Abstract
Background Anticoagulation is indicated for 4 weeks after cardioversion in patients with atrial fibrillation/flutter. We sought to examine whether there is evidence of sex or racial disparity in anticoagulant prescription following cardioversion, and whether postcardioversion anticoagulation affects outcomes. Methods and Results We identified a representative sample of Medicare patients who underwent elective electric cardioversion in an outpatient setting from 2015 to 2017. We identified patients who had an anticoagulant prescription for 3 months after the cardioversion date. Multivariable logistic regression was used to assess factors associated with a prescription of an anticoagulant after cardioversion. Cox regression analysis was used to test association of anticoagulation with a composite end point of 90-day mortality, ischemic stroke, or arterial embolism. The final study cohort included 7860 patients. Overall, 5510 patients (70.1%) received any anticoagulation following cardioversion, while 2350 (29.9%) did not. Patients who did not receive anticoagulation were younger, with a lower burden of most comorbidities. Patients were less likely to receive anticoagulation if they had dementia or atrial flutter, while patients with valvular heart disease, obesity, heart failure, peripheral vascular or coronary disease, or hypertension were more likely to receive anticoagulation. Female sex (adjusted odds ratio, 0.84; 95% CI, 0.75-0.92; P<0.001), Black and Hispanic race (adjusted odds ratio, 0.50; 95% CI, 0.38-0.65; and odds ratio, 0.56; 95% CI, 0.41-0.75, respectively; P<0.001) were independently associated with lower probability of anticoagulant prescription. Postcardioversion anticoagulation was associated with lower risk of the composite end point (adjusted hazard ratio, 0.38; 95% CI, 0.27-0.52; P<0.001). Conclusions Racial and sex disparities exist in anticoagulant prescription after outpatient elective cardioversion for atrial fibrillation.