Effect of Ticagrelor Plus Aspirin, Ticagrelor Alone, or Aspirin Alone on Saphenous Vein Graft Patency 1 Year After Coronary Artery Bypass Grafting: A Randomized Clinical Trial

Abstract

Importance: The effect of ticagrelor with or without aspirin on saphenous vein graft patency in patients undergoing coronary artery bypass grafting (CABG) is unknown.

Objective: To compare the effect of ticagrelor + aspirin or ticagrelor alone vs aspirin alone on saphenous vein graft patency 1 year after CABG.

Design, setting, and participants: Randomized, multicenter, open-label, clinical trial among 6 tertiary hospitals in China. Eligible patients were aged 18 to 80 years with indications for elective CABG. Patients requiring urgent revascularization, concomitant cardiac surgery, dual antiplatelet or vitamin K antagonist therapy post-CABG, and who were at risk of serious bleeding were excluded. From July 2014 until November 2015, 1256 patients were identified and 500 were enrolled. Follow-up was completed in January 2017.

Interventions: Patients were randomized (1:1:1) to start ticagrelor (90 mg twice daily) + aspirin (100 mg once daily) (n = 168), ticagrelor (90 mg twice daily) (n = 166), or aspirin (100 mg once daily) (n = 166) within 24 hours post-CABG. Neither patients nor treating physicians were blinded to allocation.

Main outcomes and measures: Primary outcome was saphenous vein graft patency 1 year after CABG (FitzGibbon grade A) adjudicated independently by a committee blinded to allocation. Saphenous vein graft patency was assessed by multislice computed tomographic angiography or coronary angiography.

Results: Among 500 randomized patients (mean age, 63.6 years; women, 91 [18.2%]), 461 (92.2%) completed the trial. Saphenous vein graft patency rates 1 year post-CABG were 88.7% (432 of 487 vein grafts) with ticagrelor + aspirin; 82.8% (404 of 488 vein grafts) with ticagrelor alone; and 76.5% (371 of 485 vein grafts) with aspirin alone. The difference between ticagrelor + aspirin vs aspirin alone was statistically significant (12.2% [95% CI, 5.2% to 19.2%]; P < .001), whereas the difference between ticagrelor alone vs aspirin alone was not statistically significant (6.3% [95% CI, -1.1% to 13.7%]; P = .10). Five major bleeding episodes occurred during 1 year of follow-up (3 with ticagrelor + aspirin; 2 with ticagrelor alone).

Conclusions and relevance: Among patients undergoing elective CABG with saphenous vein grafting, ticagrelor + aspirin significantly increased graft patency after 1 year vs aspirin alone; there was no significant difference between ticagrelor alone and aspirin alone. Further research with more patients is needed to assess comparative bleeding risks.

Trial registration: clinicaltrials.gov Identifier: NCT02201771.

Figure 1.. Flow of the Patients Through the Study of Post-CABG Ticagrelor and Aspirin

MSCTA indicates multislice computed tomographic angiography. The primary analysis was conducted on a per-graft basis according to the intention-to-treat principle. ^aSome patients had multiple reasons.

Figure 2.. Post Hoc Analysis for Ticagrelor + Aspirin vs Aspirin Alone and Ticagrelor Alone vs Aspirin Alone

ACS indicates acute coronary syndrome; SV, saphenous vein. P values were calculated by a generalized equation model. ^aSYNTAX scores are graded on a continuous scale in which higher scores indicate more complex coronary artery disease.