Gore, S S

Abstract Rationale Pulmonary hypertension (PH) develops in up to 50% of patients with advanced interstitial lung disease (ILD) and is associated with increased morbidity, mortality, and impaired quality of life. Early recognition is essential, as available therapy for ILD-PH has been shown to improve outcomes. Identifying physiologic markers of PH may facilitate earlier referral for right heart catheterization (RHC) and initiation of targeted treatment. Thus, this study aimed to (1) compare functional parameters between ILD patients with and without RHC-confirmed PH, and (2) assess the applicability of previously proposed ILD-PH screening criteria. Methods We retrospectively analyzed ILD transplant candidates with available pre-transplant pulmonary function tests (FVC%, DLCO%), echocardiographic right-ventricular systolic pressure (RVSP), six-minute walk distance (6MWD) with oxygen requirement, and RHC data. PH was defined according to the 2022 ESC/ERS criteria. Functional parameters were compared between patients with and without PH. Among those without a prior PH diagnosis, screening thresholds derived from previously published tools were applied (RVSP ≥ 35 mmHg, DLCO < 40%, FVC/DLCO > 1.6, 6MWD < 350 m, or oxygen use during 6MWD). Results Of 107 ILD patients evaluated, 90 had complete RHC data (48 ILD-PH, 42 ILD without PH). Group comparisons are summarized in Table 1. Patients with PH had lower DLCO% (median 18.5 [11.5-26.7] vs 26.5 [20.0-34.7], p = 0.08), higher FVC/DLCO ratios (2.68 [2.1-3.4] vs 1.7 [1.4-2.6], p = 0.08), and higher RVSP (55 [39.7-63.2] vs 39.5 [29-48] mmHg, p = 0.002). Oxygen requirement during 6MWD was more frequent in ILD-PH (79.2% vs 61.9%, p = 0.08). Among patients with PH, 38 (79.16%) had no formal diagnosis prior to pre-transplant RHC. Of these cases, all (100%) met ≥3 screening criteria, most commonly DLCO < 40% (n = 38, 100%), FVC/DLCO > 1.6 (n = 37, 97.3%), and 6MWD < 350 m (n = 33, 86.8%). Additionally, 32 patients (84.21%) met ≥4 criteria and 8 (21.05%) met all five criteria. Conclusion In ILD transplant candidates, patients with PH had worse functional profiles when compared to those without PH, and nearly 80% of PH cases were previously undiagnosed. Systematic application of validated PH screening tools in ILD populations may facilitate earlier recognition, potentially improving patient outcomes. This abstract is funded by: None

Abstract Rationale Endobronchial valve (EBV) placement is an established bronchoscopic lung volume reduction (BLVR) therapy for advanced emphysema. Although randomized trials have shown improvements in lung function, real-world data on predictors of response and complications remain limited. This study evaluated physiological and clinical outcomes after EBV placement and explored predictors of treatment response and adverse events. Methods We retrospectively analyzed 75 patients who underwent EBV placement for severe emphysema at Mayo Clinic Florida between 2018 and 2023. Demographics, comorbidities, pulmonary function test and complications data were collected before and after procedure. Responders were defined as those achieving a ≥ 15% relative increase in forced expiratory volume in one second (FEV1), ≥10% reduction in residual volume (RV), ≥25-meter increase in six-minute walk distance (6MWD), or ≥ 1-point decrease in modified Medical Research Council (mMRC) dyspnea score. Results The mean age was 70.4 ± 7.1 years, 59% were female, and the mean Body Mass Index was 25.6 ± 4.9 kg/m². Most patients were non-Hispanic White (96%) and ever-smokers (97%, median 40 pack-years). Following EBV placement, FEV1 increased by + 0.10 L (p < 0.001), forced vital capacity by + 0.17 L (p = 0.001), RV decreased by -0.69 L (p < 0.001), while total lung capacity decreased by -0.35 L (p < 0.001). Diffusing capacity, 6MWD, and mMRC did not significantly change. Responder analysis showed FEV1 improvement in 52% (34/65), RV reduction in 65% (42/65), 6MWD gain in 33% (18/55), and mMRC improvement in 33% (21/63). Complete lobar atelectasis occurred in 59% (44/75) and was significantly associated with FEV1 improvement (p < 0.01). 30-day follow up complications included pneumothorax (26.7%), COPD exacerbation (21%), and pneumonia (20%). 15% pneumothoraces were managed conservatively, 55% required chest tube, 30% needed valve removal due to persistent air leak. Valve migration and replacement occurred in 2.6% each, and valve removal in 26.6% patients. Median hospital stay was longer in patients with complications (5 vs 4 days, p = 0.003). In-hospital mortality was 5.3% but no procedure-related deaths were identified. Conclusions EBV placement is a safe and effective BLVR approach yielding significant improvements in FEV1 and reductions in hyperinflation. Pneumothorax and valve-related events were the most frequent complications. Complete lobar atelectasis strongly correlated with functional improvement, suggesting that early reassessment should be considered when collapse is not achieved to prevent complications and unnecessary valve retention. This abstract is funded by: None