B50-35 Diffuse Alveolar Hemorrhage Secondary to Acute Severe Mitral Regurgitation: A Diagnostic Challenge

Abstract Background Diffuse alveolar hemorrhage (DAH) is a potentially fatal pulmonary syndrome characterized by bleeding into the alveolar spaces, typically caused by autoimmune vasculitis, infection, or coagulopathy. Cardiac causes are rarely implicated. We report a case of acute severe mitral regurgitation (MR) presenting as recurrent hemoptysis and DAH. Case Presentation A 77 year-old male with Atrial fibrillation on Apixaban, status post pacer, COPD, Chronic kidney disease and Diabetes Mellitus who presented to the ED with hypotension and tachypnea. Initial investigation revealed pulse oximetry 74% on room air, hemoglobin of 7.0 g/dL and urine analysis negative for blood. CT chest demonstrated new bilateral ground-glass opacities. He was placed on 5L supplemental oxygen, received 2 units of packed red blood cells, IV fluids, broad-spectrum antibiotics, and Apixaban was held. By day 2, he developed hemoptysis and worsening hypoxia requiring 15L nonrebreather mask. TTE performed with mild-moderate tricuspid regurgitation, moderately elevated pulmonary systolic pressure (58.7 mmHg) and non-mobile echodensity on anterior mitral leaflet, concerning for vegetation. By day 4, he declined clinically, was transferred to MICU and intubated. Bronchoscopy was performed with copious old blood in left lower lobe, therapeutically suctioned with no visible bleed and bronchoalveolar fluid with increased blood in sequential aliquots. He was empirically treated with pulse dose steroids for three days, but serologies were ultimately negative for vasculitis. Hemoptysis persisted, hemoglobin dropped and repeat bronchoscopy on day 7 revealed no airway lesions, but stigmata of mucosal bleeding in right lung and blood oozing from left lower lobe, managed with lidocaine/epinephrine instillation. Transesophageal echocardiogram (TEE) occurred day 12, revealing flail posterior mitral leaflet with chordal rupture and severe eccentric MR. Cardiothoracic surgery performed percutaneous mitral valve repair with MitraClipx2. He had a complicated post-operative course, but no further hemoptysis, and was discharged to nursing home care. Discussion Diffuse alveolar hemorrhage caused by mitral regurgitation can result from a severe, acute regurgitant jet from the mitral valve that directs blood into the lung. When a damaged mitral valve leaks, the force of the regurgitant jet can rupture the delicate capillaries in lung tissue, leading to bleeding into the alveoli. In rare cases, a jet directed at the right upper pulmonary vein can cause a unilateral form of DAH, affecting the right lung. This case highlights the complexities surrounding DAH, and recognition of atypical etiologies, as therapeutic management varies substantially based on underlying cause. This abstract is funded by: None