Novel Magnetic Resonance Imaging Tools for Hypertrophic Cardiomyopathy Risk Stratification.

Hypertrophic cardiomyopathy (HCM) is a common genetic disorder with a well described risk of sudden cardiac death; however, risk stratification has remained a challenge. Recently, novel parameters in cardiac magnetic resonance imaging (CMR) have shown promise in helping to improve upon current risk stratification paradigms. In this manuscript, we have reviewed novel CMR risk markers and their utility in HCM. The results of the review showed that T1, extracellular volume, CMR feature tracking, and other miscellaneous novel CMR variables have the potential to improve sudden death risk stratification and may have additional roles in diagnosis and prognosis. The strengths and weaknesses of these imaging techniques, and their potential utility and implementation in HCM risk stratification are discussed.

Patient-Prosthesis Mismatch After Surgical Aortic Valve Replacement: Analysis of the PARTNER Trials.

BACKGROUND: Our objective was to compare the impact of patient-prosthesis mismatch (PPM) for 2 years after surgical aortic valve replacement within the prospective, randomized Placement of Aortic Transcatheter Valves (PARTNER) trials. METHODS: Surgical aortic valve replacement patients from the PARTNER 1, 2, and 3 trials were included. PPM was classified as moderate (indexed effective orifice area ≤0.85 cm2/m2) or severe (indexed effective orifice area ≤0.65 cm2/m2). The primary endpoint was the composite of all-cause death and heart failure rehospitalization at 2 years. RESULTS: By the predicted PPM method (PPMP), 59.1% had no PPM, 38.8% moderate PPM, and 2.1% severe PPM; whereas by the measured PPM method (PPMM), 42.4% had no PPM, 36.0% moderate, and 21.6% severe. Patients with no PPMP (23.6%) had a lower rate of the primary endpoint compared with patients with moderate (28.2%, P = .03) or severe PPMP (38.8%, P = .02). Using the PPMM method, there was no difference between the no (17.7%) and moderate PPMM groups (21.1%) in the primary outcome (P = .16). However, those with no PPMM or moderate PPMM were improved compared with severe PPMM (27.4%, P < .001 and P = .02, respectively). CONCLUSIONS: Severe PPM analyzed by PPMP was only 2.1% for surgical aortic valve replacement patients. The PPMM method overestimated the incidence of severe PPM relative to PPMP, but was also associated with worse outcome. There was higher all-cause mortality in patients with severe PPM, thus surgical techniques to minimize PPM remain critical.

[Summary: International consensus statement on nomenclature and classification of the congenital bicuspid aortic valve and its aortopathy, for clinical, surgical, interventional and research purposes]. / Resumen: Consenso internacional para la nomenclatura y clasificación de la válvula aórtica bicúspide congénita y su aortopatía, con fines clínicos, quirúrgicos, intervencionistas y de investigación.

This consensus of nomenclature and classification for congenital bicuspid aortic valve and its aortopathy is evidence-based and intended for universal use by physicians (both pediatricians and adults), echocardiographers, advanced cardiovascular imaging specialists, interventional cardiologists, cardiovascular surgeons, pathologists, geneticists, and researchers spanning these areas of clinical and basic research. In addition, as long as new key and reference research is available, this international consensus may be subject to change based on evidence-based data1.

Este consenso de nomenclatura y clasificación para la válvula aórtica bicúspide congénita y su aortopatía está basado en la evidencia y destinado a ser utilizado universalmente por médicos (tanto pediatras como de adultos), médicos ecocardiografistas, especialistas en imágenes avanzadas cardiovasculares, cardiólogos intervencionistas, cirujanos cardiovasculares, patólogos, genetistas e investigadores que abarcan estas áreas de investigación clínica y básica. Siempre y cuando se disponga de nueva investigación clave y de referencia, este consenso internacional puede estar sujeto a cambios de acuerdo con datos basados en la evidencia1.

Age- and Sex-Specific Nomographic CT Quantitative Plaque Data From a Large International Cohort.

