Incremental Role of New York Heart Association Class and Cardiopulmonary Exercise Test Indices for Prognostication in Heart Failure: A Cohort Study

Abstract

Background

The accuracy of the New York Heart Association (NYHA) classification to assess prognosis may be limited compared with objective cardiopulmonary exercise test (CPET) parameters in heart failure (HF).

Objective

To investigate the prognostic value of the NYHA classification in addition to Weber class.

Methods

Adult outpatients with HF undergoing CPET in a Brazilian tertiary care center were included. The physician-assigned NYHA class and the CPET-derived Weber class were stratified into “favorable” (NYHA I or II; Weber A or B) or “adverse” (NYHA III or IV; Weber C or D). Patients with one favorable class and one adverse class were defined as “discordant.” The primary endpoint was time to all-cause mortality. A 2-sided p value < 0.05 was considered statistically significant.

Results

A total of 834 patients were included. Median age was 57 years; 42% (351) were female, and median left ventricular ejection fraction was 32%. Among patients with concordant NYHA and Weber classes, those with adverse NYHA and Weber classes had significantly higher all-cause mortality compared to those with favorable classes (hazard ratio [HR]: 5.65; 95% confidence interval [CI]: 3.38 to 9.42). Among patients with discordant classes, there was no significant difference in all-cause mortality (HR: 1.38; 95% CI: 0.82 to 2.34). In the multivariable model, increments in NYHA class (HR: 1.55 per class increase; 95% CI: 1.26 to 1.92) and reductions in peak VO ₂ (HR: 1.47 per 3 ml/kg/min decrease; 95% CI: 1.28 to 1.70) significantly predicted mortality.

Conclusions

Physician-assigned NYHA class and objective CPET measures provide complementary prognostic information for patients with HF.