Clinical correlates and prognostic value of flow mediated dilation in patients with non-ST segment elevation acute coronary syndromes

Endothelial dysfunction can predict cardiovascular outcomes in several populations of patients. The aim of this study was to assess the severity, time course, and clinical implications of endothelial dysfunction in patients with non-ST-segment elevation (NSTE) acute coronary syndromes (ACS). Sixty patients with NSTE ACS (mean age 62 \ub1 8 years, 44 men) and 40 controls with stable coronary artery disease (CAD) (mean age 63 \ub1 10 years, 27 men) were studied. In patients with NSTE ACS and in those with stable CAD, endothelial function was assessed <12 hours after admission and at 3-month follow-up by measuring right brachial artery dilation after 5 minutes of forearm ischemia (flow-mediated dilation [FMD]). Clinical outcomes were assessed after a median follow-up period of 32 months (range 14 to 36). The primary end point was a combination of cardiac death or readmission for new ACS or recurrence of angina pectoris. FMD on admission was significantly lower in patients with NSTE ACS compared to those with stable CAD (2.1 \ub1 1.2% vs 4.8 \ub1 1.9%, p <0.001). FMD improved significantly at 3-month follow-up in patients with NSTE ACS, becoming comparable to that in patients with stable CAD (5.7 \ub1 2.6% vs 5.5 \ub1 1.7%, p = 0.93). During follow-up, 14 cardiac events (23%) occurred in patients with NSTE ACS. On multivariate analysis, only diabetes (hazard ratio 18.1, 95% confidence interval 3.9 to 83.9, p