Diabetics with Nonvalvular AFib at Increased Risk for Mortality: Study

Patients with diabetes taking insulin who also have nonvalvular atrial fibrillation (AFib) have an increased mortality risk, a new study suggests.

“Diabetes is a knock risk factor for thromboembolic events in patients with nonvalvular AFib,” the researchers wrote in their abstract. “Whether patients on insulin therapy are at an increased risk for stroke compared to patients treated solely by oral antidiabetic medications is not yet established.”

Researchers for the prospective, historical cohort study included more than 12,000 patients with diagnosed atrial fibrillation and diabetes, including 3,510 (28.7%) who had insulin-requiring diabetes. Patients were divided into groups based on their diabetes therapy regiment (insulin vs. oral antidiabetic medication).

According to the results, patients in the insulin group had higher rates of comorbidities, including hypertension, congestive heart failure, previous cerebrovascular accident/transient ischemic attack, and vascular disease (P<0.001 for all comparisons). Insulin-treated patients were less likely to be treated with anticoagulation at baseline compared with patients not treated with insulin. There was also a trend toward increased risk for stroke per 100 person-years in the insulin-treated group, and diabetic patients on insulin therapy after adjusting for confounding variables (the association was statistically significant before adjusting for confounding variables).The morality rate, however, was significantly higher in those treated with insulin than those not treated with insulin (HR=1.38; 95% CI, 1.29 to 1.48).

“In this cohort of patients with newly diagnosed nonvalvular AFib and diabetes mellitus, patients on insulin are at increased risk of all-cause mortality and have a trend of increased risk of stroke after accounting for other recognized risk factors for stroke and mortality in this population,” the researchers wrote.

The study was published in EHRA Essentials 4 You, a new scientific platform of the European Society of Cardiology.