Early cardiac catheterization is associated with lower mortality only among high-risk patients with ST- and non–ST-elevation acute coronary syndromes: Observations from the OPUS-TIMI 16 trial

Background Early cardiac catheterization has been shown to improve outcomes in patients with non–ST-elevation acute coronary syndromes but not yet in those with ST-elevation myocardial infarction (STEMI). The benefit of catheterization in both syndromes may depend on patient risk for adverse clinical outcomes. Methods We analyzed the relation between inhospital catheterization and subsequent clinical outcomes based on risk profile in 8286 patients in the OPUS-TIMI 16 Trial of patients with acute coronary syndromes. Using baseline clinical characteristics, patients were stratified into low-, intermediate-, and high-risk groups. The primary end point was 10-month mortality. The STEMI, non-STEMI (NSTEMI), and unstable angina subgroups were analyzed separately. Results Inhospital cardiac catheterization was performed in 44% of patients. Mortality rates at 10 months were 1.3%, 2.2%, and 11.3% in the low-, intermediate-, and high-risk groups, respectively. Inhospital cardiac catheterization was associated with a trend to lower mortality among the high-risk patients with STEMI (hazard ratios [HR] 0.57, 95% CI 0.33-1.01, P = .052) and NSTEMI (HR 0.65, 95% CI 0.39-1.07, P = .088) but not in those with unstable angina (HR 0.95, 95% CI 0.63-1.43, P = .82). Catheterization was not associated with any significant difference in mortality in the low-risk or intermediate-risk group. The differences among high-risk patients persisted after adjusting for baseline characteristics; inhospital catheterization was associated with significantly lower mortality in high-risk patients with ST and non-ST myocardial infarction (HR 0.65, 95% CI 0.45-0.95, P = .03). Conclusions Inhospital cardiac catheterization is associated with lower mortality in high-risk patients and no difference in mortality in low-risk and intermediate-risk patients after STEMI and NSTEMI. These data support the hypothesis that high-risk patients with either STEMI or NSTEMI may benefit from an early invasive strategy. New prospective randomized trials are warranted, particularly in the STEMI population.