Microvascular dysfunction in angiographically normal or mildly diseased coronary arteries predicts adverse cardiovascular long-term outcome

Objective To study the role of coronary flow reserve for the prediction of long-term cardiovascular event rate. Design Observational, longitudinal. Setting Single-center, coronary vasomotor testing at university hospital. Participants One hundred and twenty patients with angiographically normal or minimally diseased coronary vessel. Methods Coronary flow reserve was assessed by intracoronary Doppler and quantitative coronary angiography. Cardiovascular events during follow-up (6.5+/-3 years, range 14-125 months) were defined as sudden death, myocardial infarction, unstable angina, ischemic stroke or the need for revascularization by percutaneous transluminal coronary angioplasty or coronary as well as peripheral bypass surgery. Results Reduced coronary flow reserve was significantly associated with a poor long-term outcome: cardiovascular events occurred in seven (18%) patients in the lowest tertile of coronary flow reserve compared with four patients in the middle tertile (110%) and two patients in the upper tertile (5%) (P=0.019 by Kaplan-Meier analysis). The multivariate Cox proportional hazard model revealed coronary flow reserve as an independent predictor of prognosis (P=0.017) in addition to angiographic evidence of atherosclerosis (P=0.047) and arterial hypertension (P=0.013). Conclusions Coronary flow reserve in normal to mildly diseased arteries is an independent predictor of long-term prognosis of atherosclerosis within the next decade. (C) 2004 Lippincott Williams Wilkins.