Impact of the new pulmonary hypertension definition on long-term mortality in patients with severe aortic stenosis undergoing valve replacement

Background The new 2018 pulmonary hypertension (PH) definition includes a lower mean pulmonary artery pressure (mPAP) cut-off (>20 mmHg rather than >= 25 mmHg) and the compulsory requirement of a pulmonary vascular resistance (PVR) >= 3 Wood units (WU) to define precapillary PH. We assessed the clinical impact of the 2018 compared to the 2015 PH definition in aortic stenosis (AS) patients undergoing aortic valve replacement (AVR). Methods Severe AS patients (n = 487) undergoing pre-AVR right heart catheterization were classified according to the 2015 and 2018 definitions. Post-AVR mortality (median follow-up 44 months) was assessed. Results Based on the 2015 definition, 66 (13%) patients exhibited combined pre and postcapillary PH (CpcPH), 116 (24%) isolated post-capillary PH (IpcPH), 28 (6%) precapillary PH, and 277 (57%) no PH at all. Overall, 52 (11%) patients were reclassified: 23 no PH into IpcPH; 8 no PH into precapillary PH; 20 precapillary PH into no PH; 1 CpcPH into IpcPH. By the 2015 definition, only CpcPH patients displayed increased mortality, whereas by the 2018 definition, precapillary PH patients also experienced higher mortality than those without PH. Among the PH definition components, PVR >= 3 WU was the strongest predictor of death (hazard ratio > 4). Conclusions In severe AS, a higher number of IpcPH patients are diagnosed by the 2018 definition, even though they have the same prognosis as those without PH. Patients with true precapillary PH are more accurately identified by the 2018 definition that includes a pulmonary vascular disease criterion, that is, PVR >= 3 WU, a strong mortality predictor.

Automated summary

The 2018 definition of pulmonary hypertension lowers the mPAP cutoff and requires a PVR >= 3 WU to define precapillary PH, impacting the clinical diagnosis and prognosis of severe AS patients undergoing AVR. The 2018 definition identifies more IpcPH patients, with a similar prognosis to those without PH, while accurately identifying true precapillary PH patients.