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.

INTRODUCTION

Electrocardiographic (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).

METHODS

We 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≥1mm 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.

RESULTS

There was 59% survival to discharge of this predominantly male cohort (median age 68±12years; 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).

CONCLUSION

In CGS due to acute myocardial infarction, aVR-STE>1mm proves to be an important predictor of LMCS>50%. Such data could be helpful in further risk stratification for optimal management during CGS.