BACKGROUND: With growing adoption of coronary computed tomographic angiography (CTA), there is increasing evidence for and interest in the prognostic importance of atherosclerotic plaque volume. Manual tools for plaque segmentation are cumbersome, and their routine implementation in clinical practice is limited. OBJECTIVES: The aim of this study was to develop nomographic quantitative plaque values from a large consecutive multicenter cohort using coronary CTA. METHODS: Quantitative assessment of total atherosclerotic plaque and plaque subtype volumes was performed in patients undergoing clinically indicated coronary CTA, using an Artificial Intelligence-Enabled Quantitative Coronary Plaque Analysis tool. RESULTS: A total of 11,808 patients were included in the analysis; their mean age was 62.7 ± 12.2 years, and 5,423 (45.9%) were women. The median total plaque volume was 223 mm3 (IQR: 29-614 mm3) and was significantly higher in male participants (360 mm3; IQR: 78-805 mm3) compared with female participants (108 mm3; IQR: 10-388 mm3) (P < 0.0001). Total plaque increased with age in both male and female patients. Younger patients exhibited a higher prevalence of noncalcified plaque. The distribution of total plaque volume and its components was reported in every decile by age group and sex. CONCLUSIONS: The authors developed pragmatic age- and sex-stratified percentile nomograms for atherosclerotic plaque measures using findings from coronary CTA. The impact of age and sex on total plaque and its components should be considered in the risk-benefit analysis when treating patients. Artificial Intelligence-Enabled Quantitative Coronary Plaque Analysis work flows could provide context to better interpret coronary computed tomographic angiographic measures and could be integrated into clinical decision making.

Outcomes and performance of the ACURATE neo2 transcatheter heart valve in clinical practice: one-yearresults of the ACURATE neo2 PMCF Study.

BACKGROUND: Transcatheter aortic valve implantation is an effective treatment for patients with aortic stenosis; however, complications related to paravalvular leakage (PVL) persist, including increased risk of mortality, cardiovascular mortality, and rehospitalisation. AIMS: We sought to evaluate the clinical outcomes and valve performance at 1 year in patients with severe aortic stenosis treated with the ACURATE neo2 valve in a post-market clinical setting. METHODS: Valve Academic Research Consortium-2 safety events were assessed up to 1 year. Independent core laboratories evaluated echocardiographic measures of valve performance and hypoattenuated leaflet thickening (HALT; as measured by four-dimensional computed tomography). RESULTS: The study enrolled 250 patients (64% female; mean age: 81 years; baseline Society of Thoracic Surgeons risk score: 2.9±2.0%); 246 patients were implanted with ACURATE neo2. All-cause mortality was 0.8% at 30 days and 5.1% at 1 year. The 1-year rates for stroke and disabling stroke were 3.0% and 1.3%, respectively. Overall, HALT of >50% leaflet involvement of at least one leaflet was present in 9% of patients at 30 days and in 12% of patients at 1 year. No association was observed between the presence of HALT and 1-year clinical or haemodynamic outcomes. Early haemodynamic improvements were maintained up to 1 year (mean aortic valve gradient: 47.6±14.5 mmHg at baseline, 7.6±3.2 mmHg at 1 year; mean aortic valve area: 0.7±0.2 cm2 at baseline, 1.7±0.4 cm2 at 1 year). At 1 year, 99% of patients had mild or no/trace PVL (<1% had moderate PVL; no patient had severe PVL). CONCLUSIONS: The study outcomes confirm favourable performance and safety up to 1 year in patients treated with ACURATE neo2 in routine clinical practice. (ClinicalTrials.gov: NCT04655248).

Case Report: Stretching the limits-late valvuloplasty for THV dysfunction following redo mitral valve-in-valve implantation.

Late balloon valvuloplasty can be used to treat under-expansion-related transcatheter heart valve (THV) dysfunction. Whether this can be performed following redo-THV implantation is unknown. Herein, we report a case of a 72-year-old male presenting with symptomatic gradient elevation following redo mitral valve-in-valve implantation. The patient was successfully treated with late balloon valvuloplasty with gradient improvement. In conclusion, late valvuloplasty is effective even with several layers of valves. However, larger studies are required to clarify the role of this approach further.

Imaging Methods for Evaluation of Chronic Aortic Regurgitation in Adults: JACC State-of-the-Art Review.

A global multidisciplinary workshop was convened to discuss the multimodality diagnostic evaluation of aortic regurgitation (AR). Specifically, the focus was on assessment tools for AR severity and analyzing evolving data on the optimal timing of aortic valve intervention. The key concepts from this expert panel are summarized as: 1) echocardiography is the primary imaging modality for assessment of AR severity; however, when data is incongruent or incomplete, cardiac magnetic resonance may be helpful; 2) assessment of left ventricular size and function is crucial in determining the timing of intervention; 3) recent evidence suggests current cutpoints for intervention in asymptomatic severe AR patients requires further scrutiny; 4) left ventricular end-systolic volume index has emerged as an additional parameter that has promise in guiding timing of intervention; and 5) the role of additional factors (including global longitudinal strain, regurgitant fraction, and myocardial extracellular volume) is worthy of future investigation.

