Reassessing Pulmonary Hypertension Classification: Utilizing Criteria for Heart Failure with Preserved Ejection Fraction Instead of Pulmonary Arterial Wedge Pressure

Background: The current classification of pulmonary hypertension (PH) distinguishes between pre-capillary (PAWP ≤ 15 mmHg) and post-capillary (PAWP > 15 mmHg) forms, with left heart disease, especially heart failure with preserved ejection fraction (HFpEF), being a common cause of PH. We investigated the suitability of an HFpEF diagnosis instead of PAWP in diagnosing PH associated with HFpEF. Methods: In a retrospective, single-center analysis, we reviewed diagnoses from our database, focusing on patients initially diagnosed with idiopathic pulmonary arterial hypertension (IPAH) or PH associated with HFpEF (PH-HFpEF) based on their PAWP. These patients were reclassified, distinguishing between HFpEF and non-HFpEF cases. Patients with PH-HFpEF were further stratified by PAWP (≤15 mmHg or >15 mmHg). Results: The study included 350 patients: 214 (61.1%) with PAWP ≤ 15 mmHg and 136 (38.9%) with PAWP > 15 mmHg. Replacing the PAWP criterion with the HFpEF criterion resulted in the reclassification of 121 of 350 (34.6%) patients (115 of 214 [53.7%] from IPAH to PH-HFpEF and 6 of 136 [4.4%] from PH-HFpEF to IPAH). The final disposition was IPAH (n = 105, 30%), PH-HFpEF with PAWP ≤ 15 mmHg (n = 115, 32.9%), and PH-HFpEF with PAWP > 15 mmHg (n = 130, 37.1%). Characteristics such as age distribution, functional impairment, co-morbidities, echocardiographic indices of HFpEF, pulmonary vascular resistance, response to PH medications, and unadjusted survival were comparable between the two HFpEF cohorts but differed substantially from those with IPAH. Conclusions: PH-HFpEF patients with PAWP ≤ 15 mmHg resemble those with PAWP > 15 mmHg but differ from IPAH cases. Incorporating non-invasive HFpEF criteria could refine PH diagnostic classification.