Transcatheter Myotomy to Reduce Left Ventricular Outflow Obstruction

BACKGROUND

Left ventricular outflow tract (LVOT) obstruction is a source of morbidity in hypertrophic cardiomyopathy (HCM) and a life-threatening complication of transcatheter mitral valve replacement (TMVR) and transcatheter aortic valve replacement (TAVR). Available surgical and transcatheter approaches are limited by high surgical risk, unsuitable septal perforators, and heart block requiring permanent pacemakers.

OBJECTIVES

The authors report the initial experience of a novel transcatheter electrosurgical procedure developed to mimic surgical myotomy.

METHODS

We used septal scoring along midline endocardium (SESAME) to treat patients, on a compassionate basis, with symptomatic LVOT obstruction or to create space to facilitate TMVR or TAVR.

RESULTS

In this single-center retrospective study between 2021 and 2023, 76 patients underwent SESAME. In total, 11 (14%) had classic HCM, and the remainder underwent SESAME to facilitate TMVR or TAVR. All had technically successful SESAME myocardial laceration. Measures to predict post-TMVR LVOT significantly improved (neo-LVOT 42 mm2 [Q1-Q3: 7-117 mm2] to 170 mm2 [Q1-Q3: 95-265 mm2]; P < 0.001; skirt-neo-LVOT 169 mm2 [Q1-Q3: 153-193 mm2] to 214 mm2 [Q1-Q3: 180-262 mm2]; P < 0.001). Among patients with HCM, SESAME significantly decreased invasive LVOT gradients (resting: 54 mm Hg [Q1-Q3: 40-70 mm Hg] to 29 mm Hg [Q1-Q3: 12-36 mm Hg]; P = 0.023; provoked 146 mm Hg [Q1-Q3: 100-180 mm Hg] to 85 mm Hg [Q1-Q3: 40-120 mm Hg]; P = 0.076). A total of 74 (97.4%) survived the procedure. Five experienced 3 of 76 (3.9%) iatrogenic ventricular septal defects that did not require repair and 3 of 76 (3.9%) ventricular free wall perforations. Neither occurred in patients treated for HCM. Permanent pacemakers were required in 4 of 76 (5.3%), including 2 after concomitant TAVR. Lacerations were stable and did not propagate after SESAME (remaining septum: 5.9 ± 3.3 mm to 6.1 ± 3.2 mm; P = 0.8).

CONCLUSIONS

With further experience, SESAME may benefit patients requiring septal reduction therapy for obstructive hypertrophic cardiomyopathy as well as those with LVOT obstruction after heart valve replacement, and/or can help facilitate transcatheter valve implantation.

TABERNACL: Temporary Hemodynamic Stabilization In Vivo

BACKGROUND

Acute aortic regurgitation is life-threatening with few nonsurgical options for immediate stabilization. We propose Trans-Aortic Balloon to Ease Regurgitation Applying Counter-Pulsation (TABERNACL), a simple, on-table temporary valve using commercially available equipment to temporize acute severe aortic regurgitation.

METHODS

We hypothesize that an appropriately sized commercial balloon dilatation catheter-straddling the aortic annulus and connected to a counterpulsation console-can serve as a temporizing valve to restore hemodynamic stability in acute aortic regurgitation. We performed benchtop testing of valvuloplasty, angioplasty, and sizing balloons as counterpulsation balloons. TABERNACL was assessed in vivo in a porcine model of acute aortic regurgitation (n=8). We also tested a static undersized, continuously inflated transvalvular balloon as a spacer intended physically to obstruct the regurgitant orifice.

RESULTS

Benchtop testing identified that Tyshak II and PTS sizing (NuMed Braun) balloon catheters performed adequately as temporary valves (ie, complete inflation and deflation with each cycle) and resisted fatigue, in contrast to others. When TABERNACL was used in the acute severe regurgitation animals, there was immediate hemodynamic improvement, with a significant 35% increase in diastolic aortic pressure by 16 mm Hg ([95% CI, 7-25] P=0.0056), 34% reduction in left ventricular end-diastolic pressure by -7 mm Hg ([95% CI, -10 to -5] P=0.0006), improvement in the aortic diastolic index by 0.28 ([95% CI, 0.18-0.39] P=0.0009), and reversal of electrocardiographic myocardial ischemia. As an alternative, static balloon inflation across the aortic valve stabilized regurgitation hemodynamics at the expense of a new aortic gradient and caused excessive ectopy from balloon movement in the left ventricular outflow tract.

CONCLUSIONS

TABERNACL improves hemodynamics and reduces coronary ischemia by electrocardiography in animals with acute severe aortic regurgitation. TABERNACL valves obstruct the diastolic regurgitant orifice without systolic obstruction. This may prove a lifesaving bridge to definitive valve replacement therapy.

Non-invasive pressure-volume loops using the elastance model and CMR: a porcine validation at transient pre-loads

Aims

Pressure-volume (PV) loops have utility in the evaluation of cardiac pathophysiology but require invasive measurements. Recently, a time-varying elastance model to derive PV loops non-invasively was proposed, using left ventricular (LV) volume by cardiovascular magnetic resonance (CMR) and brachial cuff pressure as inputs. Validation was performed using CMR and pressure measurements acquired on the same day, but not simultaneously, and without varying pre-loads. This study validates the non-invasive elastance model used to estimate PV loops at varying pre-loads, compared with simultaneous measurements of invasive pressure and volume from real-time CMR, acquired concurrent to an inferior vena cava (IVC) occlusion.

Methods and results

We performed dynamic PV loop experiments under CMR guidance in 15 pigs (n = 7 naïve, n = 8 with ischaemic cardiomyopathy). Pre-load was altered by IVC occlusion, while simultaneously acquiring invasive LV pressures and volumes from real-time CMR. Pairing pressure and volume signals yielded invasive PV loops, and model-based PV loops were derived using real-time LV volumes. Haemodynamic parameters derived from invasive and model-based PV loops were compared. Across 15 pigs, 297 PV loops were recorded. Intra-class correlation coefficient (ICC) agreement was excellent between model-based and invasive parameters: stroke work (bias = 0.007 ± 0.03 J, ICC = 0.98), potential energy (bias = 0.02 ± 0.03 J, ICC = 0.99), ventricular energy efficiency (bias = -0.7 ± 2.7%, ICC = 0.98), contractility (bias = 0.04 ± 0.1 mmHg/mL, ICC = 0.97), and ventriculoarterial coupling (bias = 0.07 ± 0.15, ICC = 0.99). All haemodynamic parameters differed between naïve and cardiomyopathy animals (P < 0.05). The invasive vs. model-based PV loop dice similarity coefficient was 0.88 ± 0.04.

Conclusion

An elastance model-based estimation of PV loops and associated haemodynamic parameters provided accurate measurements at transient loading conditions compared with invasive PV loops.

Dynamic lung water MRI during exercise stress

PURPOSE

Exercise-induced dyspnea caused by lung water is an early heart failure symptom. Dynamic lung water quantification during exercise is therefore of interest to detect early stage disease. This study developed a time-resolved 3D MRI method to quantify transient lung water dynamics during rest and exercise stress.