Impact of Coronary CT Angiography-derived Fractional Flow Reserve on Downstream Management and Clinical Outcomes in Individuals with and without Diabetes.

Purpose: To compare the clinical use of coronary CT angiography (CCTA)-derived fractional flow reserve (FFR) in individuals with and without diabetes mellitus (DM). Materials and Methods: This secondary analysis included participants (enrolled July 2015 to October 2017) from the prospective, multicenter, international The Assessing Diagnostic Value of Noninvasive CT-FFR in Coronary Care (ADVANCE) registry (ClinicalTrials.gov identifier, NCT02499679) who were evaluated for suspected coronary artery disease (CAD), with one or more coronary stenosis ≥30% on CCTA images, using CT-FFR. CCTA and CT-FFR findings, treatment strategies at 90 days, and clinical outcomes at 1-year follow-up were compared in participants with and without DM. Results: The study included 4290 participants (mean age, 66 years ± 10 [SD]; 66% male participants; 22% participants with DM). Participants with DM had more obstructive CAD (one or more coronary stenosis ≥50%; 78.8% vs 70.6%, P < .001), multivessel CAD (three-vessel obstructive CAD; 18.9% vs 11.2%, P < .001), and proportionally more vessels with CT-FFR ≤ 0.8 (74.3% vs 64.6%, P < .001). Treatment reclassification by CT-FFR occurred in two-thirds of participants which was consistent regardless of the presence of DM. There was a similar graded increase in coronary revascularization with declining CT-FFR in both groups. At 1 year, presence of DM was associated with higher rates of major adverse cardiovascular events (hazard ratio, 2.2; 95% CI: 1.2, 4.1; P = .01). However, no between group differences were observed when stratified by stenosis severity (<50% or ≥50%) or CT-FFR positivity. Conclusion: Both anatomic CCTA findings and CT-FFR demonstrated a more complex pattern of CAD in participants with versus without DM. Rates of treatment reclassification were similar regardless of the presence of DM, and DM was not an adverse prognostic indicator when adjusted for diameter stenosis and CT-FFR.Clinical trial registration no. NCT 02499679Keywords: Fractional Flow Reserve, CT Angiography, Diabetes Mellitus, Coronary Artery Disease Supplemental material is available for this article. See also the commentary by Ghoshhajra in this issue.© RSNA, 2023.

Feasibility of Coronary Access Following Redo-TAVR for Evolut Failure: A Computed Tomography Simulation Study.

BACKGROUND: Coronary accessibility following redo-transcatheter aortic valve replacement (redo-TAVR) is increasingly important, particularly in younger low-risk patients. This study aimed to predict coronary accessibility after simulated Sapien-3 balloon-expandable valve implantation within an Evolut supra-annular, self-expanding valve using pre-TAVR computed tomography (CT) imaging. METHODS: A total of 219 pre-TAVR CT scans from the Evolut Low-Risk CT substudy were analyzed. Virtual Evolut and Sapien-3 valves were sized using CT-based diameters. Two initial Evolut implant depths were analyzed, 3 and 5 mm. Coronary accessibility was evaluated for 2 Sapien-3 in Evolut implant positions: Sapien-3 outflow at Evolut node 4 and Evolut node 5. RESULTS: With a 3-mm initial Evolut implant depth, suitable coronary access was predicted in 84% of patients with the Sapien-3 outflow at Evolut node 4, and in 31% of cases with the Sapien-3 outflow at Evolut node 5 (P<0.001). Coronary accessibility improved with a 5-mm Evolut implant depth: 97% at node 4 and 65% at node 5 (P<0.001). When comparing 3- to 5-mm Evolut implant depth, sinus sequestration was the lowest with Sapien-3 outflow at Evolut node 4 (13% versus 2%; P<0.001), and the highest at Evolut node 5 (61% versus 32%; P<0.001). CONCLUSIONS: Coronary accessibility after Sapien-3 in Evolut redo-TAVR relates to the initial Evolut implant depth, the Sapien-3 outflow position within the Evolut, and the native annular anatomy. This CT-based quantitative analysis may provide useful information to inform and refine individualized preprocedural CT planning of the initial TAVR and guide lifetime management for future coronary access after redo-TAVR. REGISTRATION: URL: https://www.clinicaltrials.gov; Unique identifier: NCT02701283.

