Background Ticagrelor was shown to reduce mortality in patients who underwent coronary artery bypass grafting (CABG), but its effect on graft patency is unknown.

Methods We performed a prospective, randomised, double-blind, placebo-controlled trial, comparing ticagrelor 90 mg twice daily versus placebo for 3 months added to aspirin 81 mg/day, following isolated CABG. Aspirin was started within 12 h, and study medication within 72 h after CABG. Primary outcome was graft occlusion on CT angiography (CTA) performed 3 months post CABG. Patients were followed to 12 months for death, myocardial infarction, stroke, repeat revascularisation and bleeding.

Results The study was terminated prematurely after randomising 70 patients between September 2011 and August 2014 because of slow recruitment. CTA was performed in 56 patients who completed >1 month of study drug. Graft occlusion occurred in 7/25 (28.0%) patients on ticagrelor and 17/31 (48.3%) on placebo, p=0.044. Of 207 analysable grafts, graft occlusion occurred in 9/87 (10.3%) with ticagrelor and 22/120 (18.3%) with placebo, p=0.112. Graft occlusion or stenosis ≥50% occurred in 10/87 (11.5%) ticagrelor vs 32/120 (26.7%) placebo, p=0.007. There was no major bleeding, but minor bleeding was higher with ticagrelor (31.4% vs 2.9%, p=0.003). In univariate analysis, ticagrelor use reduced graft occlusion (OR 0.32, 95% CI 0.10 to 0.97, p=0.047), which remained significant on multivariable analysis (OR 0.25, 95% CI 0.073 to 0.873, p=0.03).

Conclusions Ticagrelor added to aspirin after CABG reduced the proportion of patients with graft occlusion, and was a significant univariate and multivariable predictor of graft occlusion. These results are hypothesis-generating and should be confirmed in larger studies.

Trial registration number NCT01373411: Results.