Incidence, Clinical Characteristics and Short-Term Prognosis in Patients With Cardiogenic Shock and Various Left Ventricular Ejection Fractions After Acute Myocardial Infarction

The 2016 European Society of Cardiology Guidelines introduced a new term, mid-range left ventricular ejection fraction (mrEF) heart failure, however, the clinical characteristics and short-term outcomes in cardiogenic shock patients with mrEF after acute myocardial infarction remain unclear. This retrospective study analyzed the baseline characteristics, management, and outcomes according to the left ventricular ejection fraction (LVEF), reduced LVEF (rEF) ≤40%, mrEF 41% to 49%, and preserved LVEF (pEF) ≥50% in patients with acute myocardial infarction complicated by cardiogenic shock. The primary end point was 30-day all-cause mortality and the secondary end point was the composite events of major adverse cardiovascular events (MACEs). In 218 patients, 71 (32.6%) were patients with mrEF. Compared with those with pEF, patients with mrEF had some similar clinical characteristics to that of rEF. The 30-day all-cause mortality in patients with rEF, mrEF, and pEF were 72.7%, 56.3%, and 32.0%, respectively (p = 0.001). The 30-day MACE were 90.9%, 69.0%, and 60.2%, respectively (p = 0.001). After multivariable adjustment, patients with mrEF and rEF had comparable 30-day all-cause mortality (hazard ratio [HR] = 0.81, 95% confidence interval [CI] 0.50 to 1.33, p = 0.404), and pEF was associated with decreased risk of 30-day all-cause mortality compared with rEF (HR = 0.41, 95% CI 0.24 to 0.71, p = 0.001). In contrast, the risk of 30-day MACE in mrEF and pEF were lower than that of rEF (HR = 0.62, 95% CI 0.40 to 0.96, p = 0.031 and HR = 0.53, 95% CI 0.34 to 0.80, p = 0.003, respectively). In conclusion, 1/3 of patients with acute myocardial infarction complicated by cardiogenic shock were mrEF. The clinical characteristics and short-term mortality in patients with mrEF were inclined to that of rEF and the occurrence of early left ventricular systolic dysfunction is of prognostic significance.