Magnetic resonance imaging to assess the effect of exercise training on pulmonary perfusion and blood flow in patients with pulmonary hypertension.

Objectives: To evaluate whether careful exercise training improves pulmonary perfusion and blood flow in patients with pulmonary hypertension (PH), as assessed by magnetic resonance imaging (MR).

Methods: Twenty patients with pulmonary arterial hypertension or inoperable chronic thromboembolic PH on stable medication were randomly assigned to control (n = 10) or training groups (n = 10). Training group patients received in-hospital exercise training; patients of the sedentary control group received conventional rehabilitation. Medication remained unchanged during the study period. Changes of 6-min walking distance (6MWD), MR pulmonary flow (peak velocity) and MR perfusion (pulmonary blood volume) were assessed from baseline to week 3.

Results: After 3 weeks of training, increases in mean 6MWD (P = 0.004) and mean MR flow peak velocity (P = 0.012) were significantly greater in the training group. Training group patients had significantly improved 6MWD (P = 0.008), MR flow (peak velocity -9.7 ± 8.6 cm/s, P = 0.007) and MR perfusion (pulmonary blood volume +2.2 ± 2.7 mL/100 mL, P = 0.017), whereas the control group showed no significant changes.

Conclusion: The study indicates that respiratory and physical exercise may improve pulmonary perfusion in patients with PH. Measurement of MR parameters of pulmonary perfusion might be an interesting new method to assess therapy effects in PH. The results of this initial study should be confirmed in a larger study group.