Comprehensive Use of Cardiopulmonary Exercise Testing Identifies Adults with Congenital Heart Disease at Increased Mortality Risk in the Medium Term
Background—Parameters of cardiopulmonary exercise testing (CPX) were recently identified as strong predictors of mortality in adults with congenital heart disease (ACHD). We hypothesized that combinations of CPX parameters may provide optimal prognostic information on mid-term survival in this population.
Methods and Results—1,375 consecutive ACHD patients (age 33±13 years) underwent CPX at a single center over a period of 10 years. Peak oxygen consumption (peak VO2), ventilation per unit of carbon dioxide production (VE/VCO2 slope) and heart rate reserve (HRR) were measured. During a median follow-up of 5.8 years, 117 patients died. Peak VO2, HRR and VE/VCO2 slope were related to mid-term survival in ACHD patients. Risk of death increased with lower peak VO2 and HRR. A higher VE/VCO2 slope was also related to increased risk of death in non-cyanotic patients, while VE/VCO2 slope was not predictive of mortality in cyanotic patients. The combination of peak VO2 and HRR provided the greatest predictive information after adjusting for clinical parameters, such as negative chronotropic agents, age and presence of cyanosis. However, the incremental value of these exercise parameters was reduced in patients with peak respiratory exchange ratio below 1.0.
Conclusions—CPX provides strong prognostic information in patients with ACHD. Prognostication should be approached differently depending on the presence of cyanosis, the use of rate lowering medications and achieved level of exercise. We provide 5-year survival prospects based on CPX parameters in this growing population.
- Received July 28, 2011.
- Accepted November 7, 2011.
- Copyright © 2011, American Heart Association, Inc. All rights reserved. Unauthorized use prohibited