Fatigue as a predictor of outcome in patients with heart failure: analysis of CORONA (Controlled Rosuvastatin Multinational Trial in Heart Failure)

Abstract

Objectives: The purpose of this study was to examine the relationship between fatigue and clinical outcomes, using dyspnea as a comparator, in patients with left ventricular ejection fraction (LVEF) ≤35% enrolled in the CORONA (Controlled Rosuvastatin Multinational Trial in Heart Failure) study.

Background: Although fatigue is a common symptom in heart failure (HF), little is known about its association with prognosis.

Methods: At baseline in CORONA, fatigue "during the past few days" was measured using a 5-point exertion scale (0 = none, 1 = heavy exertion, 2 = moderate exertion, 3 = slight exertion, 4 = rest); a 4-point scale was used for dyspnea (1 to 4 as for fatigue). Patients were grouped into 3 categories: a fatigue score 0 to 1 (n = 535), fatigue score 2 (n = 1,632), and fatigue score 3 to 4 (n = 1,663); and a dyspnea score of 1 (n = 292), dyspnea score of 2 (n = 1,695), and dyspnea score of 3 to 4 (n = 1,843). The association between fatigue and dyspnea and the composite outcome of cardiovascular (CV) death or HF hospital stay and each component separately was examined using Kaplan-Meier analysis and Cox proportional-hazard models. We also examined all-cause mortality.

Results: In univariate analyses, symptom severity was associated with a higher risk of CV death or HF hospital stay (fatigue: group 3, 49% [n = 810], vs. group 1, 30% [n = 160]; dyspnea: group 3, 50% [n = 918], vs. group 1, 28% [n = 82]) and all-cause mortality (fatigue: group 3, 38% [n = 623], vs. group 1, 24% [n = 130]; dyspnea: group 3, 38% [n = 697], vs. group 1, 23% [n = 66], log-rank p < 0.0001 for all). After adjusting for other prognostic variables, including LVEF, New York Heart Association class, and N-terminal pro-B-type natriuretic peptide level, worse fatigue remained associated with higher risk of HF hospital stay but not mortality (worse dyspnea remained associated with a higher risk of both). An increase in fatigue (or dyspnea) between baseline and 6 months was also associated with worse outcomes.

Conclusions: In HF, greater fatigue is associated with worse clinical outcomes. Closer attention should be paid to this symptom in clinical practice, with more done to standardize its measurement and understand its origins, with a view to improving treatment.

Keywords: dyspnea; fatigue; heart failure; outcomes; symptoms.