Abstract 2397: The Presence of ST-Segment Elevation in Lead aVR in Cardiogenic Shock is a Predictor of Mortality
Background: The electrocardiogram (ECG) can offer important prognostic information in patients presenting with an acute myocardial infarction (AMI). In patients with ST elevation AMI, ST elevation in lead aVR correlates with significant left main coronary artery stenosis (LMS) and mortality. Whether this holds true for patients with cardiogenic shock (CS) complicating AMI is unknown. We examined ECGs from the ``SHould we emergently revascularize Occluded coronaries for Cardiogenic shock” (SHOCK) trial to determine this.
Methods: Electrocardiograms of patients with CS complicating AMI were used to identify those with ST elevation in lead aVR (STR) and those without (NSTR). Clinical and hemodynamic data, angioigraphic features and mortality of the two groups were compared. Patients with STR had ≥ 0.5 mm elevation in aVR relative to the preceding TP segment, measured 60ms from the ``J” point. Electrocardiograms were recorded within 12-h of CS onset and pre-revascularization. Exclusion criteria included left or right bundle branch block, poor quality aVR tracing, incomplete identification and absence of a TP segment. A stenosis of ≥50% defined LMS.
Results: Among the 97 patients with assessable ECGs, STR was present in 29 (30%). Groups were similar for baseline characteristics, anterior MI, use of fibrinolytic therapy, systolic blood pressure, LV systolic function and randomization within the SHOCK trial. The presence of LMS was similar for STR (33%) and NSTR (24%), p = 0.5. Patients with STR had a higher incidence of left main equivalent coronary anatomy (22% vs. 0%, p < 0.006) and a higher jeopardy score (11.0 vs. 6.0, p = 0.0001) compared to NSTR patients. Mortality at 30-d (76% vs. 47%, p = 0.03) and 1-year (84% vs. 55%, p = 0.02) was higher in the STR group versus the NSTR group.
Conclusion: Patients with and without ST elevation in lead aVR were well balanced for key variables from the SHOCK trial. Patients with ST elevation in aVR had a similar rate of LMS as those without ST elevation in lead aVR, but a larger territory of myocardium at risk. Short and long-term mortality were higher in patients with ST elevation in lead aVR. The presence of ST elevation in lead aVR in patients with CS complicating an AMI is a readily available, and clinically useful, marker of poor outcome.