Transcatheter Aortic Valve Replacement Evaluation Research Articles

A Novel Protocol for Contrast-Free Transcatheter Aortic Valve Replacement Evaluation and Implantation

BackgroundWe aimed to develop a transcatheter aortic valve replacement (TAVR) sizing algorithm and implantation method to facilitate safe and effective TAVR without contrast use in patients with severe chronic kidney disease (CKD) who do not yet require renal replacement therapy. Patients with CKD are a challenging patient subset to treat using standard TAVR care pathways which most usually require the use of iodinated contrast media both during gated computed tomography (CT) angiography sizing, and valve deployment. Iodinated contrast exposure may worsen kidney function in a dose-dependent fashion, and may result in a need for renal replacement therapy. Therefore, a method to eliminate, or greatly lessen, contrast exposure during TAVR is highly desirable. MethodsOne hundred sixty patients who underwent standard CT angiography and TAVR implantation were used to develop (100 patients) and validate (60 patients) an algorithm to predict balloon-expandable valve size using measurements available from noncontrast CT. Model accuracy was measured using Pearson correlation between algorithm-predicted valve size and actual size used based on annular area. As proof of concept, we then report a case series of 35 consecutive patients who underwent TAVR evaluation and implantation with moderate sedation and no contrast between May 2021 and April 2024. ResultsThe valve sizing algorithm incorporates sinus and sinotubular junction diameters, both available from a reformatted noncontrast, cardiac-gated CT. The algorithm demonstrated a strong correlation with the actual valve size used (development cohort R = 0.81, validation cohort R = 0.76). Thirty-five patients underwent “no-contrast TAVR” with noncontrast CT for valve sizing. Forty-eight percent were urgent inpatient TAVR. Technical procedural success, as defined by the VARC3 criteria, was 100%, with no patient deaths during the index procedure. Three patients had a mild paravalvular leak. No valve embolization or need for a second valve occurred. Four patients required a pacemaker. ConclusionsWe present a novel algorithm for TAVR evaluation and implantation without the use of iodinated contrast media in a high-risk patient subset with CKD.

Beyond Static Planning: Computational Predictive Modeling to Avoid Coronary Artery Occlusion in TAVR

BackgroundCoronary artery occlusion (CO) during transcatheter aortic valve replacement (TAVR) is a devastating complication. The objective of this study was to assess the clinical impact of a computational predictive modeling algorithm for CO during TAVR planning. MethodsFrom January 2020 to December 2022, 116 patients (7.6%) who underwent TAVR evaluation were deemed to be at increased risk of CO on the basis of traditional criteria. Patients underwent prospective computational modeling (DASI Simulations) to assess their risk of CO during TAVR; procedural modifications and clinical results were reviewed retrospectively. ResultsOf the 116 patients at risk for CO by traditional methodology, 53 had native aortic valve stenosis (45.7%), 47 had undergone previous surgical AVR (40.5%), and 16 had undergone previous TAVR (13.8%). Transcatheter valve choice, size, or implantation depth was modeled for all patients. Computational modeling predicted an increased risk of CO in 39 of 116 (31.9%) patients. Within this subcohort, 29 patients proceeded with TAVR. Procedural modifications to augment the risk of CO included bioprosthetic or native aortic scallop intentional laceration to prevent iatrogenic coronary artery obstruction during TAVR (n = 10), chimney coronary stents (n = 8), and coronary access without stents (n = 3). There were no episodes of coronary artery compromise among patients after TAVR, either for those predicted to be at high risk of CO (with procedural modifications) or those predicted to be at low risk (standard TAVR). ConclusionsThe use of preoperative simulations for TAVR in patient-specific geometry through computational predictive modeling of CO is an effective enhancement to procedure planning.

