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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. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

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. * Leaflet laceration procedures (bioprosthetic or native aortic scallop intentional laceration to prevent iatrogenic coronary artery obstruction and laceration of the anterior mitral leaflet to prevent outflow obstruction) may fail to protect against coronary and chamber obstruction in specific circumstances: very small valve-to-coronary distance (which amplifies the risk of coronary malalignment with the laceration), transcatheter aortic valve replacement inside existing transcatheter aortic valve replacement (where prior valve frames limit leaflet splay), and diffusely calcified and rigid leaflets (which limits splay). * Balloon-augmented leaflet modification is a simple procedure adjunct that appears incrementally to increase leaflet splay. Further refinement of leaflet modification strategies and the development of new techniques, such as leaflet excision, are needed. [ABSTRACT FROM AUTHOR]

Background: Coronary artery obstruction is a rare, devastating complication of transcatheter aortic valve replacement. Transcatheter electrosurgical aortic leaflet laceration (Bioprosthetic or Native Aortic Scallop Intentional Laceration to Prevent Iatrogenic Coronary Artery Obstruction [BASILICA]) is a novel technique to prevent coronary artery obstruction. We report the 1-year outcomes of the BASILICA trial. Primary end points of 30-day success and safety have been reported previously. Methods: The BASILICA trial was a prospective, multicenter, single-arm safety and feasibility study. Subjects with severe native or bioprosthetic aortic valve disease at high or extreme risk for surgery, and high risk of coronary artery obstruction, were included. End points at 1 year included death, stroke, and myocardial infarction. Source data was independently verified and end points independently adjudicated. Results: Thirty subjects were enrolled between February 2018 and July 2018. At 30 days, BASILICA was successful in 28 subjects (93.3%), there were 3 strokes (10%), including 1 disabling stroke (3.3%), 1 death (3.3%), and 1 periprocedural myocardial infarction (3.3%). Between 30 days and 1 year, there were no additional strokes, no myocardial infarction, and 2 deaths (10% 1-year mortality). No subject needed repeat intervention for aortic valve or coronary disease. Two subjects had infective endocarditis (6.7%), but neither was isolated to the aortic valve. There were no hospital admissions for heart failure. Fourteen (46.7%) subjects required repeat hospital admission for other causes. Aortic valve gradients on echocardiography, New York Heart Association functional class, and Kansas City Cardiomyopathy Questionnaire scores improved from baseline to 30 days and were maintained at 1 year. Conclusions: In these subjects with multiple comorbidities and restrictive anatomy that underwent transcatheter aortic valve replacement, there was no late stroke, myocardial infarction, or death related to BASILICA. Mitigation of coronary obstruction remained intact at 1 year and was not related to recurrent readmission. These results are reassuring for patients and physicians who wish to avoid the long-term complications related to snorkel stenting. Registration: URL: https://www.clinicaltrials.gov; Unique identifier: NCT03381989. [ABSTRACT FROM AUTHOR]

Supplemental Digital Content is available in the text. 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. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

Supplemental Digital Content is available in the text. Background: This analysis evaluated echocardiographic predictors of hypoattenuated leaflet thickening (HALT) in low-risk patients undergoing transcatheter aortic valve replacement and assessed 1-year clinical and hemodynamic consequences. HALT by computed tomography may be associated with early valve degeneration and increased neurological events. Methods: Echocardiograms were performed at baseline, discharge, 30 days, and 1 year post-procedure. Four-dimensional contrast-enhanced computed tomography assessed HALT at 30 days. Independent core laboratories analyzed images. Doppler hemodynamic parameters were tested in a univariable regression model to identify HALT predictors. One-year clinical and hemodynamic outcomes were compared between HALT (+) and (−) patients. Results: Analysis included 170 patients with Sapien 3 valves and diagnostic 30-day computed tomographies, of whom 27 (16%) had HALT. Baseline characteristics were similar between groups. After transcatheter aortic valve replacement, aortic flow was nonsignificantly reduced in patients who developed HALT. Regression analysis did not show significant association between baseline or discharge valve hemodynamics and development of HALT at 30 days. Patients with HALT had smaller aortic valve areas (1.4±0.4 versus 1.7±0.5 cm2; P =0.018) and Doppler velocity index (0.4±0.1 versus 0.5±0.1; P =0.003) than those without HALT at 30 days but not at 1 year. There was no difference in aortic mean gradient at 30 days. There was no difference between the groups in New York Heart Association class, 6-minute walk distance, and mortality at 1 year. Conclusions: There were no early hemodynamic predictors of HALT. At 30 days, patients with HALT had worse valve hemodynamics than those without HALT, but hemodynamic and clinical outcomes at 1 year were similar. Clinical Trial Registration: URL: http://www.clinicaltrials.gov. Unique identifier: NCT02628899. [ABSTRACT FROM AUTHOR]

Supplemental Digital Content is available in the text. [ABSTRACT FROM AUTHOR]

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., Competing Interests: Conflicts of interest and sources of funding: The authors are investigators on a US Government Cooperative Research and Development Agreement with Siemens Healthcare. Siemens participated in the modification of the MRI system from 1.5 T to 0.55 T. This work was funded by the Division of Intramural Research, National Heart, Lung, and Blood Institute, National Institutes of Health (grant numbers: Z01-HL006257, Z01-HL006213). F.S. received support from the Swedish Society for Medical Research, SSMF (PD20-0043), Stockholm, Sweden; the Swedish Heart-Lung Foundation (20210205), Stockholm, Sweden; and Foundation Blanceflor, Stockholm, Sweden., (Copyright © 2023 Written work prepared by employees of the Federal Government as part of their official duties is, under the U.S. Copyright Act, a “work of the United States Government” for which copyright protection under Title 17 of the United States Code is not available. As such, copyright does not extend to the contributions of employees of the Federal Government.)

