Published online before print July 27, 2009, doi: 10.1161/CIRCULATIONAHA.109.864801
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(Circulation. 2009;120:502-509.)
© 2009 American Heart Association, Inc.
Epidemiology and Prevention |
Predictive Value of Brachial Flow-Mediated Dilation for Incident Cardiovascular Events in a Population-Based Study
The Multi-Ethnic Study of Atherosclerosis
From the Department of Internal Medicine/Cardiology, University of Virginia School of Medicine, Charlottesville (J.Y.); Division of Epidemiology and Community Health, University of Minnesota, Minneapolis (A.R.F.); Department of Internal Medicine/Cardiology and the Division of Public Health Sciences, Wake Forest University School of Medicine, Winston-Salem, NC (G.L.B., J.R.C., D.M.H.); Collaborative Health Studies Coordinating Center, University of Washington, Seattle (C.J.); Department of Radiology, Tufts–New England Medical Center, Boston, Mass (J.F.P.); and Department of Cardiology, Johns Hopkins University, Baltimore, Md (W.P., J.A.L.).
Reprint requests to Joseph Yeboah, MD, MS, Department of Internal Medicine/Cardiology, University of Virginia Medical Center, Charlottesville, VA 22908. E-mail jy5y{at}hscmail.mcc.virginia.edu
Received March 13, 2009; accepted June 9, 2009.
Background— Although brachial artery flow-mediated dilation (FMD) predicts recurrent cardiovascular events, its predictive value for incident cardiovascular disease (CVD) events in adults free of CVD is not well established. We assessed the predictive value of FMD for incident CVD events in the Multi-Ethnic Study of Atherosclerosis (MESA).
Methods and Results— Brachial artery FMD was measured in a nested case-cohort sample of 3026 of 6814 subjects (mean±SD age, 61.2±9.9 years) in MESA, a population-based cohort study of adults free of clinical CVD at baseline recruited at 6 clinic sites in the United States. The sample included 50.2% female, 34.3% white, 19.7% Chinese, 20.8% black, and 25.1% Hispanic subjects. Probability-weighted Cox proportional hazards analysis was used to examine the association between FMD and 5 years of adjudicated incident CVD events, including incident myocardial infarction, definite angina, coronary revascularization (coronary artery bypass grafting, percutaneous transluminal coronary angioplasty, or other revascularization), stroke, resuscitated cardiac arrest, and CVD death. Mean (SD) FMD of the cohort was 4.4% (2.8). In probability-weighted Cox models, FMD/unit SD was significantly associated with incident cardiovascular events in the univariate model (adjusted for age and sex) (hazard ratio, 0.79; 95% confidence interval, 0.65 to 0.97; P=0.01), after adjustment for the Framingham Risk Score (FRS) (hazard ratio, 0.80; 95% confidence interval, 0.62 to 0.97; P=0.025), and in the multivariable model (hazard ratio, 0.84; 95% confidence interval, 0.71 to 0.99; P=0.04) after adjustment for age, sex, diabetes mellitus, cigarette smoking status, systolic blood pressure, high-density lipoprotein cholesterol, low-density lipoprotein cholesterol, triglycerides, heart rate, statin use, and blood pressure medication use. The c statistic (area under the curve) values of FMD, FRS, and FRS+FMD were 0.65, 0.74, and 0.74, respectively. Compared with the FRS alone, the addition of FMD to the FRS net correctly reclassifies 52% of subjects with no incident CVD event but net incorrectly reclassifies 23% of subjects with an incident CVD event, an overall net correct reclassification of 29% (P<0.001).
Conclusions— Brachial FMD is a predictor of incident cardiovascular events in population-based adults. Even though the addition of FMD to the FRS did not improve discrimination of subjects at risk of CVD events in receiver operating characteristic analysis, it improved the classification of subjects as low, intermediate, and high CVD risk compared with the FRS.
CLINICAL PERSPECTIVE
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Clinical Summaries
Circulation 2009 120: 459-460.[Extract] [Full Text]