Standardization and validation of neoLVOT assessment using three-dimensional trans-esophageal echocardiography before trans-catheter mitral valve replacement.

BACKGROUND: Trans-catheter mitral valve replacement (TMVR) procedures had emerged as an alternative solution for patients who are at high risk for mitral valve surgery. Although cardiac computed tomography (CT) remains the standard method for procedural planning, there is no full agreement on the best systolic phase for quantitation of the neoLVOT. Furthermore, a new three-dimensional trans-esophageal echocardiography (3DTEE) based software was developed to serve as filter and or an alternative for patients who cannot have CT due to any contraindication. AIM: To determine the systolic phase of the cardiac cycle that shows the narrowest NeoLVOT area in order to standardize the way of using these software and then to validate the 3DTEE-based software against the CT-based one as a gold standard, in mitral valve annulus (MA) and NeoLVOT assessment. METHODS: A single center, observational, retrospective study. Initially, a sample of 20 patients (age 62 ± 4 years, 70% men) had CT-based analysis at mid-diastole (80%), early-systole (10%), mid-systole (20%), late-systole (30%-40%), in order to detect the best systolic phase at which the neoLVOT area is the narrowest after TMVR. Then, the end systolic phase was standardized for the analysis of 49 patients (age 57 ± 6 years, 60% men), using both the commercially available CT-based software and the newly available 3DTEE-based software (3mensio Structural Heart, Pie Medical Imaging, The Netherlands). The 3DTEE derived parameters were compared with the gold standard CT-based measurements. RESULTS: The neoLVOT area was significantly narrower at end-systole (224 ± 62 mm2), compared to early-systole (299 ± 70 mm2) and mid-systole (261 ± 75 mm2), (p = .005). Excellent correlation was found between 3DTEE and CT measurements for MA AP diameter (r = .96), IC diameter (r = .92), MA area (r = .96), MA perimeter (r = .94) and NeoLVOT area (r = .96), (all p-values < .0001). Virtual valve sizing was based on annulus measurement and was identical between CT and 3DTEE. Interobserver and intraobserver agreements were excellent for all the measurements with ICCs > .80. CONCLUSIONS: End-systole is the phase that shows the narrowest neoLVOT and hence should be the standard phase used during the analysis. The 3DTEE based analysis using this new software is reliable compared to the CT-based analysis and can be serve as an alternative analysis tool in patients who cannot have CT for any clinical contraindication or as a screening test and/or filter for all patients before proceeding to a detailed CT scan.

A novel method of prosthetic leaflet modification to enable transcatheter mitral valve-in-valve replacement.

Left ventricular outflow tract (LVOT) obstruction from the displaced prosthetic anterior mitral leaflet is a life-threatening complication that can occur during valve-in-valve (ViV) transcatheter mitral valve replacement (TMVR). Laceration of the anterior mitral leaflet to prevent outflow obstruction is a well-established transcatheter technique to mitigate the risk of LVOT obstruction in high-risk anatomies. In this report, we present a novel transseptal technique of prosthetic leaflet modification to prevent LVOT obstruction during ViV TMVR.

Anatomic suitability for transapical transcatheter mitral valve implantation using a tether-based device.

BACKGROUND: Transcatheter mitral valve implantation (TMVI) is a novel therapeutic option for treating symptomatic mitral valve disease. Evaluating patient anatomical suitability is a critical step in the TMVI screening process, but currently requires specialized software and computerized device models. AIMS: This analysis sought to assess the effectiveness of simple and standardized multislice computed tomography (MSCT) anatomic measurements for their ability to discriminate between patients who passed anatomical screening for Tendyne™ TMVI. METHODS: Subjects screened for the Tendyne Expanded Clinical Study from January 2016 through September 2019 were included. Core laboratory screening measurements included mitral annular (MA) dimensions at end-systole and end-diastole, simulated device implantation, and neo-left ventricular outflow tract (LVOT) area. Additionally, nine standard measurements of patient anatomy were assessed for their predictive value of patients passing the anatomic screening process. RESULTS: Out of 496 subjects screened for eligibility, 257 subjects met clinical eligibility criteria with MA dimensions within the manufacturer's suggested range: 153 (59.5%) underwent TMVI while 104 (40.5%) were excluded from the study for other anatomic reasons (76% due to risk of LVOT obstruction). CT-derived left ventricular end-systole diameter (LVESD) had the highest discriminatory power for predicting TMVI anatomical suitability (area under the curve of 0.908, p < 0.0001). The mitral inter-commissural (IC) dimension was best predictive of annular dimensions being within range, with dimensions <30 or >50 mm resulting in a negative predictive value of 94.4%. CONCLUSIONS: MSCT-derived mitral IC dimension and LVESD easily performed measures that are effective predictors of anatomical suitability or screen failure for this tether-based TMVI device.

