Retrospective Cohort Study on NOAC vs Warfarin

A retrospective cohort study of patients with atrial fibrillation and diabetes found that the use of non–vitamin K antagonist oral anticoagulants (NOAC) was associated with a lower risk of diabetes complications and mortality than warfarin. These findings suggest that NOAC may be a better therapeutic choice for this patient population. The study is published in Annals of Internal Medicine.

Patients diagnosed with atrial fibrillation are more likely to have a stroke in their lifetime and are often prescribed long-term oral anticoagulants including warfarin and NOACs for stroke prevention. Diabetes is also common among these patients, with poor glycemic status putting them at risk for thromboembolism and cardiovascular mortality, as well. Which anticoagulant is associated with a lower risk of these complications for these patients is not clear.

Researchers from National Taiwan University and Hualien Tzu Chi Hospital conducted a study using data from Taiwan's National Health Insurance Research Database, which collects healthcare data from 23.6 million of the country's residents, to compare the hazards of diabetes complications and mortality between patients with atrial fibrillation and diabetes without end-stage renal disease receiving NOACs and those receiving warfarin. Of the 19,909 NOAC users and 10,300 warfarin users studied, those taking NOAC had significantly lower hazards of developing:

• Macrovascular complications
• Microvascular complications
• Glycemic emergency
• All-cause mortality

Analyses with propensity score matching showed similar results and several sensitivity analyses further supported the robustness of the findings. While the study could not determine the exact mechanisms of the better outcomes in NOAC users, the authors suggest possible contributing factors could include the beneficial effects of Vitamin K on insulin sensitivity and glucose tolerance and the difference in anticoagulation mechanism between NOAC and warfarin.

For more details, visit the study at: https://www.acpjournals.org/doi/10.7326/M21-3498