Commissural vs Coronary Alignment to Avoid Coronary Overlap With THV-Commissure in TAVR: A CT-Simulation Study

BackgroundCoronary alignment is proposed as an alternative to commissural alignment for reducing coronary overlap during transcatheter aortic valve replacement (TAVR). However, largescale studies are lacking. ObjectivesThis study aimed to determine the incidence of coronary overlap with commissural vs coronary alignment using computed tomography (CT) simulation in patients undergoing TAVR evaluation. MethodsIn 1,851 CT scans of native aortic stenosis patients undergoing TAVR evaluation (April 2018 to December 2022),virtual valves simulating commissural and coronary alignment were superimposed on axial aortic root images. Coronary overlap was assessed based on the angular gap between coronary artery origin and the nearest transcatheter heart valve commissure, categorized as severe (≤15°), moderate (15°-30°), mild (30°-45°), and no-overlap (45°-60°). ResultsThe overall incidence of moderate/severe and severe overlap with either coronary artery remained rare with either coronary or commissural alignment (coronary 0.52% left, 0.52% right; commissural 0.30% left, 3.27% right). Comparing techniques, coronary alignment reduced moderate/severe overlap only for the right coronary artery (0.38% vs 2.97%; P <0.0001). For the left coronary artery, both techniques showed similar moderate/severe overlap, but commissural alignment had significantly higher no-overlap rates (91.1% vs 84.9%; P < 0.0001). Fluoroscopic angle during valve deployment was strongly correlated between commissural and coronary alignment (r = 0.80; P < 0.001). ConclusionsUsing CT simulation, the incidence of coronary overlap with transcatheter heart valve-commissure is rare with commissural alignment. Coronary alignment reduced right coronary overlap, whereas commissural alignment had higher rates of no left coronary overlap. Coronary alignment should be reserved only when commissural alignment results in severe coronary overlap.

Feasibility study of using low-kilovoltage, prospective gating, high-pitch, dual-source computed tomography prior to transcatheter aortic valve replacement: analysis of image quality and radiation dose.

Computed tomography (CT) scans before transcatheter aortic valve replacement (TAVR) are used to evaluate the aortic valve and guide the selection of appropriate valve stents. Accurate imaging evaluation can ensure the success rate of surgery while reducing the incidence of complications. Multiple studies have adopted a protocol of coronary artery, aortic valve, and total aortic scan, with the patients receiving higher radiation doses. The aim of this study was to evaluate the image quality, radiation dose, and diagnostic performance of dual-source computed tomography (DSCT) with high-pitch spiral scanning for TAVR. A total of 240 patients being evaluated for TAVR were continuously enrolled. Based on the differences in electrocardiography (ECG) gating and tube voltage, the patients were divided into 4 groups: group A, 70-kV prospective ECG gating, high-pitch helical; group B, 70-kV retrospective ECG gating; group C, 100-kV prospective ECG gating, high-pitch helical; and group D, 120-kV prospective ECG gating, high-pitch helical. Image quality was evaluated on a 4-point scale. The image signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) were calculated for objective evaluation. The radiation doses of all patients were recorded. The image quality and radiation dose of each group were compared. There were no differences in age, body mass index (BMI), subjective image quality scores, CT values between the aorta and the coronary artery, or image CNR between the 4 groups. The mean radiation doses of groups A-D were 4.13±0.69, 4.79±0.58, 12.00±1.62, and 15.01±1.90 mSv, respectively. The mean radiation dose in group A (70-kV prospective ECG gating) decreased significantly (P<0.05). Using low-kilovoltage, high-pitch DSCT can provide comparable image quality for TAVR evaluation and significantly reduce the radiation dose.

Reduction of contrast medium for transcatheter aortic valve replacement planning using a spectral detector CT: a prospective clinical trial