TAVR in TAVR: Where Are We in 2023 for Management of Failed TAVR Valves?

PURPOSE OF REVIEW: As TAVR is increasingly performed on younger patients with a longer life expectancy, the number of redo-TAVR procedures is likely to increase in the coming years. Limited data is currently available on this sometimes challenging procedure. We provide a summary of currently published literature on management of patients with a failed transcatheter aortic valve. RECENT FINDINGS: Recent registry data have increased the clinical knowledge on redo-TAVR. Additionally, numerous bench studies have provided valuable insights into the technical aspects of redo-TAVR with various combinations of valve types. Redo-TAVR can be performed safely in selected cases with a high procedural success and good short-term outcomes. However, at present, the procedure remains relatively infrequent and many patients are not eligible. Bench testing can be useful to understand important concepts such as valve expansion, neoskirt, leaflet overhang, and leaflet deflection as well as their potential clinical implications.

Transcatheter Aortic-Valve Replacement in Low-Risk Patients at Five Years.

BACKGROUND: A previous analysis in this trial showed that among patients with severe, symptomatic aortic stenosis who were at low surgical risk, the rate of the composite end point of death, stroke, or rehospitalization at 1 year was significantly lower with transcatheter aortic-valve replacement (TAVR) than with surgical aortic-valve replacement. Longer-term outcomes are unknown. METHODS: We randomly assigned patients with severe, symptomatic aortic stenosis and low surgical risk to undergo either TAVR or surgery. The first primary end point was a composite of death, stroke, or rehospitalization related to the valve, the procedure, or heart failure. The second primary end point was a hierarchical composite that included death, disabling stroke, nondisabling stroke, and the number of rehospitalization days, analyzed with the use of a win ratio analysis. Clinical, echocardiographic, and health-status outcomes were assessed through 5 years. RESULTS: A total of 1000 patients underwent randomization: 503 patients were assigned to undergo TAVR, and 497 to undergo surgery. A component of the first primary end point occurred in 111 of 496 patients in the TAVR group and in 117 of 454 patients in the surgery group (Kaplan-Meier estimates, 22.8% in the TAVR group and 27.2% in the surgery group; difference, -4.3 percentage points; 95% confidence interval [CI], -9.9 to 1.3; P = 0.07). The win ratio for the second primary end point was 1.17 (95% CI, 0.90 to 1.51; P = 0.25). The Kaplan-Meier estimates for the components of the first primary end point were as follows: death, 10.0% in the TAVR group and 8.2% in the surgery group; stroke, 5.8% and 6.4%, respectively; and rehospitalization, 13.7% and 17.4%. The hemodynamic performance of the valve, assessed according to the mean (±SD) valve gradient, was 12.8±6.5 mm Hg in the TAVR group and 11.7±5.6 mm Hg in the surgery group. Bioprosthetic-valve failure occurred in 3.3% of the patients in the TAVR group and in 3.8% of those in the surgery group. CONCLUSIONS: Among low-risk patients with severe, symptomatic aortic stenosis who underwent TAVR or surgery, there was no significant between-group difference in the two primary composite outcomes. (Funded by Edwards Lifesciences; PARTNER 3 ClinicalTrials.gov number, NCT02675114.).

Diagnosis, Classification, and Management Strategies for Mitral Annular Calcification: A Heart Valve Collaboratory Position Statement.

Mitral annular calcium (MAC) with severe mitral valvular dysfunction presents a complex problem, as valve replacement, either surgical or transcatheter, is challenging because of anatomy, technical considerations, concomitant comorbidities, and advanced age. The authors review the clinical and anatomical features of MAC that are favorable (green light), challenging (yellow light), or prohibitive (red light) for surgical or transcatheter mitral valve interventions. Under the auspices of the Heart Valve Collaboratory, an expert working group of cardiac surgeons, interventional cardiologists, and interventional imaging cardiologists was formed to develop recommendations regarding treatment options for patients with MAC as well as a proposed grading and staging system using both anatomical and clinical features.

Effects of renin-angiotensin-aldosterone-system inhibitors on coronary atherosclerotic plaques: The PARADIGM registry.

