Efficacy of short-term, low-dose pulmonary vasodilators for chronic thromboembolic pulmonary hypertension: a retrospective pilot study.

BACKGROUND

Chronic thromboembolic pulmonary hypertension (CTEPH) is treated with pulmonary endarterectomy, pulmonary vasodilators (PVs), and balloon pulmonary angioplasty (BPA). PV therapy may be initiated before BPA; however, dose adjustment can delay BPA. Therefore, short-term, low-dose administration is sometimes used to enable earlier BPA; however, its efficacy and safety remain unclear.

METHODS

Twenty patients with World Health Organization functional class III/IV CTEPH, who received low-dose PVs (riociguat or selexipag) and underwent right heart catheterization and first BPA within 60 days, were retrospectively analyzed. Hemodynamic parameters and brain natriuretic peptide (BNP) levels were compared before and after PV therapy. First-session BPA complications were evaluated.

RESULTS

After a median of 18 days of therapy, mean pulmonary arterial pressure (mPAP) decreased from 42 to 40 mmHg (mean difference, -2.1 mmHg; 95% confidence limits [CL], -4.2 to -0.02; p = 0.0482), pulmonary vascular resistance (PVR) decreased from 829 to 632 dyne s·cm-5 (mean difference, -197 dyne s·cm-5; 95% CL, -227 to -117; p < 0.0001), and BNP decreased from 284 to 146 pg/mL (mean difference, -139 pg/ml; 95% CL, -203 to -75; p = 0.0002). Cardiac output and cardiac index increased significantly. Higher baseline mPAP and PVR values were associated with greater reductions in the corresponding parameters. BPA-related complications occurred in four patients (20%), all of which involved hemoptysis from peripheral lesions.

CONCLUSION

Short-term, low-dose PV therapy before BPA was associated with improvements in hemodynamic parameters and BNP levels. Baseline mPAP, PVR, and cardiac index may predict treatment response. Prospective studies are needed to refine pre-BPA strategies.