Abstract 4358585: Hemodynamic Subtypes of Pulmonary Hypertension Based on Right Heart Catheterization Data Predict Outcomes in ICI-Associated Myocarditis

Background: Pulmonary hypertension (PH) is a known complication in patients with cancer, arising from both therapies and malignancies. Immune checkpoint inhibitor (ICI)-associated myocarditis has been linked to PH in case reports, but its impact on patient outcomes remains unclear. Diverse hemodynamic profiles of pre-capillary, isolated post-capillary, and combined pre- and post-capillary PH may influence prognosis in this population. Research Question: To investigate the prevalence of PH and its hemodynamic subtypes in patients with ICI-associated myocarditis and evaluate their impact on clinical outcomes, including survival and major adverse cardiac events (MACE). Methods: This retrospective cohort study included 67 patients diagnosed with ICI-associated myocarditis at MD Anderson Cancer Center from August 2013 to December 2023 who underwent right heart catheterization. Patients were classified per 2022 ESC/ERS guidelines: pre-capillary (PCWP ≤15 mmHg, PVR >2 WU), isolated post-capillary (PCWP >15 mmHg, PVR <2 WU), and combined (PCWP >15 mmHg, PVR ≥2 WU). Clinical features, hemodynamics, and outcomes (mortality, MACE) were compared using chi-square and Mann-Whitney U tests. Univariable time to event analysis for clinical outcomes was done with Kaplan-Meier survival analysis. Results: PH was present in 55.2% (37/67) of patients, with pre-capillary PH (27.0%), isolated post-capillary PH (48.6%), and combined PH (24.3%). Combined and isolated post-capillary PH had higher right atrial pressures than pre-capillary PH (12.89 ± 3.76 mmHg, 11.94 ± 3.33 mmHg, 8.60 ± 1.84 mmHg, p = 0.0087). Combined PH had the highest mean pulmonary artery pressure (32.07 ± 6.41 mmHg, p = 0.0232). While 90-day mortality (40.5% vs 46.7%, p = 0.615) and MACE (54.1% vs 40%, p = 0.252) for PH and non-PH groups were similar, 90-day survival was significantly lower in pre-capillary PH versus other PH subgroups (40.0% vs 77.8%, p = 0.0389). Conclusions: This study demonstrates a significant burden of PH in ICI-associated myocarditis patients, with a substantial proportion of pre-capillary PH, which was associated with the worst survival outcomes. Our findings emphasize the prognostic significance of hemodynamic classification in this population. Future studies are needed to elucidate pathophysiologic mechanisms and identify targeted therapies for ICI-associated PH.