IntroductionThis study investigated the use of dual-energy spectral detector computed tomography (CT) and virtual monoenergetic imaging (VMI) reconstructions in pre-interventional transcatheter aortic valve replacement (TAVR) planning. We aimed to determine the minimum required contrast medium (CM) amount to maintain diagnostic CT imaging quality for TAVR planning.MethodsIn this prospective clinical trial, TAVR candidates received a standardized dual-layer spectral detector CT protocol. The CM amount (Iohexol 350 mg iodine/mL, standardized flow rate 3 mL/s) was reduced systematically after 15 patients by 10 mL, starting at 60 mL (institutional standard). We evaluated standard, and 40- and 60-keV VMI reconstructions. For image quality, we measured signal-to-noise ratio (SNR), contrast-to-noise ratio (CNR), and diameters in multiple vessel sections (i.e., aortic annulus: diameter, perimeter, area; aorta/arteries: minimal diameter). Mixed regression models (MRM), including interaction terms and clinical characteristics, were used for comparison.ResultsSixty consecutive patients (mean age, 79.4 ± 7.5 years; 28 females, 46.7%) were included. In pre-TAVR CT, the CM reduction to 40 mL is possible without affecting the image quality (MRM: SNR: –1.1, p = 0.726; CNR: 0.0, p = 0.999). VMI 40-keV reconstructions showed better results than standard reconstructions with significantly higher SNR (+ 6.04, p < 0.001). Reduction to 30 mL CM resulted in a significant loss of quality (MRM: SNR: –12.9, p < 0.001; CNR: –13.9, p < 0.001), regardless of the reconstruction. Across the reconstructions, we observed no differences in the metric evaluation (p > 0.914).ConclusionAmong TAVR candidates undergoing pre-interventional CT at a dual-layer spectral detector system, applying 40 mL CM is sufficient to maintain diagnostic image quality. VMI 40-keV reconstructions improve the vessel attenuation and are recommended for evaluation.Clinical relevance statementContrast medium reduction to 40 mL in pre-interventional transcatheter aortic valve replacement CT using dual-energy CT maintains image quality, while 40-keV virtual monoenergetic imaging reconstructions enhance vessel attenuation. These results offer valuable recommendations for interventional transcatheter aortic valve replacement evaluation and potentially improve nephroprotection in patients with compromised renal function.Key Points• Patients undergoing transcatheter aortic valve replacement (TAVR), requiring pre-interventional CT, are often multimorbid with impaired renal function.• Using a spectral detector dual-layer CT, contrast medium reduction to 40 mL is feasible, maintaining diagnostic image quality.• The additional application of virtual monoenergetic image reconstructions with 40 keV improves vessel attenuation significantly in clinical practice.

A Contrast Frugal Approach to Transcatheter Aortic Valve Replacement in Chronic Kidney Disease: A Pilot Study.

Transcatheter aortic valve replacement (TAVR) is now regarded as a viable treatment option for all cases of severe aortic stenosis (AS). Acute kidney injury (AKI) is common and lowers the survival of patients after TAVR and iodine-based contrast-induced nephropathy (CIN) plays a significant adverse role in AKI. Therefore, in chronic kidney disease (CKD) patients requiring pre-operative evaluation for TAVR, the risk of CIN is of particular concern. It was a single-center study including eight CKD patients who underwent pre-operative evaluation for TAVR with minimized contrast exposure by means of pre-operative contrast-sparing evaluation and intra-operative contrast minimization. All patients had glomerular filtration rate (eGFR) calculated before TAVR and on a follow-up about one month and one year post-operatively to document the impact of this TAVR protocol on prognosis of kidney function in patients with advanced CKD. New York Heart Association (NYHA) functional classification demonstrated significant improvement of symptomatology (p = 0.0001) by one-year post-TAVR. Patients' mean AS gradient was significantly improved (p = 0.00004) after the TAVR procedure. No significant post-operative paravalvular aortic regurgitation was noted on follow up echocardiogram. eGFR data showed mean eGFR for the group was slightly better (27.38 ml/min/per 1.73 m2 BSA vs. 30.38 ml/min/per 1.73 m2 BSA) after TAVR. "Contrast frugal" approach is feasible and safe for pre-TAVR evaluation and the procedure itself. Our pilot study showed no significant paravalvular leak of the prosthetic valve following this proposed protocol. No statistically significant decrease in eGFR was noted on a one-year follow-up.

Right Ventricular and Pulmonary Computed Tomography Assessments in Paradoxical Low-Flow Low-Gradient Aortic Stenosis Undergoing Transcatheter Aortic Valve Replacement

