Abstract 11653: Prognostic Value of Combination of Flow-Mediated Vasodilation and Nitroglycerine-Induced Vasodilation

Abstract

Introduction: Flow-mediated vasodilation (FMD) as an index of endothelium-dependent vasodilation and nitroglycerine-induced vasodilation as an index of endothelium-independent vasodilation in the brachial artery using high-resolution ultrasound are useful for assessing vascular function. Some studies have shown that endothelial function assessed by FMD can serve as an independent predictor of cardiovascular events. Previously, we reported that nitroglycerine-induced vasodilationcan be used as a marker for identifying patients with advanced atherosclerosis. The purpose of this study was to determine the prognostic impact of cardiovascular events between FMD and FMD combined with nitroglycerine-induced vasodilation. Methods and Results: We measured FMD and nitroglycerine-induced vasodilation in 402 subjects (mean age, 58±17 years), including patients with cardiovascular diseases. We assessed the associations between FMD combined with nitroglycerine-induced vasodilation and cardiovascular events (death from cardiovascular causes, myocardial infarction, stroke, and revascularization). During a median period of 32.3 months (interquartile range, 17.1 to 49.1 months) of follow-up, 15 subjects died (5 from cardiovascular causes), 3 myocardial infarction, 7 stroke, and 26 revascularization. The receiver operating characteristic curve analysis revealed that FMD alone predicts cardiovascular events with an area under curve of 0.67. FMD combined with nitroglycerine-induced vasodilation predicts cardiovascular events with an area under curve of 0.70. FMD < median value of 3.9% and nitroglycerine-induced vasodilation < median value of 12.2% were associated with increased cardiovascular event. After adjustment for age, sex, body mass index, cardiovascular risk factors, below median FMD and nitroglycerine-induced vasodilation group remained a strong independent indicator of cardiovascular events (hazard ratio, 4.95; 95 percent confidence interval, 1.65 to 21.43; P=0.002). Conclusions: These findings suggest that the combination of FMD and nitroglycerine-induced vasodilation measurement could more accurately predict cardiovascular events than FMD alone.