(P164) IMPACT OF DIABETES AND GLUCOSE-LOWERING THERAPY ON POST-OPERATIVE ATRIAL FIBRILLATION AFTER CARDIAC SURGERY: SECONDARY ANALYSIS OF THE SEARCH-AF CARDIOLINK-1 RANDOMIZED CLINICAL TRIAL

Background: Diabetes mellitus is an important risk factor for atrial fibrillation (AF) and is associated with an increased risk of complications for patients with AF. The impact of diabetes on post-operative AF after cardiac surgery is not well-defined.

METHODS AND RESULTS: We sought to characterize the effect of diabetes, insulin, and oral hypoglycemic agents on the incidence of post-operative atrial fibrillation (POAF) after cardiac surgery. We performed a sub-analysis from the Post-Surgical Enhanced Monitoring for Cardiac Arrhythmias and Atrial Fibrillation (SEARCH-AF) CardioLink-1 randomized trial (NCT02793895). It randomized 336 patients with risk factors for stroke (CHA2DS2-VASc score ≥2) and no history of preoperative AF were randomized to usual care or continuous cardiac rhythm monitoring for 30 days after discharge from cardiac surgery with a wearable, patched-based device. The primary outcome was occurrence of cumulative atrial fibrillation/flutter (AF/AFL) lasting for ≥6 minutes detected by continuous monitoring or AF/AFL documented by a 12-lead electrocardiogram within 30 days of randomization. We examined the association between: (i) diabetes and risk of POAF and (ii) glucose-lowering therapy among patients with diabetes and risk of POAF. Of the 176 (52%) patients with diabetes in the study cohort, 80 (45%) patients were treated with at least 1 oral hypoglycemic agent and 44 (25%) patients were treated with insulin. The incidence of POAF occurring within 30 days after discharge from surgery was similar between patients with or without diabetes (cumulative incidence: 10.8% vs. 10.0%, log-rank p=0.77). Among patients with diabetes, the incidence of POAF was highest in those who were not treated with glucose-lowering therapy (17.3%), followed by those treated with oral hypoglycemic agents (10.0%) and insulin (4.5%) (log-rank p=0.045 for trend). A trend suggesting a lower incidence of POAF was observed among cardiac surgical patients who were treated with SGLT-2 inhibitors (log-rank p=0.084 for trend).

Conclusion: Even among patients with little to no POAF immediately after cardiac surgery, the risk of POAF within 30 days after discharge is high. Among patients with diabetes, oral anticoagulation should be considered as per current guidelines. There are possible associations between specific glucose-lowering therapies and risk of POAF after cardiac surgery, meriting further investigations.