BackgroundPatients with paradoxical low-flow low-gradient aortic stenosis (pLFLG AS) have high mortality and a high degree of transcatheter aortic valve replacement (TAVR) futility. Computed tomography (CT) enables accurate simultaneous right ventricular (RV) and parenchymal lung disease evaluation, which may provide useful objective markers of AS severity, concomitant pulmonary comorbidities, and TAVR improvement. However, the prevalence of RV dysfunction and its association with pulmonary disease in pLFLG AS are unknown. The study objective was to test the hypothesis that pLFLG AS patients undergoing TAVR have decreased RV function without a significant parenchymal lung disease. MethodsBetween August 2016 and March 2020, 194 consecutive AS patients completed high-resolution CT imaging for TAVR evaluation. Subjects were stratified based on echocardiographic criteria as the study group, pLFLG (n = 27), and 2 consecutive control groups: classic severe, normal-flow, high-gradient (n = 27) and normal-flow, low-gradient (NFLG) (n = 27) AS. Blinded biventricular function and lung parenchymal disease assessments were obtained by high-resolution CT imaging. ResultsPatient demographics were similar between groups. pLFLG AS had a lower RV ejection fraction (49 ± 10%) than both classic severe (58 ± 7%, p < 0.001) and NFLG AS (55 ± 65%, p = 0.02). There were no significant differences on lung emphysema (p = 0.19), air fraction (p = 0.58), or pulmonary disease presence (p = 0.94) and severity (p = 0.67) between groups. ConclusionspLFLG AS patients have lower RV ejection fraction than classic severe and NFLG AS patients in the absence of significant parenchymal lung disease on CT imaging. These findings support the direct importance of RV function in the pathophysiology of aortic valve disease.

Iatrogenic aortic dissection of the descending aorta after percutaneous coronary intervention.

Aortic dissection is a rare and potentially fatal complication of coronary angiography. We report a case of a woman in her late 80s who underwent a left femoral approach coronary angiogram for evaluation of a transcatheter aortic valve replacement (TAVR). Following the procedure, she had a cardiac arrest and was found to have a descending aortic dissection on transoesophageal echocardiogram. Autopsy showed an acute intimal tear of the descending aorta, most likely related to catheter manipulation. Patients undergoing evaluation for TAVR, who tend to be elderly with concomitant atherosclerosis, are at risk for complications following cardiac catheterisation including aortic dissection.

Evaluating treatment-specific post-discharge quality-of-life and cost-effectiveness of TAVR and SAVR: Current practice & future directions.

Aortic stenosis is a prevalent valvular heart disease that is treated primarily by surgical aortic valve replacement (SAVR) or transcatheter aortic valve replacement (TAVR), which are common treatments for addressing symptoms secondary to valvular heart disease. This narrative review article focuses on the existing literature comparing recovery and cost-effectiveness for SAVR and TAVR. Major databases were searched for relevant literature discussing HRQOL and cost-effectiveness of TAVR and SAVR. We also searched for studies analyzing the use of wearable devices to monitor post-discharge recovery patterns. The literature focusing on quality-of-life following TAVR and SAVR has been limited primarily to single-center observational studies and randomized controlled trials. Studies focused on TAVR report consistent and rapid improvement relative to baseline status. Common HRQOL instruments (SF-36, EQ-5D, KCCQ, MLHFQ) have been used to document that TF-TAVR is advantageous over SAVR at 1-month follow-up, with the benefits leveling off following 1year. TF-TAVR is economically favorable relative to SAVR, with estimated incremental cost-effectiveness ratio values ranging from $50,000 to $63,000/QALY gained. TA-TAVR has not been reported to be advantageous from an HRQOL or cost-effectiveness perspective. While real-world experiences are less described, large-scale trials have advanced our understanding of recovery and cost-effectiveness of aortic valve replacement treatment strategies. Future work should focus on scalable wearable device technology, such as smartwatches and heart-rate monitors, to facilitate real-world evaluation of TAVR and SAVR to support clinical decision-making and outcomes ascertainment.

Identifying Cardiac Amyloid in Aortic Stenosis: ECV Quantification by CT in TAVR Patients

