B64-29 Pulmonary Veno-occlusive Disease: Diagnostic Challenge and Clinical Evolution

Abstract Introduction Pulmonary veno-occlusive disease (PVOD) is one of the causes of Group 1 pulmonary hypertension that presents with rapidly progressive clinical deterioration and often poses a diagnostic challenge. Accurate and early recognition is essential, as inappropriate use of pulmonary vasodilators may lead to pulmonary edema, whereas timely initiation of therapy and referral for lung transplantation can improve survival. Case Presentation A 32-year-old male presented to the emergency department with chills, fever, dyspnea, productive cough, and hemoptoic sputum for five days. On admission, he was hypoxemic and required high-flow nasal oxygen (40 L/min, FiO2 50%). Chest computed tomography revealed bilateral mediastinal and hilar lymphadenopathy, diffuse nodular septal thickening, and ground-glass opacities with areas of bilateral consolidation. Transthoracic echocardiography showed a systolic pulmonary artery pressure (sPAP) of 44 mmHg and right ventricular (RV) dysfunction, confirmed by cardiac magnetic resonance imaging (MRI) with a right ventricular ejection fraction (RVEF) of 32%. Right heart catheterization confirmed pulmonary hypertension: right atrial pressure 6 mmHg, left ventricular end-diastolic pressure 10 mmHg, mean pulmonary artery pressure 50 mmHg (80/35 mmHg), cardiac output 5.9 L/min, cardiac index 2.8 L/min/m², and pulmonary vascular resistance 6.77 Wood units. A robotic-assisted surgical lung biopsy demonstrated hypertrophy of the tunica media of small arteries and arterioles with concentric fibrointimal thickening, along with venous wall thickening and focal luminal occlusion, consistent with PVOD. The patient was discharged after antibiotic therapy and negative fluid balance with diuretics. He required two subsequent readmissions for recurrent pleural effusion and worsening dyspnea while awaiting initiation of targeted therapy. Sildenafil 60 mg/day and ambrisentan 10 mg/day were introduced during the second hospitalization, leading to improvement in dyspnea and oxygenation. At one-month follow-up, NT-proBNP was 308 pg/mL, six-minute walk distance was 390 meters, and he was classified as NYHA functional class II, requiring 1 L/min supplemental oxygen. He remains on the lung transplant waiting list. Discussion This case underscores the diagnostic complexity of PVOD and the importance of integrating imaging, hemodynamic, and histopathologic findings. Cautious use of pulmonary vasodilators may provide clinical stabilization and serve as a bridge to transplantation. Pulmonary veno-occlusive disease is a rare, severe, and rapidly progressive cause of Group 1 pulmonary hypertension. Accurate diagnosis and individualized management are crucial to optimize outcomes and improve transplant readiness. This abstract is funded by: None