Abstract 901: Impact of Microvascular Dysfunction on Long-Term Cardiovascular Events after Primary Coronary Intervention for Acute Myocardial Infarction in Patients Achieving TIMI Grade 3 Reperfusion
It has been reported that even if TIMI 3 flow is achieved in epicardial coronary arteries after primary percutaneous coronary intervention (PCI) for acute myocardial infarction (AMI), microvascular dysfunction results in insufficient reperfusion. Recent studies have shown that microvascular injury can be assessed from coronary flow velocity (CFV) pattern. The aim of this prospective study was to examine whether the CFV pattern predicts the long-term cardiovascular outcomes in AMI patients who achieved TIMI grade 3 reperfusion. The study population consisted of 161 consecutive patients with a first anterior AMI successfully treated with primary PCI (≤50% residual stenosis with TIMI grade 3). We examined the CFV pattern immediately after PCI using a Doppler guidewire. We defined microvascular dysfunction as a diastolic deceleration time ≤600 ms and the presence of systolic flow reversal. Patients were divided into two groups: those without microvascular dysfunction (n=126; group 1) and those with micriovascular dysfunction (n=35; group 2). We evaluated the association between the microvascular dysfunction and the long-term major adverse cardiovascular event (MACE) rates. The Kaplan-Meier survival curves showed that group 2 was poorer than group 1 in prognosis (p=0.0014). Risk-adjusted data by multivariate analysis showed that the microvascular dysfunction was the strongest predictor for long-term MACE (hazard ratio: 3.37; 95% CI, 1.59–7.15; p=0.0015). The CFV pattern immediately after PCI is an accurate predictor of the long-term cardiovascular outcomes in patients with AMI who achieved TIMI grade 3 reperfusion.