Predictors of recovery in left ventricular ejection fraction after acute myocardial infarction: from the Korean Myocardial Infarction (KorMI) registry

Abstract

Purpose: Left ventricular ejection fraction (LVEF) is a strong predictor of subsequent short- and long-term mortality and plays a major role in determining the therapeutic response in patients with acute myocardial infarction (MI). We investigated the predictors of the recovery of depressed left ventricular systolic function in patients with left ventricular systolic dysfunction soon after acute MI. Methods: We analyzed 1,112 patients, who had depressed LVEF (<50%) on echocardiography soon after acute MI and underwent the follow-up echocardiography, among 13,472 patients from the Korean Myocardial Infarction (KorMI) Registry between January 2008 and March 2012. Patients were categorized into two groups according to recovery of LVEF: Group I (n=614, 55.2%) with consistently depressed LVEF (<50%) at follow-up echocardiography and Group II (n=498, 44.8%) with recovery of LVEF more than 50%. Results: The baseline LVEF was significantly lower in the group I than in the group II (38.3±7.9 vs. 43.0±6.1%, p<0.001). The group I had more frequently a history of ischemic heart disease than the group II (18.3 vs. 10.8%, p<0.001). But, a history of diabetes, hypertension orhyperlipidemia was not significantly different. ST-segment elevation MI was more common in the group I than in the group II (66.6% vs. 56.4%, p<0.001). The patients in the group I were significantly more often prescribed diuretics and less often β-blocker and angiotensin-converting enzyme inhibitor than in group II. In multivariate analysis, the baseline LVEF more than 35% was independently the most powerful predictor for recovery of depressed LVEF with 3.61 (95% CI, 2.09-6.25) of odds ratio (p<0.001). In addition, patients who wasn't prescribed diuretics at discharge had an odds ratio of 2.51 (95% CI, 1.65-3.80, p<0.001) for recovery of depressed LVEF. Non-ST-segment elevation MI and N-terminal pro-B-type natriuretic peptide (NT-proBNP) < 500 pg/mL was independently associated with the recovery of left ventricular systolic dysfunction (odds ratio [95% CI], 2.01 [1.34-3.02], 1.60 [1.10-2.31], respectively; P < 0.05 for both). Conclusions: Our data suggest that higher baseline global left ventricular systolic function, LVEF more than 35%, would independently predict the recovery of left ventricular systolic dysfunction. As the patients with severe left ventricular dysfunction soon after acute MI, ST-segment elevation MI, need for diuretics usage, or NT-proBNP more than 500 pg/mL may have the higher risk of sustained left ventricular systolic dysfunction and heart failure, more aggressive approach and treatment should be considered in these patients.