Diagnostic and Prognostic Value of ST-segment Deviation Scores in Suspected Acute Myocardial Infarction

Background: Recent advances in digital electrocardiography technology allow evaluating ST-segment deviations in all 12 leads as quantitative variables and calculating summed ST-segment deviation scores. The diagnostic and prognostic utility of summed ST-segment deviation scores is largely unknown. Methods: We aimed to explore the diagnostic and prognostic utility of the conventional and the modified ST-segment deviation score (Better Analysis of ST-segment Elevations and Depressions in a 12- Lead-ECG-Score (BASEL-Score): sum of elevations in the augmented voltage right - lead (aVR) plus absolute, unsigned ST-segment depressions in the remaining leads) in patients presenting with suspected non-ST-segment elevation myocardial infarction. The diagnostic endpoint was non-ST-segment elevation myocardial infarction, adjudicated by two independent cardiologists. Prognostic endpoint was mortality during two-year follow up. Results: Among 1330 patients, non-ST-segment elevation myocardial infarction was present in 200 (15%) patients. Diagnostic accuracy for non-ST-segment elevation myocardial infarction as quantified by the area under the receiver-operating-characteristics curve was significantly higher for the BASEL-Score (0.73; 95% confidence interval 0.69-0.77) as compared to the conventional ST-segment deviation score (0.53; 95% confidence interval 0.49-0.57, p<0.001). The BASEL-Score provided additional independent diagnostic value to dichotomous electrocardiogram variables (ST-segment depression, T-inversion, both p<0.001) and to high-sensitivity cardiac troponin (p<0.001) as well as clinical judgment at 90 min (p<0.001). Similarly, only the BASEL-Score proved to be an independent predictor of two year mortality. Conclusions: The modified ST-segment deviation score BASEL-Score focusing on ST-segment elevation in aVR and ST-segment depressions in the remaining leads provides incremental diagnostic and prognostic information.