Hourly variability in outflow tract ectopy as a predictor of its site of origin.

INTRODUCTION: Before ablation, predicting the site of origin (SOO) of outflow tract ventricular arrhythmia (OTVA), can inform patient consent and facilitate appropriate procedural planning. We set out to determine if OTVA variability can accurately predict SOO. METHODS: Consecutive patients with a clear SOO identified at OTVA ablation had their prior 24-h ambulatory ECGs retrospectively analysed (derivation cohort). Percentage ventricular ectopic (VE) burden, hourly VE values, episodes of trigeminy/bigeminy, and the variability in these parameters were evaluated for their ability to distinguish right from left-sided SOO. Effective parameters were then prospectively tested on a validation cohort of consecutive patients undergoing their first OTVA ablation. RESULTS: High VE variability (coefficient of variation ≥0.7) and the presence of any hour with <50 VE, were found to accurately predict RVOT SOO in a derivation cohort of 40 patients. In a validation cohort of 29 patients, the correct SOO was prospectively identified in 23/29 patients (79.3%) using CoV, and 26/29 patients (89.7%) using VE < 50. Including current ECG algorithms, VE < 50 had the highest Youden Index (78), the highest positive predictive value (95.0%) and the highest negative predictive value (77.8%). CONCLUSION: VE variability and the presence of a single hour where VE < 50 can be used to accurately predict SOO in patients with OTVA. Accuracy of these parameters compares favorably to existing ECG algorithms.

Bespoke valve sizing avoids annular rupture in patients treated with a balloon-expandable transcatheter heart valve.

BACKGROUND: Annular and left ventricular outflow tract (LVOT) calcification increase the risk of annular rupture following transcatheter aortic valve replacement (TAVR). The outcomes of a strategy of routine use of a balloon-expandable valve (BEV) for all patients irrespective of annular or LVOT calcium is unknown. OBJECTIVES: We evaluated the impact of bespoke sizing on annular rupture in patients treated with a BEV. METHODS: All consecutive patients undergoing TAVR at a single centre (February 2020-February 2022) were treated only with a BEV. No other valve design was used. Annular/LVOT calcification was assessed using a standardized grading system. For each annular area, we determined the percentage valve oversizing with nominal deployment. The balloon deployment volume was then adjusted when required (over-/underfilled) to achieve over-sizing of approximately 5% in the presence of annular/LVOT calcium and 5%-10% in the absence of annular/LVOT calcium. Adjusted valve areas were assumed to change proportionately to the change in balloon deployment volume. RESULTS: Among 533 TAVR treated patients, annular/LVOT calcification was present in 166 (31.1%) and moderate or severe in 90 (16.9%). In patients with annular/LVOT calcification, the adjusted oversizing was 3.5 ± 3.6% and in patients without annular/LVOT calcification, the adjusted oversizing was 6.8 ± 4.7% (p < 0.001). There were no cases of annular rupture and no cases with more than mild paravalvular leak (PVL). Mild PVL was more frequent in patients with annular/LVOT calcium (10.8% vs 4.6%, p = 0.01). CONCLUSION: Bespoke BEV sizing by adjustment of balloon deployment volume avoided annular rupture in patients undergoing TAVR.

Intraoperative accurate assessment of septal myectomy for hypertrophic obstructive cardiomyopathy (HOCM).

