Impella^®-Assisted Revascularization of Unprotected Left Main Coronary Artery-Acute Myocardial Infarction Leading to Cardiogenic Shock

Three Case Reports

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Unprotected left main trunk coronary artery-acute myocardial infarction (ULMCA-AMI) is difficult to treat, even with the widespread use of reperfusion therapy, because of the extensive myocardial damage it causes. Impella^®, a percutaneously inserted left ventricular (LV) assist pump, may help prevent cardiogenic shock (CS) due to ULMCA-AMI by facilitating cardiac rest and enhancing LV unloading. We herein report three patients with ULMCA-AMI and CS who underwent Impella^®-assisted revascularization. One patient experienced CS during revascularization despite intra-aortic balloon pump placement, and another patient had impending cardiopulmonary arrest upon arrival at the hospital and had inadequate time to undergo coronary angiography. In both cases, simple stenosis in the left main coronary artery (LMCA) was the culprit lesion, and Impella^® insertion successfully prevented CS, avoided LV remodeling, and resulted in good outcomes. However, preventing CS in the remaining case was difficult despite Impella insertion, and veno-arterial extracorporeal membrane oxygenation was initiated. In this case, the culprit lesion was in the LMCA, with collateral vessels in the right coronary artery, which may have been associated with both LV and right ventricular (RV) systolic dysfunction. Impella^®, which is an LV assist pump, may therefore not have provided adequate support. Complete revascularization was not possible in this case, and the patient ultimately died. Impella^® for ULMCA-AMI is expected to preserve the hemodynamic stability and enable myocardial protection with complete revascularization. Nevertheless, Impella^® alone may provide insufficient support in cases of ULMCA-AMI with RV dysfunction.