Diagnostic challenge of mitral regurgitation caused by concomitant coronary obstruction and dynamic left ventricular outflow tract obstruction after transcatheter aortic valve replacement: a case report

Background: Transcatheter aortic valve replacement (TAVR) is an established therapy for severe aortic stenosis (AS), but rare complications can rapidly become life-threatening, particularly in anatomically high-risk patients. Case summary: A 94-year-old woman with very severe AS underwent transfemoral TAVR using a self-expanding valve. After transcatheter heart valve implantation, she developed haemodynamic collapse with right coronary artery obstruction and severe mitral regurgitation (MR). At that time, the aetiology of the severe MR could not be clearly identified. Although intra-aortic balloon pump (IABP) was initiated, cardiac arrest occurred, requiring extracorporeal membrane oxygenation (ECMO). Percutaneous coronary intervention was unsuccessful, necessitating conversion to coronary artery bypass grafting. ECMO was discontinued on postoperative Day 1, but recurrent haemodynamic collapse developed under IABP support, revealing left ventricular outflow tract obstruction (LVOTO) and severe MR with systolic anterior motion (SAM). Discontinuing IABP and initiating medical therapy rapidly stabilized haemodynamics. Discussion: This case illustrates the diagnostic and haemodynamic complexity of simultaneous coronary artery obstruction and dynamic LVOTO with SAM-associated MR after TAVR. Because management strategies for these conditions are inherently contradictory, identifying the dominant mechanism of shock can be challenging. Although severe MR was initially attributed to ischaemia secondary to coronary obstruction, retrospective echocardiographic review demonstrated early SAM. Subsequent changes in loading conditions and myocardial contractility unmasked LVOTO. This case emphasizes the importance of repeated echocardiographic assessment and stepwise haemodynamic reassessment when multiple mechanisms of instability coexist after TAVR.