Prognostic value of follow-up vasoreactivity test in pulmonary arterial hypertension

Background: Acute vasoreactivity test with inhaled nitric oxide (NO) is performed during diagnostic right heart cath-eterization (RHC) to identify patients with pulmonary arterial hypertension (PAH) who respond to calcium channel blockers. Our purpose was to investigate the prognostic importance of follow-up vasoreactivity test after treatment. Methods: We retrospectively analyzed 36 PAH patients (mean age, 47 years; 61 % treatment-naive), who underwent diagnostic and follow-up RHC and vasoreactivity tests at our center. The primary outcome was all-cause mortality. Results: The median time between baseline and follow-up RHC was 9.7 months. Absolute change in mean pulmo-nary arterial pressure (AmPAP) during NO challenge was less pronounced after treatment, but there was great variability among patients. Overall cohort was dichotomized into two groups: preserved vasoreactivity (AmPAP & LE; -1 mmHg) and less vasoreactivity (AmPAP & GE;0 mmHg) at follow-up RHC. Less vasoreactivity group had higher usage rate of endothelin receptor antagonists and parenteral prostacyclin analogues. During a median observation period of 6.3 years after follow-up RHC, 7 patients died, of which 6 showed less vasoreactivity at follow-up. Absolute AmPAP & GE;0 at follow-up RHC was associated with all-cause mortality in univariable Cox re-gression analysis (hazard ratio, 8.728; 95 % confidence interval, 1.045-72.887; p = 0.045), whereas other hemo-dynamic parameters were not. Absolute AmPAP & GE;0 at follow-up RHC was associated with all-cause mortality in multivariable Cox analysis adjusted for age and known PAH prognostic factors (HR, 12.814; 95 % CI, 1.088- 150.891; p = 0.043). Kaplan-Meier survival analysis revealed a significantly worse survival of less vasoreactivity group compared to preserved vasoreactivity group (log-rank test, p = 0.016). Conclusions: Follow-up vasoreactivity test after treatment could contribute to the detection of high-risk sub-groups who might need careful monitoring and referral for lung transplantation. & COPY; 2023 Japanese College of Cardiology. Published by Elsevier Ltd. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).

Automated summary

The follow-up vasoreactivity test after treatment is important for detecting high-risk sub-groups and referring them for lung transplantation in patients with pulmonary arterial hypertension (PAH) who respond to calcium channel blockers.