BACKGROUND AND AIMS: Inhibition of Renin-Angiotensin-Aldosterone-System (RAAS) has been hypothesized to improve endothelial function and reduce plaque inflammation, however, their impact on the progression of coronary atherosclerosis is unclear. We aim to study the effects of RAAS inhibitor on plaque progression and composition assessed by serial coronary CT angiography (CCTA). METHODS: We performed a prospective, multinational study consisting of a registry of patients without history of CAD, who underwent serial CCTAs. Patients using RAAS inhibitors were propensity matched to RAAS inhibitor naïve patients based on clinical and CCTA characteristics at baseline. Atherosclerotic plaques in CCTAs were quantitatively analyzed for percent atheroma volume (PAV) according to plaque composition. Interactions between RAAS inhibitor use and baseline PAV on plaque progression were assessed in the unmatched cohort using a multivariate linear regression model. RESULTS: Of 1248 patients from the registry, 299 RAAS inhibitor taking patients were matched to 299 RAAS inhibitor naïve patients. Over a mean interval of 3.9 years, there was no significant difference in annual progression of total PAV between RAAS inhibitor naïve vs taking patients (0.75 vs 0.79%/year, p = 0.66). With interaction testing in the unmatched cohort, however, RAAS inhibitor use was significantly associated with lower non-calcified plaque progression (Beta coefficient -0.100, adjusted p = 0.038) with higher levels of baseline PAV. CONCLUSIONS: The use of RAAS inhibitors over a period of nearly 4 years did not significantly impact on total atherosclerotic plaque progression or various plaque components. However, interaction testing to assess the differential effect of RAAS inhibition based on baseline PAV suggested a significant decrease in progression of non-calcified plaque in patients with a higher burden of baseline atherosclerosis, which should be considered hypothesis generating.

Predictors of Cerebral Embolic Debris During Transcatheter Aortic Valve Replacement: The SafePass 2 First-in-Human Study.

Transcatheter aortic valve replacement (TAVR) generates significant debris, and strategies to mitigate cerebral embolization are needed. The novel Emboliner embolic protection catheter (Emboline, Inc., Santa Cruz, California) is designed to capture all particles generated during TAVR. This first-in-human study sought to assess the safety and feasibility of the device and to characterize the distribution and histopathology of the debris generated during TAVR. The SafePass 2 study was a prospective, nonrandomized, multicenter, single-arm investigation of the Emboliner device. Primary end points included 30-day major adverse cardiac and cerebrovascular events (MACCE) and technical performance. Computed tomography angiography was analyzed by an independent core laboratory, and filters were sent for histopathology of captured debris. Predictors of particle number were identified using >150 µm and >500 µm size thresholds. Of 31 subjects enrolled, technical success was 100%, and 30-day MACCE was 6.5% (2 cerebrovascular accidents, with 1 attributed to subtherapeutic dosing of rivaroxaban along with atrial fibrillation and the other to possible previous small ischemic strokes on magnetic resonance imaging; neither MACCE event had a causal relation to the Emboliner). All filters contained debris, with a median of 191.0 particles >150 µm and 14.0 particles >500 µm. Histopathology revealed mostly acute thrombus and valve or arterial tissue with lesser amounts of calcified tissue. A history of atrial fibrillation predicted a greater number of particles >500 µm (p = 0.0259) and its presence on admission was associated with 4.1 times more particles >150 µm (p = 0.0130) and 8.1 times more particles >500 µm (p = 0.0086). Self-expanding valves were associated with twice the number of particles >150 µm (p = 0.0281). TASK score was positively correlated with number of particles >500 µm (p = 0.0337). The Emboliner device was safe and feasible. Emboli after TAVR appear more numerous than previously documented. Atrial fibrillation, higher TASK score, and self-expanding valve use conferred higher embolic burden. Notably, none of the tested computed tomography angiography features were able to identify with higher embolic risk. Larger-scale studies are needed to identify high-risk patients for selective embolic protection device use.

Update on Transcatheter Treatment of Mitral and Tricuspid Valve Regurgitation.

