Impact of complete revascularisation in relation to left ventricular function in patients with ST-segment elevation myocardial infarction and multivessel disease: a post hoc analysis of the COMPLETE randomised trial.

BACKGROUND: The COMPLETE trial demonstrated a reduction in cardiovascular (CV) death or new myocardial infarction (MI) after complete, rather than culprit-only, revascularisation in patients with ST-segment elevation myocardial infarction (STEMI) and multivessel disease (MVD). However, it is unknown whether this benefit varies according to baseline left ventricular ejection fraction (LVEF). AIMS: We aimed to determine the effects of complete versus culprit-only revascularisation according to LVEF. METHODS: Baseline LVEF was available for 2,214 of 4,041 randomised patients. The effect of both strategies on the first co-primary outcome of CV death or new MI and the second co-primary outcome of CV death, new MI, or ischaemia-driven revascularisation (IDR) was determined within the prespecified LVEF ranges of <45% (N=660) and ≥45% (N=1,554). An analysis of clinical outcomes by LVEF according to thirds was also conducted. RESULTS: Patients with LVEF <45% experienced a significantly higher incidence of the first co-primary outcome compared with those with LVEF ≥45% (4.2%/year vs 2.8%/year; hazard ratio [HR] 1.51, 95% confidence interval [CI]: 1.15-1.98; p=0.003). Compared with a culprit-only strategy, complete revascularisation consistently reduced the first co-primary outcome in patients with LVEF <45% (3.0%/year vs 5.5%/year; HR 0.55, 95% CI: 0.36-0.86) and those with LVEF ≥45% (2.4%/year vs 3.2%/year; HR 0.74, 95% CI: 0.52-1.04; interaction p=0.31). Complete revascularisation also consistently reduced the second co-primary outcome in patients with LVEF <45% (3.5%/year vs 7.3%/year; HR 0.49, 95% CI: 0.33-0.74) and those with LVEF ≥45% (2.7%/year vs 6.3%/year; HR 0.44, 95% CI: 0.33-0.60; interaction p=0.67). Consistent results were observed for both co-primary outcomes when LVEF was further stratified into categories of LVEF ≤35%, 36-49% and ≥50%. CONCLUSIONS: Among patients presenting with STEMI and MVD, those with reduced LVEF are at higher risk of ischaemic events than patients with preserved LVEF. There is a consistent benefit of complete revascularisation regardless of baseline LVEF.