Prevalence, Predictors, Time Course, and Long-Term Clinical Implications of Left Ventricular Functional Recovery After Mechanical Reperfusion for Acute Myocardial Infarction

This study prospectively evaluated the prevalence, predictors, time course, and prognostic impact of left ventricular (LV) functional recovery after successful primary percutaneous coronary intervention in 228 consecutive patients with acute myocardial infarctions (AMIs) and LV dysfunction. Serial echocardiographic exams were performed within 24 hours (time 1) and at 1 month (time 2) and 6 months (time 3) after AMI. Overall, 133 patients (58%) showed significant LV functional recovery (≥10% ejection fraction increase compared with time 1 or ejection fraction ≥50%) at time 3. Early (from time 1 to time 2) and late (from time 2 to time 3) functional recovery patterns were detected in 102 patients (45%) and 31 patients (14%), respectively. Independent predictors of LV functional recovery were enzymatic infarct size (p = 0.0001), time from symptom onset to reperfusion (p = 0.022), extent and severity of baseline LV wall motion abnormalities (p = 0.007), and female gender (p = 0.031). Six-month LV remodeling rates were 36% and 64% in patients with and without LV functional recovery (p = 0.0001). The five-year cardiac death rate was significantly lower in patients with LV functional recovery than in those without (8% vs 18%, respectively, p = 0.024). The time course of LV functional recovery during 6 months did not significantly affect long-term survival. In conclusion, after successful mechanical reperfusion of AMIs, nearly half of patients showed poor LV functional recovery. The presence of significant LV functional recovery 6 months after reperfused AMI, but not the specific time course of recovery, is clearly associated with a better long-term clinical outcome. Simple baseline variables can predict the improvement of cardiac function after reperfused AMI.