The value of cardiopulmonary exercise testing and stress echocardiography in the prediction of all-cause mortality in adults with end-stage renal disease

Abstract

We aimed to assess the prognostic utility of different parameters routinely assessed from cardiopulmonary exercise testing (CPET) and exercise echocardiography in adults with end-stage renal disease (ESRD). Forty-two ESRD (37 male) individuals (age: 58 ± 13 years, height: 169.30 ± 8.30 cm, weight: 81 ± 15 kg, body surface area: 1.92 ± 0.20 m²) underwent a maximal/symptom limited CPET, with a full cross-sectional echocardiogram performed at baseline and peak exercise. All participants were prospectively followed over a 10-year period, with all-cause mortality as the primary endpoint. After the follow-up period, a total of 19 participants (45%) died. Left atrial size (4.70 ± 0.70 vs. 3.65 ± 0.50 cm, P < 0.001) and anteroseptal wall thickness (1.28 ± 0.40 vs. 1.06 ± 0.02 cm, P = 0.002) were significantly greater in those that died, while peak heart rate was significantly lower (108 ± 12 vs. 128 ± 14 bpm, P < 0.001). The prevalence of myocardial ischaemia (13 vs. 8 participants, P = 0.03) was significantly greater, while peak VO₂ (9.80 ± 2.10 vs. 15.90 ± 4.30 ml·kg⁻¹·min⁻¹, P < 0.001) was significantly lower in those that died. Following multivariate cox regression, myocardial ischaemia (Hazard Ratio 3.08; 95% Confidence Interval 1.09–8.70; P = 0.03) and peak VO₂ (HR 0.73; 95% CI 0.64–0.84; P < 0.001) were significant independent predictors of 10-year all-cause mortality. This is the first study to establish peak VO₂ as powerful marker of all-cause mortality when assessed with clinical, resting and stress echocardiography parameters in people with ESRD over a 10-year follow up period. This observation indicates that, in clinical practice, CPET and exercise echocardiography may serve as valuable tools for the risk stratification of individuals with ESRD.