Differential prognostic effect of revascularization according to a simple comorbidity index in high-risk non-ST-segment elevation acute coronary syndrome.

ABSTRACT

BACKGROUND: Data on the effect of revascularization on outcome in patients with high-risk non-ST-segment elevation acute coronary syndrome (NSTEACS) and significant comorbidities are scarce. Recently, a simple comorbidity index (SCI) including 5 comorbidities (renal failure, dementia, peripheral artery disease, heart failure, and prior myocardial infarction [MI]) has shown to be a useful tool for risk stratification. Nevertheless, therapeutic implications have not been derived. HYPOTHESIS: We sought to evaluate the prognostic effect attributable to revascularization in NSTEACS according the SCI score. METHODS: We included 1017 consecutive patients with NSTEACS. The effect of revascularization on a combined end point of all-cause mortality or nonfatal MI was evaluated by Cox regression according to SCI categories. RESULTS: A total of 560 (55.1%), 236 (23.2%), and 221 (21.7%) patients showed 0, 1, and ≥2 points according to the SCI, respectively. Coronary angiography was performed in 725 patients (71.5%), and 450 patients (44.3%) underwent revascularization. During a median follow-up of 16 months (interquartile range, 12-36 months), 305 (30%) patients experienced the combined end point (202 deaths [19.9%] and 170 MIs [16.7%]). In multivariate analysis, a differential prognostic effect of revascularization was observed comparing SCI ≥2 vs 0 (P for interaction = 0.008). Thus, revascularization was associated with a greater prognostic benefit in patients with SCI ≥2 (hazard ratio [HR] 0.51, 95% confidence interval [CI] 0.29-0.89), P = 0.018), whereas no significant benefit was observed in those with 0 and 1 point (HR 1.31, 95% CI 0.88-1.94, P = 0.171 and HR 1.11, 95% CI 0.70-1.76, P = 0.651, respectively). CONCLUSIONS: In NSTEACS, the SCI score appears to be a useful tool for identifying a subset of patients with a significant long-term death/MI risk reduction attributable to revascularization.