Impact of the 2022 pulmonary hypertension definition on haemodynamic classification and mortality in patients with aortic stenosis undergoing valve replacement

Aims: With the 2022 pulmonary hypertension (PH) definition, the mean pulmonary artery pressure (mPAP) threshold for any PH was lowered from ≥25 to >20 mmHg, and the pulmonary vascular resistance (PVR) value to differentiate between isolated post-capillary PH (IpcPH) and combined pre- and post-capillary PH (CpcPH) was reduced from >3 Wood units (WU) to >2 WU. We assessed the impact of this change in the PH definition in aortic stenosis (AS) patients undergoing aortic valve replacement (AVR).

Methods and results: Severe AS patients (n = 503) undergoing pre-AVR cardiac heart catheterization were classified according to both the 2015 and 2022 definitions. The post-AVR mortality [median follow-up 1348 (interquartile range 948-1885) days] was assessed. According to the 2015 definition, 219 (44% of the entire population) patients had PH: 63 (29%) CpcPH, 125 (57%) IpcPH, and 31 (14%) pre-capillary PH. According to the 2022 definition, 321 (+47%) patients were diagnosed with PH, and 156 patients (31%) were re-classified: 26 patients from no PH to IpcPH, 38 from no PH to pre-capillary PH, 38 from no PH to unclassified PH, 4 from pre-capillary PH to unclassified PH, and 50 from IpcPH to CpcPH (CpcPH: +79%). With both definitions, only the CpcPH patients displayed increased mortality (hazard ratios ≈ 4). Among the PH-defining haemodynamic components, PVR was the strongest predictor of death.

Conclusion: In severe AS, the application of the 2022 PH definition results in a substantially higher number of patients with any PH as well as CpcPH. With either definition, CpcPH patients have a significantly increased post-AVR mortality.