The assessment of functional capacity in pulmonary hypertension (PH) is essential in the initial workup and during follow-up. Exercise capacity can be evaluated by functional class (FC), six-minute walking test (6MWT) and cardiopulmonary exercise test (CPET).CPET parameters provide prognostic information and evaluate underlying pathophysiological mechanisms responsible of exercise limitation. In this context, idiopathic pulmonary arterial hypertension (IPAH) and thromboembolic pulmonary hypertension (CTEPH) are two of the most prevalent groups of precapillary PH and the exercise limitation is the cardinal symptom.
Objective: Describe characteristics and exercise parameters in a cohort of patients with IPAH and CTEPH in a reference center in Spain.
Methods: Until December 2018, 502 patients with CTEPH and 219 with IPAH were evaluated. For this analysis we included 114 IPAH and 144 CTEPH with an initial workup assessment of functional capacity with CPET, 6MWT and FC.
Results: IPAH patients were younger and predominantly female. There were no significant differences in routine variables that assess functional capacity such as FC and 6MWT. IPAH showed worse hemodynamic parameters, however, the aerobic capacity and the parameters of ventilatory inefficiency were better than in CTEPH. Results in table.
Conclusions: CPET discriminates more accurately exercise capacity than 6MWT in patients with PH. Aerobic capacity is reduced and ventilatory inefficiency is higher in CTEPH vs IAPH despite having better hemodynamic parameters. These changes could be related to the deep alteration of pulmonary mismatch due to the presence of large areas not perfused in the CTEPH.