Predominant subtype of heart failure after acute myocardial infarction is heart failure with non-reduced ejection fraction

Aims: Patients who survive acute myocardial infarction (AMI) are at risk of being rehospitalized owing to the occurrence of acute decompensated heart failure (HF). However, the clinical characteristics of HF after AMI, especially the frequency of each HF subtype, are unclear. Methods and results: We retrospectively studied 1055 patients with AMI. We excluded 257 patients, who were admitted >48 h after the onset of AMI, died during hospitalization or after discharge, and whose echocardiogram data at index hospitalization and follow-up data were missing. The remaining 798 patients (mean age: 66.5 +/- 11.7 years) were investigated for a mean follow-up period of 4.9 years. All patients underwent emergency coronary angiography. The mean maximum creatine kinase levels were 2898 +/- 2627 IU/L, and mean left ventricular ejection fraction (LVEF) was 58.9 +/- 10.2%. Eighty-one patients (10.2%) were rehospitalized because of unexpected worsening of HF. Echocardiography data were available for 74 of the 81 patients during the acute phase of the second hospitalization, of which 30, 20, and 24 patients (41%, 27%, and 32%, respectively) were diagnosed as having HF with preserved LVEF (LVEF >= 50%), HF with mid-range LVEF (40% <= LVEF < 50%), and HF with reduced LVEF (LVEF < 40%), respectively. The ejection fraction during index hospitalization was 58.3 +/- 9.7% in the HF with preserved LVEF group, 53.3 +/- 10.2% in the HF with mid-range LVEF group, and 43.3 +/- 10.5% in the HF with reduced LVEF group (P < 0.001). Conclusions: The predominant subtypes of HF after AMI were HF with mid-range ejection fraction and preserved ejection fraction, or HF with non-reduced ejection fraction.

Automated summary

This study retrospectively analyzed 1055 patients with AMI and found that the predominant subtypes of HF after AMI were HF with mid-range ejection fraction and preserved ejection fraction, or HF with non-reduced ejection fraction. The occurrence of HF was associated with left ventricular ejection fraction, with a significant proportion of HF patients having abnormal LVEF values during follow-up.