METHODS

The method was evaluated in 15 healthy subjects and 2 patients with heart failure imaged in transitions between rest and exercise, and in a porcine model of dynamic extravascular lung water accumulation through mitral regurgitation (n = 5). Time-resolved images were acquired at 0.55T using a continuous 3D stack-of-spirals proton density weighted sequence with 3.5 mm isotropic resolution, and derived using a motion corrected sliding-window reconstruction with 90-s temporal resolution in 20-s increments. A supine MRI-compatible pedal ergometer was used for exercise. Global and regional lung water density (LWD) and percent change in LWD (ΔLWD) were automatically quantified.

RESULTS

A ΔLWD increase of 3.3 ± 1.5% was achieved in the animals. Healthy subjects developed a ΔLWD of 7.8 ± 5.0% during moderate exercise, peaked at 16 ± 6.8% during vigorous exercise, and remained unchanged over 10 min at rest (-1.4 ± 3.5%, p = 0.18). Regional LWD were higher posteriorly compared the anterior lungs (rest: 33 ± 3.7% vs 20 ± 3.1%, p < 0.0001; peak exercise: 36 ± 5.5% vs 25 ± 4.6%, p < 0.0001). Accumulation rates were slower in patients than healthy subjects (2.0 ± 0.1%/min vs 2.6 ± 0.9%/min, respectively), whereas LWD were similar at rest (28 ± 10% and 28 ± 2.9%) and peak exercise (ΔLWD 17 ± 10% vs 16 ± 6.8%).

CONCLUSION

Lung water dynamics can be quantified during exercise using continuous 3D MRI and a sliding-window image reconstruction.

Impact of Vasodilation on Oxygen-Enhanced Functional Lung MRI at 0.55 T

BACKGROUND

Oxygen-enhanced magnetic resonance imaging (OE-MRI) can be used to assess regional lung function without ionizing radiation. Inhaled oxygen acts as a T1-shortening contrast agent to increase signal in T1-weighted (T1w) images. However, increase in proton density from pulmonary hyperoxic vasodilation may also contribute to the measured signal enhancement. Our aim was to quantify the relative contributions of the T1-shortening and vasodilatory effects of oxygen to signal enhancement in OE-MRI in both swine and healthy volunteers.

METHODS

We imaged 14 anesthetized female swine (47 ± 8 kg) using a prototype 0.55 T high-performance MRI system while experimentally manipulating oxygenation and blood volume independently through oxygen titration, partial occlusion of the vena cava for volume reduction, and infusion of colloid fluid (6% hydroxyethyl starch) for volume increase. Ten healthy volunteers were imaged before, during, and after hyperoxia. Two proton density-weighted (PDw) and 2 T1w ultrashort echo time images were acquired per experimental state. The median PDw and T1w percent signal enhancement (PSE), compared with baseline room air, was calculated after image registration and correction for lung volume changes. Differences in median PSE were compared using Wilcoxon signed rank test.

RESULTS

The PSE in PDw images after 100% oxygen was similar in swine (1.66% ± 1.41%, P = 0.01) and in healthy volunteers (1.99% ± 1.79%, P = 0.02), indicating that oxygen-induced pulmonary vasodilation causes ~2% lung proton density increase. The PSE in T1w images after 100% oxygen was also similar (swine, 9.20% ± 1.68%, P < 0.001; healthy volunteers, 10.10% ± 3.05%, P < 0.001). The PSE in T1w enhancement was oxygen dose-dependent in anesthetized swine, and we measured a dose-dependent PDw image signal increase from infused fluids.

CONCLUSIONS

The contribution of oxygen-induced vasodilation to T1w OE-MRI signal was measurable using PDw imaging and was found to be ~2% in both anesthetized swine and in healthy volunteers. This finding may have implications for patients with regional or global hypoxia or vascular dysfunction undergoing OE-MRI and suggest that PDw imaging may be useful to account for oxygen-induced vasodilation in OE-MRI.

First Application of the LAMPOON Procedure to a Surgical Mitral Bioprosthesis

A cardiogenic shock patient with a history of a surgical mitral valve replacement presented to the hospital with critical mitral stenosis with thickening of prosthetic valve leaflets and thrombus in left atrial appendage. We considered TMVR inside of the degenerated bioprosthetic valve. However, there were two concerns during TMVR based on multimodality imaging assessment: 1) LVOT obstruction due to the surgical bioprosthetic leaflet, 2) stroke due to left atrial appendage thrombus. We performed TMVR with LAMPOON (laceration of the anterior leaflet of the surgical valve to prevent left ventricular outflow tract obstruction) for the bioprosthesis using cerebral protection. While the LAMPOON procedure has developed to prevent LVOT obstruction by the native anterior mitral leaflet during transcatheter mitral valve-in-ring or valve-in-mitral annular calcification, this is the first case that illustrates its use for mitral valve-in-valve replacement.

EDEN (Electrocardiographic Radial Depth Navigation): A Novel Approach to Navigate Inside Heart Muscle

BACKGROUND

Intramyocardial guidewire navigation is a novel technique that allows free transcatheter movement within ventricular muscle. Guidewire radial depth, between endocardial and epicardial surfaces, is ambiguous by x-ray and echocardiography.

OBJECTIVES

The aim of this study was to develop a simple tool, EDEN (Electrocardiographic Radial Depth Navigation), to indicate radial depth during intramyocardial guidewire navigation. Combined with routine imaging, EDEN facilitates a new family of intramyocardial catheter procedures to slice, reshape, pace, and ablate the heart.

METHODS

We mapped intramyocardial electrograms of left and right ventricular walls and septum during open- and closed-chest swine procedures (N = 53), including MIRTH (Myocardial Intramural Remodeling by Transvenous Tether) ventriculoplasty. We identified radial depth-dependent features on unipolar electrograms. We developed a machine learning-based classifier to indicate categorical position, and modeled the findings in silico to test understanding of the physiology.

RESULTS

EDEN signatures distinguished 5 depth zones throughout left and right ventricular free walls and interventricular septum. Relative ST-segment elevation magnitude best discriminated position and was maximum (40.1 ± 6.5 mV) in the midmyocardium. Subendocardial positions exhibited dominant Q waves with lower-amplitude ST segments (16.8 ± 5.8 mV), whereas subepicardial positions exhibited dominant R waves with lower-amplitude ST segments (15.7 ± 4.8 mV). EDEN was unaffected by pacing-induced left bundle branch block. ST-segment elevation declined over minutes and reappeared after submillimeter guidewire manipulation. Modeling recapitulated EDEN features. The machine learning-based classifier was 97% accurate. EDEN successfully guided MIRTH ventriculoplasty.

CONCLUSIONS

EDEN provides a simple and reproducible real-time reflection of categorical guidewire-tip radial depth during intramyocardial guidewire navigation. Used in tandem with x-ray, EDEN enables novel, transcatheter, intramyocardial therapies such as MIRTH, SESAME (Septal Surfing Along Midline Endocardium), and cerclage ventriculoplasty.

Transcatheter Electrosurgery: A Narrative Review

Transcatheter electrosurgery describes the ability to cut and traverse tissue, at a distance, without an open surgical field and is possible using either purpose-built or off-the-shelf devices. Tissue traversal requires focused delivery of radiofrequency energy to a guidewire tip. Initially employed to cross atretic pulmonary valves, tissue traversal has enabled transcaval aortic access, recanalization of arterial and venous occlusions, transseptal access, and many other techniques. To cut tissue, the selectively denuded inner curvature of a kinked guidewire (the Flying-V) or a single-loop snare is energized during traction. Adjunctive techniques may complement or enable contemporary transcatheter procedures, whereas myocardial slicing or excision of ectopic masses may offer definitive therapy. In this contemporary review we discuss the principles of transcatheter electrosurgery, and through exemplary clinical applications highlight the range of therapeutic options offered by this versatile family of procedures.

