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Impact of Aortic Valve Leaflets Calcium Volume and Distribution on Post-TAVR Conduction Abnormalities
Symon Reza1, Brandon Kovarovic1, Danny Bluestein1
1Department of Biomedical Engineering, Stony Brook University, Stony Brook, New York, USA.
Insights
Aortic leaflet calcium volume and distribution significantly impact cardiac conduction abnormalities after transcatheter aortic valve replacement (TAVR). Specific calcification patterns, especially on the left coronary leaflet, increase the risk of permanent pacemaker implantation.
Area of Science:
- Cardiovascular research
- Biomedical engineering
- Medical device innovation
Background:
- Transcatheter aortic valve replacement (TAVR) is a growing treatment for aortic stenosis, even in low-risk patients.
- Post-TAVR cardiac conduction abnormalities (CCA) and the need for permanent pacemaker implantation (PPI) are significant concerns.
Purpose of the Study:
- To investigate the influence of aortic leaflet calcium volume and distribution on the risk of post-TAVR CCA.
- To understand the mechanical interactions between the TAVR device and cardiac structures based on calcium deposits.
Main Methods:
- Utilized an electromechanically coupled four-chamber beating heart model to simulate TAVR with a self-expandable Evolut® 26 mm device.
- Modeled five virtual patient scenarios with varying calcium volumes and distributions (none, uniform, LCL, RCL, NCL).
- Simulated electrical conduction and coupled it with structural mechanics to assess tissue-device interactions, including stress and contact pressure.
Main Results:
- Increased calcium volume and specific distributions elevated mechanical stress and contact pressure near the atrioventricular node.
- The left coronary leaflet (LCL) model showed the highest stress and contact pressure (13.1 kPa), indicating a higher risk of conduction disruption.
- The non-coronary leaflet (NCL) model exhibited the lowest values (6.42 kPa), suggesting a lower risk.
Conclusions:
- Aortic leaflet calcium characteristics significantly affect mechanical forces and contact dynamics post-TAVR.
- Integrating pre-procedural assessment of leaflet calcium volume and distribution can personalize TAVR risk stratification and enhance patient outcomes.
Introduction:
Transcatheter aortic valve replacement (TAVR) is increasingly used to treat aortic stenosis, including in low-risk patients. However, post-procedural cardiac conduction abnormalities (CCA), often requiring permanent pacemaker implantation (PPI), remain a concern. This study investigates how the volume and distribution of aortic leaflet calcium deposits influence the risk of post-TAVR CCA.
Methods:
An electromechanically coupled four-chamber beating heart model was used to simulate TAVR with a self-expandable Evolut® 26 mm device. Five virtual patient scenarios were modeled with varying calcium volumes and distributions: no calcium, uniform distribution (3 Calc), and isolated calcification on the left coronary leaflet (LCL), right coronary leaflet (RCL), or non-coronary leaflet (NCL). Electrical conduction was simulated using a monodomain model and coupled with structural mechanics to evaluate tissue-device interactions. Metrics included principal stress, contact pressure, and contact pressure index (CPI) over three cardiac cycles.
Results:
Larger calcium volumes and specific leaflet distributions increased stress and contact pressure near the atrioventricular node. The LCL model exhibited the highest mechanical stress and peak contact pressure (13.1 kPa), while the NCL model showed the lowest (6.42 kPa). The RCL model had intermediate values. Elevated contact pressure and stress in the LCL case suggest an increased risk of conduction disruption and PPI.
Conclusion:
Leaflet calcium deposit volume and distribution significantly influence mechanical stress and contact dynamics near the conduction system following TAVR. These insights support the integration of clinical data, such as leaflet calcium volume and distribution into pre-procedural planning to personalize risk assessment and improve patient outcomes.
