Schmaltz HN, Southern DA, Maxwell CJ, Knudtson ML, Ghali WA; for the APPROACH Investigators. Patient Sex Does Not Modify Ejection Fraction as a Predictor of Death in Heart Failure: Insights from the APPROACH Cohort. J Gen Intern Med. 2008 Dec; 23(12):1940-6
Background: Normal and low ejection fraction (EF) heart failure patients appear to have similar outcomes.
Objective: The object of this study was to determine whether sex modifies the effects of left ventricular EF on prevalent heart failure mortality.
Design: Prospective cohort study.
Patients: Patients (n = 6, 095) with a diagnosis of heart failure and a measure of EF undergoing cardiac catheterization in Alberta, Canada between April 1999 and December 2004; follow-up continued through October 2005.
Measurements: All-cause mortality was assessed in analyses stratified by patient sex and EF (</=50% vs. >50%).
Main Results: Overall, female heart failure patients were older, had more hypertension, valvular disease, less systolic impairment and coronary artery disease. Baseline medication use was similar in the four sex-EF groups. Low EF heart failure mortality over 6.5 years was slightly higher but was not significantly modified by patient sex. This relationship remained unchanged after adjustment for differences in baseline characteristics and process of care (women normal EF, reference group; men normal EF adjusted HR 1.1, 95% CI 0.9-1.3; women low EF adjusted HR 1.5, 95% CI 1.1-2.0; men low EF adjusted HR 1.6, 95% CI 1.2-2.1).
Conclusions: Patient sex did not appear to modify the negative effects of low EF on long-term survival in this prospective study of prevalent heart failure. The small absolute difference in survival between low and normal EF heart failure highlights the need for further research into optimal therapy for the latter, a less well-understood condition.