B52-16 Mending a Broken Heart: Proactive Mechanical Support in Silent Stemi With VSD and Thrombus

Abstract Introduction Silent myocardial infarction (MI), particularly in patients with diabetes, frequently presents without chest pain, leading to delayed diagnosis and increased risk of mechanical complications. Although rare in the reperfusion era, post-infarct ventricular septal defect (VSD) and left ventricular (LV) thrombus remain associated with high mortality. We present a case of anterior ST-elevation MI (STEMI) complicated by cardiogenic shock, VSD, and LV thrombus, managed with prolonged and escalated Impella support as a bridge to definitive surgical repair. Case Description A 67-year-old man with diabetes and hypertension presented with progressive dyspnea but no chest pain. ECG demonstrated anterolateral ST-segment elevations with Q waves. Transthoracic echocardiography revealed a left ventricular ejection fraction of 25% with severe apical and anteroseptal akinesis. Emergent coronary angiography showed total occlusion of the proximal left anterior descending artery. Percutaneous coronary intervention (PCI) was complicated by no-reflow and iatrogenic left main dissection, resulting in profound cardiogenic shock. An Impella CP device was inserted via femoral access on hospital day 1. On day 2, a laminated apical LV thrombus was detected. By day 3, transthoracic echocardiography revealed a new anteroseptal VSD with left-to-right shunting. Despite surpassing the FDA-approved 96-hour support limit, Impella CP was maintained for 17 days due to persistent cardiogenic shock, with meticulous anticoagulation and serial imaging to monitor thrombus evolution and device-related complications. Management and Outcome On hospital day 18, Impella CP dysfunction required emergent escalation to an axillary Impella 5.5, surgically placed for higher-flow, longer-duration support. On hospital day 20, the patient underwent successful VSD patch repair using bovine pericardium, with rigid sternal fixation. Postoperative care included continued Impella 5.5 support, inotropes, continuous renal replacement therapy, ventilatory support, and management of atrial fibrillation, transient complete heart block requiring pacing, and sepsis. With intensive multidisciplinary coordination, the patient gradually stabilized. Discussion This case highlights the role of prolonged off-label Impella CP use and strategic escalation to Impella 5.5 as an effective bridge to surgical VSD repair. Early LV unloading helped stabilize shock physiology, while escalation provided sustained support during critical recovery. The presence of an LV thrombus complicated anticoagulation and device management. Successful outcome underscores the value of adaptable mechanical circulatory support strategies and multidisciplinary care in managing complex post-MI complications. This abstract is funded by: None