Effect of leaflet laceration on transcatheter aortic valve replacement fluid mechanics and comparison with surgical aortic valve replacement.

BACKGROUND: Leaflet thrombosis after surgical aortic valve replacement (SAVR) and transcatheter aortic valve replacement (TAVR) may be caused by blood flow stagnation in the native and neosinus regions. To date, aortic leaflet laceration has been used to mitigate coronary obstruction following TAVR; however, its influence on the fluid mechanics of the native and neosinus regions is poorly understood. This in vitro study compared the flow velocities and flow patterns in the setting of SAVR vs TAVR with and without aortic leaflet lacerations. METHODS: Two valves, (23-mm Perimount and 26-mm SAPIEN 3; Edwards Lifesciences) were studied in a validated mock flow loop under physiologic conditions. Neosinus and native sinus fluid mechanics were quantified using particle image velocimetry in the left and noncoronary cusp, with an increasing number of aortic leaflets lacerated or removed. RESULTS: Across all conditions, SAVR had the highest average sinus and neosinus velocities, and this value was used as a reference to compare against the TAVR conditions. With an increasing number of leaflets lacerated or removed with TAVR, the average sinus and neosinus velocities increased from 25% to 70% of SAVR flow (100%). Diastolic velocities were substantially augmented by leaflet laceration. Also, the shorter frame of the SAVR led to higher flow velocities compared with the longer frame of the TAVR, even after complete leaflet removal. CONCLUSIONS: Leaflet laceration augmented TAVR native and neosinus flow fields, approaching that of SAVR. These findings may have potential clinical implications for the use of single or multiple leaflet lacerations to reduce leaflet thrombosis and thus potentially improve TAVR durability.

LAMPOON techniques to prevent or manage left ventricular outflow tract obstruction in transcatheter mitral valve replacement.

Transcatheter mitral valve replacement (TMVR) is a therapeutic option for patients with severe mitral disease who are deemed inoperable due to their overall surgical risk. The close relationships between the left ventricular outflow tract (LVOT) and the anterior mitral valve leaflet can lead to LVOT obstruction, a common complication with high mortality. Predicting and preventing LVOT obstruction is therefore essential, prior to TMVR. Laceration of the Anterior Mitral leaflet to Prevent Outflow ObtructioN (LAMPOON) is a transcatheter electrosurgical technique to split the anterior mitral valve leaflet immediately prior to TMVR. The technique has been studied in a prospective clinical trial and has evolved with many iterations for specific anatomies. In this review, we discuss the different LAMPOON techniques to prevent and treat LVOT obstruction.

Transcatheter Replacement of Transcatheter Versus Surgically Implanted Aortic Valve Bioprostheses.

BACKGROUND: Surgical aortic valve replacement and transcatheter aortic valve replacement (TAVR) are now both used to treat aortic stenosis in patients in whom life expectancy may exceed valve durability. The choice of initial bioprosthesis should therefore consider the relative safety and efficacy of potential subsequent interventions. OBJECTIVES: The aim of this study was to compare TAVR in failed transcatheter aortic valves (TAVs) versus surgical aortic valves (SAVs). METHODS: Data were collected on 434 TAV-in-TAV and 624 TAV-in-SAV consecutive procedures performed at centers participating in the Redo-TAVR international registry. Propensity score matching was applied, and 330 matched (165:165) patients were analyzed. Principal endpoints were procedural success, procedural safety, and mortality at 30 days and 1 year. RESULTS: For TAV-in-TAV versus TAV-in-SAV, procedural success was observed in 120 (72.7%) versus 103 (62.4%) patients (p = 0.045), driven by a numerically lower frequency of residual high valve gradient (p = 0.095), ectopic valve deployment (p = 0.081), coronary obstruction (p = 0.091), and conversion to open heart surgery (p = 0.082). Procedural safety was achieved in 116 (70.3%) versus 119 (72.1%) patients (p = 0.715). Mortality at 30 days was 5 (3%) after TAV-in-TAV and 7 (4.4%) after TAV-in-SAV (p = 0.570). At 1 year, mortality was 12 (11.9%) and 10 (10.2%), respectively (p = 0.633). Aortic valve area was larger (1.55 ± 0.5 cm2 vs. 1.37 ± 0.5 cm2; p = 0.040), and the mean residual gradient was lower (12.6 ± 5.2 mm Hg vs. 14.9 ± 5.2 mm Hg; p = 0.011) after TAV-in-TAV. The rate of moderate or greater residual aortic regurgitation was similar, but mild aortic regurgitation was more frequent after TAV-in-TAV (p = 0.003). CONCLUSIONS: In propensity score-matched cohorts of TAV-in-TAV versus TAV-in-SAV patients, TAV-in-TAV was associated with higher procedural success and similar procedural safety or mortality.

