An assessment of ST-segment measurement variability between two core electrocardiogram laboratories

Objectives We evaluated inter-reader agreement of the ST-segment between two electrocardiogram (ECG) core laboratories. Background Accurate measurement of the ST-segment is key to diagnosis and management of acute coronary syndromes (ACS). Clinical trials also rely on adherence to the pre-specified ECG eligibility criteria. Methods 150 patients (100 ST-segment elevation (STE)-ACS, 50 non-STE-ACS) were selected. An experienced ECG reader from each laboratory measured ST-segment deviation on the baseline ECGs (nearest 0.1 mm). Results ∑ ST-segment deviation showed excellent inter-reader agreement (R = 0.965, intraclass correlation coefficient (ICC) 0.949, 95% CI (0.930–0.963)). Similar agreement was observed when ∑ ST-segment elevation (∑ STE) and ∑ ST-segment depression (∑ STD) were assessed separately. Better agreement was evident in STE-ACS cohort (ICC (95% CI): 0.968 (0.953–0.978, 0.969 (0.954–0.979), 0.931 (0.899–0.953)) compared to NSTE-ACS patients (ICC (95% CI): 0.860 (0.768–0.917), 0.816 (0.699–0.890), 0.753 (0.605–0.851) across measurement of ∑ ST-segment deviation, ∑ STE, and ∑ STD. Conclusions We demonstrated excellent agreement on ST-segment measurements between two experienced readers from two ECG core laboratories.