The presence of ST-elevation in lead aVR predicts significant left main coronary artery stenosis in cardiogenic shock resulting from myocardial infarction: The Manitoba cardiogenic shock registry

IntroductionElectrocardiographic (ECG) predictors of significant angiographic left main coronary artery stenosis (LMCS > 50%) have been described in acute myocardial infarction using ST-segment elevation in lead aVR (aVR-STE). However, there is a paucity of data on its association with LMCS > 50% in the setting of cardiogemic shock (CGS).MethodsWe investigated 210 consecutive, unselected, patients from Sept. 2002-2006 with CGS due to acute myocardial infarction undergoing cardiac catheterization. Of those, 191 patients with interpretable ECG tracings for aVR-STE analysis formed our study sample. aVR-STE was defined as ST-segment elevation ≥ 1 mm in aVR while LMCS > 50% on coronary angiogram was defined as any left main lesion that demonstrated > 50% lumen narrowing or equivalent by direct visualization or quantitative coronary angiography analysis.ResultsThere was 59% survival to discharge of this predominantly male cohort (median age 68 ± 12 years; 31% females). Fifty three (28%) cases had aVR-STE while 27 (14%) had LMCS > 50%. Of those, 16 patients who had aVR-STE also had LMCS > 50% (sensitivity 59%, specificity 77%, positive predictive value 30%, negative predictive value 92% for predicting LMCS > 50%). Multivariate analysis revealed that aVR-STE was the only significant predictor of LMCS > 50% was (p = 0.014; Odds Ratio = 3.06; 95% Confidence Interval 1.26-7.47).ConclusionIn CGS due to acute myocardial infarction, aVR-STE > 1 mm proves to be an important predictor of LMCS > 50%. Such data could be helpful in further risk stratification for optimal management during CGS.