BackgroundAmong mechanical complications of acute myocardial infarction, ventricular septal defect (VSD) is uncommon but still serious. The evolution of emergency coronary revascularisation paradoxically decreased our knowledge of this disease, making it even rarer.AimTo describe ischaemic VSD incidence, management, and associated in-hospital and 1-year outcomes over a 12-years period.MethodsA retrospective single-centre register of patients managed for ischaemic VSD between January 2009 and December 2020.ResultsNinety-seven patients were included representing 8 patients/ years and an incidence of 0.44% of ACS managed. The majority of the patients were 73-years-old males (n = 54, 56%) with STEMI presentation (n = 75, 79%) and already presented with Q necrosis on ECG (n = 70, 74%). Forty-nine (51%) patients underwent PCI, 60 (62%) inotrope/vasopressors infusion, and 70 (72%) acute mechanical circulatory support (IABP 62%, ECMO 13%, and Impella® 3%). VSD surgical repair was performed for 44 patients (45%) and 1 patient was transplanted. In-hospital mortality was 71%, and 86% at 1 year, without significant improvement over the decade. Surgery appears to be a protective factor [0.51 (0.28–0.94) p = 0.003], whereas age [1.06 (1.03–1.09), p < 0.001] and lactate [1.16 (1.09–1.23), p < 0.001] were linked to higher 1-year mortality. None of the patients that were managed medically survived 1 year.ConclusionPost-ischaemic VSD is a rare but serious complication still associated with high mortality. Corrective surgery is associated with better survival, however, timing, patient selection, and a place for mechanical circulatory support need to be defined.