Coronary Obstruction From TAVR in Native Aortic Stenosis: Development and Validation of Multivariate Prediction Model

BACKGROUND

Transcatheter aortic valve replacement (TAVR)-related coronary artery obstruction prediction remains unsatisfactory despite high mortality and novel preventive therapies.

OBJECTIVES

This study sought to develop a predictive model for TAVR-related coronary obstruction in native aortic stenosis.

METHODS

Preprocedure computed tomography and fluoroscopy images of patients in whom TAVR caused coronary artery obstruction were collected. Central laboratories made measurements, which were compared with unobstructed patients from a single-center database. A multivariate model was developed and validated against a 1:1 propensity-matched subselection of the unobstructed cohort.

RESULTS

Sixty patients with angiographically confirmed coronary obstruction and 1,381 without obstruction were included. In-hospital death was higher in the obstruction cohort (26.7% vs 0.7%; P < 0.001). Annular area and perimeter, coronary height, sinus width, and sinotubular junction height and width were all significantly smaller in the obstructed cohort. Obstruction was most common on the left side (78.3%) and at the level of the coronary artery ostium (92.1%). Coronary artery height and sinus width, but not annulus area, were significant risk factors for obstruction by logistic regression but performed poorly in predicting obstruction. The new multivariate model (coronary obstruction IF cusp height > coronary height, AND virtual valve-to-coronary distance ≤4 mm OR culprit leaflet calcium volume >600 mm3) performed well, with an area under the curve of 0.93 (sensitivity = 0.93, specificity = 0.84) for the left coronary artery and 0.94 (sensitivity = 0.92, specificity = 0.96) for the right.

CONCLUSIONS

A novel computed tomography-based multivariate prediction model that can be implemented routinely in real-world practice predicted coronary artery obstruction from TAVR in native aortic stenosis.

An interventional MRI guidewire combining profile and tip conspicuity for catheterization at 0.55T

PURPOSE

We describe a clinical grade, "active", monopole antenna-based metallic guidewire that has a continuous shaft-to-tip image profile, a pre-shaped tip-curve, standard 0.89 mm (0.035″) outer diameter, and a detachable connector for catheter exchange during cardiovascular catheterization at 0.55T.

METHODS

Electromagnetic simulations were performed to characterize the magnetic field around the antenna whip for continuous tip visibility. The active guidewire was manufactured using medical grade materials in an ISO Class 7 cleanroom. RF-induced heating of the active guidewire prototype was tested in one gel phantom per ASTM 2182-19a, alone and in tandem with clinical metal-braided catheters. Real-time MRI visibility was tested in one gel phantom and in-vivo in two swine. Mechanical performance was compared with commercial equivalents.

RESULTS

The active guidewire provided continuous "profile" shaft and tip visibility in-vitro and in-vivo, analogous to guidewire shaft-and-tip profiles under X-ray. The MRI signal signature matched simulation results. Maximum unscaled RF-induced temperature rise was 5.2°C and 6.5°C (3.47 W/kg local background specific absorption rate), alone and in tandem with a steel-braided catheter, respectively. Mechanical characteristics matched commercial comparator guidewires.

CONCLUSION

The active guidewire was clearly visible via real-time MRI at 0.55T and exhibits a favorable geometric sensitivity profile depicting the guidewire continuously from shaft-to-tip including a unique curved-tip signature. RF-induced heating is clinically acceptable. This design allows safe device navigation through luminal structures and heart chambers. The detachable connector allows delivery and exchange of cardiovascular catheters while maintaining guidewire position. This enhanced guidewire design affords the expected performance of X-ray guidewires during human MRI catheterization.

Dynamic pressure-volume loop analysis by simultaneous real-time cardiovascular magnetic resonance and left heart catheterization

BACKGROUND

Left ventricular (LV) contractility and compliance are derived from pressure-volume (PV) loops during dynamic preload reduction, but reliable simultaneous measurements of pressure and volume are challenging with current technologies. We have developed a method to quantify contractility and compliance from PV loops during a dynamic preload reduction using simultaneous measurements of volume from real-time cardiovascular magnetic resonance (CMR) and invasive LV pressures with CMR-specific signal conditioning.

METHODS

Dynamic PV loops were derived in 16 swine (n = 7 naïve, n = 6 with aortic banding to increase afterload, n = 3 with ischemic cardiomyopathy) while occluding the inferior vena cava (IVC). Occlusion was performed simultaneously with the acquisition of dynamic LV volume from long-axis real-time CMR at 0.55 T, and recordings of invasive LV and aortic pressures, electrocardiogram, and CMR gradient waveforms. PV loops were derived by synchronizing pressure and volume measurements. Linear regression of end-systolic- and end-diastolic- pressure-volume relationships enabled calculation of contractility. PV loops measurements in the CMR environment were compared to conductance PV loop catheter measurements in 5 animals. Long-axis 2D LV volumes were validated with short-axis-stack images.

RESULTS

Simultaneous PV acquisition during IVC-occlusion was feasible. The cardiomyopathy model measured lower contractility (0.2 ± 0.1 mmHg/ml vs 0.6 ± 0.2 mmHg/ml) and increased compliance (12.0 ± 2.1 ml/mmHg vs 4.9 ± 1.1 ml/mmHg) compared to naïve animals. The pressure gradient across the aortic band was not clinically significant (10 ± 6 mmHg). Correspondingly, no differences were found between the naïve and banded pigs. Long-axis and short-axis LV volumes agreed well (difference 8.2 ± 14.5 ml at end-diastole, -2.8 ± 6.5 ml at end-systole). Agreement in contractility and compliance derived from conductance PV loop catheters and in the CMR environment was modest (intraclass correlation coefficient 0.56 and 0.44, respectively).

CONCLUSIONS

Dynamic PV loops during a real-time CMR-guided preload reduction can be used to derive quantitative metrics of contractility and compliance, and provided more reliable volumetric measurements than conductance PV loop catheters.

Reshaping the Ventricle From Within: MIRTH (Myocardial Intramural Remodeling by Transvenous Tether) Ventriculoplasty in Swine

MIRTH (Myocardial Intramural Remodeling by Transvenous Tether) is a transcatheter ventricular remodeling procedure. A transvenous tension element is placed within the walls of the beating left ventricle and shortened to narrow chamber dimensions. MIRTH uses 2 new techniques: controlled intramyocardial guidewire navigation and EDEN (Electrocardiographic Radial Depth Navigation). MIRTH caused a sustained reduction in chamber dimensions in healthy swine. Midventricular implants approximated papillary muscles. MIRTH shortening improved myocardial contractility in cardiomyopathy in a dose-dependent manner up to a threshold beyond which additional shortening reduced performance. MIRTH may help treat dilated cardiomyopathy. Clinical investigation is warranted.

Transcatheter Mitral Cerclage Ventriculoplasty: From Bench to Bedside

BACKGROUND

Transcatheter mitral valve repair is beneficial in patients with mitral regurgitation (MR), left ventricular dysfunction, and persistent symptoms despite maximally tolerated medical therapy.

OBJECTIVES

The aim of this study was to evaluate the safety and feasibility of transcatheter mitral cerclage ventriculoplasty in patients with MR and either heart failure with reduced ejection fraction or preserved ejection fraction and in subjects with prior edge-to-edge repair but persistent or recurrent symptomatic MR.

