Background: The CHA₂DS₂-VASc score for thromboembolic risk in atrial fibrillation (AF) includes heart failure (HF) as a parameter. However, no distinction is made between HF with reduced ejection fraction (EF) (HFrEF; EF < 40%) and HF with preserved EF (HFpEF; EF >=50%). Little is known about the relative risk difference between these subgroups.
Objective: To determine in the national Veteran’s Administration (VA) database if there is a difference in thromboembolic risk in AF patients with HFrEF versus HFpEF.
Methods: We identified AF patients admitted with HF between 2002-2010. Baseline characteristics and stroke outcomes were determined by ICD-9 codes. EFs were collected from echocardiogram reports. Records were reviewed for five years after the index hospitalization. Propensity score matching was used to create balanced groups.
Results: A total of 19,538 patient admitted with HF with AF were identified. Propensity score matching created well balanced groups with 6,683 subjects in each arm (mean age 71±11 years, 99% male, CHA₂DS₂-VASc score 4.4±1.4, 35% on warfarin). Cumulative incidence of stroke in AF showed no significant difference between HFpEF and HFrEF (HR 0.946; 95% CI: 0.81 - 1.11; p=0.49), even after competing risk analysis (Figure 1A - HR 1.10; 95% CI: 0.94 - 1.29; p = 0.25) and including only patients not on anticoagulation (HR 1.18; 95% CI: 0.97 - 1.44; p = 0.10).
Conclusion: There is no significant difference in the risk of stroke in AF patients with HFrEF or HFpEF. This is likely due to the fact that both syndromes contribute to the atrial myopathy that is underlying AF and thromboembolic risk.