Ischemic and Bleeding Outcomes in Patients With Atrial Fibrillation and Contraindications to Oral Anticoagulation

Abstract

Objectives: This study sought to describe clinical outcomes among patients with atrial fibrillation (AF) and contraindications to oral anticoagulation (OAC).

Background: Treatment with OAC prevents stroke and death in patients with AF, but may be contraindicated among patients at high bleeding risk.

Methods: This was an observational, longitudinal analysis of a nationally representative 5% Medicare sample of patients with chronic AF and CHA₂DS₂-VASc (congestive heart failure, hypertension, age ≥75 years, diabetes mellitus, prior stroke or transient ischemic attack or thromboembolism, vascular disease, age 65-74 years, sex category) score ≥2. They were stratified by both the presence of high bleeding risk contraindications to OAC and by OAC use. We assessed 3-year ischemic and bleeding outcomes using multivariable Cox proportional hazards models adjusted for relevant patient characteristics.

Results: Among 26,684 AF patients not treated with OAC, 8,283 (31%) had a high bleeding risk contraindication, primarily a blood dyscrasia (75%) or history of gastrointestinal bleeding (40%). Without OAC, patients with contraindications had worse ischemic and bleeding outcomes at 3 years compared with those without contraindications. We also identified 12,454 patients with OAC contraindications who received OAC. Compared with patients not receiving OAC, use of OAC was associated with reduced mortality (adjusted hazard ratio [HR]: 0.79; 95% confidence interval [CI]: 0.76 to 0.83), stroke (adjusted HR: 0.90; 95% CI: 0.83 to 0.99), and all-cause hospitalization (adjusted HR: 0.93; 95% CI: 0.90 to 0.96) but increased risk of intracranial hemorrhage (adjusted HR: 1.42; 95% CI: 1.17 to 1.72).

Conclusions: High bleeding risk contraindications to OAC are common among older patients with AF, and these patients have higher mortality compared with untreated patients without OAC contraindications. The use of OAC in these patients is associated with lower rates of all-cause stroke, hospitalization, and death but higher risk of intracranial hemorrhage.

Keywords: Medicare; anticoagulation; atrial fibrillation; contraindication; outcomes.