Abstract 2150: Microvascular Dysfunction Following Percutaneous Coronary Intervention Determines Sustained Restrictive Left Ventricular Filling in Reperfused Anterior Acute Myocardial Infarction
Background: In patients with acute myocardial infarction (AMI), the short deceleration time (DT) of LV early filling by Doppler is a powerful independent predictor of heart failure and death. On the other hand, studies using intravascular Doppler guidewires have shown that the microvascular dysfunction in recanalized coronary arteries may predict long-term cardiac events and survival of AMI patients. However, the relationship between the restrictive LV filling pattern and microvascular injury after percutaneous coronary intervention (PCI) has not been elucidated. The purpose of this study was to examine the effects of the microvascular dysfunction on the LV filling.
Methods: One hundred and sixty-nine consecutive patients with first-time anterior AMI were studied following the successful PCI. Microvascular injury was evaluated on the basis of coronary flow velocity patterns. We defined the presence of microvascular dysfunction as diastolic deceleration time of ≤600 ms and the presence of systolic flow reversal. The LV filling patterns were determined by the mitral inflow pulsed-wave Doppler examination on days 3 and 7 after AMI. DT >130 ms was classified as nonrestrictive, and ≤130 ms was defined as restrictive. Patients were divided into those without (Group 1, n=118) or with (Group 2, n=51) microvascular dysfunction.
Result: DT was significantly shorter in Group 2 than in Group 1 on days 3 and 7 after infarction (127±26 vs. 186±42 ms, p<0.01; 145±25 vs. 196±45 ms, p<0.01, respectively). The restrictive LV filling patterns were observed more frequently in Group 2 than in Group 1 (59% vs. 11%, p<0.01). The restrictive LV filling persisted even under extensive heart failure therapy more frequently in Group 2 than in Group 1 (31% vs. 0%, p<0.01). Congestive heart failure requiring mechanical ventilation occurred more frequently in Group 2 than in Group 1 (27% vs. 3%, p<0.01). The in-hospital cardiac mortality rate was significantly higher in Group 2 than in Group 1 (18% vs. 0%, p<0.01).
Conclusions: The AMI patients with microvascular dysfunction even after successful PCI showed the persistent restrictive LV filling and higher morbidity and mortality. Thus, the microvascular dysfunction after revascularization might critically determine their outcome.