Insomnia in patients with acute heart failure: from the KCHF registry

Insomnia is a known risk factor for heart failure (HF) and a predictor of cardiac events in HF patients, but the clinical significance of insomnia in patients with acute HF (AHF) is not adequately evaluated. This study aimed to investigate the association between insomnia and subsequent clinical outcomes in patients with AHF.

From the Kyoto Congestive Heart Failure registry, consecutive 3414 patients hospitalized for HF who were discharged alive were divided into the 2 groups at discharge: insomnia group and non-insomnia group. We compared baseline characteristics and 1 year clinical outcomes according to the presence of insomnia. The primary outcome measure was all-cause death.

There were 330 patients (9.7%) and 3084 patients (90.3%) with and without insomnia, respectively. In the multivariable logistic regression analysis, brain-type natriuretic peptide above median value at discharge (OR = 1.50, 95% CI = 1.08-2.10, P = 0.02) and the presence of oedema at discharge (OR = 4.23, 95% CI = 2.95-6.07, P < 0.001) were positively associated with insomnia at discharge, whereas diuretics at discharge (OR = 0.60, 95% CI = 0.39-0.90, P = 0.01) were negatively associated with insomnia at discharge. The cumulative 1 year incidence of all-cause death was significantly higher in the insomnia group than in the non-insomnia group (25.1% vs. 16.2%, P < 0.001). Even after adjusting the confounders, the higher mortality risk of patients with insomnia relative to those without insomnia remained significant (HR = 1.55, 95% CI = 1.24-1.94; P < 0.001).

Patients with insomnia at discharge were associated with a higher risk of mortality than those without insomnia at discharge.