Sex differences in cardiac structure and function following acute myocardial infarction: Insights from the PARADISE-MI echocardiographic substudy

Aims: The incidence of heart failure hospitalization is higher in women than in men after myocardial infarction (MI). Sex-related differences in left ventricular (LV) remodelling may contribute to the differences in post-MI outcomes. The aim of this study was to assess sex differences in echocardiographic parameters post-MI, and whether the relationship between echocardiographic parameters and clinical outcomes differs by sex. Methods and results: In the PARADISE-MI trial, patients were randomized to sacubitril/valsartan or ramipril within 0.5 to 7 days of high-risk MI. In the pre-specified echocardiographic substudy, 544 patients underwent echocardiography at the time of randomization and after 8 months. We compared key echocardiographic parameters in men and women and their association with primary composite outcome (cardiovascular death or incident heart failure). At baseline, women had higher LV ejection fraction (LVEF), lower LV end-diastolic volume (LVEDV) index, LV end-systolic volume (LVESV) index, and LV mass index. After adjusting for baseline clinical differences, changes in these echocardiographic parameters from baseline to 8 months were not significantly different in women versus men. Lower LVEF, higher LVEDV, LVESV, left atrial volume index, and average E/e' were associated with a higher risk of the primary composite outcome. Sex did not modify the relationship between echocardiographic parameters and clinical outcome. Conclusions: Despite baseline differences in measures of cardiac function between men and women following acute high-risk MI, there were no significant sex-related changes in chamber size or LV function. Sex did not modify the association between echocardiographic parameters and clinical outcome.