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

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±0.20m2) 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.