Regional Aortic Wall Shear Stress Increases over Time in Patients with a Bicuspid Aortic Valve.

BACKGROUND: Aortic wall shear stress (WSS) is a known predictor of ascending aortic growth in patients with a bicuspid aortic valve (BAV). The aim of this study was to study regional WSS and changes over time in BAV patients. METHODS: BAV patients and age-matched healthy controls underwent 4D flow CMR. Regional, peak systolic ascending aortic WSS, aortic valve function, aortic stiffness measures and aortic dimensions were assessed. In BAV patients, 4D flow CMR was repeated after three years follow-up and both at baseline and follow-up computed tomography angiography (CTA) was acquired. Aortic growth (volume increase of ≥5%) was measured on CTA. Regional WSS differences within patients' aorta and WSS changes over time were analysed using linear mixed-effect models and were associated with clinical parameters. RESULTS: Thirty BAV patients (aged 34 years [IQR 25-41]) were included in the follow-up analysis. Additionally, another 16 BAV patients and 32 healthy controls (aged 33 years [IQR 28-48]) were included for other regional analyses. Magnitude, axial, and circumferential WSS increased over time (all p<0.001) irrespective of aortic growth. The percentage of regions exposed to a magnitude WSS >95th percentile of healthy controls increased from 21% (baseline 506/2400 regions) to 31% (follow-up 734/2400 regions) (p<0.001). WSS angle, a measure of helicity near the aortic wall, decreased during follow-up. Magnitude WSS changes over time were associated with systolic blood pressure, peak aortic valve velocity, aortic valve regurgitation fraction, aortic stiffness indexes, and normalized flow displacement (all p<0.05). CONCLUSIONS: An increase of regional WSS over time was observed in BAV patients, irrespective of aortic growth. The increasing WSSs comprising a larger area of the aorta warrants further research to investigate the possible predictive value for aortic dissection.

Prognostic value of the electrocardiogram in patients with bicuspid aortic valve disease.

BACKGROUND: Identifying bicuspid aortic valve (BAV) patients at risk for cardiac events remains challenging and the role of the electrocardiogram (ECG) has not yet been described. Therefore, this study aims to describe ECG parameters in BAV patients, and investigate their prognostic value. METHODS: In this single-center prospective study patients with BAV without a prior aortic valve replacement (AVR) were included. Transthoracic echocardiogram and 12­lead resting-ECG were obtained. Associations between ECG parameters and the composite endpoint of all-cause mortality and AVR were assessed using Cox-proportional hazard analysis. RESULTS: 120 patients with BAV were included (median age 30 years, 61% male). Median aortic jet velocity was 2.4 m/s [IQR: 1.7-3.4] and 5 patients (4%) had severe aortic regurgitation. All patients were in sinus rhythm. Any ECG abnormality was present in 57 patients (48%). Median PR-interval was 156 [IQR: 138-170] msec. A deviating QRS axis was found in 17 patients (14%) and Cornell criteria for LVH were fulfilled in 20 patients (17%). Repolarization abnormalities were present in 12 patients (10%). Median follow-up duration was 7.0 [6.3-9.8] years, during which 23 patients underwent AVR and 2 patients died. After adjusting for age, a longer PR-interval was associated with worse intervention-free survival (HR 1.02, 95% CI: 1.01-1.04). CONCLUSION: Almost half of the patients with BAV had abnormalities on their ECG. Moreover, the PR-interval may be an interesting prognostic marker for intervention-free survival in BAV patients.

Blood and Imaging Biomarkers in the Long-term Follow-up of Bicuspid Aortic Valve Patients.