ObjectivesThe purpose of this study was to validate computed tomography measured ECV (ECVCT) as part of routine evaluation for the detection of cardiac amyloid in patients with aortic stenosis (AS)-amyloid. BackgroundAS-amyloid affects 1 in 7 elderly patients referred for transcatheter aortic valve replacement (TAVR). Bone scintigraphy with exclusion of a plasma cell dyscrasia can diagnose transthyretin-related cardiac amyloid noninvasively, for which novel treatments are emerging. Amyloid interstitial expansion increases the myocardial extracellular volume (ECV). MethodsPatients with severe AS underwent bone scintigraphy (Perugini grade 0, negative; Perugini grades 1 to 3, increasingly positive) and routine TAVR evaluation CT imaging with ECVCT using 3- and 5-min post-contrast acquisitions. Twenty non-AS control patients also had ECVCT performed using the 5-min post-contrast acquisition. ResultsA total of 109 patients (43% male; mean age 86 ± 5 years) with severe AS and 20 control subjects were recruited. Sixteen (15%) had AS-amyloid on bone scintigraphy (grade 1, n = 5; grade 2, n = 11). ECVCT was 32 ± 3%, 34 ± 4%, and 43 ± 6% in Perugini grades 0, 1, and 2, respectively (p < 0.001 for trend) with control subjects lower than lone AS (28 ± 2%; p < 0.001). ECVCT accuracy for AS-amyloid detection versus lone AS was 0.87 (0.95 for 99mTc-3,3-diphosphono-1,2-propanodicarboxylic acid Perugini grade 2 only), outperforming conventional electrocardiogram and echocardiography parameters. One composite parameter, the voltage/mass ratio, had utility (similar AUC of 0.87 for any cardiac amyloid detection), although in one-third of patients, this could not be calculated due to bundle branch block or ventricular paced rhythm. ConclusionsECVCT during routine CT TAVR evaluation can reliably detect AS-amyloid, and the measured ECVCT tracks the degree of infiltration. Another measure of interstitial expansion, the voltage/mass ratio, also performed well.

Is There A Role For CCTA For CAD In TAVR Evaluation? Accuracy And Outcomes Analysis In A Low-intermediate Risk Severe Aortic Stenosis Cohort

Introduction: Coronary artery disease (CAD) evaluation via coronary computed tomography angiography (CCTA) is well established, however the role of CCTA for evaluation of CAD in patients undergoing transcatheter aortic valve replacement (TAVR) for severe aortic stenosis (AS) is uncertain due to technical limitations in patient preparation (eg withholding beta-blockers, nitroglycerin and expected calcified plaque). This study evaluated the accuracy of CCTA for CAD in predominantly low-intermediate surgical risk patients (pts) undergoing evaluation for TAVR.

Performance of endobronchial-ultrasound guided miniforceps biopsy of targeted mediastinal and hilar lesions.

Performance of endobronchial-ultrasound guided miniforceps biopsy of targeted mediastinal and hilar lesions.

Transcatheter Aortic Valve Replacement Related Thrombosis in a Patient with a Left Ventricular Assist Device

Introduction Transcatheter aortic valve replacement (TAVR) has been reported as treatment for LVAD related aortic insufficiency (AI). However, the risks of this procedure with unique LVAD physiology are not known. This case describes the diagnostic challenges and catastrophic consequences of TAVR related thrombosis in a continuous flow LVAD patient. Case Report A 68 year old male with a history of TAVR, ischemic cardiomyopathy, and VT underwent LVAD implantation as a bridge to decision. The post-op course was complicated by recurrent heart failure and severe LVAD related AI. He underwent valve-in-valve TAVR for LVAD related AI and initial aortography revealed unobstructed flow into the coronary arteries. He developed incessant VT and shock post-operatively. After failure of medical and ablative therapies, he was transferred to our institution for urgent transplant evaluation. He was listed as status 1 for heart transplantation according to current guidelines for life-threatening ventricular arrhythmia. Imaging studies did not raise suspicion for valve related complication. Admission TTE demonstrated moderate RV dysfunction and the TAVR was not well visualized, but it was well seated without regurgitation. Perioperative TEE had limited TAVR evaluation (Figure 1A-B) but there was normal flow across the inflow and outflow cannulas of the LVAD. There was no echo derived aortic valve gradients to cause clinical suspicion for TAVR thrombosis with ischemic complications, so 4D CTA was not obtained. At the time of heart transplantation, the patient was found to have a large aortic root thrombus with extension into the left main coronary artery and a large thrombus extending from the undersurface of the valve causing complete obstruction of the left ventricular outflow tract (Figure 2A-B). Summary We highlight a case of valve-in-valve TAVR related thrombosis as an unexpected cause of VT in LVAD supported patient. Valve thrombosis was not suspected with the available imaging and likely caused the patient's clinical deterioration. The risk of TAVR related complications may be increased in the setting of continuous flow LVAD physiology due to unique flow dynamics and the presence of intermittent or persistent aortic valve closure.

