CT-Based Risk Stratification of Coronary Obstruction During TAVR: Clinical Utility and a New Volumetric Parameter

Area of Science:

• Cardiology
• Medical Imaging
• Interventional Cardiology

Background:

• Coronary obstruction (CO) during transcatheter aortic valve replacement (TAVR) is a rare but serious complication.
• Computed tomography (CT)-based risk assessment algorithms are being developed to identify patients at high risk for CO.
• The clinical utility of these CT algorithms requires further investigation.

Purpose of the Study:

• To evaluate the clinical utility of a CT-derived algorithm in predicting CO during TAVR.
• To identify predictors of CO, particularly in patients who undergo coronary protection (CP).

Main Methods:

• A prospective study enrolled 164 patients at risk for CO during TAVR.
• Preprocedural CT scans were used to classify patients into risk categories using a published algorithm.
• A novel volumetric parameter, valve-to-coronary volume (VTCV), was calculated in high-risk patients.

Main Results:

• The CT algorithm stratified patients into low (58.5%), intermediate (24.4%), and high (17.1%) risk categories.
• All 7 CO events occurred in the high-risk group.
• VTCV independently predicted CO with high accuracy (AUC 0.841) and outperformed VTC distance alone, validated in an external cohort.

Conclusions:

• A CT-based algorithm effectively stratifies TAVR patients into CO risk categories.
• While coronary protection (CP) reduces CO risk, its efficacy is limited in patients with very small VTCV.
• VTCV, predictable via preprocedural CT, is a key predictor of CO and can guide CP decisions.