Impact and limitations of 3D computational modelling in transcatheter mitral valve replacement-a two-centre Dutch experience.

BACKGROUND: Transcatheter mitral valve replacement (TMVR) has emerged as a minimally invasive alternative to mitral valve surgery for patients at high or prohibitive operative risk. Prospective studies reported favourable outcomes in patients with annulus calcification (valve-in-mitral annulus calcification; ViMAC), failed annuloplasty ring (mitral valve-in-ring; MViR), and bioprosthetic mitral valve dysfunction (mitral valve-in-valve; MViV). Multi-slice computed tomography (MSCT)-derived 3D-modelling and simulations may provide complementary anatomical perspectives for TMVR planning. AIMS: We aimed to illustrate the implementation of MSCT-derived modelling and simulations in the workup of TMVR for ViMAC, MViR, and MViV. METHODS: For this retrospective study, we included all consecutive patients screened for TMVR and compared MSCT data, echocardiographic outcomes and clinical outcomes. RESULTS: Sixteen out of 41 patients were treated with TMVR (ViMAC n = 9, MViR n = 3, MViV n = 4). Eleven patients were excluded for inappropriate sizing, 4 for anchoring issues and 10 for an unacceptable risk of left ventricular outflow tract obstruction (LVOTO) based on 3D modelling. There were 3 procedure-related deaths and 1 non-procedure-related cardiovascular death during 30 days of follow-up. LVOTO occurred in 3 ViMAC patients and 1 MViR patient, due to deeper valve implantation than planned in 3 patients, and anterior mitral leaflet displacement with recurrent basal septum thickening in 1 patient. TMVR significantly reduced mitral mean gradients as compared with baseline measurements (median mean gradient 9.5 (9.0-11.5) mm Hg before TMVR versus 5.0 (4.5-6.0) mm Hg after TMVR, p = 0.03). There was no residual mitral regurgitation at 30 days. CONCLUSION: MSCT-derived 3D modelling and simulation provide valuable anatomical insights for TMVR with transcatheter balloon expandable valves in ViMAC, MViR and MViV. Further planning iterations should target the persistent risk for neo-LVOTO.

Moderate Aortic Stenosis-Advanced Imaging, Risk Assessment, and Treatment Strategies.

Moderate aortic stenosis is increasingly recognized as a disease entity with poor prognosis. Diagnosis of moderate aortic stenosis may be complemented by laboratory tests and advanced imaging techniques focused at detecting signs of cardiac damage such as increase of cardiac enzymes (N-terminal pro-B-type Natriuretic Peptide, troponin), left ventricular remodeling (hypertrophy, reduced left ventricular ejection fraction), or myocardial fibrosis. Therapy should include guideline-directed optimal medical therapy for heart failure. Patients with signs of cardiac damage may benefit from early intervention, which is the focus of several ongoing randomized controlled trials. As yet, no evidence-based therapy exists to halt the progression of aortic valve calcification.

Demographics and outcomes of patients younger than 75 years undergoing aortic valve interventions in Rotterdam.

BACKGROUND: Transcatheter aortic valve implantation (TAVI) is considered a safe and effective alternative to surgical aortic valve replacement (SAVR) for elderly patients across the operative risk spectrum. In the Netherlands, TAVI is reimbursed only for patients with a high operative risk. Despite this, one fifth of TAVI patients are < 75 years of age. We aim to compare patient characteristics and outcomes of TAVI and SAVR patients < 75 years. METHODS: This study included all patients < 75 years without active endocarditis undergoing TAVI or SAVR for severe aortic stenosis, mixed aortic valve disease or degenerated aortic bioprosthesis between 2015 and 2020 at the Erasmus University Medical Centre. Dutch authority guidelines were used to classify operative risk. RESULTS: TAVI was performed in 292 patients, SAVR in 386 patients. Based on the Dutch risk algorithm, 59.6% of TAVI patients and 19.4% of SAVR patients were at high operative risk. There was no difference in 30-day all-cause mortality between TAVI and SAVR (2.4% vs 0.8%, p = 0.083). One-year and 5­year mortality was higher after TAVI than after SAVR (1-year: 12.5% vs 4.3%, p < 0.001; 5­year: 36.8% vs 12.0%, p < 0.001). Within risk categories we found no difference between treatment strategies. Independent predictors of mortality were cardiovascular comorbidities (left ventricular ejection fraction < 30%, atrial fibrillation, pulmonary hypertension) and the presence of malignancies, liver cirrhosis or immunomodulatory drug use. CONCLUSION: At the Erasmus University Medical Centre, in patients < 75 years, TAVI is selected for higher-risk phenotypes and overall has higher long-term mortality than SAVR. We found no evidence for worse outcome within risk categories.