A Tale of Two Pressures- Medical Management Dilemmas in Post-TAVR LVOT Obstruction

Background Systolic anterior motion (SAM) of the anterior mitral valve leaflet after transcatheter aortic valve replacement (TAVR) is an extremely rare pathophysiologic phenomenon leading to left ventricular outflow tract (LVOT) obstruction. We report a case of post-TAVR LVOT obstruction leading to pulmonary edema and respiratory failure successfully treated medically with fluid challenges. Case Presentation A 91-year-old woman with severe symptomatic aortic stenosis and New York Heart Association (NYHA) functional class III was referred to our institution for TAVR evaluation. Patient was deemed to be intermediate risk based on Society of Thoracic Surgeon (STS) score of 4.7%. The baseline transthoracic echocardiogram confirmed the presence of severe aortic stenosis with peak aortic jet velocity of 5.5 m/s, aortic valve area of 0.8 cm2and mean gradient > 40 mmHg with preserved left ventricular function and mild mitral regurgitation. No intra-ventricular gradient, septal wall hypertrophy or SAM of the anterior mitral valve leaflet was noted. Patient underwent successful transfemoral TAVR with a 29 mm Medtronic Evolut PRO valve. Angiography confirmed proper valve position and no paravalvular leak. Post-procedural echocardiogram demonstrated adequate prosthesis performance with new-onset of SAM dynamic LVOT obstruction and concomitant severe mitral regurgitation leading to systolic flow reversal in both left and right pulmonary veins and apical tethering of the anterior mitral leaflet. Postoperative course was further complicated by Enterococcus sepsis leading to atrial fibrillation with rapid ventricular response resulting in systemic hypotension, pulmonary edema and impending respiratory failure. Despite the congestion in the pulmonary vasculature, the decision was made to optimize diastolic filling and preload by titrated beta-blockade and serial fluid challenges with 250 mL boluses. Patient was able to increase forward stroke volume leading to improvements in mean arterial pressure and resolution of pulmonary congestion. Conclusions The mechanism leading to SAM and LVOT obstruction after TAVR implant is poorly elucidated and rarely reported in the literature. Chronic aortic stenosis results in increased afterload to the LV that is compensated by elevated intra-ventricular pressure to allow adequate systemic perfusion. The increased intra-ventricular pressure also prevents septal inward motion and thus keeps LVOT unobstructed. With TAVR and the relief of the fixed obstruction, intra-ventricular pressure drops simultaneously with a reduction in LVOT cross-sectional area due to an increased flow velocity. A pressure gradient is created between the left atrium and LVOT that pulls the anterior mitral leaflet toward the LVOT creating a dynamic LVOT obstruction. Every effort should be made to optimize diastolic filling and contractility through titrated beta-blockade and fluid challenge.

Is MRI equivalent to CT in the guidance of TAVR? A pilot study.

To compare a comprehensive cardiovascular magnetic resonance imaging (MRI) protocol with contrast-enhanced computed tomography angiography (CTA) for guidance in transcatheter aortic valve replacement (TAVR) evaluation. Non-contrast three-dimensional (3D) 'whole heart' MRI imaging for aortic annulus sizing and measurements of coronary ostia heights, contrast-enhanced MRI angiography (MRA) for evaluation of transfemoral routes as well as aortoiliofemoral-CTA were performed in 16 patients referred for evaluation of TAVR. Aortic annulus measurements by MRI and CTA showed a very strong correlation (r=0.956, p<0.0001; effective annulus area for MRI 430±74 vs. 428±78 mm2 for CTA, p=0.629). Regarding decision for valve size there was complete consistency between MRI and CTA. Moreover, vessel luminal diameters and angulations of aortoiliofemoral access as measured by MRA and CTA showed overall very strong correlations (r= 0.819 to 0.996, all p<0.001), the agreement of minimal vessel diameter between the two modalities revealed a bias of 0.02 mm (upper and lower limit of agreement: 1.02 mm and -0.98 mm). In patients referred for TAVR, MRI measurements of aortic annulus and minimal aortoiliofemoral diameters showed good to excellent agreement. Decisions based on MRI measurements regrading prosthesis sizing and transfemoral access would not have modified TAVR-strategy as compared to a CTA-based choice. • 'Whole heart' MRI and CTA measurements of aortic annulus correlate very strongly. • MRI- and CTA-based prostheses sizing are in excellent agreement. • MRA and CTA equally guide TAVR access strategy.

