Impact of the revised hemodynamic definition on the diagnosis of precapillary pulmonary hypertension: a retrospective single-center study in China.

Background: In the 6 World Symposium on Pulmonary Hypertension (PH), the hemodynamic definition of PH was reduced from a mean pulmonary artery pressure (mPAP) ≥25 to >20 mmHg. This study aimed to evaluate the impact of the revised hemodynamic definition on the diagnosis of precapillary PH.

Methods: We retrospectively enrolled patients who underwent right heart catheterization from January 2012 to December 2018. All included patients were reassessed according to the revised hemodynamic definition.

Results: A total of 1,251 patients were included for analysis, of whom 1,044 patients had precapillary PH and 182 patients had mPAP <25 mmHg. After applying the revised definition, 33 (18.1%) of 182 patients with mPAP <25 mmHg were reclassified as having PH. However, only 7 of these 33 patients had a pulmonary vascular resistance ≥3 wood units and could be considered to have precapillary PH, accounting for 0.7% of the existing precapillary PH population. More importantly, 12 patients with mPAP ≥25 mmHg were delisted from precapillary PH for pulmonary vascular resistance <3 wood units (5 patients from Group III, 4 patients from Group IV, 3 patients from Group V). Overall, there was a net 0.5% decrease [(12-7)/1044×100%] in the population with precapillary PH.

Conclusions: The revised hemodynamic definition had a minor impact on the diagnosis of precapillary PH. It should be noted that the revised definition would influence not only patients with mPAP =21-24 mmHg, but also patients with mPAP ≥25 mmHg.