Electrocardiographic characteristics associated with in-hospital outcome in patients with left main acute coronary syndrome: For contriving a new risk stratification score.

AIM: The aim of this study was to evaluate electrocardiographic characteristics associated with in-hospital prognosis in patients with left main acute coronary syndrome.

METHODS AND RESULTS: A total of 89 left main acute coronary syndrome subjects were selected from 3357 consecutive acute coronary syndrome patients (2.7%). Patients of this study were divided into two groups; those who survived and those who died. Patients' characteristics and electrocardiogram on admission were then retrospectively analyzed between the two groups. In-hospital mortality was 28.1%. The prevalence and degree of ST-segment elevation at lead aVL were significantly higher in the deceased group than in the survival group ( p<0.001). However, those at lead aVR did not show significant differences between the two groups. Moreover, the width of the QRS-complex was significantly wider (lead V3; p<0.001), and the level of five minus the absolute value of five minus number of ST-segment elevation (5-|5-ST|; due to the highest in-hospital mortality (70%) in the five-lead ST-segment elevation group) was significantly larger in the deceased group than in the survival group ( p<0.001). The odds ratios that predicted in-hospital cardiac death were 1.03 for width of the QRS-complex at lead V3 (95% confidence interval (CI); 1.01-1.06; p=0.003), 1.74 for 5-|5-ST| (95% CI; 1.03-3.00; p=0.040), and 1.44 for ST-segment elevation at lead aVL (95% CI; 0.93-2.23; p=0.100).

CONCLUSIONS: ST-segment elevation at lead aVL rather than aVR, width of the QRS-complex at lead V3 and number of ST-segment elevation were the prognostic predictors for in-hospital mortality in patients with left main acute coronary syndrome. Electrocardiographic characteristics should be assessed in addition to the established risk score in patients with left main acute coronary syndrome.