Does T wave inversion in lead aVL predict mid-segment left anterior descending lesions in acute coronary syndrome? A retrospective study

OBJECTIVES: Limited data are available regarding the predictive value of electrocardiographic T wave inversion in lead aVL for mid-segment left anterior descending (MLAD) lesions among patients with acute coronary syndrome (ACS). SETTING: Retrospective single-centre study, using a prospectively-collected coronary angiography database from January 2012 to December 2013. PARTICIPANTS: We included consecutive adult patients with ACS who underwent urgent percutaneous coronary intervention (PCI) within 24 h after arriving at the hospital. We excluded patients who did not undergo an ECG before PCI, patients with proximal MLAD occlusion and patients diagnosed with vasospastic angina. PRIMARY AND SECONDARY OUTCOME MEASURES: The primary outcome was MLAD lesion >50%. The other outcome of interest was MLAD lesion as a cause of ACS. First, we evaluated the diagnostic values of T wave inversion in lead aVL regardless of other T wave changes for each outcome. Second, we evaluated the diagnostic values of isolated T wave inversion in lead aVL. RESULTS: Overall, 219 patients were eligible for the analysis. T wave inversion in lead aVL regardless of other T wave changes had a sensitivity of 32.9%, specificity of 48.2%, positive predictive value of 27.6% and negative predictive value of 54.5% for predicting MLAD lesions. Isolated T wave inversion in lead aVL had a sensitivity of 9.8%, specificity of 86.9%, positive predictive value of 30.8% and negative predictive value of 61.7% for predicting MLAD lesions. These diagnostic values did not change materially when focusing on patients with MLAD lesion as the cause. CONCLUSIONS: While T wave inversion in lead aVL regardless of other T wave changes had low diagnostic values for predicting MLAD lesions, isolated T wave inversion in lead aVL had a high specificity. Our inferences underscore the importance of a cautious interpretation of T wave inversion in lead aVL among patients with ACS.