Background: The New York Heart Association (NYHA) classification is a strong predictor of mortality and an established instrument for risk stratification in patients with heart disease but data on the validity of this classification in end-stage renal disease (ESRD) are sparse.
Methods: In this study, we tested the predictive value of the NYHA in patients with ESRD and compared it with that of two established indexes of disease severity, i.e. the Khan index and the renal disease severity score (RDSS). The study cohort was composed of 1322 incident patients in a dialysis registry (772 male and 550 female, age 61+/-16 years).
Results: During the follow-up period (41+/-27 months) 551 patients died. A multivariate COX model including the NYHA classification explained 39% of the variation in mortality, a figure almost identical to that of a model based on the RDSS (37%) and superior (P<0.001) to that provided by the Khan index-based model (32%). The area under the receiver operating characteristic curve of NYHA classification, as related to all-cause mortality, was 0.74 (95% CI: 0.71-0.77, P<0.001). Again, RDSS had a predictive value for mortality (0.74, 95% CI: 0.72-0.77) identical to that of NYHA and higher than that of the Khan index (0.70, 95% CI: 0.67-0.72).
Conclusion: The NYHA is a powerful predictor of mortality in ESRD and provides prognostic information equal or superior to that given by other established indexes of disease severity. Given the pervasive nature of cardiovascular disease in ESRD, this classification may be recommended for risk stratification in this population.