Risk Stratification of Patients With Moderate Aortic Stenosis Using Aortic Valve Calcium

Objectives: To evaluate whether aortic valve calcium (AVC) scoring by cardiac CT can enhance risk stratification and identify high-risk patients among those with moderate aortic stenosis (AS). Background: Moderate AS is traditionally considered benign, yet emerging evidence suggests a subset may experience adverse outcomes similar to those with severe AS. AVC scoring has been validated for diagnosing severe AS but its prognostic value in moderate AS remains unclear. Methods: A retrospective cohort study of 606 patients with moderate aortic stenosis (MAS) for whom aortic valve calcium (AVC) assessment was recommended on echocardiogram reports. Patients were categorized into two groups: those who underwent AVC (n=159) and those who did not (n=447). Primary outcomes included aortic valve replacement (AVR) and all-cause mortality. Secondary outcomes included time to severe AS diagnosis and time to AVR. Results: A significantly higher proportion of patients in the CT cohort reached a diagnosis of severe AS (28.8% vs. 19.9%, p=0.037) and underwent valve intervention (32.6% vs. 14.1%, p<0.001) compared to the no-CT cohort. Patients underwent valve intervention mostly at the severe AS stage. All-cause mortality was markedly lower in the CT cohort (7.6% vs. 24.9%, p<0.001); difference being driven by excess non-cardiovascular mortality in the no-CT cohort (61.0% vs. 7.9%, p<0.001). Patients with severe AVC (males AVC >2000 AU and females >1200 AU) were more likely to undergo valve intervention compared with non-severe AVC (HR 2.60, 95% CI 1.42-4.74, p=0.002). Patients in the CT cohort were more likely to undergo valve intervention (HR 3.17, CI 2.04-4.91, p<0.001), and had a significantly lower all-cause mortality (HR 0.32, CI 0.16-0.61, p=0.001) compared to the no-CT cohort. Conclusion: A practice algorithm incorporating AVC for risk stratification of MAS patients can lead to better outcomes. Role of AVC based decision-making in patients with MAS needs further study in a randomized trial.