Diagnostic Value of Aortic Valve Calcification Levels in the Assessment of Low-Gradient Aortic Stenosis.

BACKGROUND: In patients with low-gradient aortic stenosis (AS) and low transvalvular flow, dobutamine stress echocardiography (DSE) is recommended to determine AS severity, whereas the degree of aortic valve calcification (AVC) supposedly correlates with AS severity according to current European and American guidelines. OBJECTIVES: The purpose of this study was to assess the relationship between AVC and AS severity as determined using echocardiography and DSE in patients with aortic valve area <1 cm2 and peak aortic valve velocity <4.0 m/s. METHODS: All patients underwent DSE to determine AS severity and multislice computed tomography to quantify AVC. Receiver-operating characteristics curve analysis was used to assess the diagnostic value of AVC for AS severity grading as determined using echocardiography and DSE in men and women. RESULTS: A total of 214 patients were included. Median age was 78 years (25th-75th percentile: 71-84 years) and 25% were women. Left ventricular ejection fraction was reduced (<50%) in 197 (92.1%) patients. Severe AS was diagnosed in 106 patients (49.5%). Moderate AS was diagnosed in 108 patients (50.5%; in 77 based on resting transthoracic echocardiography, in 31 confirmed using DSE). AVC score was high (≥2,000 for men or ≥1,200 for women) in 47 (44.3%) patients with severe AS and in 47 (43.5%) patients with moderate AS. AVC sensitivity was 44.3%, specificity was 56.5%, and positive and negative predictive values for severe AS were 50.0% and 50.8%, respectively. Area under the receiver-operating characteristics curve was 0.508 for men and 0.524 for women. CONCLUSIONS: Multi-slice computed tomography-derived AVC scores showed poor discrimination between grades of AS severity using DSE and cannot replace DSE in the diagnostic work-up of low-gradient severe AS.

Physical and Computational Modeling for Transcatheter Structural Heart Interventions.

Structural heart disease interventions rely heavily on preprocedural planning and simulation to improve procedural outcomes and predict and prevent potential procedural complications. Modeling technologies, namely 3-dimensional (3D) printing and computational modeling, are nowadays increasingly used to predict the interaction between cardiac anatomy and implantable devices. Such models play a role in patient education, operator training, procedural simulation, and appropriate device selection. However, current modeling is often limited by the replication of a single static configuration within a dynamic cardiac cycle. Recognizing that health systems may face technical and economic limitations to the creation of "in-house" 3D-printed models, structural heart teams are pivoting to the use of computational software for modeling purposes.

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

Left ventricular outflow tract obstruction (LVOTO) is a notorious complication of transcatheter mitral valve replacement (TMVR). Computed tomography-derived simulations can predict neo-LVOTO post-TMVR, whereas alcohol septal ablation (ASA) can mitigate neo-LVOTO risk. We report a case of sequential ASA of 2 adjacent septal branches to resolve unexpected neo-LVOTO post-TMVR.

Transcatheter Aortic Valve Replacement for Pure Native Aortic Valve Regurgitation: The PANTHEON International Project.

