Prognostic Role of Prior Heart Failure Hospitalization Among Patients Hospitalized for Worsening Chronic Heart Failure

Abstract

Background: Hospitalization for heart failure (HF) is associated with increased risk of death among patients with chronic HF. The degree to which hospitalization for HF is a distinct biologic entity with independent prognostic value versus a marker of higher risk chronic HF patients is unclear.

Methods: After excluding patients with new-onset HF, the ASCEND-HF trial (Acute Study of Clinical Effectiveness of Nesiritide in Decompensated Heart Failure) included 4205 patients hospitalized for worsening chronic HF with reduced or preserved ejection fraction. The present analysis compared patients by presence or absence of prior HF hospitalization within 12 months and by timing of prior HF hospitalization relative to index hospitalization. Associations with 180-day all-cause mortality were assessed, including adjustment for 27 prespecified clinical factors.

Results: Overall, 2241 (53.3%) patients had a HF hospitalization within the prior 12 months and 1964 (46.7%) did not. Mortality rates at 180 days were 15.5% and 11.9%, respectively. In unadjusted analyses, prior HF hospitalization was associated with increased risk of 180-day mortality (HR, 1.35 [95% CI, 1.14-1.59]; P<0.01). After adjustment, the point estimate was attenuated and the association not statistically significant (HR, 1.18 [95% CI, 0.99-1.40]; P=0.064). Similarly, after adjustment, compared with patients without prior hospitalization, prior HF hospitalization was not associated with mortality, irrespective of timing (0-4 months: HR, 1.10 [95% CI, 0.87-1.39], P=0.41; 4-8 months: HR, 0.95 [95% CI, 0.70-1.27]; P=0.72; 8-12 months: HR, 1.06 [95% CI, 0.74-1.51], P=0.77; >12 months: HR, 0.81 [95% CI, 0.63-1.06], P=0.12).

Conclusions: In this cohort of patients hospitalized for worsening HF, prior HF hospitalization was not associated with 180-day mortality after comprehensively accounting for patient characteristics measured during the index patient visit. Clinical confounders measured at the point-of-care may explain previously observed associations between prior HF hospitalization and mortality, and these clinical factors may be a more direct means of predicting patient survival. Registration: URL: https://www.clinicaltrials.gov; Unique identifier: NCT00475852.

Keywords: heart failure; hospitalization; mortality; prognosis.

Figure 1.. Selection of the study cohort and timing of prior HF hospitalization.

This study included 4205 patients hospitalized with worsening chronic heart failure (HF). Of these, 2241 (53.3%) patients had a HF hospitalization in the prior 12 mo and 1964 (46.7%) patients did not. In examination of more precise timing of prior HF hospitalization, 1374, 547, 320, and 1007 patients had a most recent prior HF hospitalization at 0 to 4, >4 to 8, >8 to 12, and >12 mo before study baseline, respectively. Overall, 957 patients had no prior history of a HF hospitalization at any time. ASCEND-HF indicates Acute Study of Clinical Effectiveness of Nesiritide in Decompensated Heart Failure.

Figure 2.. Risk of 180-d All-Cause Mortality for Patients with Prior HF Hospitalization in Past 12 mo Across Subgroups.

EF indicates ejection fraction; HF, heart failure; and HR, hazard ratio.