Directional Radial Force Alignment Predicts Pacemaker Implantation After Balloon-Expandable Transcatheter Aortic...

Area of Science:

• Cardiology
• Medical Imaging
• Biomedical Engineering

Background:

• Conduction disturbances are common after transcatheter aortic valve implantation (TAVI), often necessitating permanent pacemaker (PPM) implantation.
• Predicting PPM risk is crucial for optimizing TAVI procedures and patient outcomes.

Purpose of the Study:

• To evaluate the "Vectorial Angle," a novel computed tomography (CT)-derived biomechanical parameter, as a predictor of PPM following balloon-expandable TAVI.
• To compare the Vectorial Angle's predictive value against traditional anatomical and electrocardiographic factors.

Main Methods:

• Retrospective cohort study of 67 patients undergoing balloon-expandable TAVI.
• Pre-procedural CT scans were used to define the Vectorial Angle at the elliptical left ventricular outflow tract (e-LVOT) level.
• Analysis included multivariate logistic regression and receiver operating characteristic (ROC) curve analysis.

Main Results:

• The Vectorial Angle emerged as an independent predictor of PPM requirement (OR 0.935 per 1° increment, p=0.007).
• A narrower Vectorial Angle (≤52°) was associated with increased PPM risk (AUC=0.806, p=0.001).
• Shorter membranous septal length (MSL) was also an independent predictor (OR 0.447 per 1 mm increment, p=0.011).

Conclusions:

• The Vectorial Angle is a novel, independent pre-procedural predictor of PPM after balloon-expandable TAVI.
• This parameter highlights the importance of spatial orientation between the valve's radial force and conduction tissue.
• The Vectorial Angle complements conventional assessments like MSL for predicting conduction-system vulnerability.