Impact of duration of ischemia on left ventricular diastolic properties following reperfusion for acute myocardial infarction.

We sought the correlation between duration of myocardial ischemia and severe left ventricular (LV) diastolic dysfunction (restrictive filling pattern [RFP]) in patients with acute ST-elevation myocardial infarction (STEMI). Duration of ischemia determines infarct size and survival after STEMI. However, the impact of duration of ischemia on LV diastolic function has not been previously studied. Ninety-five consecutive patients with first-ever STEMI underwent transthoracic echocardiography 3 days after primary percutaneous coronary intervention (PCI). RFP was defined as a mitral inflow E/A ratio >2.0 and/or E-wave deceleration time <140 ms. Composite major adverse cardiovascular events (death, reinfarction, heart failure, revascularization) were determined at 12 months. Twenty patients (21%) had RFP on day 3. Symptom-to-reperfusion time in the RFP group was 413 ± 287 versus 252 ± 138 minutes in the non-RFP group (p = 0.014). Peak troponin T levels were higher in the RFP group (12.2 ± 8.4 vs 5.7 ± 3.6 ng/ml, p = 0.002). Logistic regression identified symptom-to-reperfusion time (hazard ratio 1.02, 95% confidence interval 1.01 to 1.03, p = 0.010) and infarct size by peak troponin T levels (hazard ratio 1.54, 95% confidence interval 1.14 to 2.10, p = 0.005) as independent predictors of RFP. Major adverse cardiovascular events occurred in 10 patients (50%) in the RFP group and 6 patients (8%) in the non-RFP group. On multivariate Cox proportional hazards analysis, RFP was an independent predictor of major adverse cardiovascular events at 12 months (hazard ratio 5.43, 95% confidence interval 1.52 to 19.39, p = 0.001). In conclusion, delayed reperfusion after STEMI was associated with severe LV diastolic dysfunction, which in turn independently predicted adverse long-term outcomes. LV diastolic dysfunction represents a significant pathophysiologic link among duration of myocardial ischemia, infarct size, and outcomes.