Sequential Alcohol Septal Ablation to Resolve LV Outflow Tract Obstruction After Transcatheter Mitral Valve Replacement

Figure 1. Baseline TTE and Computed Tomography Angiography (A) Transthoracic echocardiography (TTE) showing a nondilated left ventricle. (B) TTE showing a mean aortic bioprosthesis gradient of 19 mm Hg. (C) TTE showing a mitral valve mean gradient of 10 mm Hg and pressure half-time of 230 milliseconds (estimated mitral valve area 0.96 cm2). Computed tomography angiography 2-chamber (D), short-axis (E), and 4-chamber (F) views showing severe mitral annulus calcification, protruding into the basal anterior, lateral, and inferior wall. (G) Three-dimensional modeling of the ascending aorta showing multiple calcifications.

Figure 2. 3-Dimensional CT-Derived Transcatheter Mitral Valve Replacement Simulation and Neo-LVOT Area Calculation (A) Baseline 3-chamber computed tomography (CT) view. (B) Baseline CT-derived 3-dimensional model shows virtual SAPIEN 3 implantation. (C) Based on automatic neo-left ventricular outflow tract (LVOT) area calculation, SAPIEN 3 implantation results in a neo-LVOT area of 135 mm2. (D) Three-chamber CT view post–alcohol septal ablation (ASA). (E) CT-derived 3-dimensional model post-ASA shows LVOT expansion compared with baseline simulation. (F) Neo-LVOT area calculation post-ASA shows neo-LVOT area expansion to 273 mm2.

Figure 3. Transcatheter Mitral Valve Replacement Procedure (A) SAPIEN 3 transcatheter heart valve deployment. (B) Three-dimensional transesophageal echocardiography (TEE) image of implanted SAPIEN 3 in mitral valve position. (C) TEE images of the mitral valve show no mitral regurgitation or paravalvular leakage. (D) TEE shows a low residual mitral peak (5 mm Hg) and mean (2 mm Hg) gradient. (E) TEE pulsed wave Doppler shows a left ventricular outflow tract peak gradient of 36 mm Hg and mean gradient of 22 mm Hg directly after SAPIEN 3 implantation in the mitral position. (F) TEE continuous wave Doppler across the aortic valve shows a peak gradient of 57 mm Hg and mean gradient of 36 mm Hg directly after SAPIEN 3 implantation in the mitral position. (G) Successful implantation of 23 mm Evolut PRO+ transcatheter heart valve inside aortic bioprosthesis.

Figure 4. 3-Dimensional CT-Derived Model and Neo-LVOT Area Calculation (A) Three-chamber CT view post-transcatheter mitral valve replacement (TMVR). (B and C) CT-derived 3-dimensional model post-TMVR shows neo-LVOT obstruction with a neo-LVOT area of 56 mm2. (D) Three-chamber CT view after second ASA. (E and F) CT-derived three-dimensional model after second ASA shows significantly increased neo-LVOT area (333 mm2). Abbreviations as in Figure 2.

Figure 5. Second ASA Procedure and LVOT Gradients (Before and After) (A and B) ASA of the second septal perforator (indicated by dashed white circle). (C and D) Echocardiography 6 weeks after second ASA shows a significant decrease in LVOT peak and mean gradient (22 mm Hg and 14 mm Hg, respectively) compared with the LVOT gradient during TMVR (peak 36 mm Hg; mean 22 mm Hg). (E and F) Echocardiography 6 weeks after second ASA shows a significant decrease in aortic valve peak and mean gradient (33 mm Hg and 21 mm Hg) compared with the aortic valve gradient during TMVR (peak 57 mm Hg; mean 36 mm Hg). Abbreviations as in Figure 2 and 4.

Figure 6. Computed Tomography Angiography 3-Chamber View at Different Time Points (A) Baseline situation. Virtual TMVR implantation (indicated by yellow lines) results in LVOT obstruction. Basal septum thickness is 21.6 mm. (B) Post first ASA. Basal septum thickness has decreased (now 15.4 mm). Virtual TMVR implantation exhibits a suitable neo-LVOT. (C) Post-TMVR. Unanticipated, recurrent thickening of the basal septum (18.3 mm) is observed. Displacement of the anterior mitral valve leaflet toward the LVOT further compromises the neo-LVOT. (D) Post second ASA. A significant decrease of the basal septum thickness and neo-LVOT expansion is observed. Basal septum thickness is 15.7 mm. Abbreviations as in Figure 2 and 4.

Figure 7. Timeline of Clinical Events Abbreviations as in Figure 2.