Background: Bicuspid aortic valve (BAV) is a common congenital heart defect. Patients with BAV are at risk for long-term complications such as valve stenosis and regurgitation. This study aimed to investigate sex differences in blood and imaging biomarkers and to describe the long-term prognostic value of blood and echocardiographic biomarkers. Methods: Patients were included from 2 prospective observational cohort studies; they underwent venous blood sampling and transthoracic echocardiography including speckle tracking. Analyzed blood biomarkers were red-cell distribution width (RDW), creatinine, C-reactive protein (CRP), troponin T, N-terminal pro B-type natriuretic peptide (NT-proBNP), and transforming growth factor-beta (TGF-ß). Sex differences were analyzed at baseline. Associations between biomarkers and arrhythmia-free and intervention-free survival were determined by Cox regression, adjusted for age and sex. Results: A total of 182 patients with BAV were included: median age 34; interquartile range [IQR]: 23-46 years; 55.5% male. CRP, NT-proBNP, and RDW were higher in women, whereas creatinine, troponin T and TGF-ß were higher among men. After a median follow-up time of 6.9 (IQR: 6.5-9.9) years, arrhythmia-free and intervention-free survival was, 81.0% and 73.1%, respectively. NT-proBNP was associated with both arrhythmia-free and intervention-free survival (hazard ratio [HR], 1.94, P = 0.005 and HR, 2.06, P = 0.002, respectively). On echocardiography higher left atrial (LA) size, left ventricular end-diastolic diameter (LVEDD), left ventricular (LV) mass index and E/e' ratio were associated with lower arrhythmia-free survival, whereas higher LA size, LV mass index, aortic valve peak velocity, and aortic regurgitation were associated with lower intervention-free survival. Conclusions: Differences were observed in blood biomarkers between men and women with BAV. Besides LV systolic parameters, diastolic LV function and NT-proBNP should have a more prominent role as prognostic markers in clinical care.

Contexte: La bicuspide valvulaire aortique (BVA) est une anomalie cardiaque congénitale fréquente. Les patients atteints d'une BVA présentent des risques de complications à long terme, comme la sténose valvulaire ou la régurgitation valvulaire. Cette étude visait 1) à évaluer les différences entre les sexes en ce qui concerne les biomarqueurs sanguins et les biomarqueurs à l'imagerie; et 2) à décrire la valeur pronostique à long terme des biomarqueurs sanguins et échocardiographiques. Méthodologie: Des patients de 2 études de cohortes observationnelles prospectives ont été inclus dans l'analyse. Des échantillons de sang veineux ont été prélevés, et des échocardiographies transthoraciques, y compris le suivi des marqueurs acoustiques, ont été effectuées. Les biomarqueurs sanguins analysés étaient les suivants : indice de distribution des globules rouges (IDR), créatinine, protéine C-réactive (CRP), troponine T, propeptide natriurétique de type B N-terminal (NT-proBNP) et facteur de croissance transformant ß (TGF-ß). Les différences entre les sexes ont été analysées au départ. Les liens entre les biomarqueurs et la survie sans arythmie et sans intervention ont été déterminés par la régression de Cox, avec correction en fonction de l'âge et du sexe. Résultats: Cent quatre-vingt-deux patients présentant une BVA étaient inclus (âge médian de 34 [écart interquartile : 23-46] ans, 55,5 % hommes). La CRP, la NT-proBNP et l'IDR étaient plus élevées chez les femmes, alors que la créatinine, la troponine T et le TGF-ß étaient plus élevés chez les hommes. Après une période de suivi médiane de 6,9 (écart interquartile : 6,5-9,9) ans, les taux de survie sans arythmie et sans intervention étaient respectivement de 81,0 % et de 73,1 %. La NT-proBNP a été associée à la survie sans arythmie (rapport des risques instantanés [RRI] : 1,94, p = 0,005) et à la survie sans intervention (RRI : 2,06, p = 0,002). À l'échocardiographie, des valeurs élevées pour la taille de l'oreillette gauche, le diamètre télédiastolique du ventricule gauche (VG), l'indice de masse du VG et le rapport E/e' étaient associées à un faible taux de survie sans arythmie, alors que des valeurs élevées pour la taille de l'oreillette gauche, l'indice de masse du VG, la vitesse maximale aortique et la régurgitation aortique étaient associées à un faible taux de survie sans intervention. Conclusions: Les biomarqueurs sanguins variaient en fonction du sexe des personnes présentant une BVA. Outre les paramètres systoliques du VG, la fonction VG diastolique et la NT-proBNP devraient être davantage utilisées comme marqueurs pronostiques en soins cliniques.