Prevalence, Cardiac Phenotype, and Outcomes of Transthyretin Variants in the UK Biobank Population.

Importance: The population prevalence of cardiac transthyretin amyloidosis (ATTR) caused by pathogenic variation in the TTR gene (vATTR) is unknown. Objective: To estimate the population prevalence of disease-causing TTR variants and evaluate associated phenotypes and outcomes. Design, Setting, and Participants: This population-based cohort study analyzed UK Biobank (UKB) participants with whole-exome sequencing, electrocardiogram, and cardiovascular magnetic resonance data. Participants were enrolled from 2006 to 2010, with a median follow-up of 12 (IQR, 11-13) years (cutoff date for the analysis, March 12, 2024). Sixty-two candidate TTR variants were extracted based on rarity (minor allele frequency ≤0.0001) and/or previously described associations with amyloidosis if more frequent. Exposure: Carrier status for TTR variants. Main Outcomes and Measures: Associations of TTR carrier status with vATTR prevalence and cardiovascular imaging and electrocardiogram traits were explored using descriptive statistics. Associations between TTR carrier status and atrial fibrillation, conduction disease, heart failure, and all-cause mortality were evaluated using adjusted Cox proportional hazards models. Genotypic and diagnostic concordance was examined using International Statistical Classification of Diseases, Tenth Revision codes from the hospital record. Results: The overall cohort included 469 789 UKB participants (mean [SD] age, 56.5 [8.1] years; 54.2% female and 45.8% male). A likely pathogenic/pathogenic (LP/P) TTR variant was detected in 473 (0.1%) participants, with Val142Ile being the most prevalent (367 [77.6%]); 91 individuals (0.02%) were carriers of a variant of unknown significance . The overall prevalence of LP/P variants was 0.02% (105 of 444 243) in participants with European ancestry and 4.3% (321 of 7533) in participants with African ancestry. The LP/P variants were associated with higher left ventricular mass indexed to body surface area (ß = 4.66; 95% CI, 1.87-7.44), and Val142Ile was associated with a longer PR interval (ß = 18.34; 95% CI, 5.41-31.27). The LP/P carrier status was associated with a higher risk of heart failure (hazard ratio [HR], 2.68; 95% CI, 1.75-4.12) and conduction disease (HR, 1.88; 95% CI, 1.25-2.83). Higher all-cause mortality risk was observed for non-Val142Ile LP/P variants (HR, 1.98; 95% CI, 1.06-3.67). Thirteen participants (2.8%) with LP/P variants had diagnostic codes compatible with cardiac or neurologic amyloidosis. Variants of unknown significance were not associated with outcomes. Conclusions and Relevance: This study found that approximately 1 in 1000 UKB participants were LP/P TTR variant carriers, exceeding previously reported prevalence. The findings emphasize the need for clinical vigilance in identifying individuals at risk of developing vATTR and associated poor outcomes.

Prevalence and outcome of dual aortic stenosis and cardiac amyloid pathology in patients referred for transcatheter aortic valve implantation.

AIMS: Cardiac amyloidosis is common in elderly patients with aortic stenosis (AS) referred for transcatheter aortic valve implantation (TAVI). We hypothesized that patients with dual aortic stenosis and cardiac amyloid pathology (AS-amyloid) would have different baseline characteristics, periprocedural and mortality outcomes. METHODS AND RESULTS: Patients aged ≥75 with severe AS referred for TAVI at two sites underwent blinded bone scintigraphy prior to intervention (Perugini Grade 0 negative, 1-3 increasingly positive). Baseline assessment included echocardiography, electrocardiogram (ECG), blood tests, 6-min walk test, and health questionnaire, with periprocedural complications and mortality follow-up. Two hundred patients were recruited (aged 85 ± 5 years, 50% male). AS-amyloid was found in 26 (13%): 8 Grade 1, 18 Grade 2. AS-amyloid patients were older (88 ± 5 vs. 85 ± 5 years, P = 0.001), with reduced quality of life (EQ-5D-5L 50 vs. 65, P = 0.04). Left ventricular wall thickness was higher (14 mm vs. 13 mm, P = 0.02), ECG voltages lower (Sokolow-Lyon 1.9 ± 0.7 vs. 2.5 ± 0.9 mV, P = 0.03) with lower voltage/mass ratio (0.017 vs. 0.025 mV/g/m2, P = 0.03). High-sensitivity troponin T and N-terminal pro-brain natriuretic peptide were higher (41 vs. 21 ng/L, P < 0.001; 3702 vs. 1254 ng/L, P = 0.001). Gender, comorbidities, 6-min walk distance, AS severity, prevalence of disproportionate hypertrophy, and post-TAVI complication rates (38% vs. 35%, P = 0.82) were the same. At a median follow-up of 19 (10-27) months, there was no mortality difference (P = 0.71). Transcatheter aortic valve implantation significantly improved outcome in the overall population (P < 0.001) and in those with AS-amyloid (P = 0.03). CONCLUSIONS: AS-amyloid is common and differs from lone AS. Transcatheter aortic valve implantation significantly improved outcome in AS-amyloid, while periprocedural complications and mortality were similar to lone AS, suggesting that TAVI should not be denied to patients with AS-amyloid.