METHODS

The National Heart, Lung, and Blood Institute Division of Intramural Research Transcatheter Mitral Cerclage Ventriculoplasty Early Feasibility Study (NCT03929913) was an investigator-initiated prospective multicenter study. The primary endpoint was technical success measured at exit from the catheterization laboratory. Follow-up included heart failure quality-of-life assessments and serial imaging with echocardiography and cardiac computed tomography.

RESULTS

Nineteen subjects consented and underwent cerclage, 63% with heart failure with reduced ejection fraction and 37% with heart failure with preserved ejection fraction, with ischemic cardiomyopathy in 26% and nonischemic cardiomyopathy in 74%. There were no procedural deaths, strokes, or transient ischemic attacks or other major cardiovascular adverse events. The primary endpoint was met in 17 subjects. Cerclage induced sustained reductions in mitral regurgitant volume (-41%) and effective orifice area (-33%) after a median of 337 days. Cerclage resulted in improvements in 6-minute walking distance (+78 m) and Kansas City Cardiomyopathy Questionnaire Overall Summary Score (+22 points) at 30 days that were maintained after a median of 265 days. New complete heart block developed in 6 of 17 subjects. Three deaths occurred on postprocedural days 79, 159, and 756, unrelated to cerclage.

CONCLUSIONS

Transcatheter mitral cerclage ventriculoplasty resulted in significant and sustained improvements in mitral regurgitation and in heart failure quality-of-life assessments.

Assessing the Hemodynamic Impact of Anterior Leaflet Laceration in Transcatheter Mitral Valve Replacement: An in silico Study

Background

A clinical study comparing the hemodynamic outcomes of transcatheter mitral valve replacement (TMVR) with vs. without Laceration of the Anterior Mitral leaflet to Prevent Outflow Obstruction (LAMPOON) has never been designed nor conducted.

Aims

To quantify the hemodynamic impact of LAMPOON in TMVR using patient-specific computational (in silico) models.

Materials

Eight subjects from the LAMPOON investigational device exemption trial were included who had acceptable computed tomography (CT) data for analysis. All subjects were anticipated to be at prohibitive risk of left ventricular outflow tract (LVOT) obstruction from TMVR, and underwent successful LAMPOON immediately followed by TMVR. Using post-procedure CT scans, two 3D anatomical models were created for each subject: (1) TMVR with LAMPOON (performed procedure), and (2) TMVR without LAMPOON (virtual control). A validated computational fluid dynamics (CFD) paradigm was then used to simulate the hemodynamic outcomes for each condition.

Results

LAMPOON exposed on average 2 ± 0.6 transcatheter valve cells (70 ± 20 mm² total increase in outflow area) which provided an additional pathway for flow into the LVOT. As compared to TMVR without LAMPOON, TMVR with LAMPOON resulted in lower peak LVOT velocity, lower peak LVOT gradient, and higher peak LVOT effective orifice area by 0.4 ± 0.3 m/s (14 ± 7% improvement, p = 0.006), 7.6 ± 10.9 mmHg (31 ± 17% improvement, p = 0.01), and 0.2 ± 0.1 cm² (17 ± 9% improvement, p = 0.002), respectively.

Conclusion

This was the first study to permit a quantitative, patient-specific comparison of LVOT hemodynamics following TMVR with and without LAMPOON. The LAMPOON procedure achieved a critical increment in outflow area which was effective for improving LVOT hemodynamics, particularly for subjects with a small neo-left ventricular outflow tract (neo-LVOT).

Transcatheter Myotomy to Relieve Left Ventricular Outflow Tract Obstruction: The Septal Scoring Along the Midline Endocardium Procedure in Animals

BACKGROUND

Left ventricular outflow tract obstruction complicates hypertrophic cardiomyopathy and transcatheter mitral valve replacement. Septal reduction therapies including surgical myectomy and alcohol septal ablation are limited by surgical morbidity or coronary anatomy and high pacemaker rates, respectively. We developed a novel transcatheter procedure, mimicking surgical myotomy, called Septal Scoring Along the Midline Endocardium (SESAME).

METHODS

SESAME was performed in 5 naive pigs and 5 pigs with percutaneous aortic banding-induced left ventricular hypertrophy. Fluoroscopy and intracardiac echocardiography guided the procedures. Coronary guiding catheters and guidewires were used to mechanically enter the basal interventricular septum. Imparting a tip bend to the guidewire enabled intramyocardial navigation with multiple df. The guidewire trajectory determined the geometry of SESAME myotomy. The myocardium was lacerated using transcatheter electrosurgery. Cardiac function and tissue characteristics were assessed by cardiac magnetic resonance at baseline, postprocedure, and at 7- or 30-day follow-up.

RESULTS

SESAME myotomy along the intended trajectory was achieved in all animals. The myocardium splayed after laceration, increasing left ventricular outflow tract area (753 to 854 mm², P=0.008). Two naive pigs developed ventricular septal defects due to excessively deep lacerations in thin baseline septa. No hypertrophy model pig, with increased septal thickness and left ventricular mass compared with naive pigs, developed ventricular septal defects. One animal developed left axis deviation on ECG but no higher conduction block was seen in any animal. Coronary artery branches were intact on angiography with no infarction on cardiac magnetic resonance late gadolinium imaging. Cardiac magnetic resonance chamber volumes, function, flow, and global strain were preserved. No myocardial edema was evident on cardiac magnetic resonance T1 mapping.

CONCLUSIONS

This preclinical study demonstrated feasibility of SESAME, a novel transcatheter myotomy to relieve left ventricular outflow tract obstruction. This percutaneous procedure using available devices, with a safe surgical precedent, is readily translatable into patients.

Transcaval Versus Transaxillary TAVR in Contemporary Practice: A Propensity-Weighted Analysis

OBJECTIVES

The aim of this study was to compare transcaval and transaxillary artery access for transcatheter aortic valve replacement (TAVR) at experienced medical centers in contemporary practice.

BACKGROUND

There are no systematic comparisons of transcaval and transaxillary TAVR access routes.

METHODS

Eight experienced centers contributed local data collected for the STS/ACC TVT Registry (Society of Thoracic Surgeons/American College of Cardiology Transcatheter Valve Therapy Registry) between 2017 and 2020. Outcomes after transcaval and axillary/subclavian (transaxillary) access were adjusted for baseline imbalances using doubly robust (inverse propensity weighting plus regression) estimation and compared.

RESULTS

Transcaval access was used in 238 procedures and transaxillary access in 106; for comparison, transfemoral access was used in 7,132 procedures. Risk profiles were higher among patients selected for nonfemoral access but similar among patients requiring transcaval and transaxillary access. Stroke and transient ischemic attack were 5-fold less common after transcaval than transaxillary access (2.5% vs 13.2%; OR: 0.20; 95% CI: 0.06-0.72; P = 0.014) compared with transfemoral access (1.7%). Major and life-threatening bleeding (Valve Academic Research Consortium 3 ≥ type 2) were comparable (10.0% vs 13.2%; OR: 0.66; 95% CI: 0.26-1.66; P = 0.38) compared with transfemoral access (3.5%), as was blood transfusion (19.3% vs 21.7%; OR: 1.07; 95% CI: 0.49-2.33; P = 0.87) compared with transfemoral access (7.1%). Vascular complications, intensive care unit and hospital length of stay, and survival were similar between transcaval and transaxillary access. More patients were discharged directly home and without stroke or transient ischemic attack after transcaval than transaxillary access (87.8% vs 62.3%; OR: 5.19; 95% CI: 2.45-11.0; P < 0.001) compared with transfemoral access (90.3%).

