Optimal timing of revascularization for patients with non-ST segment elevation myocardial infarction and severe left ventricular dysfunction

Abstract

Optimal timing of revascularization for patients who presented with non-ST segment elevation myocardial infarction (NSTEMI) and severe left ventricular (LV) dysfunction is unclear. A total of 386 NSTEMI patients with severe LV dysfunction from the nationwide, multicenter, and prospective Korea Acute Myocardial Infarction Registry V (KAMIR-V) were enrolled. Severe LV dysfunction was defined as LV ejection fraction ≤ 35%. Patients with cardiogenic shock were excluded. Patients were stratified into two groups: PCI within 24 hours (early invasive group) and PCI over 24 hours (selective invasive group). Primary endpoint was major adverse cardiac and cerebrovascular events (MACCE) including all-cause death, non-fatal MI, repeat revascularization, and stroke at 12 months after index procedure. Early invasive group showed higher incidence of in-hospital death (9.4% vs 3.3%, P = .036) and cardiogenic shock (11.5% vs 4.6%, P = .030) after PCI. Early invasive group also showed higher maximum troponin I level during admission (27.7 ± 44.8 ng/mL vs 14.9 ± 24.6 ng/mL, P = .001), compared with the selective invasive group. Early invasive group had an increased risk of 12-month MACCE, compared with selective invasive group (25.6% vs 17.1%; adjusted HR = 2.10, 95% CI 1.17-3.77, P = .006). Among NSTEMI patients with severe LV dysfunction, the early invasive strategy did not improve the clinical outcomes. This data supports that an individualized approach may benefit high-risk NSTEMI patients rather than a routine invasive approach.

Figure 1.

Study flow. D2BT = door-to-balloon time, KAMIR = Korea Acute Myocardial Infarction Registry, LVEF = left ventricular ejection fraction, MACCE = major adverse cardiac and cerebrovascular event, NSTEMI = non-ST segment elevation myocardial infarction, PCI = percutaneous coronary intervention, STEMI = ST segment elevation myocardial infarction.

Figure 2.

Comparison of MACCE According to Treatment Strategy. Comparison of cumulative incidence and Kaplan–Meier curves of 30-day (A) and 12-month (B) outcomes after early invasive (≤24 hours) or selective (>24 hours) invasive strategies. ^†Adjusted for age, sex, hypertension, diabetes mellitus, chronic kidney disease, GRACE score, and left ventricular ejection fraction. CI = confidence interval, GRACE = Global Registry of Acute Coronary Events, HR = hazard ratio, MACCE = major adverse cardiac and cerebrovascular event.

Figure 3.

Comparison of MACCE at 12-Month According to Treatment Strategy after Propensity Score Matching. Comparison of cumulative incidence and Kaplan–Meier curves of 12-month outcomes after early invasive (≤24 hours) or selective (>24 hours) invasive strategies. CI = confidence interval, HR = hazard ratio, MACCE = major adverse cardiac and cerebrovascular event.