Prevalence and prognostic impact of ST-segment elevation in lead aVR among patients with cardiac arrest

In acute coronary syndrome, ST-segment elevation in lead aVR (STE-aVR) indicates global myocardial ischaemia, often related to multivessel or severe left main disease, and correlates with increased mortality. The prevalence and prognostic significance of STE-aVR in cardiac arrest (CA) patients is unknown.

We identified patients (≥18 years) with CA between 2011 and 2022 who achieved return of spontaneous circulation (ROSC). The first electrocardiogram post-ROSC was assessed for STE-aVR, defined as ≥1 mm ST-segment elevation at the J point, measured by two trained assessors. Multivariable logistic regression was used to analyse the association between STE-aVR and outcomes (in-hospital mortality and poor neurologic outcome), adjusted for patient and arrest characteristics. Including 443 CA patients, the median (interquartile range) age was 61 years (50-72 years), with 60.5% (n = 268) male, 65.7% (n = 291) presenting with out-of-hospital CA (OHCA), and 29.8% (n = 132) with shockable rhythms. ST-segment elevation in lead aVR was observed in 18.3% (n = 81) of patients. Those with STE-aVR were more likely to present with OHCA and less likely to have a shockable rhythm (both, P < 0.05). ST-segment elevation in lead aVR was associated with higher in-hospital mortality (86.4% vs. 65.8%, P < 0.001) and poor neurologic outcomes (90.1% vs. 72.9%, P = 0.001). After multivariable adjustment, STE-aVR remained associated with higher in-hospital mortality [odds ratio (OR) 2.23; 95% confidence interval (CI): 1.02-4.84, P = 0.04], but not a poor neurologic outcome (OR 2.12; 95% CI: 0.90-4.98, P = 0.09).

ST-segment elevation in lead aVR was present in one in five CA survivors and was independently associated with higher in-hospital mortality.