Background and Importance The ESC/ERS Guidelines for treating pulmonary hypertension (PH) recommend vasoreactivity testing (VT) during right heart catheterisation for patients with idiopathic/hereditable/drug-associated PH (IPH/HPH/DAPH) and subsequent treatment with calcium channel blockers in those with a positive result.

Aim and Objectives To evaluate the consistency in conducting VT in patients with IPH/HPH/DAPH and to ascertain whether positive test outcomes lead to the initiation of calcium channel blocker therapy.

Material and Methods We carried a multicentre cross-sectional observational study in three hospitals including adults treated between 2006 and 2023. We reviewed clinical charts for all patients with a PH type-I diagnosis to identify IPH/HPH/DAPH patients. For these patients we reviewed catheterisation data to find VT; If a positive result was found, prescription ambulatory data was reviewed in search for prescriptions of calcium channel blockers.

We estimated the number of patients who could potentially benefit from calcium channel blockers, based on the assumption that 10% of patients will exhibit a positive VT test.

Results The study encompassed 176 Type-I PH patients across three tertiary hospitals, including 125 women (71.0%) with a median age of 58 (IQR: 24). Underlying aetiologies were congenital heart disease 38.6% (68), Connective Tissue Disease 27.8% (49), Portopulmonary Hypertension 6.8% (12), HIV 3.4% (6), IPH 15.3% (27), and 1.1% DAPH (2).

VT was reviewed for a subset of 29 patients (27 IPH and two DAPH). Of these, 12 underwent VT with five returning positive results and consequently receiving prescriptions for calcium channel blockers. For the remaining 17 patients, four had missing catheterisation data, and 13 underwent catheterisation but were not tested for vasoreactivity. If the aforementioned rate remains consistent, an estimated 1–2 patients could benefit from calcium channel blockers.

Conclusion and Relevance VT was not consistently carried out in IPH/HPH/ADPH patients; a subset of patients could benefit from high dose calcium channel blockers. For those patients with a positive result, calcium channel blockers were adequately prescribed.

Hospital pharmacists could play a role in reviewing new prescriptions of PH-specific therapy in order to identify patients not tested for vasoreactivity.

Conflict of Interest No conflict of interest.