ST-elevation in precordial leads major predictor in acute total left main occlusion, study finds

China: A new study published in BMC Cardiovascular Diseases shows that in unprotected left main (ULM) artery occlusion, ST-segment elevation (STE) in the precordial leads predicted the lack of collateral circulation, but STE in aVR and STE in both aVR and aVL predicted various collateral filling areas.

There is a scarcity of information on the clinical features, electrocardiogram (ECG) findings, and outcomes of patients with acute myocardial infarction (AMI) caused by total unprotected left main artery blockage. As a result, Chunwei Liu and colleagues conducted this study to examine the collateral circulation, clinical characteristics, and ECG features of patients with acute total ULM blockage (TIMI 0) and to investigate the association between these parameters and clinical outcomes.

A total of 44 patients, between 2009 and 2021, with AMI due to total ULM blockage were treated at our hospital with primary percutaneous coronary intervention (PCI). The ECG, collateral circulation, clinical and procedural features, as well as in-hospital mortality, were all assessed retrospectively.

The key findings of this study were as follow:

1. Twenty-five people came with shock, and 18 died in the hospital.

2. Nineteen individuals had ST-segment elevation myocardial infarction (STEMI), while 25 had non-ST-segment elevation myocardial infarction (NSTEMI).

3. The absence of collateral circulation was linked with ST-segment elevation (STE) in I and STEMI, whereas the presence of collateral circulation was associated with STE in aVR.

4. Patients with STE in both aVR and aVL in the NSTEMI group had a greater collateral filling of the left anterior descending coronary artery (LAD) region, whereas patients with STE in aVR had a greater collateral filling of the LAD and the left circumflex artery territory.

5. Patients with partial ULM obstruction had greater STE in aVR, less STE in aVR and aVL, and less STEMI than patients with entire ULM occlusion.

6. Shock, TIMI 0–2 flow after PCI, non-STE in aVR, STEMI, and STE in I all predicted in-hospital death.

7. STEMI and the lack of collateral flow were both linked with shock.

In conclusion, STE in both aVR and aVL leads is a good sign for distinguishing entire ULM obstruction from partial ULM occlusion. Patients who report with STE in both channels aVR and aVL should be identified as high-risk and undergo immediate coronary angiography.

Reference:

Liu, C., Yang, F., Zhang, J. et al. Electrocardiographic patterns predict the presence of collateral circulation and in-hospital mortality in acute total left main occlusion. BMC Cardiovasc Disord 22, 144 (2022). https://doi.org/10.1186/s12872-022-02585-x