Angiographic Localisation of Culprit Vessel in Non ST Elevated Acute Coronary Syndrome

Introduction: Coronary Artery Disease (CAD) is a major cause of mortality and morbidity. Among Acute Coronary Syndrome (ACS), Non ST Elevated Acute Coronary Syndrome (NSTE-ACS) continues to increase. Unlike ST Elevated Myocardial Infarction (STEMI), association of ischaemic changes in Electrocardiogram (ECG) with culprit lesion localisation in NSTE-ACS has not been well reported.

Aim: To investigate the association between ECG abnormalities and angiographic localisation of culprit vessel in patients of NSTE-ACS.

Materials and Methods: This observational, prospective study was conducted in SCB Medical college and Hospital, Cuttack, Odisha, India, from December 2019 to November 2020. A total of 200 eligible patients of newly diagnosed NSTE-ACS were included. Demographic and risk factor assessment, clinical examination and routine blood investigations were done. All patients had an admission Electrocardiogram (ECG), Echocardiography (Echo) and Coronary Angiography (CAG) done within 72 hours of admission. Admission ECG was associated with CAG to assess predictive value in localisation of culprit vessel. Sensitivity, Specificity, Positive Predictive Value (PPV), Negative Predictive Value (NPV), Likelihood Ratio (LR), pre and post-test odds of individual ECG findings were assessed. Statistical Package for the Social Sciences (SPSS) version 24.0 was used for statistical analysis.

Results: Sensitivity, specificity, PPV, NPV, LR+, pretest odds and post-test odds of anterior wall, inferior wall, lateral wall and augmented Vector Right (aVR) group ECG changes in predicting Left Anterior Descending (LAD), Right Coronary Artery (RCA), Left Circumflex Artery (LCX) and Left main or Triple Vessel Disease (LM/TVD) as culprit artery were 75.9%, 90.5%, 91.7%, 73.1%, 7.96, 1.38 and 10.98; 69.1%, 91.5%, 87.8%, 76.9%, 8.14, 0.89 and 7.21; 64%, 93%, 87.3%, 77.4%, 9.10, 0.75 and 6.86 and 69.2%, 96.3%, 90%, 86.7%, 18.66, 0.48 and 8.98, respectively. Sensitivity, specificity, PPV and NPV of anterior and lateral, inferior and lateral and anterior and inferior wall ECG changes in predicting LAD and LCX, RCA and LCX and LAD and RCA as culprit vessels were 75.0%, 82.6%, 27.27% and 97.43%; 47.0%, 88.5%, 27.5% and 94.73% and 53.3%, 83.2%, 20.51% and 95.65%, respectively. The ECG was normal in 31% of which Myocardial Infarction with Non Obstructive Coronary Artery (MINOCA) (34%) and Single Vessel Disease (SVD) (30.6%) were prevalent. The MINOCA were mostly seen in normal ECG pattern.

Conclusion: An ECG is a moderately sensitive but highly specific parameter in predicting LAD, LCX, RCA and LM/TVD as culprit vessels in Non ST Segment Elevation Myocardial Infarction- Acute Coronary Syndromes (NSTE-ACS). Double territory ECG changes have a poor association in predicting culprit vessel. However, a good association was noted for (anterior and lateral) wall ECG changes in predicting LAD and LCX as culprit arteries.