Overview: Can CAC scores predict obstructive CAD differently for men and women?
Coronary artery calcium (CAC) scoring has emerged as a noninvasive tool to help stratify the risk of coronary artery disease (CAD). A recent retrospective study examined whether CAC thresholds that predict obstructive CAD vary between women and men who present with symptoms. The findings suggest that while CAC can aid in identifying obstructive disease in both sexes, the optimal threshold values are not identical, raising important implications for how clinicians interpret CAC results in women versus men.
Background: Why sex-specific thresholds matter
Obstructive CAD, defined as significant blockage of a coronary artery, remains a leading cause of cardiovascular events worldwide. CAC scoring quantifies calcified plaque in the coronary arteries and correlates with overall atherosclerotic burden. However, there are well-established sex differences in the presentation and progression of CAD. Women often exhibit smaller coronary vessels and may develop nonobstructive disease differently from men, potentially altering the performance of CAC as a diagnostic threshold tool. The study aimed to determine whether sex-specific cutoff points improve the accuracy of predicting obstructive CAD in symptomatic patients, thereby guiding further testing such as invasive angiography or functional imaging.
Study design and key methods
Researchers conducted a retrospective analysis of patients with chest pain or equivalent symptoms who underwent CAC scoring and invasive coronary angiography or equivalent diagnostic confirmation. The primary outcome was the presence of obstructive CAD, typically defined by a stenosis severity meeting clinical thresholds. The investigators used receiver operating characteristic (ROC) curves and related metrics to identify optimal CAC thresholds for predicting obstructive CAD in women and men separately. They also examined sensitivity, specificity, and the trade-offs each threshold entailed for clinical decision-making.
Findings: Sex-specific thresholds improve diagnostic performance
The study found that CAC thresholds predictive of obstructive CAD differed between sexes. In both cohorts, higher CAC scores correlated with a greater likelihood of obstructive disease, but the exact cutoff values varied. For example, one sex might have a lower threshold that optimizes sensitivity (capturing most true cases) at the cost of specificity, while the other sex might benefit from a higher threshold that emphasizes specificity (reducing false positives). Importantly, using sex-specific cutoffs improved overall diagnostic accuracy compared with a single, universal threshold. This nuanced approach helps clinicians better distinguish patients who need invasive confirmation from those who can be safely managed with noninvasive strategies or watchful waiting.
Clinical implications: How to apply these findings
Integrating sex-specific CAC thresholds into practice could refine referral patterns for invasive testing and guide risk stratification in symptomatic patients. Clinicians may consider applying different CAC benchmarks when evaluating men versus women presenting with chest pain, shortness of breath, or abnormal stress tests. However, the study also underscores the need for careful interpretation within the broader clinical context, including risk factors, symptoms, ECG results, and noninvasive imaging findings. Importantly, CAC scoring remains one piece of the diagnostic puzzle; thresholds should augment, not replace, comprehensive clinical assessment.
Limitations and future directions
As a retrospective analysis, the study is subject to inherent biases such as selection bias and variability in imaging protocols. The generalizability of the sex-specific thresholds requires validation across diverse populations, clinical settings, and CAC scoring equipment. Prospective trials and meta-analyses could further clarify how best to implement sex-specific thresholds in guidelines and decision-support tools. Future research might also explore how other factors—age, body mass index, comorbidities, and risk factor control—interact with CAC scores to influence the predictive value for obstructive CAD in both sexes.
Bottom line
Coronary artery calcium scoring remains a valuable, noninvasive biomarker for obstructive CAD risk in symptomatic patients. The evolving evidence that thresholds differ by sex highlights the importance of personalized interpretation. Incorporating sex-specific CAC cutoffs into clinical pathways could improve diagnostic accuracy, reduce unnecessary testing, and ensure timely identification of obstructive disease in both women and men.
