Aetiology of chronic heart failure in patients from a super‐aged society: the KUNIUMI registry chronic cohort

AIMS: With the rapidly increasing ageing population, heart failure is an urgent challenge, particularly in developed countries. The study aimed to investigate the main aetiologies of chronic heart failure in a super‐aged society. METHODS AND RESULTS: The KUNIUMI registry chronic cohort is a community‐based, prospective, observational study of chronic heart failure in Awaji Island, Japan. Inhabitants of this island aged ≥65 years accounted for 36.3% of the population. In the present study, data from patients with symptomatic heart failure were extracted from the registry. A total of 1646 patients were enrolled from March 2019 to March 2021, accounting for ~1.3% of the inhabitants of Awaji Island. We analysed 852 patients with symptomatic heart failure. The mean age was high (78.7 ± 11.1 years), with 357 patients (41.9%) being female. The proportion of women increased significantly with advancing age and constituted more than half of the patients aged 85 years and older (P < 0.01). The prevalence of atrial fibrillation, and in particular long‐standing persistent atrial fibrillation, increased at 70 years of age (P < 0.01). The proportion of patients with heart failure with preserved ejection fraction increased to ~60% when age was over 75 years. Although ischaemic heart disease accounted for 35.0% of chronic heart failure aetiologies, valvular heart disease was the most common cause of chronic heart failure (49.8%). The major types of valvular heart disease were mitral regurgitation and tricuspid regurgitation (27.2% and 21.7%, respectively), both of which increased significantly with age (P < 0.01). The incidence of aortic valve stenosis increased markedly over the age of 85 years (P < 0.01). Atrial functional mitral regurgitation increased with age and was the major cause of mitral regurgitation in patients aged >75 years. Patients with atrial functional mitral regurgitation had a higher prevalence of atrial fibrillation (especially long‐standing persistent atrial fibrillation) and a larger left atrial volume index when compared with patients with other types of mitral regurgitation (P < 0.001, respectively). CONCLUSIONS: The KUNIUMI registry chronic cohort showed a change in heart failure aetiology to valvular heart disease in a super‐aged society. Effective and comprehensive countermeasures are required to prepare for the rapid rise in heart failure incidence in a super‐aged society.