Understanding the Challenge of Obstructive CAD
Coronary artery disease (CAD) remains a leading cause of morbidity and mortality worldwide. For patients presenting with symptoms suggestive of CAD, noninvasive tools that quickly and accurately stratify risk are invaluable. Coronary artery calcium (CAC) scoring has emerged as a powerful, accessible measure of atherosclerotic burden. A new retrospective study delves into whether CAC thresholds can predict obstructive CAD differently in women and men, offering a potential path toward sex-specific diagnostic precision.
Why CAC Thresholds Matter
CAC scoring quantifies calcium deposits in the coronary arteries, reflecting the cumulative atherosclerotic process. Traditionally, higher CAC scores correlate with greater likelihood of obstructive disease, guiding decisions about further testing or invasive evaluation. However, biology differs between sexes, with women often presenting with CAD at an older age and sometimes with less calcified plaques. The study in question set out to determine if gender-specific CAC cutoffs could more accurately identify obstructive CAD in symptomatic patients.
Key Findings: Sex Differences in Thresholds
The researchers reviewed medical records from symptomatic patients who underwent CAC scoring followed by definitive diagnostic testing for obstructive CAD. They aimed to identify CAC thresholds that best distinguished those with obstructive disease (typically defined as significant lumen narrowing) from those without it, separately for women and men. The core finding: thresholds that optimize sensitivity and specificity varied by sex. In practical terms, a CAC score associated with a given probability of obstructive CAD in men might not translate to the same risk level in women.
Several important nuances emerged. First, the discriminative power of CAC, while helpful in both sexes, tended to differ in performance metrics such as the area under the receiver operating characteristic curve (AUC). Second, the optimal cutoffs often shifted toward higher CAC values in one sex to balance the risk of false negatives against the burden of unnecessary further testing. These patterns support the concept that a single, one-size-fits-all CAC threshold may underperform when applied to a mixed-sex population.
Crucially, the study emphasizes that CAC should not be used in isolation. Instead, CAC thresholds can be integrated with clinical assessment, traditional risk factors, and other imaging or functional tests to refine diagnostic pathways for obstructive CAD in men and women alike.
Clinical Implications: Toward Personalized Diagnostics
The prospect of sex-specific CAC thresholds offers several practical benefits. For clinicians, calibrated thresholds could improve diagnostic confidence, reduce unnecessary invasive testing, and streamline resource use in laboratories and imaging suites. For patients, a more nuanced approach means potentially faster risk stratification and a clearer understanding of what their CAC score implies about obstructive CAD risk.
Nevertheless, the findings also highlight caution. Sex-specific thresholds may not be universally applicable across diverse populations or different CAC scoring methods. Researchers advocate for prospective validation in large, representative cohorts and for incorporating CAC thresholds within comprehensive risk models that account for age, comorbidity, and symptom presentation.
What Comes Next for Research and Practice
Future work should explore how sex-specific CAC thresholds perform when combined with other diagnostic tools, such as CTA (coronary computed tomography angiography) or functional testing, to create integrated, gender-sensitive diagnostic pathways. Additionally, longitudinal studies could reveal how sex-specific CAC thresholds relate to long-term outcomes, including major adverse cardiovascular events, guiding both acute management and secondary prevention.
Bottom Line
For symptomatic patients facing possible obstructive CAD, CAC scoring remains a valuable noninvasive test. The emerging evidence of sex-specific thresholds signals a move toward more personalized diagnostics, recognizing that men and women may reach similar diagnostic conclusions through different CAC cutoffs. Clinicians should consider sex-aware interpretation of CAC results as part of a holistic assessment designed to optimize care for all patients with suspected obstructive CAD.
