Title : Rare case of mitral valve aneurysm with perforation resulting in severe mitral regurgitation - A case report
Abstract:
Introduction: Mitral Valve Aneurysm (MVA) is a rare complication involving a discrete protrusion of the mitral leaflet towards left atrium with systolic expansion and diastolic collapse. Persistent MVA may result in perforation and rupture of aneurysm causing mitral regurgitation. Its formation is associated with congenital conditions like left ventricular outflow tract obstruction, connective tissue disorders like Marfan’s syndrome, structural causes like mitral valve prolapse as well as acquired factors like rheumatic fever, Libman- Sachs endocarditis and Infective Endocarditis (IE). Despite advances in clinical practice, timely diagnosis and adequate management of IE remains challenging therefore this case highlights the importance of Transoesophageal Echocardiography (TEE) in better visualization of a complex condition such as valve perforation and management options for cases where surgical treatment is deemed unsuitable.
Case Presentation: A 72-year-old male with multiple comorbidities presented with fluid overload and renal dysfunction. He had a recent admission for sepsis, wet gangrene and atrial fibrillation, which were treated medically. Blood cultures at the time grew Staphylococcus aureus. Upon investigating, a transthoracic echocardiogram showed multiple echogenic structures attached to the posterior mitral valve leaflet, raising suspicion of vegetations, P2 scallop aneurysm- Figure 1. Subsequently A Transoesophageal Echocardiogram (TEE) was performed which confirmed the presence of a calcified Posterior Mitral Valve Leaflet (PMVL) with an aneurysm along with perforation, resulting in severe MR, likely due to Infective Endocarditis (IE)- Figure 2. Following multidisciplinary team discussion, the patient was treated with antibiotics (intravenous followed by oral) for 6-8 weeks course due to high surgical risk and multiple comorbidities with future consideration of surgery if functional status improves.
Discussion: Mitral Valve Aneurysm (MVA) is a saccular outpouching of the mitral leaflet, with anterior leaflet being more commonly involved than the posterior leaflet and reported incidence of 0.2 to 0.29%. Various cardiac conditions and non-cardiac causes have been associated with formation of aneurysms. Large aneurysm is more likely to rupture than small ones. Infective Endocarditis (IE) is a fatal disease with a mortality rate of 20-25%. It is an infection of endocardium most commonly affecting aortic and mitral valves, whereas involvement of tricuspid and pulmonary valves is seen in less than 10% of the cases. Due to the non-specific clinical manifestation and unexpected course, delayed diagnosis may have adverse outcome. Echocardiography is the primary investigation for establishing the diagnosis of IE. Real Time Three Dimensional TEE has shown to provide spatial configuration of cardiac structures and their anomalies and is considered superior to TTE in diagnosing complex cardiac lesions.
Conclusion: MVA is an uncommon condition, resembling mitral valve prolapse or regurgitation clinically, and may occur as an isolated pathology. Our study highlights the diagnostic capability of TEE which is considered superior to TTE in delineating the diagnosis of mitral valve perforation as the former allows clear visualization of complex mitral valve lesions. Prompt recognition and timely management is crucial in the prevention of mortality in patients with IE leading to perforation. Management of IE must be individualized and the decision to opt medical or surgical course depends on risk-to-benefit balance. Although international guidelines have standardized management options for patients with IE, duration of medications and timing of surgery, there is need for involvement of multi-disciplinary team in cases where IE is accompanied by complex conditions. This case underscores the need for case by case assessment and management.
