Management patterns in relation to risk stratification among patients with non-ST elevation acute coronary syndromes

Background: Randomized clinical trials have established the efficacy of an early invasive management strategy for high-risk non-ST elevation acute coronary syndromes (ACSs). We examined the use of in-hospital cardiac catheterization and medications in relation to risk across the broad spectrum of non-ST elevation ACSs. Methods: We evaluated 4414 patients with non-ST elevation ACSs in the prospective, multicenter, Canadian ACS 1 (September 1, 1999-June 30, 2001) and ACS 2 (October 1, 2002-December 31, 2003) Registries. Patients were stratified into low-,intermediate-, and high-risk groups based on tertiles of the calculated Global Registry of Acute Coronary Events risk score (a validated predictor of in-hospital mortality). Results: Although in-hospital mortality rates were similar, the in-hospital use of cardiac catheterization increased significantly over time (38.8% in the ACS 1 Registry vs 63.5% in the ACS 2 Registry; P <. 001). The rates of cardiac catheterization in the low-, intermediate-, and high-risk groups were 48.0%, 41.1%, and 27.3% in the ACS 1 Registry, and 73.8%, 66.9%, and 49.7% in the ACS 2 Registry, respectively (P <. 001 for trend for both). After adjusting for other confounders, intermediate- risk (adjusted odds ratio, 0.75; 95% confidence interval, 0.63-0.90; P <. 001) and high-risk (adjusted odds ratio, 0.35; 95% confidence interval, 0.28-0.45; P <. 001) patients remained less likely to undergo cardiac catheterization compared with low- risk patients. Furthermore, there existed a similar inverse relationship between risk and the use of in-hospital revascularization and medications. Conclusions: Despite temporal increases in the use of cardiac catheterization and revascularization in the management of non-ST elevation ACSs, evidence-based invasive and pharmacological therapies remain paradoxically targeted toward low- risk patients. Strategies to eliminate this treatment-risk paradox must be implemented to fully realize the benefits and optimize the cost-effectiveness of invasive management.