Etiology, comorbidity and prognosis of hospitalized patients with congestive heart failure

Introduction

Congestive heart failure (CHF) is a growing public health problem in China, mainly because of aging of the population and the increased prevalence of CHF in the elderly. The aim of present study was to investigate the major causes, comorbidities and in-hospital mortality of patients with CHF.

Methods

A retrospective study was performed in 6,960 patients (4,352 males, 2,608 females) with a validated primary discharge diagnosis of CHF hospitalized from 1 January 1993 through 31 December 2007, at Chinese PLA General Hospital in Beijing. The patients were divided into five groups based on the number of etiologies and comorbidities from one to five or more than five. A comparative analysis was performed to explore the major causes, comorbidities and in-hospital mortality of patients among the groups.

Results

The mean (± SD) age of patients was 53 ± 17 years in the one-comorbidity group, 60 ± 16 years in the two-comorbidity group, 65 ± 14 years in the three-comorbidity group, 70 ± 13 years in the four-comorbidity group and 72 ± 11 years in the five-comorbidity group. The major causes of hospitalized patients with CHF were coronary artery disease (44.9%), vavular heart disease (27.5%), cor pulmonale (9.6%) and cardiomyopathy (7.4%). The comorbidities of CHF were hypertension (38.6%), atrial fibrillation (23.1%), diabetes mellitus (18.3%), pneumonia (11.6%) and renal failure (7.1%). The single comorbidity was predominant in younger patients while multiple comorbidity was predominant in the elderly (P < 0.001). The most common single etiology was vavular heart disease, the most common triple etiology was coronary artery disease complicated with hypertension and diabetes mellitus. Cox regression analysis showed higher hospital mortality rates associated with increased numbers of etiology and comorbidity (hazard ratio (HR) from 0.98, 95% CI 0.71 to 1.36 to HR 1.59, 95% CI 1.23 to 2.05, to HR 1.90, 95% CI 1.43 to 2.51, to HR 2.47, 95% CI 1.81 to 3.35, P < 0.001).

Conclusions

This study demonstrates that the older a hospitalized patient with CHF is, the more comorbidities they have. The major causes and comorbidities of hospitalized patients with CHF are coronary artery disease, vavular heart disease, cor pulmonale, cardiomyopathy, hypertension, atrial fibrillation, diabetes mellitus, pneumonia and renal failure. The single etiology or comorbidity is predominant in younger patients, while multiple etiology or comorbidity is predominant in the elderly. A higher in-hospital mortality rate of CHF is associated with an increased number of etiologies and comorbidities.