Dual antiplatelet therapy after cardiac bypass surgery is no more effective than acetylsalicylic acid alone and also increases the risk of serious bleeding. This is shown in a study by researchers at Karolinska Institutet and the University of Gothenburg published in the journal the New England Journal of Medicine.

Today, dual antiplatelet therapy is recommended in international treatment guidelines after heart bypass surgery for acute coronary artery disease. The current study compares two different antithrombotic, i.e., blood-thinning, treatments. One is single antiplatelet therapy with acetylsalicylic acid (Aspirin) alone, the other is dual antiplatelet therapy with acetylsalicylic acid and ticagrelor (Brilique).

“There is no doubt that this patient group needs antiplatelet therapy. However, it has so far been unclear whether dual drug therapy after surgery further reduces the risk of death, blood clots, and other cardiovascular complications,” says Anders Jeppsson, professor of thoracic surgery at the University of Gothenburg and senior physician in thoracic surgery at Sahlgrenska University Hospital, as well as initiator and chair of the study’s steering committee.

The 2,201 patients in the study were randomly assigned to receive either ticagrelor and acetylsalicylic acid or acetylsalicylic acid alone. The average age of the participants was 66 years, and 14.4% were women. The follow-up period was 12 months from the date of surgery.

The results show no difference between the groups in terms of the study’s primary focus: a composite measure of the risks of death, heart attack, stroke, or the need for another coronary artery procedure. The proportion affected within one year was just under 5% in both groups.

Major bleedings occurred

However, the researchers found that the groups differed when major bleeding as a side effect was included. Major bleeding occurred in 4.9% of those who received dual therapy, compared with 2% in the other group.

The researchers behind the study emphasize that patients need to be followed up for longer than one year, but they can still draw certain conclusions.

“The results are important because they probably mean that we should change our treatment of patients after coronary artery surgery. The currently recommended treatment with dual antiplatelet therapy offers no benefits—on the contrary, it increases the risk of serious bleeding complications compared with treatment with acetylsalicylic acid alone,” says last author Ulrik Sartipy, adjunct professor at the Department of Molecular Medicine and Surgery, Karolinska Institutet, and senior physician in thoracic surgery at Karolinska University Hospital.