Shelley Gooden

Date: 14 February 2023

Time: 2 pm

Location/meeting link: https://gatech.zoom.us/j/92706314254

Advisor: Lakshmi Prasad Dasi, PhD (Georgia Institute of Technology) 

Committee Members: 

Ajit P. Yoganathan, PhD (Georgia Institute of Technology) 

Brandon Dixon, PhD (Georgia Institute of Technology) 

Mani A. Vannan, MD (Piedmont Heart Institute) 

Vinod H. Thourani, MD (Piedmont Heart Institute) 

Konstantinos D. Boudoulas, MD (The Ohio State University) 

Predicting Hemodynamic and Biomechanical Implications of MitraClip Transcatheter Edge-To-Edge Therapy on Treatment of Functional Mitral Regurgitation 

Mitral regurgitation (MR) is the leading cause of heart valve disease, where moderate MR is present in at least 1.7% of the adult population, increasing to 11.7% in those age 75 years and older. MR occurs when the two leaflets of the mitral valve (MV) do not close properly when they should. Left untreated, MR severity can increase and lead to heart failure. Patients with moderate-to-severe or severe MR who remain symptomatic despite optimal medical therapy and are deemed at high surgical risk by a heart team are candidates for transcatheter edge-to-edge repair with the commercially available MitraClip. Though clinical trials show promising outcomes, challenges with MitraClip use include sufficient reduction of MR while preventing elevated MV pressure gradient (MVG), as these two unfavourable outcomes worsen prognosis. Optimal use and predictive modeling of MVG post-MitraClip is not well defined, especially with four device sizes available in the current G4 generation. Further guidelines to optimize MitraClip usage is needed, as transcatheter MV repair has overtaken surgical repair in the United States. Impact of MitraClip size was first assessed using an excised porcine ventricular functional MR model, where residual regurgitation with device size was found to be dependent upon baseline MR conditions, and post-therapy MVG was found to increase most with the largest device size. A parameterization approach was developed to simplify human MV geometries, and MitraClip placement was simulated. Post-therapy MVG was found to be greatest for smaller MVs and for larger device size. Forward flow measured by clinical means (CW Doppler) and by the engineering means (conservation of mass) showed strong correlation. Applying this in vivo, a post-therapy MVG predictive model was developed, which showed good agreement to in vivo outcomes. The outcomes of this thesis can help clinicians assess patient MitraClip candidacy and help optimize MitraClip treatment strategies by predicting post-therapy MVG.