A guide to fluoroscopic identification and design of bioprosthetic valves: a reference for valve-in-valve procedure.

Surgical aortic valve replacement remains the therapy of choice in majority of patients with aortic stenosis. Bioprosthetic heart valves are often preferred over mechanical valves as they preclude the need for anticoagulation with its associated risks of bleeding and thromboembolism. However, bioprosthetic heart valves undergo structural deterioration and eventually fail. Reoperation is the standard treatment for structural failure of the bioprosthetic valve, stenosis or regurgitation but can carry a significant risk, especially in elderly patients with multiple comorbidities. Transcatheter aortic valve implantation has recently been established as a feasible alternative to conventional valve surgery for the management of high-risk elderly patients with aortic stenosis. This treatment modality has also been shown to be of benefit in the management of degenerated aortic bioprosthesis as a valve-in-valve procedure. The success of this procedure depends on a good understanding of the failing bioprostheses. This not only includes the device design but its radiological/fluoroscopic appearance and how it correlates with the implanted valve, as transcatheter aortic valve implantation is performed under fluoroscopic guidance. Here we illustrate the fluoroscopic appearance of 11 commercially available surgical bioprostheses and two commercially available transcatheter heart valves and discuss important aspects in their design which can influence outcome of a valve-in-valve procedure. We have also collated relevant information on the aspects of the design of a bioprosthetic valve, which are relevant to the valve-in-valve procedure.

Transapical transcatheter aortic valve implantation in a complex aortic surgical patient: A case involving the youngest valve-in-valve implantation with a 29 mm transcather valve.

The present article reports a case involving a 29-year-old man who developed severe cardiac failure (New York Heart Association class IV). He had a complex surgical history, beginning with the repair of an anterior sinus of Valsalva aneurysm and closure of a ventricular septal defect at eight months of age. His residual Valsalva aneurysm and mixed aortic valve disease necessitated mechanical aortic valve replacement at 14 years of age. One year later, he developed coagulase-negative staphylococcal prosthetic valve infective endocarditis, necessitating an additional replacement of his valve with a pulmonary homograft. Subsequent follow-up revealed a dilated ascending aorta (6 cm) and increased regurgitation through his homograft, with significant dilation of the left ventricle. At 20 years of age, he underwent excision of the aneurysmal ascending aorta and arch of the aorta, and the aortic valve was replaced with a 29 mm bioprosthetic valve. This proved satisfactory for nine years until he presented at Guy's and St Thomas' National Health Services Foundation Trust (London, United Kingdom) with severe aortic regurgitation. His logistic EuroScore was 5.9 and Parsonnet score was 17 but, due to extensive previous surgery, he was considered and accepted for transcatheter aortic valve implantation. A 29 mm Edwards Sapien valve (Edwards Lifesciences, USA) was successfully implanted using a valve-in-valve procedure. The patient remained well and symptom free at early follow-up. Technical aspects of this complex adult congenital case that, to the authors' knowledge is the youngest case of transcatheter aortic valve implantation and the first 29 mm valve-in-valve procedure, are discussed.