P152 - EVALUATION OF HEMODYNAMIC CRITERIA FOR VASODILATOR CHALLENGE IN PULMONARY HYPERTENSION WITH ADVANCED HEART FAILURE: A PROSPECTIVE STUDY OF CLINICAL AND RIGHT HEART FAILURE OUTCOMES

Background: Pulmonary hypertension (PH) is a complication of heart failure (HF). Evaluation for advanced HF therapies (AHFT) requires right heart catheterization (RHC) to assess PH and its reversibility through vasodilator challenge (VC). PH that does not reverse after AHFT is associated with increased mortality, likely related to right ventricular afterload mismatch and right heart failure (RHF). We previously reported that current VC criteria apply to a small subset of PH patients, leaving many with milder yet high-risk PH untested. Furthermore, RHF remains difficult to define and is not consistently reported in large databases. This raises the question of whether lowering VC thresholds could improve prediction of adverse outcomes following AHFT. We conducted a prospective, single-center cohort study (NCT05672719) to lower the VC threshold, and examine associations between pre-transplant hemodynamics, VC responses, and post-transplant RHF.

METHODS AND RESULTS: Consecutive patients referred for AHFT evaluation were enrolled at the time of RHC, performed using standardized protocols at the Cardiac Catheterization Clinical Research Laboratory, Mount Sinai Hospital. PH classification and revised VC criteria were applied uniformly. We report one-year outcomes for patients who underwent AHFT, including survival, RHF, and major postoperative complications. RHF was defined according to the 2020 Mechanical Circulatory Support–Academic Research Consortium criteria. Interim analysis of 65 patients identified 26 who underwent 27 distinct AHFT, including 22 (81.5%) heart transplants and 5 (18.5%) HeartMate 3 LVAD implants. Three patients (11.1%) died – two following LVAD implantation and one after transplant. The average post-AHFT hospital stay was 48.1 ± 59.4 days. Renal replacement therapy was required in six patients (22.2%), and four (14.8%) required mechanical circulatory support. RHF developed in 19 cases (71%) – 16 (59.3%) mild, two (7.4%) moderate, and one (3.7%) severe. Compared to patients who developed RHF, those without RHF had significantly lower pulmonary artery diastolic pressures (10 ± 8 mmHg vs. 16 ± 4 mmHg, p = 0.01), pulmonary artery wedge pressures (11 ± 9 mmHg vs. 17 ± 6 mmHg, p = 0.06), and mean pulmonary artery pressures (19 ± 12 mmHg vs. 26 ± 7 mmHg, p = 0.07) measured during index RHC, though differences in wedge and mean pressures did not reach significance. VC was performed in 11 RHF and 3 non-RHF cases per revised criteria.

Conclusion: In this prospective study, we observed a high incidence of RHF complicating AHFT, associated with baseline PH. Further analysis will examine the relationship between hemodynamic responses to VC and RHF risk after AHFT.