Abstract 3909: Flow-Mediated Dilation of Brachial Artery Predicts Incident Cardiovascular Events in Older Adults (Cardiovascular Health Study).
INTRODUCTION: Impaired brachial flow-mediated dilation (FMD) is associated with a number of cardiovascular risk factors. However, the relationship between impaired FMD and subsequent clinical cardiovascular (CVD) events is less well established especially in older adults whose FMD is generally greatly diminished.
HYPOTHESIS: We assessed the hypothesis that brachial artery FMD predicts incident CVD events in a population based cohort of older adults.
METHODS AND DESIGN: Brachial FMD was measured at year ten in 2792 adults aged 72–98 years, participating in the Cardiovascular Health Study (CHS), a population based cohort study of adults > 65 years recruited at four clinic sites in USA. The subjects consisted of 82.7% Caucasians and 60% females. Log rank test and Cox proportional hazard models were used to examine the association between FMD and five years of adjudicated incident myocardial infarction, stroke, congestive heart failure, CHD death, angioplasty, cardiac bypass surgery and claudication.
RESULTS 1129(40.4%) subjects had an adjudicated event over the five year period. Event-free survival rates for the composite outcome were significantly higher in subjects with %FMD> median (2.9%) compared with subjects with %FMD ≤ median (>median 61.04% vs ≤median 53.07% log rank p<0.0001).In the Cox Proportional hazard analysis (CPHA) %FMD remained a significant predictor of the composite outcome after adjusting for age, gender, ACE inhibitor use, statin use, B-blocker use, diabetes mellitus, cigarettes smoking, hypertension and total cholesterol (hazard ratio 0.786, p=0.021).%FMD was also a significant predictor of the composite outcome when the adjusted Cox proportional hazard analysis was stratified by gender (hazard ratio 0.789, p=0.032) and race (hazard ratio 0.788, p=0.024). Secondary analysis showed event-free survival rates for CHD events(myocardial infarction,CHF,angioplasty or CABG) significantly higher in subjects with %FMD >median compared with those with%FMD <median ( 73.3% vs 65.9% respectively, log rank <0.0001) and also in the adjusted CPHA %FMD was a significant predictor of CHD events (hazard ratio 0.777, p=0.046).
CONCLUSION: FMD is a significant predictor of future clinical cardiovascular events in older adults.