Importance of non-cardiovascular comorbidities in atrial fibrillation and heart failure with preserved ejection fraction.

Aims: Atrial fibrillation (AF) and heart failure (HF) with preserved ejection fraction (HFpEF) are interlinked and frequently coexisting conditions. To date, patients with AF and HFpEF have limited evidence guiding their management. This study aimed to investigate the predictors of adverse outcomes among patients with AF and HFpEF.

Methods: The Fushimi AF Registry is a community-based prospective survey of AF patients in Fushimi-ku, Kyoto, Japan. From the registry, we explored predictors for a composite of cardiac death or HF hospitalization among AF patients with HFpEF (defined as having a prior HF hospitalization or New York Heart Association class ≥2 in association with heart disease and left ventricular ejection fraction ≥50%). Besides, we investigated whether the scoring using the predictors identified by the Fushimi AF Registry could stratify the outcomes in patients with AF and HFpEF registered in another independent Kyoto Congestive Heart Failure Registry.

Results: Of 755 patients with AF and HFpEF [mean age: 77.5 ± 9.9 years; female: 391 (52%); paroxysmal AF: 258 (34%); and mean CHA₂DS₂-VASc score: 4.5 ± 1.5], cardiac death or HF hospitalization occurred in 246 patients (33%) during the median follow-up period of 4.4 years in the Fushimi AF Registry. Using multivariate Cox regression analysis, age ≥75 years [hazard ratio (HR): 1.72, 95% confidence interval (CI): 1.26-2.36] and non-cardiovascular comorbidities such as anaemia (HR: 1.83, 95% CI: 1.37-2.46), chronic kidney disease (HR: 1.69, 95% CI: 1.27-2.26), diabetes mellitus (HR: 1.55, 95% CI: 1.15-2.09) and chronic obstructive pulmonary disease (HR: 1.87, 95% CI: 1.08-3.22) were independent predictors of adverse outcomes. Meanwhile, cardiovascular comorbidities including coronary artery disease, valvular heart disease or cardiomyopathy were not significantly associated with adverse outcomes. These results were also the case when analysed for patients with AF and HFpEF who registered in the Kyoto Congestive Heart Failure registry (N = 878). The score assigning 1 point for each five predictors (age, anaemia, chronic kidney disease, diabetes mellitus and chronic obstructive pulmonary disease; ranging 0-5 points) stratified the incidence of adverse outcomes among patients with AF and HFpEF registered in the Kyoto Congestive Heart Failure Registry as well as among those in the Fushimi AF Registry (both log-rank; P < 0.001).

Conclusions: Non-cardiovascular comorbidities such as anaemia, diabetes mellitus and kidney or pulmonary disease in addition to advanced age were independent predictors of adverse outcomes in patients with AF and HFpEF. Our study suggests the importance of focusing on these non-cardiovascular comorbidities for individualized risk stratification and optimal management in patients with AF and HFpEF.