CONCLUSIONS

Patients undergoing transcaval TAVR had lower rates of stroke and similar bleeding compared with transaxillary access in a contemporary experience from 8 US centers. Both approaches had more complications than transfemoral access. Transcaval TAVR access may offer an attractive option.

Safeguards and pitfalls for Bioprosthetic or Native Aortic Scallop Intentional Laceration to Prevent Iatrogenic Coronary Artery Obstruction during transcatheter aortic valve replacement-the BASILICA technique

Coronary artery obstruction is a devastating complication of transcatheter aortic valve replacement (TAVR). Bioprosthetic or native Aortic Scallop Intentional Laceration to prevent Iatrogenic Coronary Artery Obstruction (BASILICA) is a transcatheter, electrosurgical technique that was developed to prevent obstruction due to sinus effacement or sinus sequestration. BASILICA creates a midline laceration of one (solo) or both (doppio) offending aortic leaflets and has been performed in over 1,000 patients at high risk for obstruction. The procedure has been studied in the prospective BASILICA IDE Trial and data from the International BASILICA Registry of 214 patients supports efficacy and safety; procedural success was achieved in 94.4% and at thirty days 95.3% were free from culprit coronary artery obstruction, all-cause mortality was 2.8% and disabling stroke was reported in only 0.5%. In this review we discuss screening for patients at high risk for coronary artery obstruction, technical details related to performing the BASILICA procedure and how to troubleshoot a BASILICA procedure.

Balloon-Augmented Leaflet Modification With Bioprosthetic or Native Aortic Scallop Intentional Laceration to Prevent Iatrogenic Coronary Artery Obstruction and Laceration of the Anterior Mitral Leaflet to Prevent Outflow Obstruction: Benchtop Validation and First In-Man Experience

BACKGROUND

Bioprosthetic or native aortic scallop intentional laceration to prevent iatrogenic coronary artery obstruction (BASILICA) and laceration of the anterior mitral leaflet to prevent outflow obstruction (LAMPOON) reduce the risk of coronary and left ventricular outflow obstruction obstruction during transcatheter aortic valve replacement and transcatheter mitral valve replacement. Despite successful laceration, BASILICA or LAMPOON may fail to prevent obstruction caused by inadequate leaflet splay in patients having challenging anatomy such as very small valve-to-coronary distance, diffusely calcified, rigid leaflets, or undergoing transcatheter aortic valve replacement inside existing transcatheter aortic valve replacement. We describe a novel technique of balloon-augmented (BA) leaflet laceration to enhance leaflet splay.

METHODS

We measured the incremental leaflet splay from BA-BASILICA in vitro. From November 2019 to March 2021, 16 patients underwent BA-BASILICA and 4 BA-LAMPOON at 3 centers.

RESULTS

BA-BASILICA increased benchtop leaflet tip splay 17%, maximum splay angle 30%, and splay area 23%, resulting in a more rounded apex and larger effective area. Sixteen patients at risk for inadequate BASILICA leaflet splay, including 4 transcatheter aortic valve replacement inside existing transcatheter aortic valve replacement, underwent BA-BASILICA. All had successful leaflet laceration. One had coronary obstruction requiring immediate orthotopic stenting. Two underwent elective orthotopic coronary stenting through the transcatheter valve cells for leaflet prolapse without coronary ischemia. There were no deaths during the procedure or at 30 days. Four patients at risk for inadequate anterior mitral leaflet splay underwent BA-LAMPOON. All had successful target leaflet laceration without left ventricular outflow obstruction obstruction or procedural death. One died within 30 days.

CONCLUSIONS

BA leaflet laceration enhances leaflet splay in vitro and may allow transcatheter aortic valve replacement and transcatheter mitral valve replacement in patients otherwise ineligible for traditional BASILICA or LAMPOON due to challenging anatomy. Graphic Abstract: A graphic abstract is available for this article.

Early Leaflet Thickening, Durability and Bioprosthetic Valve Failure in TAVR

All bioprosthetic valves, both surgical and transcatheter, have a finite lifespan before their leaflets inevitably degenerate, leading to stenosis or regurgitation. As younger, low-risk patients receive a transcatheter aortic valve, it is expected that they will most likely outlive their bioprosthetic valve. The heterogeneity of studies regarding surgical valve durability makes the interpretation of the data challenging. Leaflet thickening is seen in transcatheter heart valves but currently there is no evidence that it leads to premature valve deterioration or clinical events. Standardized definitions of structural valve deterioration should allow for comparisons between future clinical trials to assess the durability of different transcatheter heart valves.

One-Year Outcomes After Treatment of Ostial In-Stent Restenosis in Left Circumflex Versus Left Anterior Descending or Right Coronary Artery

The prognosis of left circumflex (LC) versus non-LC in-stent restenosis (ISR) ostial lesions following treatment has not been assessed. We aimed to assess this prognosis. Anecdotally, treatment of ostial LC ISR has been associated with high recurrence rates. We performed a retrospective analysis of patients from our institution who underwent coronary intervention of an ostial ISR lesion between 2003 and 2018. The primary endpoint was target lesion revascularization (TLR) and major adverse cardiovascular events (MACE). Overall, 563 patients underwent ostial ISR lesion intervention, 144 for an ostial LC ISR lesion. Compared to patients with ostial ISR in non-LC lesions, patients with ostial LC ISR were older, had higher rates of diabetes mellitus and previous coronary bypass surgery. At 1-year follow-up, TLR-MACE rates were 26.6% in the LC group versus 18.4% in the non-LC group (p = 0.036). The TLR rate was also higher in the LC group compared to the non-LC group (p = 0.0498). Univariate and multivariate analyses demonstrated a higher TLR-MACE rate for LC versus non-LC ostial ISR lesions. In conclusion, our study shows increased event rates after treatment of LC versus non-LC ISR lesions. Further studies should be done to assess the optimal treatment approach for ostial LC ISR.

Transcatheter Versus Surgical Aortic Valve Replacement in Young, Low-Risk Patients With Severe Aortic Stenosis

Transcatheter aortic valve replacement (TAVR) is approved for all patient risk profiles and is an option for all patients irrespective of age. However, patients enrolled in the low- and intermediate-risk trials were in their 70s, and those in the high-risk trials were in their 80s. TAVR has never been systematically tested in young (<65 years), low-risk patients. Unanswered questions remain, including the safety and effectiveness of TAVR in patients with bicuspid aortic valves; future coronary access; durability of transcatheter heart valves; technical considerations for surgical transcatheter heart valve explantation; management of concomitant conditions such as aortopathy, mitral valve disease, and coronary artery disease; and the safety and feasibility of future TAVR-in-TAVR. The authors predict that balancing these questions with patients' clear preference for less invasive treatment will become common. In this paper, the authors consider each of these questions and discuss risks and benefits of theoretical treatment strategies in the lifetime management of young patients with severe aortic stenosis.

BASILICA Trial: One-Year Outcomes of Transcatheter Electrosurgical Leaflet Laceration to Prevent TAVR Coronary Obstruction

[Figure: see text].

