Continental differences in clinical characteristics, management, and outcomes in patients hospitalized with worsening heart failure results from the EVEREST (Efficacy of Vasopressin Antagonism in Heart Failure: Outcome Study with Tolvaptan) program

Abstract

Objectives: Our aim was to examine continental and regional differences in baseline characteristics and post-discharge clinical outcomes in the EVEREST (Efficacy of Vasopressin Antagonism in Heart Failure: Outcome Study with Tolvaptan) trial.

Background: Continental and regional differences in clinical trials of acute heart failure syndromes (AHFS) have not been well studied.

Methods: We analyzed data from the EVEREST trial, which randomized 4,133 patients hospitalized for worsening (HF) and left ventricular ejection fraction < or =40% to oral tolvaptan, a vasopressin antagonist, or placebo and followed for a median of 9.9 months. Baseline characteristics, mortality, and outcomes were analyzed across North America (n = 1,251), South America (n = 688), Western Europe (564 patients), and Eastern Europe (n = 1,619).

Results: There were major differences between the 4 groups in the severity, etiology, and management of HF. Unadjusted 1-year mortality and cardiovascular mortality/HF hospitalization were 30.4% and 52.5% in North America, 27.2% and 41.6% in South America, 27.1% and 47.3% in Western Europe, and 20.5% and 35.3% in Eastern Europe. After adjustment, South American patients had the highest overall mortality (hazard ratio: 1.42, 95% confidence interval: 1.15 to 1.76), while Eastern European patients had the lowest cardiovascular death and HF hospitalization rate (hazard ratio: 0.84, 95% confidence interval: 0.73 to 0.97), compared with patients in North America.

Conclusions: Major continental and regional differences in HF severity, etiology, and management exist among AHFS patients, resulting in varied post-discharge outcomes, despite pre-defined selection criteria. These differences should be taken into account when planning global trials in AHFS. (Efficacy of Vasopressin Antagonism in Heart Failure: Outcome Study with Tolvaptan [EVEREST]; NCT00071331).