Bleeding Events Before Coronary Angiography in Patients With Non-ST-Segment Elevation Acute Coronary Syndrome

Upstream administration of antithrombotic drugs to patients with non-ST-segment elevation acute coronary syndromes before coronary angiography is a common practice despite an incomplete understanding of the risks and benefits.

The authors analyzed the incidence of bleeding and ischemic events occurring before angiography and assessed their association with antithrombotic drugs and mortality risk.

All patients from the ACUITY (Acute Catheterization and Urgent Intervention Triage Strategy) trial with planned angiography after enrollment were included. Bleeding events were classified according to the ACUITY scale as major or nonmajor bleeding. Kaplan-Meier and Cox proportional hazards analyses were performed.

Of 13,726 patients, 275 (2.0%) bled before angiography, including 52 (0.4%) with major bleeding. Forty-four (0.3%) experienced myocardial infarction. The median time from randomization to coronary angiography was 4.5 h (interquartile ratio [IQR]: 1.7 to 19.7 h) for patients who did not bleed while waiting for angiography and 27.9 h (IQR: 21.9 to 65.6 h) for patients who bled while waiting for angiography (p < 0.001). Bleeding events accrued linearly over time, reaching 10.4% at 96 h post-randomization. Independent predictors of bleeding before angiography included age (adjusted hazard ratio [HR]: 1.03 per year of age; 95% confidence interval [CI]: 1.01 to 1.04; p < 0.001), renal insufficiency (adjusted HR: 1.48; 95% CI: 1.07 to 2.04; p = 0.02), and use of multiple antithrombotic drugs (adjusted HR: 1.33; 95% CI: 1.14 to 1.56; p < 0.001). Bleeding before coronary angiography was associated with longer hospitalization (4.8 days [IQR: 3.0 to 8.9 days] vs. 3.0 days [IQR: 1.9 to 5.9 days]; p < 0.001). Patients who bled before angiography were more likely to die within 1 year than patients who did not bleed (8.5% vs. 4.1%; p < 0.001; adjusted HR: 1.89 (95% CI: 1.23 to 2.90; p = 0.004).

Upstream antithrombotic treatment of patients with non-ST-segment elevation acute coronary syndromes awaiting coronary angiography is associated with excess bleeding with mortality implications. Bleeding avoidance strategies before angiogram, including early angiography, may negate the need to prolong upstream antithrombotic treatment and improve the overall risk-benefit balance for these patients. (Acute Catheterization and Urgent Intervention Triage Strategy [ACUITY]; NCT00093158).