Value of cardiopulmonary exercise testing and big endothelin plasm levels to predict short-term prognosis of patients with chronic heart failure

Objectives. We tested the hypothesis that, in patients with stable heart failure, measuring big endothelin-1 (ET-1) plasm level at rest predicts short-term prognosis better than peak oxygen consumption (Vimage2max) at exercise. Background. Cardiopulmonary exercise testing and evaluation of neurohumoral plasm factors are established tools to estimate survival in patients with heart failure. No data, however, exist comparing the prognostic value of both marker categories simultaneously. Methods. Two hundred twenty-six heart failure patients were studied in regard to combined end point of death and prioritization for urgent cardiac transplantation within 1 year follow-up. Results. During the study period 149 patients were without cardiac events (group A), 69 patients died or were urgently transplanted (group B) and 8 patients were alive after nonurgent heart transplant operation. Norepinephrine (p < 0.0001), atrial natriuretic peptide (p < 0.001), big endothelin plasm levels (p < 0.0001 as well as workload, Vimage2max and achieved percentage of predicted peak oxygen consumption (pVo2max) (all p < 0.0001) differed significantly between groups and B. In multivariate stepwise regression analysis, however, only big ET-1 plasm concentration (×2 = 74.4, p < 0.0001), New York Heart Association function class (×2 = 33.9, p < 0.0001), maximal workload (×2 = 7.2, p < 0.01, and plasm atrial natriuretic peptide (ANP) concentration (×2 = 4.6, p < 0.05) were independently related to outcome. Peak oxygen consumption or pVimage2max did not reach statistical significance in this model. Event-free survival rates were significantly lower in patients with big ET-1 level of 4.3 fmol/ml or more than with lower big ET-1 levels (p < 0.0001). Conclusion. We conclude that in patients with chronic heart failure who are stable on oral therapy measuring big ET-1 and ANP plasm levels may be valuable noninvasive adjunct to improve the prognostic accuracy of detecting high risk patients compared with exercise testing alone.