Surgical restoration of the left ventricular outflow tract (LVOT) is necessary for patients suffering from hypertrophic obstructive cardiomyopathy (HOCM), when symptoms are present despite the administration of medical treatment. One point of great significance during the procedure is the evaluation of the LVOT gradient after completion of septal myectomy. Most physicians choose to measure this value by transesophageal echocardiography (TEE) in combination with the direct measurement with the use of needles inserted into the aorta and left ventricle. In this article, we present the implementation of a new technique to estimate the peak-to-peak pressure gradient between the left ventricle and the aorta intraoperatively using a single double lumen central venous catheter inserted through the antegrade cardioplegia cannulation site across the aortic valve into the left ventricle.

A novel technique-Prophylactic septal radiofrequency ablation to prevent left ventricular outflow tract obstruction with transcatheter mitral valve replacement (RADIO-TMVR).

Transcatheter mitral valve replacement (TMVR) with off-label use of aortic balloon-expandable transcatheter heart valves has emerged as a therapeutic option in high-surgical risk patients with severe mitral annular calcification. Left ventricular outflow tract (LVOT) obstruction post valve deployment is a major limitation. We describe a case of septal reduction therapy using radiofrequency ablation (RFA) when established methods of septal reduction were either ineffective or not feasible. RFA permitted successful enlargement of the LVOT area and subsequent TMVR.

Balloon assisted translocation of the mitral anterior leaflet to prevent left ventricular outflow obstruction (BATMAN): A novel technique for patients undergoing transcatheter mitral valve replacement.

INTRODUCTION: Transcatheter mitral valve replacement (TMVR) is an option for patients at high risk for mitral valve replacement or repair via sternotomy or left thoracotomy approach. TMVR carries up to 22% risk of left ventricular outflow tract (LVOT) obstruction. Severe LVOT obstruction can have devastating hemodynamic and clinical consequences. HYPOTHESIS: We previously presented a novel technique to prevent LVOT obstruction during transapical retrograde mitral valve replacement, by penetrating and ballooning the anterior mitral leaflet (AML), resulting in creation of a "hole" and posterior translocation of AML, then deploying the valve. METHODS: Three patients underwent TMVR at Saint Louis University for severe mitral regurgitation after being deemed too high risk for surgery, and not candidates for a Mitra-clip procedure. These patients were deemed to be at risk for LVOT obstruction based on the preprocedural evaluation. Via transapical approach, a needle was advanced "through," perforating the AML and wire was placed in the left atrium. Over the wire, an 20-mm valvuloplasty balloon was positioned "within" the anterior leaflet and inflated leading to translocation of the AMVL. Then the valve was deployed. RESULTS: This novel technique has been performed on three patients at our institution. Sapien S3 transcatheter valves were used in all three patients, with 100% procedural success rate. Intraoperative TEE demonstrated no significant LVOT obstruction, cardiopulmonary bypass time was 42-44 min. CONCLUSION: The balloon assisted translocation of the mitral anterior leaflet to prevent left ventricular outflow obstruction technique described here may offer the option of transcatheter mitral valve implantation in patients at high risk of LVOT obstruction. A variation of this technique to allow application in cases with transseptal approach is under investigation.

Aortic valve area using computed tomography-derived correction factor to improve the validity of left ventricular outflow tract measurements.

AIMS: Given the inherent inaccuracies stemming from the assumption that the left ventricular outflow tract (LVOT) is circular, this study aimed to improve the accuracy of transthoracic echocardiography (TTE)-based aortic valve area (AVA) calculation using continuity equation (CE) by introducing a correction factor (CF) derived from multidetector computed tomography angiography (MDCTA) images and validate it in aortic stenosis (AS) patients. METHODS AND RESULTS: This retrospective study used MDCTA images of 400 patients for modeling and 403 TTE dataset for validation. Echocardiographic parasternal long-axis view was modeled using MDCTA, and LVOT diameter (D1) was measured. Direct planimetry of LVOT area was performed and subsequently converted into a theoretical circle. The assumed circle (D2) diameter was derived, and D2/D1 was calculated and termed as the CF. The CF was 1.13, and it improved the agreement between MDCTA- and TTE-derived LVOT areas and correlation between AVA and peak velocity, mean pressure gradient, and velocity ratio. In discordant subgroups of severe AS, the CF reclassified patients to moderate AS in 40% in the low flow (LF), low gradient (LG), and low ejection fraction (EF) group; 53% in the LF, LG, and normal EF group; and 68% in the LF, high gradient, and normal EF group. CONCLUSIONS: CF of 1.13 derived from MDCTA improved the accuracy of TTE-derived LVOT area and AVA and improved correlation with hemodynamic variables in AS patients. Reclassification of AS patients using CF may have clinical applicability for patient selection for early intervention.

