Can Antiplatelet Therapy Affect the Life of Coronary Grafts?

The antiplatelet treatment strategy providing optimal balance between thrombotic and bleeding risks in patients undergoing myocardial revascularization surgery is unclear.

What does seem somewhat certain is that some antiplatelet therapy is necessary to prevent early thrombosis, mainly in vein grafts, but (as opposed to what happens with angioplasty) there are other relevant factors such as duct quality, expertise in anastomoses, distal outflow tract, and even the degree of obstruction in proximal lesions to anastomoses. There are many variables and any conclusion leading us to think that a change in antiplatelet therapy may tilt the scales would require a high number of patients involved.

This double-blind study randomized patients to 90 mg ticagrelor or 100 mg aspirin. The primary endpoint was a composite of cardiovascular death, myocardial infarction, repeat revascularization, and stroke 12 months after the surgery. The safety endpoints were Bleeding Academic Research Consortium (BARC) classification ≥4 for peri-procedural or in-hospital bleeding, and BARC ≥3 for bleeding after discharge.

The study was prematurely halted, having recruited 1859 out of 3850 planned patients, due to no differences observed between study arms in interim analyses.

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At 12 months after the surgery, the primary endpoint occurred in 9.7% of patients in the ticagrelor group vs. 8.2% of patients in the aspirin group (p = 0.28). For these groups, all-cause mortality rates were 2.5% vs. 2.6%, respectively (p = 0.89). Separate analyses of all other primary endpoint components did not show significant differences either.

The same happened with the safety endpoint (bleeding, basically): 3.7% for the ticagrelor group vs. 3.2% for the aspirin group (p = 0.53).

Conclusion

In this prematurely terminated trial (which is, therefore statistically underpowered), no significant differences were observed between ticagrelor vs. aspirin therapy in patients undergoing myocardial revascularization surgery in terms of both efficacy and bleeding.

Original title: Randomized trial of ticagrelor vs. aspirin in patients after coronary artery bypass grafting: the TiCAB trial.

Reference: Heribert Schunkert et al. European Heart Journal (2019) 0, 1–10.

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