Predictive Model for Thrombus Formation After Transcatheter Valve Replacement

Purpose Leaflet thrombosis is a significant adverse event after transcatheter aortic valve (TAV) replacement (TAVR). The purpose of our study was to present a semi-empirical, mathematical model that links patient-specific anatomic, valve, and flow parameters to predict likelihood of leaflet thrombosis. Methods The two main energy sources of neo-sinus (NS) washout after TAVR include the jet flow downstream of the TAV and NS geometric change in volume due to the leaflets opening and closing. Both are highly dependent on patient anatomic and hemodynamic factors. As rotation of blood flow is prevalent in both the sinus of Valsalva and then the NS, we adopted the vorticity flux or circulation ( CYRILLIC CAPITAL LETTER GHE) as a metric quantifying overall washout. Leaflet thrombus volumes were segmented based on hypo-attenuating leaflet thickening (HALT) in post-TAVR patient's gated computed tomography. CYRILLIC CAPITAL LETTER GHE was assessed using dimensional scaling as well as computational fluid dynamics (CFD) respectively and correlated to the thrombosis volumes using sensitivity and specificity analysis. Results CYRILLIC CAPITAL LETTER GHE in the NS, that accounted for patient flow and anatomic conditions derived from scaling arguments significantly better predicted the occurrence of leaflet thrombus than CFD derived measures such as stasis volumes or wall shear stress. Given results from the six patient datasets considered herein, a threshold CYRILLIC CAPITAL LETTER GHE value of 28.0 yielded a sensitivity and specificity of 100% where patients with Gamma < 28 developed valve thrombosis. A 10% error in measurements of all variables can bring the sensitivity specificity down to 87%. Conclusion A predictive model relating likelihood of valve thrombosis using CYRILLIC CAPITAL LETTER GHE in the NS was developed with promising sensitivity and specificity. With further studies and improvements, this predictive technology may lead to alerting physicians on the risk for thrombus formation following TAVR.

Automated summary

Leaflet thrombosis is a major complication after TAVR, and a semi-empirical, mathematical model using vorticity flux (CYRILLIC CAPITAL LETTER GHE) was found to be more effective in predicting thrombus occurrence compared to measures derived from CFD. By analyzing both dimensional scaling and CFD, the model showed promising sensitivity and specificity in predicting valve thrombosis following TAVR.