TY - JOUR T1 - Contrasting cardiopulmonary responses to incremental exercise in patients with schistosomiasis-associated and idiopathic pulmonary arterial hypertension with similar resting hemodynamic impairment JF - European Respiratory Journal JO - Eur Respir J VL - 38 IS - Suppl 55 SP - p2307 AU - Fabricio Valois AU - Roberta Ramos AU - Eloara Ferreira AU - Jaquelina Arakaki AU - José Alberto Neder AU - Luiz Eduardo Nery Y1 - 2011/09/01 UR - http://erj.ersjournals.com/content/38/Suppl_55/p2307.abstract N2 - Schistosomiasis is the most common cause of pulmonary arterial hypertension (PAH) worldwide. It has been reported that schistosomiasis-associated PAH (Sch-PAH) has better hemodynamic profile at diagnosis and a more benign clinical course as compared with idiophatic PAH (IPAH) [Fernandes, C.J.C.S. et al. JACC 2010; 59:715-20]. We hypothesized that Sch-PAH subjects have better physiological responses to incremental cardiopulmonary exercise test (CPET) than IPAH patients, even at similar resting pulmonary hemodynamic impairment. We performed CPET and hemodynamic study in 8 Sch-PAH and 9 IPAH patients. None of them had received any PAH therapy. There were no significant between-group differences on cardiac index (2.1±0.3 vs 2.4±0.7 L/min, p=0.21), pulmonary vascular resistance (p=0.32) and mean pulmonary artery pressure (p=0.48). However, the peak oxygen uptake (V'O2) was greater in Sch-PAH (75±21 vs 54±16%pred, p=0.016), as well as the ratio of increases of V'O2 to work rate (8.2±1.1 vs 6.8±1.8 mL/min/W, p=0.024). Also, the slope of the ventilatory response as a function of CO2 output was lower in Sch-PAH (41±4 vs 59±18 L2/min2, p= 0.04), with a shallower heart rate response for a given change in V'O2 (80±21 vs 123±39 beats.ml/min2, p=0.02), and a greater peak oxygen pulse (p<0.05). In conclusion, Sch-PAH patients had better physiological responses to exercise than IPAH subjects at similar resting hemodynamic profile. Our data suggest a more preserved hemodynamic response to exercise in Sch-PAH, that might explain its better clinical course as compared with IPAH. ER -