Prognostic Implications of Mid-Range Left Ventricular Ejection Fraction on Patients Presenting With ST-Segment Elevation Myocardial Infarction

The new European Society of Cardiology guidelines reclassified heart failure according to left ventricular ejection fraction, recognizing patients with mid-range EF (mrEF; 40% to 49%) as a distinct group. We sought to investigate the clinical profile, in-hospital outcomes, and long-term mortality of ST-elevation myocardial infarction (STEMI) patients treated with primary percutaneous coronary intervention who had mrEF. We conducted a retrospective study of 2,086 consecutive patients with STEMI between December 2007 and June 2016 who underwent primary percutaneous coronary intervention and had a comprehensive echocardiographic examination performed within 72 hours of hospital admission. Patients were stratified according to their left ventricular ejection fraction-mrEF (40% to 49%), reduced EF (rEF; <40%), and preserved EF (pEF; ≥50%) groups and evaluated for baseline characteristics, in-hospital outcomes, as well as for long-term mortality. A total of 858 of 2,086 patients (41%) had mrEF, 215 of 2086 (10%) had rEF, and 1,013 of 2,086 (48%) had pEF. Patients with mrEF had nearly similar baseline co-morbidities and similar 30-day mortality compared with patients with pEF (2% vs 1%, p = 0.17). In a univariate analysis, long-term mortality was higher compared with those with pEF (9.8% vs 7.2%, p <0.01). In a multivariate Cox regression model, mrEF was independently associated with increased long-term mortality risk compared with pEF (hazard ratio 1.4, 95% CI 1.02 to 1.93, p = 0.04). In conclusion, among STEMI patients, those with mrEF at presentation constitute a distinct group in terms of baseline characteristics, in-hospital outcomes, and long-term mortality.