Multimorbidity and multiple causes of death in heart failure

Patients with heart failure (HF) usually have multiple comorbid conditions that interact with HF, either leading to its development, aggravating its progression or reducing the effectiveness of treatment. Although the prevalence of HF comorbidities has been studied, more evidence is needed on the strength of their independent association with HF and HF mortality. To examine the strength of association between HF and associated medical conditions. We analysed data from the Baker Biobank, encompassing 6530 adults aged between 18 and 69 years, collected between January 2000 and December 2011. Mortality was determined through linkage to the National Death Index. Medical conditions were self-reported by patients at enrolment to the Biobank. The strength of association between HF and co-occurring medical conditions as a cause of illness and death was assessed using multivariate logistic regression. Hazards of mortality were determined using Cox regression models. Most HF patients (92.2%) had at least one additional medical condition. The most common comorbidities were hypertension, arrhythmia and dyslipidaemia. Coronary artery disease was the most common cause of death co-occurring with HF. HF patients had significantly higher odds of arrhythmia [odds ratio (OR) = 3.3; 95% confidence interval (CI): 2.7, 3.9). Patients with kidney disease had 3 (95% CI: 2.1, 4.4) times higher odds of co-occurring HF as a cause of death compared to those without kidney disease. Patients with a history of HF had 3.6 (95% CI: 2.45, 5.24) times higher hazard of mortality from kidney disease. In multimorbidity analysis, other cardiovascular diseases had a strong association with HF. However, in multiple causes of death analysis, there was a strong association between kidney disease and HF.