Cardiology and Healthcare

Statement of the Problem: Conduction abnormalities after Transcatheter Aortic Valve Implantation (TAVI) still occur while indications for TAVI expand to younger and lower risk patients. The role of contact pressure generated by the valve frame in the development of conduction abnormalities post TAVI remains unknown.

 

Method: A European multi-center study was conducted including 112 patients with severe aortic valve stenosis who had undergone a pre-procedural CT and was treated

by a self-expanding valve. A patient specific region of the aortic root containing the atrioventricular conduction pathway was selected on CT based on the inferior border of the membranous septum. Computer simulation analysis was performed in all cases to quantify contact pressure and contact pressure index (percentage of area subjected to pressure) in the region of interest.

 

Findings: 62 patients (55%) developed new conduction abnormalities. Maximum contact pressure and contact pressure index (median [IQR]) were significantly higher in patients with new conduction abnormalities (0.51 MPa [0.43-0.70] and (33% [22-44]) compared to patients without (0.29 MPa [0.06-0.50] and 12% [1-28]) (Fig. 1A). Multivariable analysis showed that maximum contact pressure and contact pressure index were independently associated with the occurrence of new conduction abnormalities (p=0.01). By ROC analysis a cut-off

value was determined for maximum contact pressure and contact pressure index consisting of respectively 0.39 MPa and 14% (Fig. 1B).

 

Conclusion: Patient-specific computer simulation showed that maximum contact pressure and contact pressure index was

associated with new conduction abnormalities after TAVI. Patient-specific computer simulation may have an added value in TAVI planning.