Risk stratification for postoperative cardiovascular events via noninvasive assessment of endothelial function: A prospective study

Brachial artery endothelial function is impaired in individuals with atherosclerosis and coronary risk factors and improves with risk reduction therapy. However, the predictive value of brachial artery endothelial dysfunction for future cardiovascular events is unknown. We preoperatively examined brachial artery vasodilation using ultrasound in 187 patients undergoing vascular surgery. Patients were prospectively followed for 30 days after surgery. Forty-five patients had a postoperative event, including cardiac death (3), myocardial infarction (12), unstable angina/ischemic ventricular fibrillation (2), stroke (3), or elevated troponin I, reflecting myocardial necrosis (25). Preoperative endothelium-dependent flow-mediated dilation was significantly lower in patients with an event (4.9+/-3.1%) than in those without an event (7.3+/-5%; P