Risk of Aortic Root Rupture in Bicuspid Aortic Stenosis: The ABC Sizing Algorithm for SAPIEN 3 Valves

Area of Science:

• Cardiology
• Medical Imaging
• Surgical Innovation

Background:

• Transcatheter aortic valve replacement (TAVR) is a common procedure for aortic valve stenosis.
• Bicuspid aortic valve anatomy presents unique challenges in TAVR sizing and risk assessment.
• Aortic root rupture is a rare but serious complication following TAVR.

Purpose of the Study:

• To evaluate the predictive accuracy of the ABC Bicuspid Sizing Algorithm for aortic root rupture.
• To identify specific anatomical and sizing criteria associated with rupture risk.
• To assess the algorithm's utility in stratifying risk for patients with bicuspid aortic valves undergoing TAVR.

Main Methods:

• Retrospective multicenter study involving 170 patients (23 rupture cases, 147 controls) across 15 centers.
• Computed tomography (CT) analysis performed blinded to rupture status.
• Application of the ABC algorithm with defined high-risk criteria including oversizing, intercommissural distance, and calcium volume/distribution.

Main Results:

• Patients with rupture had significantly higher total calcium volume, smaller intercommissural distance difference, smaller maximum sinus difference, and greater annular oversizing.
• The ABC algorithm demonstrated high sensitivity (100%) and specificity (89.1%) in identifying rupture cases.
• High diagnostic odds ratio (374.5) and positive likelihood ratio (9.19) indicate strong predictive power.

Conclusions:

• High calcium volume, narrow sinus dimensions, and excessive valve oversizing are significantly associated with aortic root rupture.
• The ABC algorithm shows promising performance for risk stratification in bicuspid aortic valve patients undergoing TAVR with SAPIEN 3 valves.
• The algorithm aids in identifying patients at higher risk for aortic root rupture, potentially guiding procedural decisions.