Effect of Supervised Training Therapy on Pulmonary Arterial Compliance and Stroke Volume in Severe Pulmonary Arterial Hypertension and Inoperable or Persistent Chronic Thromboembolic Pulmonary Hypertension

Abstract

<b><i>Background:</i></b> Pulmonary arterial compliance (PAC) is a prognostic parameter in pulmonary arterial hypertension (PAH) reflecting the elasticity of the pulmonary vessels. <b><i>Objectives:</i></b> The objective of this post hoc analysis of a prospective randomized controlled trial (RCT) was to assess the effect of exercise training on PAC and stroke volume (SV) in patients with PAH and persistent/inoperable chronic thromboembolic pulmonary hypertension (CTEPH). <b><i>Method:</i></b> From the previous RCT, 43 out of 87 patients with severe PAH (<i>n</i> = 29) and CTEPH (<i>n</i> = 14) had complete haemodynamic examinations at baseline and after 15 weeks by right heart catheterization and were analysed (53% female, 79% World Health Organization functional class III/IV, 58% combination therapy, 42% on supplemental oxygen therapy, training group <i>n</i> = 24, and control group <i>n</i> = 19). Medication remained unchanged for all patients. <b><i>Results:</i></b> Low-dose exercise training at 4–7 days/week significantly improved PAC (training group 0.33 ± 0.65 mL/mm Hg vs. control group −0.06 ± 1.10 mL/mm Hg; mean difference 0.39 mL/mm Hg, 95% confidence interval [CI] 0.15–0.94 mL/mm Hg; <i>p</i> = 0.004) and SV (training group 9.9 ± 13.4 mL/min vs. control group −4.2 ± 11.0 mL/min; mean difference 14.2 mL, 95% CI 6.5–21.8 mL; <i>p</i> &#x3c; 0.001) in the training versus control group. Furthermore, exercise training significantly improved cardiac output and pulmonary vascular resistance at rest, peak oxygen consumption, and oxygen pulse. <b><i>Conclusions:</i></b> Our findings suggest that supervised exercise training may improve right ventricular function and PAC at the same time. Further prospective studies are needed to evaluate these findings.