Associations between rheumatoid arthritis, incident heart failure, and left ventricular ejection fraction

BACKGROUND: Rheumatoid arthritis (RA) is an independent risk factor for heart failure (HF). Yet, the association between RA and left ventricular ejection fraction (LVEF) in incident HF is not well studied, nor are outcomes of HF in RA by LVEF. METHODS: We identified incident HF patients between 2003 and 2018 through the Swedish Heart Failure Registry, enriched with data from national health registers. Using logistic regression, associations between a prior diagnosis of RA and LVEF among HF patients and vs age, sex, and geographical area matched general population controls without HF were assessed. Additionally, associations between HF with vs without a prior diagnosis of RA, by LVEF, and outcomes up to 5 years after HF diagnosis were investigated using Cox regression. LVEF was primarily dichotomized at 40% and secondarily categorized as <40%, 40% to 49%, and ≥50%. Covariates included demographics and cardiovascular comorbidities. RESULTS: Among 20,916 incident HF patients, 331 (1.6%) had RA vs 1,047/103,501 (1.0%) of HF-free controls. The odds ratio (OR) for RA was 1.4 (95% CI: 1.1-1.8) in LVEF<40% vs HF-free controls and 1.6 (95% CI: 1.3-2.0) in LVEF≥40% vs HF-free controls. Among HF patients, RA was more common in HF with LVEF ≥40% (1.9%) vs LVEF<40% (1.3%), corresponding to OR 1.4 (95% CI: 1.1-1.7). No associations between RA and cardiovascular outcomes were observed across LVEF. An association between RA and all-cause mortality was observed only for patients with LVEF<40% (hazard ratio: 1.4; 95% CI: 1.1-1.8). CONCLUSIONS: RA was independently associated with incident HF, particularly HF with LVEF≥40%. RA did not associate with cardiovascular outcomes following HF diagnosis but was associated with increased risk of all-cause mortality in HF with LVEF<40%.