Proteinuria is independently associated with heart failure events in patients with atrial fibrillation: the Fushimi AF registry

Aims: Previous studies have shown that proteinuria is independently associated with the incidence of atrial fibrillation (AF), and is also associated with the incidence of cardiovascular events such as stroke and thromboembolism in patients with AF. However, the association of proteinuria with heart failure (HF) events in patients with AF remains unclear.

Methods and results: The Fushimi AF Registry is a community-based prospective study of patients with AF. Of the entire cohort of 4489 patients, 2164 patients had available data of proteinuria. We compared the clinical background and outcomes between patients with proteinuria (n = 606, 28.0%) and those without (n = 1558, 72.0%). Patients with proteinuria were older and had a higher prevalence of major co-morbidities. During the median follow-up of 5.0 years, the incidence rates of HF events (composite of cardiac death or HF hospitalization) were higher in patients with proteinuria than those without (4.1% vs. 2.1% person-year, P < 0.01). Multivariate analyses revealed that proteinuria was an independent risk factor of the incidence of HF events [adjusted hazard ratio (HR): 1.40, 95% confidence interval (CI): 1.13-1.74]. This association was consistent among the various subgroups, except for the age subgroup in which there was a significant interaction (P < 0.01) between younger (<75 years) (unadjusted HR: 3.03, 95% CI: 2.12-4.34) and older (≥75 years) patients (unadjusted HR: 1.59, 95% CI: 1.23-2.05).

Conclusion: Our community-based large prospective cohort suggests that proteinuria is independently associated with the incidence of HF events in Japanese patients with AF.