Comorbidity burden and revascularization benefit in elderly patients with acute coronary syndrome

To evaluate the interaction between comorbidity burden and the benefits of in-hospital revascularization in elderly patients with non-ST-segment elevation acute coronary syndrome (NSTEACS).

This retrospective study included 7211 patients aged ≥ 70 years from 11 Spanish NSTEACS registries. Six comorbidities were evaluated: diabetes, peripheral artery disease, cerebrovascular disease, chronic pulmonary disease, renal failure, and anemia. A propensity score was estimated to enable an adjusted comparison of in-hospital revascularization and conservative management. The end point was 1-year all-cause mortality.

In total, 1090 patients (15%) died. The in-hospital revascularization rate was 60%. Revascularization was associated with lower 1-year mortality; the strength of the association was unchanged by the addition of comorbidities to the model (HR, 0.61; 95%CI, 0.53-0.69; P=.0001). However, the effects of revascularization were attenuated in patients with renal failure, peripheral artery disease, and chronic pulmonary disease (P for interaction=.004, .007, and .03, respectively) but were not modified by diabetes, anemia, and previous stroke (P=.74, .51, and .28, respectively). Revascularization benefits gradually decreased as the number of comorbidities increased (from a HR of 0.48 [95%CI, 0.39-0.61] with 0 comorbidities to 0.83 [95%CI, 0.62-1.12] with ≥ 5 comorbidities; omnibus P=.016). The results were similar for the propensity score model. The same findings were obtained when invasive management was considered the exposure variable.

In-hospital revascularization improves 1-year mortality regardless of comorbidities in elderly patients with NSTEACS. However, the revascularization benefit is progressively reduced with an increased comorbidity burden. Renal failure, peripheral artery disease, and chronic lung disease were the comorbidities with the most detrimental effects on revascularization benefits.