Long-term benefits of 12-months DAPT post-CABG revealed in DACAB trial follow-up

Compared with aspirin monotherapy or ticagrelor monotherapy, one-year treatment with ticagrelor dual antiplatelet therapy (DAPT) after surgery decreased the risk of major adverse cardiovascular events (MACE) five years after coronary artery bypass grafting.

Coronary artery bypass surgery, a procedure to restore blood flow to the heart, often necessitates management strategies to prevent clotting complications in the grafts and stents used during the operation. Antiplatelet medications, such as aspirin and clopidogrel, are routinely prescribed to reduce the risk of blood clots that could lead to heart attacks or strokes.

Yunpeng Zhu, associate professor, Department of Cardiovascular Surgery, Ruijin Hospital Shanghai Jiao Tong University School of Medicine, Shanghai, China, and colleagues aimed to assess the effect of different antiplatelet strategies on clinical outcomes after CABG.

For this purpose, the researchers conducted a five-year follow-up of randomized DACAB trials at six tertiary hospitals in China, with enrolment between 2014 and 2015; and completion of a five-year follow-up from 2019 to 2021.

It included 500 patients aged 18-80 years (including 18.2% women) who had elective coronary artery bypass grafting surgery and completed the DACAB trial. Patients were randomized in a 1:1:1 ratio to ticagrelor 90 mg twice daily plus aspirin 100 mg once daily (DAPT; n=168), ticagrelor monotherapy 90 mg twice daily (n=166), or aspirin monotherapy 100 mg once daily (n=166) for one year after surgery. Following the first year, antiplatelet therapy was prescribed as per the standard of care by treating physicians.

The primary outcome was MACE (a composite of all-cause death, stroke, myocardial infarction, and coronary revascularization), analyzed using the intention-to-treat principle. The risk between treatment groups was compared using time-to-event analysis. Multiple post hoc sensitivity analyses examined the findings' robustness.

The study led to the following findings:

• Follow-up at five years for major adverse cardiovascular events was completed for 477 of 500 patients; 148 patients had major adverse cardiovascular events, including 39 in the dual antiplatelet therapy group, 54 in the ticagrelor monotherapy group, and 55 in the aspirin monotherapy group.
• The risk of major adverse cardiovascular events at five years was significantly lower with dual antiplatelet therapy versus aspirin monotherapy (22.6% versus 29.9%; hazard ratio 0.65) and versus ticagrelor monotherapy (22.6% versus 32.9%).
• Results were consistent in all sensitivity analyses.

"This five-year follow-up extension study of the DACAB trial suggests that one year of dual antiplatelet therapy improves clinical outcomes after CABG," the researchers concluded.

Reference:

Zhu Y, Zhang W, Dimagli A, Han L, Cheng Z, Mei J, Chen X, Wang X, Zhou Y, Xue Q, Hu J, Tang M, Wang R, Song Y, Kang L, Redfors B, Gaudino M, Zhao Q. Antiplatelet therapy after coronary artery bypass surgery: five year follow-up of randomised DACAB trial. BMJ. 2024 Jun 11;385:e075707. doi: 10.1136/bmj-2023-075707. PMID: 38862179; PMCID: PMC11165385.