Analysis of Admission Electrocardiographic Patterns in Survivors and Non-Survivors of Unprotected Left Main Acute Coronary Syndrome Undergoing Percutaneous Coronary Intervention

Introduction: The optimal treatment strategy for left main coronary artery disease continues to be debated. This is particularly evident for the high risk subgroup of patients presenting with acute coronary syndrome (ACS) and who are underrepresented in published trials. The electrocardiogram (ECG) represents one of the first line diagnostic tests for evaluating patients with possible ACS. Specific acute ECG abnormalities can raise the suspicion of significant left main (LM) involvement. Our aim, therefore, was to analyze the ECG patterns of ACS patients undergoing percutaneous coronary intervention (PCI) of unprotected left main coronary artery (ULMCA) lesions. Methods: Between February 2004 and December 2012 there were 67 patients with left main coronary stenosis (mean age 70 ± 18 years) who underwent acute PCI. We retrospectively analyzed the patients' electronic charts and obtained data on personal history, medication, clinical status, cardiac biomarkers, electrocardiograms on admission, details of the performed coronary angiography with subsequent PCI and patient outcome. In 25 of the patients the urgent PCI was performed on a protected vessel (post CABG with at least one functional graft to LAD/LCX), and we excluded these patients. Results: Follow-up data was available from 42 patients (100%). The cumulative mortality rate (in hospital and at 6 months) in patients with acute interventions in symptomatic LMCA stenosis was 23.8% (10 patients). The most common ECG patterns were significant ST-segment elevation in lead aVR, significant ST-segment depression in leads V4-V6, and first degree atrioventricular (AV) block. Conclusion: In our analysis the most common ECG patterns in patients with acute coronary syndrome related to left main disease were significant ST-segment elevation in lead aVR, significant ST-segment depression in leads V4-V6 and AV block. In this study with a small sample size and limited cases there were no specific ECG patterns on admission that were indicative of an adverse outcome in ACS patients related to an unprotected left main culprit lesion.