The prognostic importance of left ventricular function in patients with ST-segment elevation myocardial infarction: The HORIZONS-AMI trial

Abstract

Left ventricular (LV) dysfunction during and after hospitalization for ST-segment elevation myocardial infarction (STEMI) is associated with increased mortality. Whether baseline LV dysfunction impacts STEMI outcomes is not well studied. Furthermore, whether bivalirudin and paclitaxel-eluting stents (PES) are beneficial in patients with LV dysfunction is unknown. We studied the impact of left ventricular ejection fraction (LVEF) on outcomes of patients with STEMI in the HORIZONS-AMI trial. LVEF was determined in 2648 (73.5%) of 3602 enrolled STEMI patients, who were divided into three groups according to LV function: (1) severely impaired (LVEF <40%); (2) moderately impaired (LVEF 40–50%); and (3) normal (LVEF ≥50%). Compared to patients with normal LV function, those with severely impaired LVEF had higher 1-year rates of net adverse clinical events (27.1 vs. 14.2%, p<0.0001), major adverse cardiovascular events (20.7 vs. 9.5%, p<0.0001), cardiac death (10.6 vs. 1.2%, p<0.0001), and non-coronary artery bypass graft major bleeding (12.5 vs. 6.6%, p=0.001), differences which persisted after adjustment for baseline characteristics. Among patients with LVEF <40%, treatment with bivalirudin compared to heparin+GPIIb/IIIa inhibitors resulted in reduced 1-year mortality (5.8 vs. 18.3%, p=0.007). Patients with LVEF <40% receiving PES rather than bare metal stents had lower rates of 1-year ischaemia-driven target lesion revascularization (2.9 vs. 12.6%, p=0.02) and reinfarction (4.5 vs. 14.7%, p=0.03). Among patients with STEMI undergoing primary percutaneous coronary intervention, adverse events are markedly increased in those with LVEF <40% during the index revascularization procedure. Nevertheless, these high-risk patients experience substantial clinical benefits from bivalirudin and PES. © 2013, The European Society of Cardiology. All rights reserved.