Validation of the European Society of Cardiology pretest probability models for obstructive coronary artery disease in high-risk population.

Objective: The pre-test probability (PTP) model for obstructive coronary artery disease (CAD) was updated in 2019 by the European Society of Cardiology (ESC). To our knowledge, this model was never externally validated in a population with a high incidence of CAD. The aim of this study is to validate the new PTP ESC model in our population, which has a high CAD incidence, and to compare it with the previous PTP ESC model from 2013.

Methods: We retrospectively analysed 1294 symptomatic patients with suspected CAD referred to our centre between 2015 and 2019. In all patients, the PTP score was calculated based on age, gender, and symptoms according to the ESC model from 2013 (2013-ESC-PTP) and 2019 (2019-ESC-PTP). All patients underwent invasive coronary angiography (ICA).

Results: Of the 1294 patients, obstructive CAD was diagnosed in 533 patients (41.2%). The 2019-ESC-PTP model categorised significantly more patients into the low probability group (PTP < 15%) than the 2013-ESC-PTP model (39.8% vs. 5.6%, p < 0.001). Obstructive CAD prevalence was underestimated using 2019-ESC-PTP at all PTP levels (calibration intercept 1.15, calibration slope 0.96). The 2013-ESC-PTP overestimated obstructive CAD prevalence (calibration intercept -0.24, calibration slope 0.73). The discrimination measured with an area under the curve was similar for both models, indicating moderate accuracy of the models.

Conclusion: In high-risk Serbian population, both the 2013 and 2019 ESC-PTP models had moderate accuracy in diagnosing CAD, with the 2019-ESC-PTP underestimating the prevalence of CAD and the 2013-ESC-PTP overestimating it. Further studies are warranted to establish PTP models for high-risk countries.