Evaluation of acute myocardial infarction patients with mid-range ejection fraction after emergency percutaneous coronary intervention

Abstract Background There is currently no classification for acute myocardial infarction (AMI) according to left ventricular ejection fraction (LVEF). We aimed to perform a retrospective analysis of patients undergoing emergency percutaneous coronary intervention (PCI), comparing the clinical characteristics, in-hospital acute heart failure and all-cause death events of AMI patients with mid-range ejection fraction (mrEF), preserved ejection fraction (pEF) and reduced ejection fraction (rEF). Material and methods Totally 1270 patients were stratified according to their LVEF immediately after emergency PCI into pEF group (LVEF 50% or higher), mrEF group (LVEF 40%–49%) and rEF group (LVEF <40%). Kaplan-Meier curves and log rank tests were used to assess the effects of mrEF, rEF and pEF on the occurrence of acute heart failure and all-cause death during hospitalisation. The Cox proportional hazards model was used for multivariate correction. Results Compared with mrEF, rEF was an independent risk factor for acute heart failure events during hospitalisation (HR 5.01, 95% CI 3.53 to 7.11, p<0.001), and it was also an independent risk factor for all-cause mortality during hospitalisation (HR 7.05, 95% CI 4.12 to 12.1, p<0.001); Compared with mrEF, pEF was an independent protective factor for acute heart failure during hospitalisation (HR 0.49, 95% CI 0.30 to 0.82, p=0.01), and it was also an independent protective factor for all-cause death during hospitalisation (HR 0.33, 95% CI 0.11 to 0.96, p=0.04). Conclusions mrEF patients with AMI undergoing emergency PCI share many similarities with pEF patients in terms of clinical features, but the prognosis is significantly worse than that of pEF patients, suggesting that we need to pay attention to the management of mrEF patients with AMI.