interested in a pulmonary career scored 14 of 20 while those not interested scored 11 (P = .027). Pneumothorax, misplaced central line, and pneumoperitoneum were diagnosed correctly 9%, 26%, and 46% of the time, respectively. Only 20 of 131 (15%) participants felt their CXR training sufficient.
We identified factors associated with successful CXR interpretation, including level of training, field of training, interest in a pulmonary career and overall certainty. Although interpretation improved with training, important diagnoses were missed.
PMCID: PMC1484801  PMID: 16704388
education; medical; radiography; thoracic; clinical competence; educational measurement

Results 1-5 (5)