Abstract 21012: Comprehensive Use of Cardiopulmonary Exercise Testing Identifies Adults with Congenital Heart Disease at Increased Mortality Risk in the Medium Term
Introduction: Parameters of cardiopulmonary exercise testing (CPET) were recently identified as strong predictors of mortality in adults with congenital heart disease (ACHD). However, it is unclear how these parameters should be combined to best obtain prognostic information.
Hypothesis: We hypothesized that different combinations of CPET parameters may provide optimal prognostic information on mid-term survival in this population depending on the presence of cyanosis and achieved level of exercise.
Methods: 1,375 consecutive ACHD patients (age 33±13 years) underwent CPET at a single centre over a period of 10 years. Peak oxygen consumption (peak VO2), anaerobic threshold (AT), ventilation per unit of carbon dioxide production (VE/VCO2 slope) and heart rate reserve (HRR: peak minus resting heart rate) were measured.
Results: During a median follow-up of 4.8 years, 99 patients died. Depending on the presence of cyanosis and the ability to reach AT, different parameters emerged as optimal prognostic markers. Amongst non-cyanotic patients being unable to achieve AT, VE/VCO2 slope (P=0.006) was the strongest prognosticator, with a VE/VCO2 slope > 41 associated with an estimated 5-year mortality above 5%. For non-cyanotic patients who achieved AT, peak VO2 (P=0.005) and HRR (P=0.004) emerged as the strongest prognosticators. A combination of these parameters provided additional prognostic information with a peak VO2 less than 50% and HRR less than 60 beats/min relating to an estimated 5-year mortality above 15%. When cyanotic patients were assessed, only HRR retained independent prognostic value (P=0.005) with HRR less than 64 beats/min associated with an estimated 5-year mortality >10%.
Conclusions: CPET provides strong prognostic information in patients with ACHD. However, as different physiologic mechanisms apply to non-cyanotic versus cyanotic patients and CPET parameters can be dependent on maximal exercise, prognostication should be approached differently depending on the presence of cyanosis and the ability to achieve AT. We provide herewith 5-year survival prospects based on CPET parameter algorithms in this growing population.
- © 2010 by American Heart Association, Inc.