Bicuspid aortic valve with associated aortopathy, significant left ventricular hypertrophy or concomitant hypertrophic cardiomyopathy: A diagnostic and therapeutic challenge

Due to its prevalence of 0.5%to 2%in the general population,with a 75%predominance among men,bicuspid aortic valve is the most common congenital heart defect.It is frequently accompanied by other cardiac congenital anomalies,and clinical presentation can vary significantly,with stenosis being the most common manifestation,often resulting in mild to moderate concentric hypertrophy of the left ventricle.Echocardiography is the primary diagnostic modality utilized for establishing the diagnosis,and it is often the sole diagnostic tool relied upon by clinicians.However,due to the heterogeneous clinical presentation and possible associated anomalies(which are often overlooked in clinical practice),it is necessary to employ various diagnostic methods and persist in finding the accurate diagnosis if multiple inconsistencies exist.By employing this approach,we can effectively manage these patients and provide them with appropriate treatment.Through a clinical case from our practice,we provide an overview of the literature on bicuspid aortic valve with aortophaty and the possible association with hypertrophic cardiomyopathy,diagnostic methods,and treatment options.This review article highlights the critical significance of achieving an accurate diagnosis in patients with bicuspid aortic valve and significant left ventricular hypertrophy.It is crucial to exclude other possible causes of left ventricular outflow tract obstruction,such as sub-or supra-aortic obstructions,and hypertrophic cardiomyopathy.

Bicuspid aortic valve hemodynamics does not promote remodeling in porcine aortic wall concavity

AIM: To investigate the role of type-I left-right bicuspid aortic valve(LR-BAV) hemodynamic stresses in the remodeling of the thoracic ascending aorta(AA) concavity, in the absence of underlying genetic or structural defects.METHODS: Transient wall shear stress(WSS) profiles in the concavity of tricuspid aortic valve(TAV) and LR-BAV AAs were obtained computationally. Tissue specimens excised from the concavity of normal(nondilated) porcine AAs were subjected for 48 h to those stress environments using a shear stress bioreactor. Tissue remodeling was characterized in terms of matrix metalloproteinase(MMP) expression and activity via immunostaining and gelatin zymography.RESULTS: Immunostaining semi-quantification results indicated no significant difference in MMP-2 and MMP-9 expression between the tissue groups exposed to TAV and LR-BAV AA WSS(P = 0.80 and P = 0.19, respectively). Zymography densitometry revealed no difference in MMP-2 activity(total activity, active form and latent form) between the groups subjected to TAV AA and LR-BAV AA WSS(P = 0.08, P = 0.15 and P = 0.59, respectively).CONCLUSION: The hemodynamic stress environment present in the concavity of type-I LR-BAV AA does not cause any significant change in proteolytic enzyme expression and activity as compared to that present in the TAV AA.

Splanchnic-aortic inflammatory axis in experimental portal hypertension

Splanchnic and systemic low-grade inflammation has been proposed to be a consequence of long-term prehepatic portal hypertension.This experimental model causes minimal alternations in the liver,thus making a more selective study possible for the pathological changes characteristic of prehepatic portal hypertension.Low-grade splanchnic inflammation after longterm triple partial portal vein ligation could be associated with liver steatosis and portal hypertensive intestinal vasculopathy.In fact,we have previously shown that prehepatic portal hypertension in the rat induces liver steatosis and changes in lipid and carbohydrate metabolism similar to those produced in chronic inflammatory conditions described in metabolic syndrome in humans.Dysbiosis and bacterial translocation in this experimental model suggest the existence of a portal hypertensive intestinal microbiome implicated in both the splanchnic and systemic alterations related to prehepatic portal hypertension.Among the systemic impairments,aortopathy characterized by oxidative stress,increased levels of proinflammatory cytokines and profibrogenic mediators stand out.In this experimental model of long-term triple portal vein ligated-rats,the abdominal aortic proinflammatory response could be attributed to oxidative stress.Thus,the increased aortic reduced-nicotinamide-adenine dinucleotide phosphate[NAD(P)H]oxidase activity could be associated with reactive oxygen species production and promote aortic inflammation.Also,oxidative stress mediated by NAD(P)H oxidase has been associated with risk factors for inflammation and atherosclerosis.The splanchnic and systemic pathology that is produced in the long term after triple partial portal vein ligation in the rat reinforces the validity of this experimental model to study the chronic low-grade inflammatory response induced by prehepatic portal hypertension.

