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.