Pulmonary artery pressure-perfusion relation during exercise in patients with chronic thromboembolic pulmonary hypertension using pulmonary arteriography and right-heart catheterization.

Background: In pulmonary hypertension (PH), pulmonary artery pressure (PAP) does not increase to pulmonary perfusion (PP) < 50%. During exercise, PAP may be increased even at PP > 50% for the early detection of PP disorders. The relationship between PP estimated by pulmonary angiography (PAG) and PAP was evaluated in patients with chronic thromboembolic PH (CTEPH) treated by balloon pulmonary angioplasty with near-normal PH. Methods: Thirty-one patients (age 60 ± 11 years) with CTEPH underwent catheterization at rest and during exercise. Each segmental PP was determined by visualization of its segmental pulmonary artery and graded from 0 to 3 in the PAG. PP was estimated as the percentage PAG (%PAG) score-%summed total of all segmental PP/the full score-54. Results: The mean PAP (mPAP) increased from 28 ± 6 mmHg to 46 ± 10 mmHg during exercise. Transpulmonary pressure gradient, the value of mPAP with the pulmonary artery wedge pressure substituted at peak exercise, was negatively correlated with %PAG score (rs = -0.56, p < 0.001) and elevated at > 50% PP. Conclusions: The PAP-PP relationship at peak exercise was correlated, shifting from the relationship at rest, and the PAP started to rise with PP > 50%.