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 similar to 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 similar 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 mitrel 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.