Single-Barrel, Double-Barrel, and Fenestrated Endografts to Facilitate Transcatheter Pulmonary Valve Replacement in Large RVOT.

OBJECTIVES: The aim of this study was to test the hypothesis that narrowing the landing zone using commercially available endografts would enable transcatheter pulmonary valve replacement (TPVR) using commercially available transcatheter heart valves. BACKGROUND: TPVR is challenging in an outsized native or patch-repaired right ventricular outflow tract (RVOT). Downsizing the RVOT for TPVR is currently possible only using investigational devices. In patients ineligible because of excessive RVOT size, TPVR landing zones were created using commercially available endografts. METHODS: Consecutive patients with native or patch-repaired RVOTs and high or prohibitive surgical risk were reviewed, and this report describes the authors' experience with endograft-facilitated TPVR (EF-TPVR) offered to patients ineligible for investigational or commercial devices. All EF-TPVR patients were surgery ineligible, with symptomatic, severe pulmonary insufficiency, enlarged RVOTs, and severe right ventricular (RV) enlargement (>150 ml/m2). TPVR and surgical pulmonary valve replacement (SPVR) were compared in patients with less severe RV enlargement. RESULTS: Fourteen patients had large RVOTs unsuitable for conventional TPVR; 6 patients (1 surgery ineligible) received investigational devices, and 8 otherwise ineligible patients underwent compassionate EF-TPVR (n = 5 with tetralogy of Fallot). Three strategies were applied on the basis of progressively larger RVOT size: single-barrel, in situ fenestrated, and double-barrel endografts as required to anchor 1 (single-barrel and fenestrated) or 2 (double-barrel) transcatheter heart valves. All were technically successful, without procedure-related, 30-day, or in-hospital deaths. Two late complications (stent obstruction and embolization) were treated percutaneously. One patient died of ventricular tachycardia 36 days after EF-TPVR. Compared with 48 SPVRs, RV enlargement was greater, but 30-day and 1-year mortality and readmission were no different. The mean transvalvular pressure gradient was lower after EF-TPVR (3.8 ± 0.8 mm Hg vs. 10.7 ± 4.1 mm Hg; p < 0.001; 30 days). More than mild pulmonary insufficiency was equivalent in both (EF-TPVR 0.0% [n = 0 of 8] vs. SPVR 4.3% [n = 1 of 43]; p = 1.00; 30 days). CONCLUSIONS: EF-TPVR may be an alternative for patients with pulmonic insufficiency and enlarged RVOTs ineligible for other therapies.

Antegrade Intentional Laceration of the Anterior Mitral Leaflet to Prevent Left Ventricular Outflow Tract Obstruction: A Simplified Technique From Bench to Bedside.

BACKGROUND: Intentional laceration of the anterior mitral leaflet (LAMPOON) is an effective adjunct to transcatheter mitral valve replacement that prevents left ventricular outflow tract (LVOT) obstruction. To date, LAMPOON has been performed in over 150 patients using a retrograde approach that can be technically challenging. A modified antegrade transseptal technique may simplify the procedure. METHODS: Antegrade LAMPOON was developed and tested in nonsurvival pig experiments. Thereafter, antegrade LAMPOON was performed in patients at prohibitive risk of LVOT obstruction. Clinical, procedural, and angiographic details were abstracted from medical records of their index procedure, and were compared with findings in comparable patients at risk of fixed-LVOT obstruction in the LAMPOON investigational device exemption trial. RESULTS: Eight patients at risk of fixed LVOT obstruction underwent antegrade LAMPOON. Leaflet traversal and laceration were technically successful in all. There were no cases of clinically significant LVOT obstruction (mean LVOT gradient at discharge: 5.4±1.4 mm Hg). One patient suffered a ventricular wire perforation, unrelated to the antegrade LAMPOON technique, and did not survive to discharge. At the time of discharge, no patients had an increase of >10 mm Hg in LVOT gradient compared with baseline. Procedure times (from traversal to transcatheter mitral valve replacement) were shorter, compared with the retrograde technique in the LAMPOON investigational device exemption trial (39±09 versus 65±35 minutes). All patients survived (8/8, 100%) the procedure, and 7/8 (88%) survived to 30 days, similar to subjects in the LAMPOON investigational device exemption trial. CONCLUSIONS: Antegrade LAMPOON is an effective, reproducible, and simplified strategy to lacerate the anterior leaflet before transcatheter mitral valve replacement. The authors recommend the technique as the new standard for LAMPOON.

