Acute Occlusion of a “Protected” Left Main Coronary Artery Manifesting as an Acute Coronary Syndrome with Heart Failure: How much Protected it is?

Despite the progress made in technological advancements, the utilization of stenting for both protected and unprotected left main coronary artery (LMCA) disease remains associated with elevated rates of long-term mortality and significant adverse clinical events, sometimes manifesting as cardiogenic shock. A considerable number of individuals retain the opportunity to receive catheter-based interventional therapy as a viable substitute for re-operative coronary artery bypass grafting (CABG). Despite the changed appearance, patients with acute blockage of the protected LMCA still have major adverse cardiac events (MACE) at a similar rate. Acute occlusion of the unprotected LMCA as an acute coronary syndrome (ACS) is uncommon, but that of the protected LMCA is relatively rare. We present a case of a post-CABG patient who developed ACS as a posterior wall myocardial infarction and acute left ventricular failure due to obstruction of a protected LMCA with substantial stenosis across its distal segment extending to the left circumflex (LCx) artery. The pharmaco-invasive management of the protected LMCA thrombotic occlusion with primary percutaneous coronary intervention resulted in significant patient improvement. These lesions are amenable to complex and high-risk coronary intervention with current technology, and the results have been quite encouraging in terms of long-term survival.