Magnetic resonance imaging abnormalities in the basal interventricular septum of patients with left ventricular outflow tract arrhythmias.

INTRODUCTION: Concealed structural abnormalities were detected by delayed enhancement - magnetic resonance imaging (DE-MRI) in patients with apparently idiopathic tachycardia of left ventricular (LV) origin. Basal septal fibrosis was evaluated as a potential arrhythmia substrate in patients with left ventricular outflow tract (LVOT) arrhythmias. METHODS AND RESULTS: A total of 22 patients with LVOT arrhythmias, including frequent monomorphic premature ventricular complexes (PVCs) in 15 patients and ventricular tachycardia (VT) in 7 patients, underwent catheter ablation and DE-MRI. A total of 19 patients with frequent PVCs and 17 patients with idiopathic VT of other origin served as a control group. Basal septal intramural fibrosis as thin strip-shaped intramyocardial DE or as marked intramyocardial DE involving >25% of wall thickness was detected more frequently in patients with LVOT arrhythmias (41% and 32%) than in patients with non LVOT arrhythmias (14% and 3%). After successful ablation, 4/16 patients with basal septal intramural fibrosis and LVOT PVCs (n = 3) or LVOT VT (n = 1) compared with no patient without basal septal fibrosis experienced episodes of sustained VT with similar or different QRS morphology resulting in ICD therapy in three patients. Follow-up DE-MRI after PVC ablation (17 ± 7 months) revealed an increase in LV ejection fraction from 49 ± 5% to 56 ± 5% (n = 9) but the amount of septal DE remained unchanged. CONCLUSIONS: Basal septal intramural fibrosis may serve as the arrhythmia substrate in a substantial part of patients with premature ventricular complexes (PVCs) and VT originating from the LVOT and identifies patients with continued risk for VT recurrence after initially successful ablation of LVOT arrhythmias.

Gradient variability in hypertrophic cardiomyopathy: New insights from computer-assisted, high fidelity, rest and exercise hemodynamic analysis.

OBJECTIVES: This study examines the intrapatient variability in peak instantaneous left ventricular outflow tract (LVOT) gradients and aortic pulse pressures during rest, exercise, and after ventricular ectopy. BACKGROUND: Although the variability in LVOT gradients in patients with hypertrophic cardiomyopathy (HCM) is well known, the predictors of such variation are not. We hypothesized that quantitative invasive analysis of gradient variation could identify useful predictors of maximal gradients. METHODS: Variability in continuously recorded, high-fidelity left ventricular and aortic pressure waveforms were evaluated by computer-assisted analysis in the resting state (N = 659 beats) and during supine exercise (N = 379 beats) in a symptomatic patient with a resting LVOT gradient >30 mmHg and frequent ventricular ectopy. RESULTS: At rest, the peak left ventricular and aortic pressures at the time of the peak instantaneous LVOT gradient for all sinus and postectopic beats followed consistent regression slopes characterizing the potential energy loss between the LV cavity and aorta. During exercise, similar regression slopes were identified, and these converged with the resting slopes at the point of the maximal measured LVOT gradient. Component analysis of the LVOT gradient suggests that resting beat-to-beat variability provides information similar to post-ectopic pressures for predicting maximal gradients in obstructive-variant HCM. CONCLUSIONS: Our study suggests that computer-assisted analysis of hemodynamic variability in HCM may prove useful in characterizing the severity of obstruction. Further study is warranted to confirm the reproducibility and utility of this finding in a population with clinically significant exercise-induced gradients.

Cardiac Computed Tomography (CT) Evaluation of Valvular Heart Disease in Transcatheter Interventions.

