(237) Spontaneous Leaflet Fracture: A Rare Complication of Mechanical Mitral Valve Replacement

Introduction: Mechanical mitral valve replacement (MVR) is widely used as the treatment for managing mitral valve regurgitation. With advancing technology, mechanical valve fractures have become exceedingly rare. I report herein the fifth case of acute mitral valve regurgitation due to an On-X mechanical leaflet escape.

Description: A 50-year-old female with a history of mitral valve prolapse s/p mechanical MVR six months prior presented to the emergency department with sudden dyspnea. Her initial vitals were significant for a heart rate of 146 and a respiratory rate of 26. Labs were only significant for elevated lactic acid. CT chest reported right-sided pneumonia. TTE showed a high gradient across the mitral valve with possible surrounding leak, however, given significant tachycardia the valve was not clearly evaluated. She was admitted to the medical ICU.
As the night progressed, she was intubated and hemodynamically decompensated. A pulmonary artery catheter yielded the following results: CVP 15, PCWP 30, CI 2.37, SVR 1126, MvO2 70%. TEE found acute severe mitral valve regurgitation and the inability to visualize one of the leaflets. OR examination showed a single intact leaflet. After valve replacement, she was placed on VA-ECMO and sent to CT, which revealed the loose leaflet in the abdominal aorta. Endoscopic retrieval was unsuccessful. The patient continued to develop worsening multiorgan failure and the family decided to withdraw support.

Discussion: Complications from valve replacements can vary in severity and be difficult to evaluate. As seen in this case, laboratory workup and imaging can be misleading, causing diversion from accurate diagnosis. The use of a pulmonary artery catheter has fallen out of favor for the management of a patient in shock; however, in this case it was the determining factor that tipped the scales towards the correct pathology. When faced with a spontaneous leaflet fracture from a mechanical valve, emergency surgery becomes the only treatment option, emphasizing the time-sensitive nature of the diagnosis. The rarity does not lend itself well to accurately predict proper management nor mortality. To date there have been four reported adult On-X mitral mechanical valve fracture cases in which one patient passed away and three survived.