Bailout transcatheter edge-to-edge mitral valve repair for acute mitral regurgitation attributable to systolic anterior motion during transcatheter aortic valve implantation: a case report

Systolic anterior motion (SAM) of the mitral valve is a rare but life-threatening complication of transcatheter aortic valve implantation (TAVI) that can cause acute severe mitral regurgitation (MR) and/or left ventricular outflow tract (LVOT) obstruction, leading to rapid haemodynamic deterioration. Evidence supporting the use of transcatheter edge-to-edge mitral valve repair (M-TEER) for SAM-related MR during TAVI, particularly in the absence of significant LVOT obstruction, is limited.

A 78-year-old woman with severe symptomatic aortic stenosis and multiple comorbidities underwent transfemoral TAVI. Immediately after predilatation, she experienced haemodynamic collapse and required percutaneous cardiopulmonary support. Transoesophageal echocardiography revealed SAM of the anterior mitral leaflet with severe MR without apparent LVOT obstruction. Although a transcatheter aortic valve was subsequently implanted, severe MR with haemodynamic instability persisted. As medical management did not stabilize haemodynamics, bailout M-TEER was performed 3 days after TAVI. Thereafter, MR improved from severe to mild and haemodynamic stabilization rapidly occurred. The patient was discharged with New York Heart Association class I and remained asymptomatic. Sustained MR improvement was observed during 6-month follow-up.

In this case, SAM-related MR without apparent LVOT obstruction developed immediately after predilatation in a patient with a sigmoid septum, and off-label M-TEER achieved haemodynamic stabilization. Although evidence supporting M-TEER for SAM-related MR during TAVI is limited to case reports and small case series, this case suggests that M-TEER may be considered a bailout option for selected patients when MR is the primary cause of haemodynamic collapse, even without apparent LVOT obstruction.