PURPOSE OF REVIEW: Mitral and tricuspid regurgitation represents a clinical challenge. They are associated with a poor prognosis, and many patients are not eligible for conventional surgery. Transcatheter therapies have been the focus of numerous studies and devices over the past decade. Here, we provide a summary of current options for transcatheter treatment of these 2 entities. RECENT FINDINGS: Recent studies have demonstrated the benefits of edge-to-edge repair for increasing numbers of patients. Encouraging early results with transcatheter valve replacement are also becoming available. To date, transcatheter edge-to-edge repair is currently the first-line transcatheter treatment for both mitral and tricuspid regurgitation for many patients who are not candidates for surgery. A number of transcatheter replacement devices are under development and clinical investigation but, for the most part, their current use is limited to compassionate cases or clinical trials.

Valve-in-Valve Transcatheter Mitral Valve Replacement: A Large First-in-Human 13-Year Experience.

BACKGROUND: Favourable early outcomes have been reported following valve-in-valve transcatheter mitral valve replacement (TMVR). However, reports of long-term outcomes are lacking. We aimed to evaluate early and late outcomes in a large first-in-human valve-in-valve TMVR 13-year experience. METHODS: All patients undergoing valve-in-valve TMVR in our centre from 2008 to 2021 were included. Clinical and echocardiographic outcomes, defined according to the Mitral Valve Academic Research Consortium, were reported. RESULTS: A total of 119 patients were analysed: mean age 76.8 ± 10.2 years, mean Society of Thoracic Surgeons score 10.7 ± 6.8%, 55.4% female, 63.9% transapical access. Thirty-day mortality was 2.5% for the total population and 0.0% after transseptal TMVR. Maximum follow-up was 13.1 years. During a median follow-up of 3.4 years (interquartile range 1.8-5.3 years), 55 patients (46.2%) died, mainly from noncardiovascular causes. Valve hemodynamics were acceptable at 5 years, with 2.5% structural dysfunction. Patients treated from 2016 on (n = 68; 57.1%), following the advent of routine use of the Sapien 3 valve, CT screening, and transseptal access, were compared with those treated before 2016 (n = 51; 42.9%). Patients from 2016 on had a higher technical success rate (100.0% vs 94.1%; P = 0.04), shorter hospitalisation (P < 0.001), trending lower 30-day mortality (1.5% vs 3.9%; P = 0.4) and better 5-year survival (74.7% vs 41.1%; P = 0.03). CONCLUSIONS: Valve-in-valve TMVR can be performed with little morbidity and low mortality. Mid- to long-term survival remains limited owing to advanced age and comorbidities. Structural bioprosthetic valve dysfunction was rare and redo TMVR feasible in selected patients. Outcomes continue to improve, but the role for valve-in-valve TMVR in lower surgical risk patients remains unclear.

Redo-TAVI with SAPIEN 3 in SAPIEN XT or SAPIEN 3 - impact of pre- and post-dilatation on final THV expansion.

BACKGROUND: When a balloon-expandable transcatheter heart valve (THV) is chosen to treat a failed balloon-expandable THV, there is a risk of underexpansion with a potential impact on performance. AIMS: We aimed to assess the impact of pre- and post-dilatation on the expansion of balloon-expandable THVs after redo-transcatheter aortic valve implantation (TAVI). METHODS: Redo-TAVI was performed on the bench with a 23 mm SAPIEN 3 (S3) implanted within a 23 mm SAPIEN XT (SXT) or a 23 mm S3, both of which served as the "failed" THVs. Pre- and/or post-dilatation was performed using a 23 mm non-compliant TRUE balloon. Expansion of the index and redo-THVs were assessed before and after pre-/post-dilatation using microcomputed tomography (micro-CT), and THV hydrodynamic testing was conducted. RESULTS: Without pre- or post-dilatation, the S3 was underexpanded, for all combinations, particularly in the mid-portion of the THV (18.6 mm and 19.7 mm representing 81% and 86% of the nominal diameter inside the SXT and S3, respectively). Pre- and post-dilatation had an additive effect on diameter expansion of the redo-THV, which remained constrained in most combinations. The only combination to achieve nominal expansion was the S3 in S3 when both pre- and post-dilatation were performed. The S3 remained underexpanded inside the SXT despite pre- and post-dilatation (93% in the mid-portion). Improved redo-THV expansion was accompanied by 2.7 mm (12%) overexpansion of the index THV. While all samples had acceptable hydrodynamic performance, the underexpanded samples had worse leaflet pinwheeling. CONCLUSIONS: When performing redo-TAVI with a 23 mm S3 inside a 23 mm SXT or S3, only the S3 in S3 with the use of pre- and post-dilatation reached full expansion. This underlines the importance of CT assessment of THV expansion and the role of pre-/post-dilatation.