Effect of Guideline-Based Therapy on Left Ventricular Systolic Function Recovery After ST-Segment Elevation Myocardial Infarction.

Little is known about the proportion of ST-segment elevation myocardial infarction (STEMI) patients treated with primary percutaneous coronary intervention, who have reduced left ventricular ejection fraction (LVEF) within 48 hours (baseline) of admission and exhibit LVEF recovery under optimal guideline-based medical treatment. Therefore, the present study evaluates the evolution of LVEF in patients after STEMI and under guideline-based medical therapy. In 2,853 STEMI patients treated with primary percutaneous coronary intervention, echocardiography was performed at baseline and at 6 months follow-up. Patients with previous myocardial infarction, reinfarction, coronary artery bypass grafting or incomplete echocardiographic data at 6 months follow-up were excluded. Reduced LVEF at baseline was defined as <40%. LVEF recovery was defined as LVEF >50% at 6 months follow-up. The prevalence of LVEF <40% at baseline was 13% (n = 371 patients; mean age 60 [range 33 to 88] years; 76% men). At follow-up, 31% of patients remained with a LVEF <40%, 30% showed a LVEF between 41% and 49% and in 39% of patients LVEF improved to >50%. There were no differences in usage of guideline-based medications at discharge across groups. On multivariable analysis, peak troponin T levels (odds ratio [OR] 0.895; p < 0.001), baseline LVEF (OR 1.069; p = 0.023) and absence of significant mitral regurgitation (OR 0.376; p = 0.018) were independently associated with LV recovery at follow-up. In conclusion, the prevalence of LVEF <40% is low. With optimal medical therapy, LVEF normalizes in 39% of patients. Smaller enzymatic infarct size, baseline LVEF and absence of mitral regurgitation were independently associated with LVEF recovery at follow-up.