Glycemic Control and Coronary Stent Failure in Diabetic Patients

March 21st, 2025

Diabetes mellitus is a well-established risk factor for coronary artery disease (CAD), and, once diagnosed, patients with diabetes experience higher mortality than those without. Current guidelines recommend coronary artery bypass grafting (CABG) over percutaneous coronary intervention (PCI) for patients with multivessel CAD, since PCI is associated with a higher risk of recurrent ischemic events and increased intermediate-term mortality. Despite these recommendations, PCI remains a widely used treatment for diabetic patients in clinical practice.

Stent failure, measured by target lesion revascularization, has been suggested to occur more frequently in diabetic patients than in those without diabetes. However, limited research has specifically explored whether glycemic control influences the likelihood of stent failure. A study used a large Swedish national healthcare registry to examine whether hemoglobin A1c (HbA1c) levels, rather than simply the presence of diabetes, were associated with stent failure risk in patients who received second-generation drug-eluting stents.

Researchers analyzed data from 52,457 adults with type 2 diabetes who underwent PCI between 2010 and 2020. After excluding those with missing HbA1c or other clinical data, the final study cohort included 24,411 patients with 29,029 implanted stents. The average age was 68 years, and 26% of participants were female. The majority (75%) underwent PCI in the setting of an acute coronary syndrome, and 40% had multivessel disease. Over a median follow-up of 6.4 years, there were 1,873 recorded cases of stent failure, with 1,159 due to in-stent restenosis (ISR) and 771 attributed to stent thrombosis.

The study found a clear relationship between poor glycemic control and increased stent failure risk. Patients with HbA1c levels above 7% had a higher risk of stent failure compared to those with HbA1c below this threshold. The failure rate was nearly double (15.6% vs. 8.9%) for individuals with HbA1c levels above 10% compared to those with levels between 6.1% and 7%. This association persisted regardless of insulin use and other clinical risk factors. Younger patients, particularly those younger than 65 years of age, showed a stronger correlation between poor glycemic control and stent failure than older patients.

The authors concluded that inadequate glycemic control in diabetic patients receiving drug-eluting stents is linked to a significantly higher risk of stent failure, primarily driven by ISR. While the study strengthens the evidence for a connection between HbA1c and stent performance, several questions remain unanswered. It is unclear whether tighter glycemic control immediately after PCI could improve long-term stent outcomes or whether the HbA1c level at the time of PCI is the most critical factor.

When determining whether diabetic patients should undergo PCI or CABG. a more refined, multidisciplinary approach involving both cardiologists and cardiac surgeons may help ensure optimal treatment decisions for diabetic patients undergoing coronary revascularization. Further research is needed to determine whether aggressive glycemic management after PCI can mitigate the risk of ISR and improve long-term cardiovascular outcomes.

For a closer look at the relationship between glycemic control and coronary stent failure in diabetic patients, click here.