Survival among Heart Failure Older Adults with Three Highest Impact Comorbidities in the United States

Abstract

Introduction Heart failure (HF) mortality remains high in the United States in spite of the decline in HF incidence in recent decades. HF patients are more likely to suffer from multiple comorbidities, contributing to increased mortality. It is important to identify the most predictive comorbidities of mortality and promote treatment for HF patients with these comorbidities. Objective We describe the prevalence of several comorbidities in HF patients and quantify their impact on mortality. Methods Sample (31,126) included adult (50 + years of age) participants from the 1999-2004 National Health and Nutrition Examination Survey (NHANES) and 2015 linked mortality data. Presence of HF is defined based on the subject's response to the question: ‘Have you ever been told by a physician that you had heart failure?’ Prediction of mortality among HF patients with comorbidities is obtained by using Cox proportional hazards regression, after the adjustment of gender, age, and race. Results The prevalence of self-reported comorbidity among 512 HF subjects is: emphysema (12.5%), kidney weakness or failure (13.1%), diabetes mellitus (34.8%), CHD (44.3%), stroke (20.9%), and anemia (11.7%). The HF subjects with the three highest impact commodities (emphysema, kidney weakening or failure, and diabetes mellitus) are associated with increased hazards of mortality compared to subjects without commodities. The hazard ratios (HR) and 95% confidence intervals (CI) are: emphysema (1.87: 1.35-2.60), kidney weakness or failure (1.50: 1.08-2.08), and diabetes mellitus (1.42: 1.12-1.80). Subsequently, subjects are classified into 4 groups according to these 3 comorbidities and their hazard of mortality is compared. Group 1 is the reference group consisting of subjects without any of the three comorbidities. Group 2 consists of subjects with all three comorbidities. Group 3 consists of subjects with emphysema only. Group 4 consists of subjects without emphysema. The three groups each have a significantly higher hazard of mortality than the reference group, with HR and 95% CI as 5.07 (1.22, 21.0), 1.99 (1.31, 3.03) and 1.59 (1.08, 2.36), respectively. Conclusion Three comorbidities, emphysema, kidney weakness or failure, and diabetes mellitus, are considered to be the major predictors of mortality in HF subjects. Health providers should prompt care for the three comorbidities in order to improve survival in HF patients.