Dynamic nature of the LVOT following transcatheter mitral valve replacement with LAMPOON: new insights from post-procedure imaging

AIMS

To characterize the dynamic nature of the left ventricular outflow tract (LVOT) geometry and flow rate in patients following transcatheter mitral valve replacement (TMVR) with anterior leaflet laceration (LAMPOON) and derive insights to help guide future patient selection.

METHODS AND RESULTS

Time-resolved LVOT geometry and haemodynamics were analysed with post-procedure computed tomography and echocardiography in subjects (N = 19) from the LAMPOON investigational device exemption trial. A novel post hoc definition for LVOT obstruction was employed to account for systolic flow rate and quality of life improvement [obstruction was defined as LVOT gradient >30 mmHg or LVOT effective orifice area (EOA) ≤1.15 cm2]. The neo-LVOT and skirt neo-LVOT were observed to vary substantially in area throughout systole (64 ± 27% and 25 ± 14% change in area, respectively). The peak systolic flow rate occurred most commonly just prior to mid-systole, while minimum neo-LVOT (and skirt neo-LVOT) area occurred most commonly in early-diastole. Subjects with LVOT obstruction (n = 5) had smaller skirt neo-LVOT values across systole. Optimal thresholds for skirt neo-LVOT area were phase-specific (260, 210, 200, and 180 mm2 for early-systole, peak flow, mid-systole, and end-systole, respectively).

CONCLUSION

The LVOT geometry and flow rate exhibit dynamic characteristics following TMVR with LAMPOON. Subjects with LVOT obstruction had smaller skirt neo-LVOT areas across systole. The authors recommend the use of phase-specific threshold values for skirt neo-LVOT area to guide future patient selection for this procedure. LVOT EOA is a 'flow-independent' metric which has the potential to aid in characterizing LVOT obstruction severity.

Preventing Coronary Obstruction During Transcatheter Aortic Valve Replacement: Results From the Multicenter International BASILICA Registry

OBJECTIVES

This study sought to determine the safety of the BASILICA (bioprosthetic or native aortic scallop intentional laceration to prevent iatrogenic coronary artery obstruction) procedure.

BACKGROUND

Transcatheter aortic valve replacement causes coronary artery obstruction in 0.7% of cases, with 40% to 50% mortality. BASILICA is a procedure to prevent coronary obstruction. Safety and feasibility in a large patient cohort is lacking.

METHODS

The international BASILICA registry was a retrospective, multicenter, real-world registry of patients at risk of coronary artery obstruction undergoing BASILICA and transcatheter aortic valve replacement. Valve Academic Research Consortium-2 definitions were used to adjudicate events.

RESULTS

Between June 2017 and December 2020, 214 patients were included from 25 centers in North America and Europe; 72.8% had bioprosthetic aortic valves and 78.5% underwent solo BASILICA. Leaflet traversal was successful in 94.9% and leaflet laceration in 94.4%. Partial or complete coronary artery obstruction was seen in 4.7%. Procedure success, defined as successful BASILICA traversal and laceration without mortality, coronary obstruction, or emergency intervention, was achieved in 86.9%. Thirty-day mortality was 2.8% and stroke was 2.8%, with 0.5% disabling stroke. Thirty-day death and disabling stroke were seen in 3.4%. Valve Academic Research Consortium-2 composite safety was achieved in 82.8%. One-year survival was 83.9%. Outcomes were similar between solo and doppio BASILICA, between native and bioprosthetic valves, and with the use of cerebral embolic protection.

CONCLUSIONS

BASILICA is safe, with low reported rates of stroke and death. BASILICA is feasible in the real-world setting, with a high procedure success rate and low rates of coronary artery obstruction.

Tip-to-Base LAMPOON for Transcatheter Mitral Valve Replacement With a Protected Mitral Annulus

OBJECTIVES

The purpose of this study was to evaluate tip-to-base intentional laceration of the anterior mitral leaflet to prevent left ventricular outflow tract obstruction (LAMPOON) in patients undergoing transcatheter mitral valve replacement (TMVR) in annuloplasty rings or surgical mitral valves.

BACKGROUND

LAMPOON is an effective adjunct to TMVR that prevents left ventricular outflow tract obstruction (LVOTO). Laceration is typically performed from the base to the tip of the anterior mitral leaflet. A modified laceration technique from leaflet tip to base may be effective in patients with a prosthesis that protects the aortomitral curtain.

METHODS

This is a multicenter, 21-patient, consecutive retrospective observational cohort. Patients underwent tip-to-base LAMPOON to prevent LVOTO and leaflet overhang, or therapeutically to lacerate a long anterior mitral leaflet risking or causing LVOTO. Outcomes were compared with findings from patients in the LAMPOON investigational device exemption trial with a prior mitral annuloplasty.

RESULTS

Twenty-one patients with a annuloplasty or valve prosthesis-protected mitral annulus underwent tip-to-base LAMPOON (19 preventive, 2 rescue). Leaflet laceration was successful in all and successfully prevented or treated LVOTO in all patients. No patients had significant LVOTO upon discharge. There were 2 cases of unintentional aortic valve injury (1 patient underwent emergency transcatheter aortic valve replacement and 1 patient underwent urgent surgical aortic valve replacement). In both cases, the patients had a supra-annular ring annuloplasty, and the retrograde aortic guiding catheter failed to insulate the guidewire lacerating surface from the aortic root. All patients survived to 30 days. Compared with classic retrograde LAMPOON, there was a trend toward shorter procedure time.

CONCLUSIONS

Tip-to-base laceration is a simple, effective, and safe LAMPOON variant applicable to patients with an appropriately positioned mitral annular ring or bioprosthetic valve. Operators should take care to insulate the lacerating surface from adjacent structures.

Advances in Transcatheter Electrosurgery for Treating Valvular Heart Disease

Delivery of electrosurgery energy through catheters and guidewires enables interventionists to ‘cut’ through obstructive intravascular lesions or across cardiac chambers. A novel application of transcatheter electrosurgery is to make controlled lacerations in heart valve leaflets. This review describes three applications of transcatheter electrosurgery of aortic and mitral valve leaflets to enable transcatheter heart valve implantation. Intentional laceration of the anterior mitral leaflet to prevent left ventricular outflow obstruction splits and splays the anterior mitral valve and enables transcatheter mitral valve replacement without left ventricular outflow tract obstruction. Technique modifications and novel applications are described. Bioprosthetic or native aortic scallop intentional laceration to prevent iatrogenic coronary artery obstruction enables transcatheter aortic valve replacement without coronary artery obstruction. The technique is described and novel uses, especially in the setting of repeat transcatheter aortic valve replacement, are discussed. Finally, electrosurgical laceration and stabilization of mitral valve clip devices (ELASTA-Clip) enables transcatheter mitral valve replacement after MitraClip implantation. In conclusion, transcatheter electrosurgery is an important and versatile new tool in structural heart intervention.

Real-world experience of suture-based closure devices: Insights from the FDA Manufacturer and User Facility Device Experience

OBJECTIVES

We analyzed post-marketing surveillance data from the United States Food and Drug Administration (FDA) Manufacturer and User Facility Device Experience (MAUDE) database for suture-based vascular closure devices (VCDs) - Perclose ProGlide (Abbott, Chicago, Illinois) and Prostar XL (Abbott).

BACKGROUND

Suture-based VCDs are mostly used for large-bore femoral arterial access-site closure. Real-world, contemporary experience on the most commonly reported complications and modes of failure associated with these devices is limited.

