Extent of coronary artery disease and clinical outcomes with ticagrelor monotherapy versus aspirin after coronary artery bypass grafting: insights from the TiCAB trial

OBJECTIVES: Patients with extensive coronary artery disease (CAD) have a higher risk of cardiovascular events. This post hoc analysis of the Ticagrelor in CABG (TiCAB) trial examined the association of ticagrelor monotherapy versus aspirin with clinical outcomes after coronary artery bypass grafting (CABG) in relation to the extent of CAD. METHODS: The TiCAB trial randomized CABG patients to ticagrelor (90 mg twice daily) or aspirin (100 mg daily) for 12 months. Patients were stratified by SYNTAX score terciles: low (≤22), intermediate (23-32) and high (≥33). The primary end-point was major adverse cardiac and cerebrovascular events (MACCE) at 12 months, including cardiovascular death, myocardial infarction, stroke or repeat revascularization. Secondary end-points included individual MACCE components and major bleeding events. Cox proportional hazards models were used to assess treatment effects. RESULTS: Among 752 patients, 33.4% had low, 36.0% intermediate and 30.6% high SYNTAX scores (median 26.5 [20.0-33.0]). MACCE rates were similar across groups (low: 7.8%; intermediate: 9.2%; high: 8.8%; P = 0.87), though the incidence of repeat revascularization differed significantly among SYNTAX score groups (P = 0.02). Ticagrelor did not show a significant MACCE benefit over aspirin in any SYNTAX score group (low: HR 2.27, 95% CI 0.87-5.94; intermediate: HR 1.02, 95% CI 0.46-2.27; high: HR 1.76, 95% CI 0.70-4.46; Pint=0.41). Secondary outcomes, including bleeding, aligned with overall trial results. CONCLUSIONS: This analysis did not find a differential benefit of ticagrelor versus aspirin across CAD complexity levels as measured by the SYNTAX score. Further studies are warranted to refine antiplatelet strategies for patients with complex CAD undergoing CABG.