Simultaneous ST-elevation in lead augmented vector right (aVR) and III in non-ST-elevation acute coronary syndromes

The value of ST-elevation in lead augmented vector right (aVR) remains controversial in clinical practice. This study aimed to investigate the association of simultaneous ST-elevation in lead aVR and III with angiographic findings and clinical outcomes in patients with non-ST-elevation acute coronary syndromes (NSTEACS).

In this observational study, patients who had been diagnosed with NSTEACS and presented with ST-elevation in lead aVR and without ST-elevation in any other two contiguous leads were enrolled from January 2018 to June 2019. Demographic, baseline clinical, angiographic and interventional characteristics as well as clinical outcomes were collected and recorded on standardized case report forms.

A total of 157 patients meeting the criteria were finally enrolled in this study and classified into two groups according to the presence of ST-elevation in lead III. Patients in the two groups were similar in average age and previous history of hypertension, diabetes mellitus, hyperlipidemia, chronic kidney disease, stroke, and peripheral vascular diseases (all P>0.05). Patients with ST-elevation in lead III tended to present with myocardial hypertrophy in the echocardiography (P=0.02). The cases with ST-elevation in lead III showed higher high sensitivity troponin T (hs-TnT; P=0.08) and creatinine kinase MB isoenzyme (CK-MB; P<0.01) whereas those without ST-elevation in lead III showed higher N-terminal pro brain natriuretic peptide (NT-proBNP; P=0.02). Of note, patients with ST-elevation in lead III presented with more ST-depression in multiple leads [especially in lead I, augmented vector left (aVL), V3-V6] as well as higher degree of ST-depression (all P<0.05) and were more likely to develop multi-vessel and left main trunk (LM) lesions (P=0.04), with 20% of the cases having a LM lesion and 60% having triple vessel lesions. Patients with ST-elevation in lead III were at increased risk of 3-year major adverse cardiovascular events (MACEs), despite no significant statistical difference between the two groups (hazard ratio =1.29; P=0.26).

The NSTEACS cases with simultaneous ST-elevation in lead III and aVR tended to present with more multiple leads with ST-depression, higher degree of ST-depression, and more LM or multi-vessel lesions, suggesting a broader range of severe myocardial ischemia. The concurrent presentation of ST-elevation in lead III and aVR may play a vital role in the diagnosis, risk-stratification, and prediction of poor prognosis during the management of NSTEACS patients.