Technical Feasibility of a Combined Noncontrast Magnetic Resonance Protocol for Preoperative Transcatheter Aortic Valve Replacement Evaluation.

The aim of this study was to prospectively evaluate the technical feasibility of a noncontrast magnetic resonance angiography (MRA) protocol using investigational prototype self-navigated 3D (SN3D) radial whole-heart and quiescent-interval single-shot (QISS) pulse sequences regarding their potential in planning transcatheter aortic valve replacement (TAVR). Five patients (76±7 y) with severe aortic valve stenosis and prior computed tomographic angiography (CTA) for TAVR planning and 10 healthy volunteers (28±6 y) underwent noncontrast MRA on a 1.5 T system. A SN3D whole-heart acquisition was used to assess the aortic root anatomy. Evaluation of the aortoiliac access route was performed with both SN3D and QISS. Measurements were compared among SN3D, QISS, and CTA using a paired t test or 1-way analysis of variance. Image quality ratings and contrast-to-noise ratios (CNR) were analyzed using Mann-Whitney U tests. Interobserver agreement was evaluated using Cohen's κ. The combined SN3D and QISS protocol provided a 10.1±1.6-minute acquisition time. TAVR-relevant evaluation was technically feasible in healthy volunteers. All measurements showed good agreement with CTA in patients (all P>0.098). SN3D and QISS produced similar image quality both in volunteers and in patients (all P>0.122). There was no difference in qualitative ratings between MRA and CTA (all P>0.119). Interobserver agreement was good for MRA (κ=0.71 to 0.76) and excellent for CTA (κ=0.82 to 0.84). Thoracic SN3D provided a similar CNR compared with CTA (P=0.117). CTA yielded higher CNR in the abdominopelvic region compared with QISS (P=0.006). A noncontrast MRA protocol combining SN3D and QISS acquisitions for the assessment of cardiac and vascular access route anatomy has technical feasibility for TAVR planning.

Standard imaging techniques in transcatheter aortic valve replacement.

Transcatheter aortic valve replacement (TAVR) has become a widely accepted therapeutic option for patients with severe, symptomatic aortic stenosis at intermediate, high, or extreme risk for conventional surgery as determined through a heart team approach. Two valve prostheses are currently available and the Food and Drug Administration (FDA) approved in the United States for TAVR: the self-expandable Medtronic CoreValve (Medtronic, Inc., Minneapolis, MN, USA) and the balloon-expandable Edwards Sapien Valve (Edwards Lifesciences, Irvine CA, USA). The preoperative evaluation for TAVR includes transthoracic echocardiography (TTE) for the diagnosis of aortic stenosis. Cardiac computed tomography (CTA) has become the imaging modality of choice for annular sizing. Aortic root dimensions and coronary ostia height, and the degree of annular and left ventricular outflow tract calcification are also assessed to estimate the risk of coronary obstruction, annular rupture, and postoperative aortic regurgitation. Finally, CTA is essential to determine the adequacy of the peripheral vasculature for a transfemoral approach. Intraoperatively, fluoroscopy is mandatory for valve positioning, whereas the use of TTE or transesophageal echocardiography (TEE) varies by center. TTE is used for postoperative surveillance of valve function.

Transcatheter Aortic Valve Replacement Versus Surgery in Women at High Risk for Surgical Aortic Valve Replacement (from the CoreValve US High Risk Pivotal Trial)