METHODS

Post-marketing surveillance data from the FDA MAUDE database, for the ProGlide system and for the Prostar XL system, were analyzed, yielding 827 Perclose ProGlide reports and 175 Prostar XL reports.

RESULTS

Of the 827 reports of major complications involving the Perclose ProGlide devices, 404 reports involved injury, and one involved death related to the device. In the Prostar XL analysis, 94 reports involved injury, and one involved death. Bleeding from vessel injury was the most common adverse outcome described with both devices, followed by hematoma and thrombus. Surgical repair was the most commonly used treatment strategy. In terms of device malfunction, suture-related malfunction (212 reports) was most commonly seen in the Perclose ProGlide group, while failed deployment was most commonly seen in the Prostar XL group.

CONCLUSIONS

Our analysis of the MAUDE database demonstrates that in real-world practice, suture-based VCDs were found to be associated with complications, including vascular injury, difficulties with the device itself, and even death. Ongoing user education and pre-procedural patient selection are important to minimize risks associated with suture-based vascular closure devices.

Right transradial coronary angiography in the setting of tortuous brachiocephalic/thoracic aorta ("elephant head"): Impact on fluoroscopy time and contrast use

OBJECTIVES

Assess the impact on fluoroscopy time and contrast use in patients with tortuous brachiocephalic/thoracic aortas undergoing right transradial coronary angiography (RTCA) and provide strategies to manage.

BACKGROUND

Unfavorable anatomy with severe brachiocephalic/thoracic tortuosity, referred to as an "elephant head," remains a significant obstacle for RTCA.

METHODS

We reviewed the coronary angiograms of patients who underwent RTCA and had tortuous aortas. Angiography was attempted first using a universal catheter (Tiger) and switched to a left coronary specific catheter (Judkins Left [JL]) if challenging. Fluoroscopy time, contrast volume, and greatest distance from the patient's midline to the catheter in the aorta were recorded.

RESULTS

Forty-nine patients (62.6 ± 12.0 years, 69.4% male) were included. Fifteen (30.6%) patients underwent successful angiography with a Tiger catheter; 34 (69.4%) patients required switching to JL catheter. The average distance of Tiger catheters to the midline of the spine was 0.78 ± 0.41 cm versus 1.28 ± 0.44 cm (p = .001) in JL catheters. Tiger catheter use resulted in less fluoroscopy time (6.48 ± 4.73 min) and contrast use (58.87 ± 43.53 ml) than in cases switched to JL (13.26 ± 10.76 min [p = .026]; 86.5 ± 69.95 ml [(p = .017]).

CONCLUSIONS

For patients undergoing RTCA with significant brachiocephalic/thoracic aorta tortuosity, "elephant head," a Tiger catheter can be used efficiently for curvatures <1 cm from the middle of the spine. We propose that for curvatures >1 cm, operators should consider immediately switching to a JL catheter.

Real-World Experience of the MANTA Closure Device: Insights From the FDA Manufacturer and User Facility Device Experience (MAUDE) Database

BACKGROUND/PURPOSE

The MANTA vascular closure device (VCD) is the first commercially available dedicated closure device for large-bore femoral arterial access-site closure and was approved by the United States Food and Drug Administration (FDA) in February 2019. Real-world data on the most commonly reported complications and modes of failure associated with the MANTA closure device are limited. We analyzed post-marketing surveillance data from FDA's Manufacturer and User Facility Device Experience (MAUDE) database for the MANTA VCD (Teleflex, Wayne, Pennsylvania).

METHODS/MATERIALS

Post-marketing surveillance data from the FDA MAUDE database from February 2019 through March 2020 were analyzed, yielding 170 reports.

RESULTS

Of the 170 reports of major complications involving MANTA devices, 141 reports involved either injury (136) or death (5) related to the device. Of the 141 reports, bleeding was the most common adverse outcome described (45), followed by vessel occlusion (30) and vessel dissection (21). Device malfunction incidents (29 reports) were reported in 4 main categories: failed deployment (16 reports), malposition of the collagen (9), insufficient information (3), and device dislocation (1).

CONCLUSIONS

Our analysis of the MAUDE database demonstrates that in real-world practice, the MANTA VCD was found to be associated with complications, including death, vascular injury, and difficulties with the device itself. Ongoing user education, proctoring, and pre-procedural patient selection are important to minimize risks associated with the MANTA VCD.

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.

National trends and 30-day readmission rates for next-day-discharge transcatheter aortic valve replacement: An analysis from the Nationwide Readmissions Database, 2012-2016

Transcatheter aortic valve replacement (TAVR) has evolved toward a minimalist approach, resulting in shorter hospital stays. Real-world trends of next-day discharge (NDD) TAVR are unknown. This study aimed to evaluate underlying trends and readmissions of NDD TAVR.

METHODS

This study was derived from the Nationwide Readmissions Database from 2012 to 2016. International Classification of Diseases, Ninth and Tenth Revisions, codes were used to identify patients. Any discharge within 1 day of admission was identified as NDD. NDD TAVR trends over the years were analyzed, and any admissions within 30 days were considered readmissions. A hierarchical logistic regression model was used to identify predictors of readmission.

RESULTS

Of 49,742 TAVR procedures, 3,104 were NDD. The percentage of NDD TAVR increased from 1.5% (46/3,051) in 2012 to 12.2% (2,393/19,613) in 2016. However, the 30-day readmission rate remained the same over the years (8.6%). The patients' mean age was 80.3 ± 8.4 years. Major readmission causes were heart-failure exacerbation (16%), infections (9%), and procedural complications (8%). In 2016, there were significantly higher late conduction disorder and gastrointestinal bleeding readmission rates than in 2012-2015. Significant predictors of readmission were anemia, baseline conduction disease, cardiac arrhythmias, heart failure, chronic kidney disease, chronic obstructive pulmonary disease, neoplastic disorders, and discharge to facility.

CONCLUSIONS

The percentage of NDD TAVR increased over the years; however, readmission rates remained the same, with a higher rate of conduction abnormality-related hospitalizations in 2016. Careful discharge planning that includes identification of baseline factors that predict readmission and knowledge of etiologies may further prevent 30-day readmissions.

Risk of Coronary Obstruction and Feasibility of Coronary Access After Repeat Transcatheter Aortic Valve Replacement With the Self-Expanding Evolut Valve: A Computed Tomography Simulation Study

BACKGROUND

The supra-annular leaflet position and tall stent frame of the self-expanding Evolut PRO or Evolut PRO+ transcatheter heart valves (THVs) may cause coronary occlusion during transcatheter aortic valve replacement (TAVR)-in-TAVR and present challenges for future coronary access. We sought to evaluate the risk of TAVR-in-TAVR with Evolut PRO or Evolut PRO+ THVs and the feasibility of future coronary access.

METHODS

The CoreValve Evolut PRO Prospective Registry (EPROMPT; NCT03423459) prospectively enrolled patients with symptomatic severe aortic stenosis to undergo TAVR using a commercially available latest generation self-expanding THV at 2 centers in the United States. Computed tomography was performed 30 days after TAVR, which we used to simulate TAVR-in-TAVR with a second Evolut PRO or Evolut PRO+ THV and evaluate for risk of coronary obstruction and feasibility of future coronary access.

RESULTS

Eighty-one patients enrolled with interpretable computed tomography are reported herein. Computed tomography simulation predicted sinus of Valsalva sequestration and resultant coronary obstruction during future TAVR-in-TAVR in up to 23% of patients. Computed tomography simulation predicted that the position of the pinned THV leaflets would hinder future coronary access in up to 78% of patients after TAVR-in-TAVR.

