The Effects of Race on Peak Oxygen Consumption and Survival in Patients With Systolic Dysfunction

Abstract

Background The relationship of peak exercise oxygen consumption (VO 2) to survival in black heart failure (HF) patients is not well established. We examined the effects of race on peak VO 2 values and survival in HF patients with systolic dysfunction. Methods and Results This study evaluated consecutive ambulatory HF patients who underwent symptom-limited stress tests with breath-by-breath expired gas analyses using ramped treadmill protocols. The relationship between cardiopulmonary exercise parameters and patient transplant-free survival was assessed by race. This study included 580 HF patients (mean age 52 ± 12 years; 28% females; 22% blacks; mean left ventricular ejection fraction 26 ± 12%; mean body mass index 28.7 ± 5.4; 73% on β-blocker). Black patients had a significantly lower peak VO 2 than white patients (14.2 ± 5.2 versus 16.4 ± 7.0; P < .0001), despite adjusting for identified covariates. However, there was no significant difference in the 1-year transplant-free survival between black and white HF patients (87% versus 85%; P = NS). Peak VO 2 was significantly associated with survival in both racial groups. Conclusions Black HF patients had significantly lower peak VO 2, but yet had equivalent survival rates at 1 year. Further study is warranted to clarify the impact of these racial differences on the timing of cardiac transplantation black HF patients.