Current and Evolving Multimodality Cardiac Imaging in Managing Transthyretin Amyloid Cardiomyopathy.

Amyloid transthyretin (ATTR) amyloidosis is a protein-misfolding disease characterized by fibril accumulation in the extracellular space that can result in local tissue disruption and organ dysfunction. Cardiac involvement drives morbidity and mortality, and the heart is the major organ affected by ATTR amyloidosis. Multimodality cardiac imaging (ie, echocardiography, scintigraphy, and cardiac magnetic resonance) allows accurate diagnosis of ATTR cardiomyopathy (ATTR-CM), and this is of particular importance because ATTR-targeting therapies have become available and probably exert their greatest benefit at earlier disease stages. Apart from establishing the diagnosis, multimodality cardiac imaging may help to better understand pathogenesis, predict prognosis, and monitor treatment response. The aim of this review is to give an update on contemporary and evolving cardiac imaging methods and their role in diagnosing and managing ATTR-CM. Further, an outlook is presented on how artificial intelligence in cardiac imaging may improve future clinical decision making and patient management in the setting of ATTR-CM.

Routine 4D Cardiac CT to Identify Concomitant Transthyretin Amyloid Cardiomyopathy in Older Adults with Severe Aortic Stenosis.

Background Transthyretin amyloid cardiomyopathy (ATTR-CM) often coexists with severe aortic stenosis (AS). Although strain analysis from cardiac MRI and echocardiography was demonstrated to predict coexisting ATTR-CM, comparable data from four-dimensional (4D) cardiac CT are lacking despite wide availability. Purpose To evaluate the diagnostic performance of 4D cardiac CT-derived parameters in identifying ATTR-CM in older adults considered for transcatheter aortic valve implantation (TAVI). Materials and Methods This prospective single-center screening study for ATTR-CM included consecutive patients with severe AS considered for TAVI who underwent 4D cardiac CT between August 2019 and August 2021 approximately 1 day before technetium 99m (99mTc) 3,3-diphosphono-1,2-propanodicarboxylic-acid (DPD) scintigraphy. The diagnostic performance of CT-based left ventricular (LV), right ventricular, and left atrial dimensions, ejection fraction (EF), and myocardial strain were evaluated against 99mTc-DPD scintigraphy as the reference standard to identify ATTR-CM. Predictors and an unweighted cardiac CT score were validated with internal bootstrapping. The assignment of variables to the score was based on cutoff values achieving the highest Youden index J. Results Among 263 participants (mean age, 83 years ± 4.6 [SD]; 149 male and 114 female participants), 99mTc-DPD scintigraphy (Perugini grade 2 or 3) confirmed coexisting ATTR-CM in 27 (10.3%). CT-derived LV mass index, LV and LA global longitudinal strain (GLS), and relative apical longitudinal strain each predicted the presence of ATTR-CM with an area under the curve (AUC) of at least 0.70. Implementing these parameters with cutoff values of 81 g/m2 or higher, -14.9% or higher, less than 11.5%, and 1.7 or higher in the CT score, respectively, yielded high diagnostic performance (AUC = 0.89; 95% CI: 0.81, 0.94; P < .001) robust to internal bootstrapping validation (AUC = 0.88; 95% CI: 0.82, 0.94). If two criteria were fulfilled, the sensitivity and specificity in the detection of ATTR-CM were 96.3% (95% CI: 81.0, 99.9) and 58.9% (95% CI: 52.3, 65.2), respectively. Conclusion When compared against 99mTc-DPD scintigraphy as the reference standard, routine 4D cardiac CT in older adults considered for TAVI provided high diagnostic performance in the detection of concomitant ATTR-CM by assessing LV and left atrial GLS, relative apical longitudinal strain, and LV mass index. ClinicalTrials.gov registration no.: NCT04061213 © RSNA, 2023 Supplemental material is available for this article. See also the editorial by Tavakoli and Onder in this issue.

Imaging of Bioprosthetic Valve Dysfunction after Transcatheter Aortic Valve Implantation.