CONCLUSIONS

Further THV design improvements and leaflet modification strategies are needed to mitigate the risk of coronary obstruction during TAVR-in-TAVR with self-expanding THVs and to facilitate future coronary access. Registration: URL: https://www.clinicaltrials.gov. Unique identifier: NCT03423459.

Procedural Outcomes of Patients Undergoing Percutaneous Coronary Intervention for De Novo Lesions in the Ostial and Proximal Left Circumflex Coronary Artery

Ostial coronary artery lesions can be challenging during percutaneous coronary intervention (PCI) because of elastic fiber content, calcium burden, and angulation. We assessed procedural and clinical major adverse cardiac events (MACE) associated with PCI for ostial lesions, focusing on ostial left circumflex (LC) lesions compared with ostial left anterior descending artery (LAD) and right coronary artery lesions. All patients with ostial or very proximal coronary artery lesions treated with PCI at MedStar Washington Hospital Center (Washington, DC) from 2003 to 2018 were included. The primary end point was target lesion revascularization (TLR)-MACE, defined as the composite of all-cause mortality, Q-wave myocardial infarction (MI), and TLR at 1 year. A total of 4,759 patients with available 1-year follow-up were included: 2,236 ostial/very proximal LAD, 980 ostial/very proximal LC, and 1,543 ostial/very proximal right. The presenting clinical syndrome for the LC group was mainly stable or unstable angina, whereas MI was more common in the LAD. At 1 year, the TLR-MACE rate was 16.7% in the LC group versus 12.5% in the LAD and 11.8% in the right group (p = 0.001). Mortality rates were 11.2% in the LC group versus 8.4% in the LAD and 6% in the right group (p <0.001). A Cox model showed that dialysis had the highest impact on TLR-MACE. In conclusion, compared with PCI of ostial or very proximal LAD or right lesions, PCI of ostial or very proximal LC lesions was associated with higher rates of TLR-MACE.

Anatomical Characteristics Associated With Hypoattenuated Leaflet Thickening in Low-Risk Patients Undergoing Transcatheter Aortic Valve Replacement

BACKGROUND/PURPOSE

This sub-analysis of the prospective Low Risk TAVR (LRT) trial determined anatomical characteristics associated with hypoattenuated leaflet thickening (HALT), which may contribute to early transcatheter heart valve (THV) degeneration.

METHODS/MATERIALS

The LRT trial enrolled 200 low-risk patients between February 2016 and February 2018. All subjects underwent baseline and 30-day CT studies, analyzed by an independent core laboratory. Additional measurements, namely THV expansion, eccentricity, depth, and commissural alignment, were made by consensus of three independent readers. HALT was observed only in the Sapien 3 THV, so Evolut valves were excluded from this analysis.

RESULTS

In the LRT trial, 177 subjects received Sapien 3 THVs, of whom 167 (94.3%) had interpretable 30-day CTs and were eligible for this analysis. Twenty-six subjects had HALT (15.6%). Baseline characteristics were similar between groups. There was no difference in THV size implanted and baseline aortic-root geometry between groups. In patients who developed HALT, THV implantation depth was shallower than in patients who did not develop HALT (2.6 ± 1.1 mm HALT versus 3.3 ± 1.8 mm no-HALT, p = 0.03). There were more patients in the HALT group with commissural malalignment (40% vs. 28%; p = 0.25), but this did not reach statistical significance. In a univariable regression model, no predetermined variables were shown to independently predict the development of HALT.

CONCLUSIONS

This study did not find anatomical or THV implantation characteristics that predicted the development of HALT at 30 days. This study cannot exclude subtle effects or interaction between factors because of the small number of events.

Electrosurgical Detachment of MitraClips From the Anterior Mitral Leaflet Prior to Transcatheter Mitral Valve Implantation

OBJECTIVES

The aim of this study was to test the hypothesis that transcatheter electrosurgery might allow intentional detachment of previously placed MitraClip(s) from the anterior leaflet to recreate a single mitral orifice for transcatheter mitral valve implantation (TMVI), leaving the retained MitraClip(s) securely fastened to the posterior leaflet and without interfering with the mitral bioprosthesis.

BACKGROUND

Patients with severe mitral regurgitation or stenosis despite edge-to-edge mitral repair with the MitraClip typically have few therapeutic options because the resultant double orifice precludes TMVI. Transcatheter electrosurgery may allow detachment of failed MitraClip(s) from the anterior leaflet to recreate a single orifice for TMVI.

METHODS

This was a single-center, 5-patient, consecutive, retrospective observational cohort. Patients underwent transcatheter electrosurgical laceration and stabilization of failed MitraClip(s) to recreate a single orifice, leaving the MitraClip(s) securely fastened to the posterior leaflet. Subsequently, patients underwent TMVI with an investigational device, the Tendyne mitral bioprosthesis, on a compassionate basis. Patients were followed up to 30 days.

RESULTS

MitraClip detachment from the anterior leaflet and Tendyne implantation were successful in all patients. All patients survived to discharge. All patients were discharged with grade 0 central mitral regurgitation. Two patients had moderate perivalvular mitral regurgitation that did not require reintervention. During the follow-up period of 30 days, there were no deaths, cases of valve dysfunction, or reintervention. There was no evidence of erosion or bioprosthetic valve dysfunction attributable to the retained MitraClip(s) still attached to the posterior leaflet.

CONCLUSIONS

Transcatheter electrosurgical detachment of failed MitraClips from the anterior leaflet followed by TMVI is technically feasible and safe at 30 days. Longer term study is needed to determine the clinical benefit of this approach and new algorithms for TMVI sizing following electrosurgical laceration and stabilization of a failed MitraClip to avoid perivalvular leak.

Adverse Events and Modes of Failure Related to Rotational Atherectomy System: The Utility of the MAUDE Database

BACKGROUND/PURPOSE

Coronary artery calcification is a marker of advanced atherosclerosis and a predictor of adverse clinical outcomes. Rotational atherectomy (RA) can effectively modify calcified lesions, optimizing procedural outcomes. We interrogated the most commonly reported adverse events involving rotational atherectomy systems (Rotablator and Rotapro) by analyzing post-marketing surveillance data from the Food and Drug Administration Manufacturer and User Facility Device Experience (MAUDE) database.

METHODS/MATERIALS

We queried MAUDE from September 1, 2016, through December 31, 2019. After excluding duplicate reports, we included 363 reports for Rotablator and 63 reports for Rotapro in the final analysis.

RESULTS

Percentages represent the proportion of total submitted MAUDE reports. The most commonly reported complications for Rotablator and Rotapro included dissection (2.7% and 6.3%, respectively) and perforation (4.1% and 19%, respectively). The most commonly reported device-related issues included detachment or structural damage, or both, for Rotablator (39.1%) and entrapment of the device component for Rotapro (47.6%). The most commonly damaged device component was the Rotawire, whereas the most commonly entrapped device component was the Rotaburr for both device configurations. Rotablator and Rotapro device-related complications were most commonly reported for the left anterior descending artery.

CONCLUSION

An analysis of the MAUDE database demonstrates that in real-world practice, RA devices are associated with important complications. Ongoing surveillance of safety profiles, patient outcomes, and failure modes of RA devices is warranted. Our analysis provides important insights into the mechanisms of failure of RA devices and associated complications but cannot verify causality.