Disparities in management patterns and outcomes of patients with non-ST-elevation acute coronary syndrome with and without a history of cerebrovascular disease

Abstract

Cerebrovascular (CVD) disease is commonly associated with coronary artery disease and adversely affects outcome. The goal of the present study was to examine the temporal management patterns and outcomes in relation to previous CVD in a contemporary "real-world" spectrum of patients with acute coronary syndrome (ACS). From 1999 to 2008, 14,070 patients with non-ST-segment elevation ACS were recruited into the Canadian Acute Coronary Syndrome I (ACS I), ACS II, Global Registry of Acute Coronary Events (GRACE/GRACE(2)), and Canadian Registry of Acute Coronary Events (CANRACE) prospective multicenter registries. We stratified the study patients according to a history of CVD and compared their treatment and outcomes. Patients with a history of CVD were older, more likely to have pre-existing coronary artery disease, elevated creatinine, higher Killip class, and ST-segment deviation on admission. Despite presenting with greater GRACE risk scores (137 vs 117, p <0.001), patients with previous CVD were less likely to receive evidence-based antiplatelet and antithrombin therapies during the initial 24 hours of hospital admission. They were also less likely to undergo in-hospital coronary angiography and revascularization. These disparities in medical and invasive management were preserved temporally across all 4 registries. Patients with concomitant CVD had worse in-hospital outcomes. Previous CVD remained an independent predictor of in-hospital mortality (adjusted odds ratio 1.43, 95% confidence interval 1.06 to 1.92, p = 0.019) after adjusting for other powerful prognosticators in the GRACE risk score. However, it was independently associated with a lower use of in-hospital coronary angiography (adjusted odds ratio 0.70, 95% confidence interval 0.60 to 0.83, p <0.001). Underestimation of patient risk was the most common reason for not pursuing an invasive strategy. Revascularization was independently associated with lower 1-year mortality (adjusted odds ratio 0.48, 95% confidence interval 0.33 to 0.71, p <0.001), irrespective of a history of CVD. In conclusion, for patients presenting with non-ST-segment elevation-ACS, a history of CVD was independently associated with worse outcomes, which might have been, in part, because of the underuse of evidence-based medical and invasive therapies.