Systolic Dysfunction in Urban Japan

Niigata-Sado Heart Failure Study

Abstract

Background Heart failure (HF), which can be caused by left ventricular systolic dysfunction (LVSD), is a growing problem in developed countries with a large aging population. The aim of the present study was to characterize outpatients with LVSD in the adult population (45-84 years) in an urban Japanese community (Niigata City), and delineate their characteristics in comparison with those in a rural one (Sado). Methods and Results Over a 5-year period, 1,297 patients (67% males) with LVSD (defined as ejection fraction ≤50%) were extracted from 87,953 echocardiography records available in 15 hospitals in Niigata City. The proportion of LVSD increased progressively with age (p-for-trend <0.0001), reaching 1-2% in those aged ≥75 years. The prevalence of comorbidities was noticeable (47% had hypertension, 41% myocardial ischemia, 34% atrial fibrillation, 33% previous hospitalization because of congestive HF, 27% cerebral stroke). In comparison with Sado, Niigata patients were younger, with a higher prevalence of comorbidities (hypertension, diabetes, dyslipidemia, and cerebral stroke). Conclusions As the proportion of LVSD cases increases progressively with age, it is expected to simulate a future epidemic. The differences between patients' characteristics and disease patterns in urban and rural communities may favor individually tailoring preventive strategies for HF in these areas. (Circ J 2008; 72: 349 - 357)