Objectives: To study the inter-physician reliability using the universal classification (UC) of acute myocardial infarction (AMI) compared to the ST-segment classification (STC). The UC is based on clinical, electrocardiographic (ECG), and pathophysiologic characteristics compared to the STC, which is mainly ECG based.
Methods: In this registry of consecutive patients with AMI presenting to a tertiary hospital, we studied the inter-physician reliability [weighted kappa (wK)] using the UC and the STC. Two physician investigators independently classified each patient with AMI according to the UC and STC, and a third senior physician investigator resolved any disagreement.
Results: The study included Type 1=226 (89.7%), Type 2=16 (6.3%), Type 3=3 (1.2%), Type 4a=1 (0.4%), Type 4b=4 (1.6%), Type 5=2 (0.8%), ST-segment-elevation AMI (STEMI)=140 (55.6%), and non-ST-segment-elevation AMI (NSTEMI)=112 (44.4%). Inter-physician reliability using the UC was very good (wK=0.84, 95% CI 0.68-0.99) and using the STC was good (wK=0.78, 95% CI 0.70-0.86). Of patients with Type 1 AMI, 57.1% were STEMI and 42.9% were NSTEMI. In contrast, of patients with Type 2 AMI, 18.8% were STEMI and 81.2% were NSTEMI.
Conclusion: The UC is a reliable method to classify patients with AMI and performs better than the STC in this study. Validation of the two classifications should be performed in large prospective studies.
Copyright © 2011 Elsevier Inc. All rights reserved.