PURPOSE OF REVIEW: To establish the actual role of CT in the growing field of transcatheter valve interventions (THV). RECENT FINDINGS: The development of empirical CT measurements, which are linked with outcomes. CT is a reliable technique for assessing risk and planning transcatheter valve interventions for mitral and aortic valves. Pulmonic and tricuspid valve assessment with CT imaging is still in the early stages but there is room for development.

Evaluation of Hypertrophic Cardiomyopathy: Newer Echo and MRI Approaches.

PURPOSE OF REVIEW: This review discusses the basic and evolving echocardiographic and cardiac magnetic resonance (CMR) approaches in the diagnosis and management of patients with hypertrophic cardiomyopathy (HCM). RECENT FINDINGS: Newer imaging technologies and techniques in both echocardiography and CMR have proved to add incremental value to our understanding of HCM. 3D reconstruction in echocardiography and CMR allows for more accurate morphological and volumetric assessment of the left ventricle. Echocardiographic and CMR-based left atrial assessment, including for its mechanical properties, has been shown to be correlated to outcomes and development of atrial fibrillation. Tissue characterization and scar burden quantification by late gadolinium enhancement on CMR has revolutionized our understanding of fibrotic processes in HCM and their contribution to disease severity and clinical outcomes. Cardiac imaging plays a crucial role in HCM patients. Using echocardiography and CMR as complementary modalities allows for improved diagnostics, optimization of treatment, and better prognostication.

The role of surgical transcatheter valve implantation for the treatment of severe mitral annular calcification.

With a rise in the aging population, mitral annular calcification is increasingly encountered with an incidence of 10% in over 70 years old. This with increasing patient comorbidities presents a technical challenge due to the risk of atrioventricular disruption which is associated with high operative mortality of up to 75%. We describe two cases of severe mitral disease with marked annular calcification successfully treated with a balloon expandable transcatheter valve which was deployed on cardiopulmonary bypass via a trans-atrial approach.

[Surgical treatment of patients with obstructive hypertrophic cardiomyopathy]. / Khirurgicheskie i anesteziologicheskie aspekty lecheniia bol'nykh s gipertroficheskoi kardiomiopatiei.

OBJECTIVE: To analyze in-hospital results of surgical treatment of patients with obstructive hypertrophic cardiomyopathy. MATERIAL AND METHODS: There were 15 patients (8 women and 6 men) with obstructive hypertrophic cardiomyopathy and severe mitral insufficiency for the period from November 2017 to March 2019. Mean age of patients was 55.9±7.1 years. All patients had chronic heart failure NYHA class III and secondary coronary insufficiency. RESULTS: Surgical correction of LVOT obstruction and mitral valve repair with elimination of systolic anterior motion were technically successful in all cases. There was no need for mitral valve replacement in all patients. Heart failure NYHA class I-II in early postoperative period was observed in all cases. CONCLUSION: Careful preoperative planning with a comprehensive analysis of hemodynamic and anatomical features of LV and certain surgical experience are essential for adequate correction of LVOT obstruction without atrioventricular node injury and mitral valve repair.

Validating a prediction modeling tool for left ventricular outflow tract (LVOT) obstruction after transcatheter mitral valve replacement (TMVR).

OBJECTIVE: Demonstrate proof-of-concept validation of a computed tomography (CT) computer-aided design prediction modeling tool to identify patients at risk for left ventricular outflow tract (LVOT) obstruction in transcatheter mitral valve replacement (TMVR). BACKGROUND: LVOT obstruction is a significant and even fatal consequence of TMVR. METHODS: From August 2013 to August 2017, 38 patients in 5 centers underwent TMVR with compassionate use of balloon-expandable valves for severe mitral valve dysfunction because of degenerative surgical mitral ring, bioprosthesis, or severe native mitral stenosis from to severe mitral annular calcification. All patients had preprocedural CT scans performed for anatomic screening, intraprocedural TEE and invasive hemodynamics performed. Preprocedural prediction modeling was performed utilizing computer-aided design (CAD) of the neo-LVOT post-TMVR. Post-TMVR CT scans were obtained and compared to pre-TMVR LVOT modeling datasets for validation. RESULTS: All patients underwent successful TMVR without device embolization. Seven of the 38 patients experienced LVOT obstruction, defined as an increase of ≥10 mmHg LVOT peak gradient post-TMVR. Anatomic screening using CT was validated in 20/38 patients as preprocedural predicted neo-LVOT surface area correlated well with post-TMVR measurements (R2 = 0.8169, P < 0.0001). A receiver operating curve curve found a predicted neo-LVOT surface area of ≤ 189.4 mm2 to have 100% sensitivity and 96.8% specificity for predicting TMVR-induced LVOT obstruction. CONCLUSION: CAD design and CT postprocessing are indispensable tools in predicting LVOT obstruction and necessary for anatomic screening in percutaneous TMVR.

