Understanding CAC and Obstructive CAD
Coronary artery calcium (CAC) scoring is a widely used, noninvasive test that measures calcified plaque in the coronary arteries. While CAC can help assess a patient’s risk of heart disease in general, its role in predicting obstructive coronary artery disease (CAD) among those with chest pain or other symptoms is complex. A recent retrospective analysis sought to clarify whether sex influences the thresholds at which CAC becomes a meaningful predictor of obstructive CAD, potentially refining how clinicians interpret CAC results for women and men alike.
Key Findings: Thresholds Separate by Sex
The study analyzed symptomatic patients who underwent CAC testing in conjunction with invasive coronary angiography or functional testing. Researchers aimed to determine specific CAC score cutoffs that best differentiate those with obstructive CAD from those without, with a particular focus on whether men and women reach those thresholds at different CAC levels.
While CAC independently correlates with the presence of obstructive CAD in both sexes, the optimal thresholds were not identical. The investigators found that sex-specific thresholds improved diagnostic performance compared with a single, one-size-fits-all cutoff. In practical terms, clinicians may classify risk differently for women and men when CAC scores are in intermediate ranges, guiding decisions about further testing and treatment more precisely.
Why Sex Matters in CAC Interpretation
Biological differences in plaque composition, coronary anatomy, and the presentation of ischemic symptoms can influence CAC’s predictive value. Women often present with different CAD patterns and may have smaller vessel size, which might affect how calcium deposits relate to obstructive disease. By establishing thresholds that reflect these sex-based differences, the study argues for tailored interpretation rather than relying solely on a universal CAC threshold.
Clinical Implications for Practice
For clinicians, integrating sex-specific CAC thresholds could improve risk stratification among symptomatic patients. This approach may help identify those who would benefit from invasive coronary angiography or additional functional testing, while sparing others from unnecessary procedures. In turn, more accurate predictions of obstructive CAD can influence medical management decisions, such as initiating anti-anginal therapy, optimizing risk factors, or pursuing revascularization when appropriate.
Limitations and Future Directions
As a retrospective study, the findings warrant prospective validation in diverse patient populations. Factors such as age, comorbidities, and CI/clinical presentation should be considered when applying sex-specific CAC thresholds in routine care. Further research could explore how CAC thresholds interact with other noninvasive tests and imaging modalities, and whether incorporating additional biomarkers enhances predictive accuracy for obstructive CAD in both women and men.
Bottom Line for Patients and Providers
The evolving understanding of CAC suggests that a patient’s sex may influence how calcium scores relate to obstructive CAD. Clinicians can consider sex-specific CAC thresholds as a tool to refine diagnostic pathways for symptomatic individuals, balancing the benefits of early detection with the risks and costs of invasive testing. As evidence grows, guidelines may increasingly endorse tailored CAC interpretation to better serve both women and men facing chest pain or other CAD symptoms.
