Iatrogenic mitral chordal rupture induced by microaxial flow pump in acute myocardial infarction complicated by cardiogenic shock-a case report.

Background: Mechanical circulatory support devices, such as microaxial flow pumps (mAFP), are used in the management of cardiogenic shock, particularly in the setting of ST-segment elevation myocardial infarction. While these devices are potentially life-saving, their use is not without risk and might be associated with rare but serious complications, including structural cardiac injury. Case summary: We report the case of a 41-year-old male with known polysubstance abuse who experienced an out-of-hospital cardiac arrest due to ST-segment elevation myocardial infarction. Following successful return of spontaneous circulation and emergent percutaneous coronary intervention, a mAFP was implanted for haemodynamic stabilization. Echocardiographic monitoring initially confirmed correct positioning without evidence of valvular dysfunction. However, on Day 4, imaging revealed entrapment of the mAFP within the mitral valve's subvalvular apparatus. Following careful device explantation, the patient showed new-onset severe mitral regurgitation (MR) due to posterior leaflet chordal rupture. Transoesophageal echocardiography confirmed a flail P3 segment. The presence of severe MR hindered adequate recompensation and complicated the weaning process from ventilatory support. The immediately consulted multidisciplinary Heart Team recommended early surgical intervention. The patient subsequently underwent successful mitral valve repair, resulting in clinical stabilization and eventual discharge to a rehabilitation facility in improved condition. Discussion: This case highlights a potential rare iatrogenic complication of mAFP support and emphasizes the necessity of meticulous echocardiographic surveillance, timely recognition of complications, and guideline-based multidisciplinary decision-making in the management of critically ill patients.