The objective of this study was to compare outcomes in women after surgical aortic valve replacement (SAVR) versus transcatheter aortic valve replacement (TAVR) using a self-expanding prosthesis in patients with severe aortic stenosis who were at high risk for SAVR. Although registries and meta-analyses have suggested that TAVR is of considerable benefit in women, perhaps even more so than in men, a rigorous evaluation of TAVR with a self-expanding valve versus SAVR in women from a randomized trial has not been performed. Patients with severe aortic stenosis were randomized 1:1 to either TAVR or SAVR. Outcomes at 1year are reported. Treatment was attempted in a total of 353 women (183 TAVR and 170 SAVR). Baseline characteristics and predicted risk of the 2 groups were comparable, although the frequency of diabetes mellitus was lower in patients undergoing TAVR (33.3% vs 45.3%; p= 0.02). TAVR-treated patients experienced a statistically significant 1-year survival advantage compared with SAVR patients (12.7% vs 21.8%; p= 0.03). The composite all-cause mortality or major stroke rate also favored TAVR (14.9% vs 24.2%; p= 0.04). Quality of life, as measured by the Kansas City Cardiomyopathy Questionnaire summary score, for both the TAVR and SAVR groups increased significantly from baseline to 1year. In conclusion, female TAVR patients had lower 1-year mortality and lower 1-year all-cause mortality or major stroke compared with women undergoing SAVR, with both cohorts experiencing improved quality of life. Further studies specifically in women are warranted to validate these findings.

The Odyssey of TAVR from concept to clinical reality.

On 16 April 2002, my colleagues and I performed, in an inoperable and desperately ill man with critical calcific aortic stenosis (AS), the first clinical percutaneous implantation of an aortic valve bioprosthesis. As of 2013, more than 80,000 patients have been treated; and transcatheter aortic valve replacement (TAVR), so strongly criticized by all the experts throughout the early years, continues to grow in parallel with its constant technological improvements. Transcatheter aortic valve replacement can now be recognized as a medical breakthrough. It is a revolutionary technology that meets an unfulfilled clinical need for a common disease, is validated by rigorous evidence-based studies, and is applicable worldwide. We report here the main phases of this 20-year odyssey and briefly consider the prospects of TAVR, which remains in continuous development.

Abstract 261: Where Clinical Practice, Emerging Medical Technology, And Evaluation Intersect In A Healthcare System Based On Equal Access: The Example Of Transcatheter Aortic Valve Replacement

BACKGROUND: Transcatheter aortic valve replacement (TAVR) is an emerging treatment for frequently elderly patients with severe symptomatic aortic stenosis considered at too high risk for conventional surgery. However, this less invasive treatment has important implications in a universal public payer healthcare system with limited resources. In early 2011, the province of Quebec’s Ministry of Health requested an evaluation of TAVR by INESSS, a government-funded independent body that assists evidence-based policy-making with literature reviews, field evaluations and outcomes research. The Ministry also asked INESSS to be involved in the creation of a provincial registry. At the time of the request, 4 centers were already performing TAVR and others were developing programs. METHODS: We conducted a systematic literature review (2008-2011) on effectiveness, safety, economic, and ethical issues, in collaboration with a committee of independent clinical experts (4 interventional cardiologists, 4 cardiac surgeons). The committee’s role was to help interpret and contextualize existing evidence and to collaborate in the development of a provincial registry. We proposed clinical, process of care and economic variables for a registry based on the literature review and the clinicians’ perspectives. RESULTS: According to the literature, outcomes of TAVR are promising for carefully selected patients with respect to 1-year survival, functional improvement, and quality of life. Limitations in the evidence base include uncertain longer-term benefits and device durability due to a lack of studies with lengthy follow-up; an important risk of stroke and high rates of hospitalization post-intervention in the one available randomized controlled trial; lack of standardization of data definitions across studies; and insufficient evidence on cost-effectiveness and cost-utility. We recommended that: (1) TAVR be offered only to patients declined for surgery and who would likely have improved quality of life as a result of the procedure; (2) patients be fully informed of the relative novelty of the procedure and uncertainty about associated risks and longer-term benefits; (3) selection of patients involve a multi-disciplinary team and be uniform in terms of criteria and process across centers to ensure equal access; (4) the patient selection process be documented; (5) TAVR programs receive specific funding that includes financing of a registry; (6) a mandatory registry be used to collect data on baseline patient characteristics, procedures, outcomes, and costs, to inform both participating centres and the Ministry; and (7) TAVR be performed by a limited number of expert centers to maintain a sufficient volume of procedures. CONCLUSIONS: The practice of TAVR in the province of Quebec will be guided by the results of a systematic review of existing evidence and future evidence from a provincial registry developed by an independent body in collaboration with clinical experts. We believe that this evaluation model will meet the challenges posed by the introduction of innovative technology in a universal healthcare system with limited resources.