Sex Differences in Computed Tomographic Angiography in Patients with Low and Intermediate Pretest Probability of Coronary Artery Disease

Background: Multi-slice computed tomography (MSCT) coronary angiography has become one of the hot spots in cardiovascular imaging technology. Many of the sex-based research have shown that women have different pathogenesis, clinical presentation and complication related to coronary artery disease (CAD) as compared to the males. The aim of this study investigated the relationship between gender and coronary artery calcium (CAC) in patients with chest discomfort with low and intermediate pretest probability of CAD who underwent Coronary computed tomography angiography (CCTA) and referrals by gender for subsequent invasive coronary angiography and revascularization.

Methods: This prospective cohort study included 200 patients suspected to have coronary artery disease, negative or equivocal stress tests, with no prior known coronary artery disease (CAD), intermediate pretest probability for CAD according to the scoring method of (15-65 points), and Low likelihood for CAD (< 15 points). Patients were divided into two groups according to gender and were followed up. All patients underwent Full history taking, full clinical examination, routine laboratory investigation, resting and exercise ECG, echocardiography, CT coronary angiography and invasive Coronary angiography.

Results: Patients with mild calcium score level were significantly higher in no CAD group than CAD group (p <0.001) and patients with high calcium score were significantly higher in CAD group than no CAD group (p <0.001). In univariate regression analysis age, typical chest pain, obesity, coronary Ca score, and hyperlipidemia are independent predictors for CAD in females. In multivariate regression analysis, age, typical chest pain, hypertension, and coronary Ca score are predictors for CAD in males. Coronary calcium score is a good predicator for CAD (AUC =0.901, 95% CI =0.851-0.938, p value <0.001). At cut off value > 101, it has 70.97% sensitivity, 90.79% specificity, 92.6% PPV, and 65.7% NPV. Moreover, it is a good predicator for CAD in females (AUC =0.894, 95% CI =0.823 – 0.944, p value <0.001). At cut off value > 101, it has 60.71% sensitivity, 91.67% specificity, 87.2% PPV, and 71.4% NPV.

Conclusions: In patients with chest discomfort with low and intermediate pretest probability of CAD who underwent CCTA and subsequent invasive coronary angiography and revascularization, female patients had lower age, hypertension, pretest probability score, calcium score, atypical angina, nonanginal chest pain and obstructive CAD but had higher BMI, typical angina than males’ group. In females, coronary calcium score is a good predicator for CAD. When its level exceeds 100, it has 60.71% sensitivity and 91.67% specificity. In addition, it was found that in females typical chest pain and coronary Ca score are predictors for CAD and in males, age, typical chest pain, hypertension, and coronary Ca score are predictors for CAD.