Nickenig, Georg

BACKGROUND: Bicuspid aortic valve (BAV) is a frequent congenital heart defect with a high heritability. Despite this, only a limited number of genes have been associated with the disease, and the molecular mechanisms remain unexplained in most cases. This study aimed to further understand the genetic architecture of BAV. METHODS: A genome-wide association study meta-analysis including 9631 cases among 65 677 participants was performed. Genes were prioritized using transcriptomic analyses based on RNA sequencing in relevant tissues, including human fetal and adult aortic valves. The impact of the knockdown or knockout of 4 candidate genes on cardiac development was verified in zebrafish. A polygenic risk score was developed, its association with BAV was evaluated in an independent cohort, and its association with a wide range of phenotypes (n=976) was evaluated in UK Biobank (n=355 618 individuals). RESULTS: Thirty-six genomic loci were identified, including 32 that were not described previously. Among the prioritized genes, KANK2 and ERBB4 were identified as potentially causal through transcriptomic analyses, colocalization, and Mendelian randomization based on gene expression in human aortic valves (n=484), whereas PRDM6 and STRN were prioritized using similar analyses from aortic (n=326) and left ventricular tissues (n=326), respectively. Targeting 4 candidate genes ( WNT4 , LEF1 , STRN , and KANK2 ) in zebrafish led to disruption in cardiac development. A polygenic risk score was associated with an odds ratio of 2.07 (95% CI, 1.90–2.25; P =5.43×10 -62 ) per SD for BAV and significantly associated with thoracic aortic aneurysm and atrial fibrillation in UK Biobank. CONCLUSIONS: This study supports a significant polygenic contribution to BAV, where the combination of multiple common variants in genes involved in heart morphogenesis disrupts aortic valve development.

Abstract Background and Aims The TRISCEND II trial demonstrated superior clinical benefits for patients with ≥severe tricuspid regurgitation (TR) treated with the EVOQUE transcatheter tricuspid valve replacement (TTVR) system plus medical therapy vs medical therapy alone. This work reports 1-year and 18-month outcomes in patients stratified by baseline TR severity. Methods The multicentre, prospective TRISCEND II trial enrolled 400 patients with symptomatic, ≥severe TR, and randomized 2:1 to TTVR (n = 267) or control (n = 133). In a post hoc analysis, patients were stratified into severe TR (n = 172) and massive/torrential TR (n = 220) cohorts. Clinical and quality-of-life outcomes were reported at 1 year, with Kaplan–Meier estimates for all-cause mortality and heart failure (HF) hospitalization assessed at 18 months. Study oversight included an independent echocardiographic core laboratory, clinical events committee, and data safety monitoring board. Results One year after TTVR, TR was ≤mild in 95.2% of severe TR and 95.3% of massive/torrential TR patients. The primary safety and effectiveness endpoint (win ratio) favoured TTVR over control regardless of baseline TR severity: severe {1.64 [95% confidence interval (CI): 1.11, 2.43]} and massive/torrential [2.20 (1.55, 3.14)]. At 18 months, TTVR patients had similar mortality to controls [rate difference: severe 0.2% (−11.6, 11.9), massive/torrential −5.8% (−17.6, 6.0)], whereas HF hospitalization rates favoured TTVR in the massive/torrential cohort [vs control, severe 9.8% (−3.0, 22.7), massive/torrential -15.2% (−28.9, −1.5)]. Conclusions Patients with ≥severe TR benefit from TTVR, experiencing improvements in TR severity, functional capacity, and quality of life regardless of baseline TR severity, with a signal for greater benefit in patients with more advanced disease.