Patients undergoing coronary-artery bypass grafting (CABG) following ACS are usually recommended to use aspirin lifelong to decrease the chance of adverse events. Present guidelines approved the use of dual antiplatelet therapy (DAPT) with aspirin and a P2Y12 inhibitor, such as ticagrelor or clopidogrel. The evidence for DAPT specifically in CABG patients remains limited compared with that in non-surgical populations. The purpose of the TACSI trial (Dual Antiplatelet Therapy with Ticagrelor and Acetylsalicylic Acid versus Acetylsalicylic Acid Only after Isolated Coronary Artery Bypass Grafting in Patients with Acute Coronary Syndrome) was to determine whether DAPT had superior patient outcomes relative to aspirin alone.
This registry-based, open-label trial was conducted in 22 cardiothoracic centers in Denmark, Finland, Iceland, Norway, and Sweden. Between June 2018 and February 2024, 6,967 patients were screened, and 2,215 underwent randomization. After exclusions for ineligibility, a total of 2,201 patients were included in the intention-to-treat analysis: 1,104 were assigned to ticagrelor plus aspirin and 1,097 to aspirin alone. The dosing regimen consisted of ticagrelor 90 mg twice per day and aspirin 75 mg to 100 mg daily.
The primary endpoint was a composite measure of all-cause mortality, myocardial infarction, or stroke, and revascularization after 1 year. Net adverse clinical events, major bleeding, dyspnea, and renal failure were secondary and safety endpoints. The average age of participants was 66 years, with a female proportion of 14.4%. At baseline, 27.5% of participants had diabetes and 68.5% hypertension, while nearly 88% had emergency or urgent CABG surgery. The most common surgical indication was non-ST-segment elevation myocardial infarction, accounting for 57.6% of cases.
At 1 year, the primary outcome occurred in 53 patients (4.8%) in the ticagrelor and aspirin (T+A) regimen and 50 patients (4.6%) in the aspirin-only regimen (Hazard ratio: HR, 1.06; 95% confidence interval: CI, 0.72-1.56; P = 0.77). This indicates that there was no difference between the two groups in the rates of death, myocardial infarction, stroke, or repeat revascularization.
Patients receiving DAPT experienced significantly more net adverse clinical events than those treated with aspirin alone (9.1% vs 6.4%; HR, 1.45; 95% CI, 1.07-1.97). Major bleeding occurred more frequently in the group receiving ticagrelor plus aspirin (4.9%) than in those treated with aspirin alone (2.0%) (HR, 2.50; 95% CI, 1.52-4.11). Severe dyspnea occurred with more frequency in the DAPT group (18.2% vs 6.4%). Overall mortality remained low with eight deaths (0.7%) in the DAPT group, and 2 deaths (0.2%) in the aspirin group. Treatment adherence was significantly less with DAPT; by 1 year after randomization, only 64.1% of patients remained on ticagrelor, while 92.3% of the patients in the aspirin group continued monotherapy.
The results challenge current guidelines in Europe and the United States recommending dual antiplatelet therapy following CABG surgery for acute coronary syndrome. While dual therapy is beneficial after percutaneous coronary intervention in multiple studies, there was no evidence from the TACSI trial of any added value in surgical patients. Instead, the trial showed an increased risk of bleeding, with no difference in ischemic events.
The researchers acknowledged several limitations, including fewer events than anticipated and marked non-adherence to ticagrelor, which may have affected the results. Nevertheless, results demonstrated that aspirin alone is still the safer and similarly effective therapy in the first year after CABG for acute coronary syndrome. The TACSI Trial, conducted with support from the Swedish Research Council and the Swedish Heart Lung Foundation, will continue to follow patients for 10 years to evaluate any potential long-term differences, including graft patency and survival.
References: Jeppsson A, James S, Moller CH, et al. Ticagrelor and Aspirin or Aspirin Alone after Coronary Surgery for Acute Coronary Syndrome. N Engl J Med. 2025. doi:10.1056/NEJMoa2508026
