Background: Insulin use may be a better predictor of stroke risk and morbidity and mortality than diabetes in patients with atrial fibrillation (AF).
Objectives: Determine if the increased risk of stroke observed in patients with AF and diabetes is restricted to those treated with insulin.
Methods: We analyzed the association between diabetes and treatment and the occurrence of stroke/systemic embolism, myocardial infarction (MI), all-cause death, vascular death, composite outcomes, and bleeding risk in the ROCKET AF trial.
Results: In a cohort of 14,264 patients, there were 40.3% (n = 5746) with diabetes, 5.9% (n = 842) on insulin, 18.9% (n = 2697) on oral medications, and 11.9% (n = 1703) diet-controlled. Compared to those without diabetes, patients with non-insulin-treated diabetes had increased risks of stroke (hazard ratio [HR] 1.33, 95% confidence interval [CI] 1.06-1.68), MI (HR 1.64, 95% CI 1.17-2.30), all-cause death (HR 1.26, 95% CI 1.08-1.46), vascular death (HR 1.33, 95% CI 1.11-1.60), and composite outcomes (HR 1.37, 95% CI 1.18-1.157). Patients with insulin-treated diabetes had a significantly higher risk of MI (HR 2.31, 95% CI 1.33-4.01) and composite outcomes (HR 1.57, 95% CI 1.19-2.08) compared to those without diabetes. There were no significant differences between insulin-treated and non-insulin-treated diabetes for any outcome.
Conclusion: Among patients with AF and diabetes, there were no significant differences in outcomes in insulin-treated diabetes compared to non-insulin-treated diabetes.