Surgical Relief of Left Ventricular Outflow Tract Obstruction in Adults With Congenital Aortic Stenosis and Associated Aortic Annulus Hypoplasia and/or Subaortic Obstruction.

BACKGROUND: In children and adolescents, a Ross/Konno operation is commonly done to both enlarge the aortic root and provide a competent aortic valve with relief of left ventricular outflow tract obstruction (LVOTO). Optimum management is not so straightforward in adults. METHODS: Between 1995 and 2014, 16 patients of mean age 39.4 years (18-57 years) with hypoplastic aortic annulus (AA) measuring 20mm and less, and mean aortic valve/LVOT gradient of 61mmHg (30-70mmHg) presented for surgery. RESULTS: Eight patients with mean LVOT/AA diameter 19.6mm (18-20mm) underwent an "inclusion-cylinder" type Ross procedure (RP). Eight patients with more severe LVOT/AA obstruction, with mean diameter of 17.4mm (16-19mm) underwent mechanical aortic valve replacement (AVR) with standard Konno-type aortoventriculoplasty. There was zero early and late mortality; with mean follow-up of 11.6 years (3-21 years) in the Ross group and 6 years (2-10 years) in the Konno-AVR group. One patient in the Konno-AVR group had reoperation after 2 years for RVOT obstruction. The postoperative echocardiograms of these patients at last follow-up show residual mean gradient across LVOT/AA of 4.4mmHg (2-6mmHg) after RP, and 11.9mmHg (8-17mmHg) after Konno-AVR. CONCLUSIONS: In adults, the "inclusion-cylinder" Ross-procedure is a good alternative for mild to moderate aortic root hypoplasia. However, for cases with severe LVOT obstruction, a Ross-Konno is not possible with the same method of autologous support used in a non-Konno RP, and this could be expected to have an impact on late durability and the need for further intervention, in a group that has already undergone multiple procedures in childhood. Both methods of RP and Konno-AVR lead to excellent early and late results.

Alcohol Septal Ablation for Hypertrophic Obstructive Cardiomyopathy: A 16-Year Australian Single Centre Experience.

BACKGROUND: Alcohol septal ablation (ASA), is a well-established treatment for symptomatic hypertrophic obstructive cardiomyopathy (HOCM). We report the acute, short and long-term clinical and echocardiographic outcomes of our experience in a single Australian centre over 16 years. METHODS: We retrospectively analysed consecutive patients presenting to our centre for ASA between March 2000 and July 2016. Local databases were interrogated along with direct patient or physician contact occurred where required. RESULTS: Alcohol septal ablation was performed in 80 patients with symptomatic, medication refractory HOCM (mean age 61±15 years; range 22-84 years; 50% male). All patients had transthoracic echocardiography prior to the procedure, within 48hours of the procedure, 6 weeks, 6 months, 1 year and yearly thereafter to a median follow-up of 80±40months. At baseline, mean resting and provoked LVOT gradients were 80±49mmHg and 97±40mmHg respectively. Compared with baseline, ASA led to a reduction in resting LVOT gradients at all time points, particularly at 2 days-52±41mmHg, p<0.001; 12 months-29±34mmHg, p<0.001; and last follow-up 12±21mmHg, p<0.001. Provoked LVOT gradients were also reduced at 2 days-64±44mmHg and last follow-up of 19±29mmHg, p<0.001. Compared to baseline (19.8±4.2mm), ASA was associated with a reduction in interventricular septal (IVS) thickness at all time intervals with last echocardiographic follow-up at 80 months being 16.0±4.9mm, (