Transcatheter aortic valve implantation (TAVI) has become the standard of care in elderly high-risk patients with symptomatic severe aortic stenosis. Recently, TAVI has been increasingly performed in younger-, intermediate- and lower-risk populations, which underlines the need to investigate the long-term durability of bioprosthetic aortic valves. However, diagnosing bioprosthetic valve dysfunction after TAVI is challenging and only limited evidence-based criteria exist to guide therapy. Bioprosthetic valve dysfunction encompasses structural valve deterioration (SVD) resulting from degenerative changes in the valve structure and function, non-SVD resulting from intrinsic paravalvular regurgitation or patient-prosthesis mismatch, valve thrombosis, and infective endocarditis. Overlapping phenotypes, confluent pathologies, and their shared end-stage bioprosthetic valve failure complicate the differentiation of these entities. In this review, we focus on the contemporary and future roles, advantages, and limitations of imaging modalities such as echocardiography, cardiac computed tomography angiography, cardiac magnetic resonance imaging, and positron emission tomography to monitor the integrity of transcatheter heart valves.

Impact of right ventricular-pulmonary arterial coupling on clinical outcomes in patients undergoing transcatheter aortic valve implantation.

AIMS: The interplay between pulmonary hypertension (PH) and right ventricular (RV) function is reflected in an index of RV function to pulmonary artery (PA) systolic pressure (PASP). The present study aimed to assess the importance of RV-PA coupling on clinical outcomes after transcatheter aortic valve implantation (TAVI). METHODS AND RESULTS: In a prospective TAVI registry, clinical outcomes of TAVI patients with RV dysfunction or PH were stratified according to coupling or uncoupling of tricuspid annular plane systolic excursion (TAPSE) to PASP, and compared to those of patients with normal RV function and absence of PH. The median TAPSE/PASP ratio was used to differentiate uncoupling (>0.39) from coupling (<0.39). Among 404 TAVI patients, 201 patients (49.8 %) had RVD or PH at baseline: 174 patients had RV-PA uncoupling, and 27 had coupling at baseline. RV-PA hemodynamics normalized in 55.6 % of patients with RV-PA coupling and in 28.2 % of patients with RV-PA uncoupling, and deteriorated in 33.3 % of patients with RV-PA coupling and in 17.8 % of patients with no RVD, respectively, at discharge. Patients with RV-PA uncoupling after TAVI showed a trend towards an increased risk of cardiovascular death at 1 year as compared to patients with normal RV-function (HRadjusted 2.06, 95 % CI 0.97-4.37). CONCLUSION: After TAVI, RV-PA coupling changed in a significant proportion of patients and is a potentially important metric for risk stratification of TAVI patients with RVD or PH. TWEET: "Patients with right ventricular dysfunction and pulmonary hypertension are at increased risk of death after TAVI. Integrated right ventricular to pulmonary artery hemodynamics change after TAVI in a significant proportion of patients and is instrumental to refine risk stratification." CLINICAL TRIAL REGISTRATION: https://www. CLINICALTRIALS: gov: NCT01368250.

Incidence of Prosthesis-Patient Mismatch in Valve-in-Valve with a Supra-Annular Valve.

BACKGROUND: Transcatheter aortic valve replacement (TAVR) for a degenerated surgical bioprosthesis (valve-in-valve [ViV]) has become an established procedure. Elevated gradients and patient-prosthesis mismatch (PPM) have previously been reported in mixed TAVR cohorts. We analyzed our single-center experience using the third-generation self-expanding Medtronic Evolut R prosthesis, with an emphasis on the incidence and outcomes of PPM. METHODS: This is a retrospective analysis of prospectively collected data from our TAVR database. Intraprocedural and intrahospital outcomes are reported. RESULTS: Eighty-six patients underwent ViV-TAVR with the Evolut R prosthesis. Mean age was 75.5 ± 9.5 years, 64% were males. The mean log EuroScore was 21.6 ± 15.7%. The mean time between initial surgical valve implantation and ViV-TAVR was 8.8 ± 3.2 years. The mean true internal diameter of the implanted surgical valves was 20.9 ± 2.2 mm. Post-AVR, 60% had no PPM, 34% had moderate PPM, and 6% had severe PPM. After ViV-TAVR, 33% had no PPM, 29% had moderate, and 39% had severe PPM. After implantation, the mean transvalvular gradient was reduced significantly from 36.4 ± 15.2 to 15.5 ± 9.1 mm Hg (p < 0.001). No patient had more than mild aortic regurgitation after ViV-TAVR. No conversion to surgery was necessary. Estimated Kaplan-Meier survival at 1 year for all patients was 87.4%. One-year survival showed no significant difference according to post-ViV PPM groups (p = 0.356). CONCLUSION: ViV-TAVR using a supra-annular valve resulted in low procedural and in-hospital complication rates. However, moderate or severe PPM was common, with no influence on short-term survival. PPM may not be a suitable factor to predict survival after ViV-TAVR.