Objectives: There is still little evidence to support routine dual antiplatelet therapy (DAPT) with P2Y12 antagonists following coronary artery bypass grafting (CABG). The Arterial Re-vascularization Trial (ART) was designed to compare 10-year survival after bilateral versus single internal thoracic artery grafting. We aimed to get insights into the effect of DAPT (with clopidogrel) following CABG on 1 year outcomes by performing a post-hoc ART anal-ysis.

Methods: Among patients enrolled in the ART (n=3102), 609 (21%) and 2308 (79%) were discharged on DAPT or aspirin alone respectively. The primary endpoint was the incidence of major adverse cerebrovascular and cardiac events (MACCE) at 1 year including cardiac death, myocardial infarction, cerebrovascular accident and reintervention; safety endpoint was bleeding requiring hospitalization. Propensity score (PS) matching was used to create comparable groups.

Results: Among 609-PS matched pairs, MACCE occurred in 34 (5.6%) and 34 (5.6%) in the DAPT and aspirin alone groups respectively with no significant difference between the two groups (HR 0.97; 95%CI 0.59-1.59; P=0.90). Only 188 (31%) subjects completed 1 year of DAPT and in this subgroup, MACCE rate was 5.8% (HR 1.11; 95%CI 0.53-2.30; P=0.78). In the overall sample, bleeding rate was higher in DAPT group (2.3% versus 1.1%; P=0.02) although this difference was no longer significant after matching (2.3% vs 1.8%; P=0.54).

Conclusions: Based on these findings, when compared to aspirin alone, DAPT with clopidogrel prescribed at discharge was not associated with a significant reduction of adverse cardiac and cerebrovascular events at 1 year following CABG.