Medical students need to understand core neuroscience principles as a foundation for their required clinical experiences in neurology. In fact, they need a solid neuroscience foundation for their clinical experiences in all other medical disciplines also because the nervous system plays such a critical role in the function of every organ system. Because of the rapid pace of neuroscience discoveries, it is unrealistic to expect students to master the entire field. It is also unnecessary, as students can expect to have ready access to electronic reference sources no matter where they practice. In the preclerkship phase of medical school, the focus should be on providing students with the foundational knowledge to use those resources effectively and interpret them correctly. This article describes an organizational framework for teaching the essential neuroscience background needed by all physicians. This is particularly germane at a time when many medical schools are reassessing traditional practices and instituting curricular changes such as competency-based approaches, earlier clinical immersion, and increased emphasis on active learning. This article reviews factors that should be considered when developing the preclerkship neuroscience curriculum, including goals and objectives for the curriculum, the general topics to include, teaching and assessment methodology, who should direct the course, and the areas of expertise of faculty who might be enlisted as teachers or content experts. These guidelines were developed by a work group of experienced educators appointed by the Undergraduate Education Subcommittee (UES) of the American Academy of Neurology (AAN). They were then successively reviewed, edited, and approved by the entire UES, the AAN Education Committee, and the AAN Board of Directors., (© 2021 American Academy of Neurology.)

Background: Transcatheter mitral valve replacement using aortic transcatheter heart valves has recently become an alternative for patients with degenerated mitral bioprostheses, failed surgical repairs with annuloplasty rings or severe mitral annular calcification who are poor surgical candidates. Outcomes of these procedures are collected in the Society of Thoracic Surgeons/American College of Cardiology/Transcatheter Valve Therapy Registry. A comprehensive analysis of mitral valve-in-valve (MViV), mitral valve-in-ring (MViR), and valve-in-mitral annular calcification (ViMAC) outcomes has not been performed. We sought to evaluate short-term outcomes of early experience with MViV, MViR, and ViMAC in the United States., Methods: Retrospective analysis of data from the Society of Thoracic Surgeons/American College of Cardiology Transcatheter Valve Therapy Registry., Results: Nine hundred three high-risk patients (median Society of Thoracic Surgeons score 10%) underwent MViV (n=680), MViR (n=123), or ViMAC (n=100) between March 2013 and June 2017 at 172 hospitals. Median age was 75 years, 59.2% female. Technical and procedural success were higher in MViV. Left ventricular outflow tract obstruction occurred more frequently with ViMAC (ViMAC=10%, MViR=4.9%, MViV=0.7%; P <0.001). In-hospital mortality (MViV=6.3%, MViR=9%, ViMAC=18%; P =0.004) and 30-day mortality (MViV=8.1%, MViR=11.5%, ViMAC=21.8%; P =0.003) were higher in ViMAC. At 30-day follow-up, median mean mitral valve gradient was 7 mm Hg, most patients (96.7%) had mitral regurgitation grade ≤1 (+) and were in New York Heart Association class I to II (81.7%)., Conclusions: MViV using aortic balloon-expandable transcatheter heart valves is associated with a low complication rate, a 30-day mortality lower than predicted by the Society of Thoracic Surgeons score, and superior short-term outcomes than MViR and ViMAC. At 30 days, patients in all groups experienced improvement of symptoms, and valve performance remained stable. Registration: URL: https://www.clinicaltrials.gov; Unique identifier: NCT02245763.

Objectives: To characterize the prevalence, time of onset, and cause of neuromuscular dysfunction in patients with severe sepsis., Methods: We conducted a prospective cohort study in which participants with severe sepsis underwent weekly neurologic examinations and nerve conduction studies (NCSs) within 72 hours of developing severe sepsis until intensive care unit (ICU) discharge. Electromyography was preformed if clinical weakness developed or if there was a significant reduction in nerve conduction response amplitudes., Results: Abnormal NCS were present upon enrollment in 63% of patients (31/48). The presence of abnormal baseline NCS was predictive of hospital mortality (55% vs 0% for patients with normal baseline NCS; p < 0.001). Development of acquired neuromuscular dysfunction could be predicted by NCS done on day 7. Twenty patients remained in the ICU long enough to have serial NCSs; 50% of these patients developed acquired neuromuscular dysfunction. Most patients with acquired neuromuscular dysfunction had electrophysiologic evidence of both critical illness myopathy and critical illness neuropathy., Conclusion: Changes in nerve conduction studies occur in the majority of patients early in the course of severe sepsis and predict the development of acquired neuromuscular dysfunction and mortality in intensive care unit patients. Most patients with acquired neuromuscular dysfunction after sepsis have both critical illness myopathy and critical illness neuropathy.