Dual antiplatelet therapy after heart bypass surgery is not more effective than aspirin alone – and it increases the risk of excessive bleeding. This has now been shown in a study of 2,201 patients at 22 Nordic heart surgery units.

The study was published on Monday in The New England Journal of Medicine at the same time that the results are being presented in Madrid at this year’s ESC Congress, the leading international cardiology congress.

The lead investigator is Anders Jeppsson, professor in cardiothoracic surgery at the University of Gothenburg and senior consultant at Sahlgrenska University Hospital, as well as initiator and chair of the steering committee of the TACSI trial.

The TACSI study compares two different antiplatelet (blood thinning) therapies after heart bypass surgery for acute coronary heart disease. On the one hand single antiplatelet therapy with acetylsalicylic acid (Aspirin) alone, and on the other hand dual antiplatelet therapy with aspirin and ticagrelor (Brilique). Dual antiplatelet therapy is currently recommended for these patients in international guidelines.

It is unequivocal that this patient group needs antiplatelet therapy. However, until now it has been unclear whether dual therapy after surgery further reduces the risks of death and cardiovascular complications after the operation.

The 2,201 patients included in the study were randomly assigned to receive either ticagrelor and aspirin (1,104 patients) or aspirin alone (1,097 patients). The average age of the participants was 66 years and the proportion of women was 14.4 percent. The follow-up period was 12 months after surgery.

The results show no difference between the groups within the study’s primary focus: a composite measure of the risks of dying, having a heart attack or stroke, or needing another coronary intervention. The proportion affected within one year was just under 5 percent for both groups.

However, the researchers found that the groups did differ if excessive bleeding was also included. When including excessive bleeding, the proportion affected was 9.1 percent in the group receiving both ticagrelor and aspirin and 6.4 percent in the group receiving aspirin alone. Excessive bleeding was seen in 4.9 percent of patients on dual therapy, as compared to 2.0 percent in the other patient group.

Anders Jeppsson notes that while the patients need to be followed up for more than one year, we can still draw some conclusions:

“Our 12-month data do not support the use of dual therapy over aspirin alone in patients with acute coronary syndrome who have undergone heart bypass surgery. We did not observe any improvement in serious cardiovascular events, but a higher risk of excessive bleeding in the dual antiplatelet therapy group,” he says.

Fact box:

The TACSI Study

The study is being published in The New England Journal of Medicine and presented at the European Society of Cardiology’s ESC Congress 2025 in Madrid.

The TACSI study is a prospective registry-based randomized study using data from the SWEDEHEART quality registry and patients’ medical records.

The study has been conducted at all 22 Nordic thoracic surgery units.

The study was funded by the Swedish Research Council, the Swedish Heart Lung Foundation and the Swedish state under the ALF agreement.

Heart bypass surgery (CABG)

Heart bypass surgery (Coronary Artery Bypass Grafting, CABG) is the most common heart surgery. It is performed on patients with severe narrowing of the coronary arteries.

CABG is elective in cases of stable coronary artery disease or performed as an emergency procedure in cases of heart attack or severe angina.

The procedure involves grafting of a blood vessel, often taken from the leg or chest, to the heart. The graftl carries oxygenated blood past the narrowing in the heart’s coronary artery, thereby ensuring that the heart receives enough oxygen.