Effect of Bicuspid Aortic Valve Cusp Fusion on Aorta Wall Shear Stress: Preliminary Computational Assessment and Implication for Aortic Dilation

The bicuspid aortic valve (BAV) is a major congenital valvular abnormality and is associated with a high prevalence of aortic dilation, whose expression depends on the type of leaflet fusion. Although BAV hemodynamics is considered a potential pathogenic contributor, the impact of BAV fusion on ascending aorta (AA) wall shear stress (WSS) remains largely unknown. A fluid-structure interaction approach was implemented to predict the hemodynamics and WSS characteristics in realistic AA models subjected to the flow of a normal tricuspid aortic valve (TAV) and three BAV morphotypes (left-right coronary cusp fusion (LR), right-non coronary cusp fusion (RN) and non-left coronary cusp fusion (NL)). TAV flow conditions subjected the proximal and middle AA to a streamlined flow typical of flows in bends, while BAV flow conditions generated increased flow helicity. The LR-BAV orifice jet generated flow abnormalities primarily in the proximal AA, which were marked by a uniform WSS overload along the wall circumference and contrasted WSS directionalities on the wall convexity and concavity. Flow abnormalities generated by the RN-BAV and NL-BAV inlet flow conditions were more diffuse and consisted of WSS overloads in the convexity of the proximal and middle AA and contrasted WSS directionalities in the anterior and posterior wall regions. This study demonstrates the impact of the BAV morphotype on AA hemodynamics and provides quantitative evidence for the existence of WSS abnormalities in aortic wall regions prone to dilation.

Predictors for Dilated Aorta in Repaired and Unrepaired Tetralogy of Fallot

Aortic root pathology has been described in patients with Tetralogy of Fallot, although the most common reason for repeat surgery in the adult after TOF repair relates to problems in the right ventricular outflow tract, the aortic root is often forgotten. Objective: We sought to determine those patients with known Fallot tetrallogy at risk for progressive dilatation of the thoracic aorta and explore the common predictors present in this patient group. Methods and Results: A multicenter observational study which enrolled 100 patients (50 surgically repaired and 50 before surgical repair of TOF) with standardized reassessment of echocardiographic parameters and multislice CT angiography of the heart and great vessels data. The data were reviewed and analyzed according to the demographic, morphological, surgical and clinical details. We used standard nomograms and Z score for aortic root dimensions at the level of aortic annulus, sino-tubular junction and sinus of Valsalva based on body surface area. For surgically repaired patients, all the measured diameters across aortic annulus, STJ & sinus of Valsalva were larger in the dilated unrepaired group with mean & median of 24.63 (3.99) & 25 (15 - 35), 27.2 (4.26) & 27 (17 - 40), 35.97 (4.59) & 36 (24 - 45) mm respectively compared to a mean & median of 13.2 (2.62) & 13 (9 - 17), 14.53 (2.90) & 14 (10 - 19), 20.53 (3.40) & 21 (14 - 25) mm respectively in the not dilated unrepaired group with significant statistical difference (p value < 0.0001). Also Z score among unrepaired dilated TOF patients was larger in comparison to the non dilated unrepaired group with significant statistical difference (p value < 0.0001). For unrepaired patients, all the measured diameters across aortic annulus, STJ & sinus of Valsalva were larger in the dilated unrepaired group with mean & median of 24.63 (3.99) & 25 (15 - 35), 27.2 (4.26) & 27 (17 - 40), 35.97 (4.59) & 36 (24 - 45) mm respectively compared to a mean & median of 13.2 (2.62) & 13 (9 - 17), 14.53 (2.90) & 14 (10 - 19), 20.53 (3.40) & 21 (14 - 25) mm respectively in the not dilated unrepaired group with significant statistical difference (p value < 0.0001). Also Z score among unrepaired dilated TOF patients at the level of annulus, STJ & sinus of Valsalva was larger in comparison to the non dilated unrepaired group with significant statistical difference (p value < 0.0001). Conclusions: The first important finding of this study is the occurrence of significant aortic root dilatation in 22% of patients after intra-cardiac repair of TOF. Older age at repair, long shunt to repair interval and residual ventricular septal defect are the most common variables associated with aortopathy and aortic regurgitation in such group of patients. The second important finding is the occurrence of aortic root dilatation in 70% of patients before surgical repair of TOF;whereas male sex and TOF with pulmonary atresia appeared to be the most common variables associated with aortopathy and aortic regurgitation in this group of patients.