Sex Differences in Two International Guidelines for Assessing Obstructive Coronary Artery Disease in Symptomatic Outpatients by Coronary Computed Tomographic Angiography

Background: Low-risk individuals are unlikely to benefit from noninvasive testing, and women tend to have a lower prevalence of coronary artery disease (CAD). This study compared the performance of two current guidelines that differ by sex to assess stable chest pain outpatients, including symptom-based (2016 National Institute for Health and Care Excellence, NICE) and risk-based strategies (2019 European Society of Cardiology, ESC).Methods: A total of 542 outpatients referred for coronary computed tomography angiography (CCTA) at a single-centre were retrospectively included in this study. A risk assessment was calculated for each outpatient according to the two guidelines. Patients were classified into low and high-risk groups according to each strategy. The presence of coronary artery disease was the endpoint. Net reclassification improvement (NRI) was used to assess the performance of the two strategies. Results: The prevalence of CAD was 27%. The sensitivity, specificity, positive predictive value and negative predictive value for ESC and NICE were 90.4%, 54.3%, 42.2%, 93.9% and 78.8%, 35.6%, 31.1% and 82.0% respectively. Compare to NICE, the NRI for ESC were 30.32%. The ESC guidelines classified 55.56% of women and 28.14% of men into the low-risk group. The ESC guidelines had a higher predictive value for coronary artery disease compared to the NICE guidelines, with a positive NRI in men (15.55%) and women (34.46%) respectively.Conclusions: The ESC guidelines offered a more accurate calculation of risk assessment than the NICE guidelines. Patient sex influenced applying the recent ESC guidelines, which would result in a significant decrease in inappropriate testing of women but an increase in appropriate noninvasive testing of men.