Introduction: Metabolic dysregulation has been recognized as a prognostic marker in idiopathic pulmonary arterial hypertension (IPAH).

Objectives: We aimed to investigate the association between cardiometabolic risk factors and vascular reactivity of pulmonary arteries in patients with IPAH.

Patients and methods: Between June 2009 and January 2015, we recruited 66 consecutive patients with IPAH. We assessed main cardiometabolic risk factors, inflammatory markers, and markers of IPAH severity. Hemodynamic evaluation included pulmonary vasoreactivity testing with the use of inhaled nitric oxide. Reduced mean pulmonary artery pressure was considered a marker of acute vasoreactivity. Acute responders were treated with calcium channel blockers and classified as long‑term responders if they had sustained vasoreactivity (near‑normal hemodynamics and World Health Organization functional class I or II) for at least 1 year.

Results: Thirteen patients (19.7%) showed a positive response to acute pulmonary vasoreactivity testing; however, only 9 (13.6%) remained vasoreactive at follow‑up. Machine‑learning algorithms indicated 4 variables associated with acute vasoreactivity of pulmonary arteries: high‑density lipoprotein cholesterol (HDL‑C), right atrial pressure, cardiac index, and creatinine level, and 4 predictors of long‑term vasoreactivity: HDL‑C, 6‑minute walking distance, creatinine level, and high‑sensitive C‑reactive protein level.

Conclusions: HDL‑C level is associated with pulmonary vasoreactivity in acute testing and predicts long‑term responsiveness to calcium channel blockers in patients with IPAH.