Effect of Eccentric Cycling on Oxygen Uptake and Hemodynamics in Patients With Pulmonary Vascular Disease

Eccentric cycling exercise (ECC) allows training at low metabolic costs and may therefore be valuable for patients with precapillary pulmonary hypertension (PH) due to pulmonary vascular disease (PVD). What are the ventilatory and circulatory responses of ECC vs concentric cycling exercise (CON) in patients with PVD? This was a randomized controlled crossover trial in which patients diagnosed with PVD, defined as either pulmonary arterial or chronic thromboembolic PH, performed CON and ECC cycling tests at identical submaximal work rates, following stepwise incremental protocols. Oxygen uptake and additional cardiorespiratory responses were measured breath-by-breath by ergospirometry. Hemodynamic parameters (eg, systolic pulmonary arterial pressure [sPAP], tricuspid annular plain systolic excursion) were measured by echocardiography. Thirty-three patients (19 with pulmonary arterial hypertension and 14 with chronic thromboembolic PH; 13 female; mean age, 50 ± 15 years) were included. At identical work rates during ECC compared with CON, oxygen uptake was significantly lower by −200 mL/min (−40%; 95% CI, −272 to −129; P < .01), minute ventilation was significantly lower by −5.5 L/min (−30%; 95% CI, −9.2 to −3.1; P < .01), and sPAP was significantly lower by −12 mm Hg (−20%; 95% CI, −20 to −4; P < .01). Right ventricular-arterial coupling, as measured by tricuspid annular plain systolic excursion/sPAP, was 0.11 mm/mm Hg higher (31%; 95% CI, 0.04-0.18; P < .01). No adverse events occurred. This study supports the hypothesis that ECC is a feasible and well-tolerated exercise modality for patients with PVD, with lower oxygen demand and a reduced load on the right ventricle. Future studies should investigate whether ECC improves exercise capacity, muscle force, and possibly hemodynamics during prolonged rehabilitation programs in patients with PVD. ClinicalTrials.gov; No.: NCT05186987; URL: www.clinicaltrials.gov