Left ventricular outflow obstruction predicts increase in systolic pressure gradients and blood residence time after transcatheter mitral valve replacement

• Published in: Scientific reports Vol. 8; no. 1; pp. 15540 - 11
• Main Authors: De Vecchi, Adelaide, Marlevi, David, Nordsletten, David A., Ntalas, Ioannis, Leipsic, Jonathon, Bapat, Vinayak, Rajani, Ronak, Niederer, Steven A.
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 19.10.2018; Nature Publishing Group
• Subjects: 59; 631/114/2397; 631/443/592/75/591; Aged; Aged, 80 and over; Blood Pressure; Cardiac Catheterization - methods; Catheters; Computer applications; Computer Simulation; Data processing; Decision making; Female; Heart diseases; Heart Valve Prosthesis Implantation - methods; Hemodynamics; Humanities and Social Sciences; Humans; Male; Mathematical models; Medicin och hälsovetenskap; Middle Aged; Mitral valve; Mitral Valve - surgery; multidisciplinary; Science; Science (multidisciplinary); Simulation; Ventricle; Ventricular Outflow Obstruction; Left Ventricular Outflow Tract (LVOT); Blood Residence Time; LVOT Obstruction; Transcatheter Mitral Valve Replacement (TMVR); Systolic Pressure Gradient
• ISSN: 2045-2322; 2045-2322
• DOI: 10.1038/s41598-018-33836-7

Left ventricular outflow tract (LVOT) obstruction is a relatively common consequence of transcatheter mitral valve replacement (TMVR). Although LVOT obstruction is associated with heart failure and adverse remodelling, its effects upon left ventricular hemodynamics remain poorly characterised. This study uses validated computational models to identify the LVOT obstruction degree that causes significant changes in ventricular hemodynamics after TMVR. Seven TMVR patients underwent personalised flow simulations based on pre-procedural imaging data. Different virtual valve configurations were simulated in each case, for a total of 32 simulations, and the resulting obstruction degree was correlated with pressure gradients and flow residence times. These simulations identified a threshold LVOT obstruction degree of 35%, beyond which significant deterioration of systolic function was observed. The mean increase from baseline (pre-TMVR) in the peak systolic pressure gradient rose from 5.7% to 30.1% above this threshold value. The average blood volume staying inside the ventricle for more than two cycles also increased from 4.4% to 57.5% for obstruction degrees above 35%, while the flow entering and leaving the ventricle within one cycle decreased by 13.9%. These results demonstrate the unique ability of modelling to predict the hemodynamic consequences of TMVR and to assist in the clinical decision-making process.