Differences in treatment, outcomes, and quality of life among patients with heart failure in Canada and the United States

Objectives: The aim of this study was to compare clinical outcomes, resource utilization, and health-related quality of life between Canadian and U.S. patients enrolled in ASCEND-HF (Acute Study of Clinical Effectiveness of Nesiritide in Decompensated Heart Failure). A further aim was to supplement the within-trial analysis with a contemporaneous population-based comparison of all patients hospitalized with primary diagnoses of heart failure (HF) in the 2 countries.

Background: Little is known about intercountry differences in outcomes of patients with HF in Canada and the United States.

Methods: Trial patients consisted of 465 Canadian and 2,684 U.S. patients enrolled in ASCEND-HF. Population-level cohorts consisted of 1.9 million U.S. and 81,016 Canadians hospitalized for HF in 2007 and 2008.

Results: Canadian patients in ASCEND-HF were older, were more likely to be white, and had lower body weights and blood pressures than U.S. patients. Canadians also had lower baseline-adjusted odds of 30-day mortality (odds ratio: 0.46; 95% confidence interval: 0.23 to 0.92) and better health-related quality of life than U.S. patients. In both countries, trial patients differed significantly from population-level cohorts. In contrast to ASCEND-HF, unadjusted in-hospital mortality at the population level was significantly lower in the United States (3.4%) compared with Canada (11.1%) (p < 0.01).

Conclusions: Intercountry differences in outcomes of patients hospitalized with HF differed significantly between trial and population cohorts. Further study on how cardiac care is delivered in the 2 countries and how it influences the results of clinical trials and population-level outcomes, especially in the long term, is warranted. (A Study Testing the Effectiveness of Nesiritide in Patients With Acute Decompensated Heart Failure; NCT00475852).