Repeat Transcatheter Aortic Valve Replacement for Transcatheter Prosthesis Dysfunction.

BACKGROUND: Transcatheter aortic valve replacement (TAVR) use is increasing in patients with longer life expectancy, yet robust data on the durability of transcatheter heart valves (THVs) are limited. Redo-TAVR may play a key strategy in treating patients in whom THVs fail. OBJECTIVES: The authors sought to examine outcomes following redo-TAVR. METHODS: The Redo-TAVR registry collected data on consecutive patients who underwent redo-TAVR at 37 centers. Patients were classified as probable TAVR failure or probable THV failure if they presented within or beyond 1 year of their index TAVR, respectively. RESULTS: Among 63,876 TAVR procedures, 212 consecutive redo-TAVR procedures were identified (0.33%): 74 within and 138 beyond 1 year of the initial procedure. For these 2 groups, TAVR-to-redo-TAVR time was 68 (38 to 154) days and 5 (3 to 6) years. The indication for redo-TAVR was THV stenosis in 12 (16.2%) and 51 (37.0%) (p = 0.002) and regurgitation or combined stenosis-regurgitation in 62 (83.8%) and 86 (62.3%) (p = 0.028), respectively. Device success using VARC-2 criteria was achieved in 180 patients (85.1%); most failures were attributable to high residual gradients (14.1%) or regurgitation (8.9%). At 30-day and 1-year follow-up, residual gradients were 12.6 ± 7.5 mm Hg and 12.9 ± 9.0 mm Hg; valve area 1.63 ± 0.61 cm2 and 1.51 ± 0.57 cm2; and regurgitation ≤mild in 91% and 91%, respectively. Peri-procedural complication rates were low (3 stroke [1.4%], 7 valve malposition [3.3%], 2 coronary obstruction [0.9%], 20 new permanent pacemaker [9.6%], no mortality), and symptomatic improvement was substantial. Survival at 30 days was 94.6% and 98.5% (p = 0.101) and 83.6% and 88.3% (p = 0.335) at 1 year for patients presenting with early and late valve dysfunction, respectively. CONCLUSIONS: Redo-TAVR is a relatively safe and effective option for selected patients with valve dysfunction after TAVR. These results are important for applicability of TAVR in patients with long life expectancy in whom THV durability may be a concern.

Novel Transcatheter Mitral Valve Prosthesis for Patients With Severe Mitral Annular Calcification.

BACKGROUND: Treatment of mitral regurgitation (MR) in the setting of severe mitral annular calcification (MAC) is challenging due to the high risk for fatal atrioventricular groove disruption and significant paravalvular leak. OBJECTIVES: The objective of this study was to evaluate the potential for transcatheter mitral valve replacement in patients with severe MAC using an anatomically designed mitral prosthesis. METHODS: Nine patients (77 ± 6 years of age; 5 men) were treated with the valve, using transapical delivery performed under general anesthesia and with guidance from transesophageal echocardiography and fluoroscopy. RESULTS: Device implantation was successful with relief of MR in all 9 patients. There were no procedural deaths. In 1 patient, left ventricular outflow tract obstruction occurred due to malrotation of the prosthesis, and successful alcohol septal ablation was performed. During a median follow-up of 12 months (range 1 to 28 months), there was 1 cardiac death, 1 noncardiac death, no other mortality, and no prosthetic dysfunction, and MR remained absent in all treated patients. Rehospitalization for heart failure occurred in 2 patients who did not die subsequently. Clinical improvement with mild or no symptoms occurred in all patients alive at the end of follow-up. CONCLUSIONS: Transcatheter mitral valve replacement in severe mitral annular calcification with a dedicated prosthesis is feasible and can result in MR relief with symptom improvement. Further evaluation of this approach for these high-risk patients is warranted.