An experimental study to diagnose coronary artery disease using five treadmill scores

Abstract

Objectives: Exercise is the first step of a cardiovascular stress test, including electrocardiography (ECG) and blood pressure monitoring. Typically, a treadmill or bicycle is used to carry out the exercise for this stress test. Computer-derived criteria and a scoring system have been proposed and tested in hopes of improving the diagnostic accuracy of the exercise ECG for diagnosing coronary artery disease (CAD). Many treadmill scores have not been compared with one another in the same population, so questions remain concerning their diagnostic accuracy. The study aimed to correlate the diagnostic accuracy of ST segment response with various treadmill scores. Material and Methods: A total of 100 consecutive patients with suspected CAD referred for exercise testing at ACS Medical College and Hospital, Chennai, Tamil Nadu, between December 2021 and June 2022 were included in the study. The Institutional Review Board approved the study protocol at our institution, and all patients provided written informed consent. A treadmill test was conducted using commercially available equipment. All patients were subjected to symptom-limited exercise testing following the standard Bruce and modified Bruce protocols. A series of five scores were calculated using data collected from the patients to calculate the probability of CAD occurrence. Results: The study included 100 patients with an average age of 48.4 ± 1 years. Obesity (41%), hypertension (80%), diabetes (86%), current smokers (62%), family history of CAD (46%), and hypercholesterolemia (46%) were all observed in the study. The receiver operator characteristic (ROC) plot’s area under the curve (AUC) (standard error) for the Detrano score was 0.46 ± 0.59. This was significantly lower than the AUC of each treadmill score. The AUC of the ROC plots of the Duke treadmill score (DTS), veterans affairs (VA), and consensus scores were 0.47 ± 0.58, 0.63 ± 0.56, and 0.61 ± 0.57, respectively. Conclusion: The Morise score remains helpful in our study population for detecting CAD and determining risk strata. DTS and Detrano had comparable accuracy when calculated from intermediate and high probability scores and ST responses (44% and 43%, respectively). VA and consensus had lower accuracy than others (37% and 29%, respectively).