Individuals with diabetes are more likely to suffer complications after stent surgery

Patients with diabetes have an increased risk of complications after stent implantation, according to a study from Karolinska Institutet in Sweden published in Diabetes Care. The study, which includes over 160,000 patients, emphasises the importance of tailoring treatment strategies for this specific patient group.

Researchers have conducted a comprehensive study to investigate the risk of stent complications in patients with diabetes. The study consists of data from over 160,000 patients who received drug-eluting stents (small tubes placed in the coronary arteries of the heart that slowly release drugs to reduce the risk of the vessel becoming blocked again) between 2010 and 2020. The patients were divided into three groups: type 1 diabetes, type 2 diabetes, and patients without diabetes.

The results show that patients with type 1 diabetes have more than twice the risk of stent complications compared to patients without diabetes. For patients with type 2 diabetes, the risk is also elevated, but not as significantly. Complications include both narrowing of the artery in the stent and blood clots in the stent.

“Our results show that people with diabetes, especially type 1 diabetes, have a much higher risk of stent complications. Therefore, it is important to carefully consider how we treat these patients,” says first author Irene Santos-Pardo, researcher at the Department of Clinical Science and Education, Södersjukhuset, Karolinska Institutet.

The study also shows that the risk of stent complications is highest during the first few months after stent implantation. During the first month, the incidence of stent complications was 9.27 per 100 person-years for patients with type 1 diabetes, compared with 4.34 for patients without diabetes. After six months, the risk decreased but remained higher for patients with diabetes.

“We need to continue to investigate how we can improve treatment for patients with diabetes who undergo stent implantation. Our results indicate that there is a need to adapt treatment and follow-up for them,” says last author Thomas Nyström, professor at the Department of Clinical Science and Education, Södersjukhuset, Karolinska Institutet.

The study is a collaboration between researchers at Karolinska Institutet and the Germans Trias i Pujol Institute in Barcelona. It has been funded by, among others, the Swedish Heart-Lung Foundation and Region Stockholm. The researchers report no conflicts of interest.

Publication: “Coronary stent failure in patients with diabetes: A nationwide observational study from SWEDEHEART”, Irene Santos-Pardo, Mikael Andersson Franko, Robin Hofmann, Thomas Nyström, Diabetes Care, online 27 November 2025, doi: 10.2337/dc25-1624.