BACKGROUND: Transcatheter aortic valve replacement (TAVR) in patients with pure severe native aortic valve regurgitation (NAVR) has been associated with suboptimal results. The available evidence concerns mostly outdated transcatheter heart valves (THVs). OBJECTIVES: The aim of this study was to investigate the performance of new-generation THVs in patients treated for pure severe NAVR. METHODS: The PANTHEON (Performance of Currently Available Transcatheter Aortic Valve Platforms in Inoperable Patients With Pure Aortic Regurgitation of a Native Valve) study retrospectively included patients who underwent TAVR with currently available devices (both self-expanding [SE] and balloon expandable [BE]) for severe NAVR. Technical and device success rates as well as a composite of all-cause mortality and heart failure rehospitalization at 1 year were evaluated. The rate and clinical consequences of acute transcatheter valve embolization or migration (TVEM) were also considered. RESULTS: A total of 201 patients were included. Overall technical and device success rates were 83.6% and 76.1%, respectively, and did not differ between SE and BE devices. These figures were due mostly to TVEM occurrence (14.6% vs 16.1%; P = 0.47) and residual moderate or greater aortic regurgitation (9.2% vs 10.1%; P = 0.87). Patients who experienced TVEM compared with those without TVEM had a significantly higher incidence of the composite endpoint at 1 year (25.7% vs 15.8%; P = 0.05). CONCLUSIONS: Despite improved THV platforms and techniques, TAVR for pure severe NAVR remains a challenging procedure, with significant risk for TVEM. SE and BE platforms demonstrated comparable performance in this setting. (Performance of Currently Available Transcatheter Aortic Valve Platforms in Inoperable Patients With Pure Aortic Regurgitation of a Native Valve [PANTHEON]; NCT05319171).

Invasive Real Time Biventricular Pressure-Volume Loops to Monitor Dynamic Changes in Cardiac Mechanoenergetics During Structural Heart Interventions: Design and Rationale of a Prospective Single-Center Study.

Background: Transcatheter valvular interventions affect cardiac and hemodynamic physiology by changing ventricular (un-)loading and metabolic demand as reflected by cardiac mechanoenergetics. Real-time quantifications of these changes are scarce. Pressure-volume loop (PVL) monitoring appraises both load-dependent and load-independent compounds of cardiac physiology including myocardial work, ventricular unloading, and ventricular-vascular interactions. The primary objective is to describe changes in physiology induced by transcatheter valvular interventions using periprocedural invasive biventricular PVL monitoring. The study hypothesizes transcatheter valve interventions modify cardiac mechanoenergetics that translate into improved functional status at 1-month and 1-year follow-up. Methods: In this single-center prospective study, invasive PVL analysis is performed in patients undergoing transcatheter aortic valve replacement or tricuspid or mitral transcatheter edge-to-edge repair. Clinical follow-up is per standard of care at 1 and 12 months. This study aims to include 75 transcatheter aortic valve replacement patients and 41 patients in both transcatheter edge-to-edge repair cohorts. Results: The primary outcome is the periprocedural change in stroke work, potential energy, and pressure-volume area (mmHg mL-1). The secondary outcomes comprise changes in a myriad of parameters obtained by PVL measurements, including ventricular volumes and pressures and the end-systolic elastance-effective arterial elastance ratio as a reflection of ventricular-vascular coupling. A secondary endpoint associates these periprocedural changes in cardiac mechanoenergetics with functional status at 1 month and 1 year. Conclusions: This prospective study aims to elucidate the fundamental changes in cardiac and hemodynamic physiology during contemporary transcatheter valvular interventions.

Early detection of left ventricular diastolic dysfunction using conventional and speckle tracking echocardiography in a large animal model of metabolic dysfunction.

Left ventricular (LV) diastolic dysfunction is one of the important mechanisms responsible for symptoms in patients with heart failure. The aim of the current study was to identify parameters that may be used to detect early signs of LV diastolic dysfunction in diabetic pigs on a high fat diet, using conventional and speckle tracking echocardiography. The study population consisted of 16 healthy Göttingen minipigs and 18 minipigs with experimentally induced metabolic dysfunction. Echocardiography measurements were performed at baseline and 3-month follow-up. The ratio of peak early (E) and late filling velocity (E/A ratio) and the ratio of E and the velocity of the mitral annulus early diastolic wave (E/Em ratio) did not change significantly in both groups. Peak untwisting velocity decreased in the metabolic dysfunction group (- 30.1 ± 18.5 vs. - 23.4 ± 15.5 °/ms) but not in controls (- 38.1 ± 23.6 vs. - 42.2 ± 23.0 °/ms), being significantly different between the groups at the 3-month time point (p < 0.05). In conclusion, whereas E/A ratio and E/Em ratio did not change significantly after 3 months of metabolic dysfunction, peak untwisting velocity was significantly decreased. Hence, peak untwisting velocity may serve as an important marker to detect early changes of LV diastolic dysfunction.