Congenitally bicuspid aortic valves: a surgical pathology study of 542 cases (1991 through 1996) and a literature review of 2,715 additional cases

Population-based treated prevalence, risk factors, and outcomes of bicuspid aortic valve in a pediatric Medicaid cohort

Background:

We investigated the treated prevalence of bicuspid aortic valve in a pediatric population with congenital heart disease and its incident complications.

Materials and Methods:

A 15-year retrospective data set was analyzed. Selection criteria included age ≤17 years, enrollees in the South Carolina State Medicaid program and diagnosed as having bicuspid aortic valve on one or more service visits.

Results:

The 15-year-treated prevalence of predominantly isolated bicuspid aortic valve was 2% (20/1000) of pediatric congenital heart disease cases, with a non-African American: African-American ratio of 3.5:1, and a male:female ratio of 1.6:1. Aortic stenosis (28.0%), ventricular septal defect (20.6%), and coarctation of the aorta (20.6%) were the most prevalent coexisting congenital heart lesions. Of the 378 bicuspid aortic valve cases examined, 10.3% received aortic valve repair/replacement, which was significantly more likely to be performed in children with diagnosed aortic stenosis (adjusted odds ratio = 12.90; 95% confidence interval = 5.66–29.44). Cohort outcomes over the study period indicated that 9.5% had diagnosed heart failure, but <1% had diagnosed supraventricular tachycardia, infective endocarditis, aneurysm, dissection, or death.

Conclusions:

The majority of isolated bicuspid aortic valve cases without aortic stenosis did not require surgical intervention. Outcomes for cases requiring repair/replacement were relatively benign.

Diagnosis and Outcomes of Transcatheter Aortic Valve Implantation in Bicuspid Aortic Valve Stenosis

Bicuspid aortic valve is the most common congenital cardiac malformation. Aortic valve replacement is often required in older patients but the surgical risk is often extremely high. As Transcatheter aortic valve implantation (TAVI) is an established therapy for intermediate and high surgical risk patients with symptomatic severe aortic valve stenosis (AS). Advances in technology and knowledge have led to TAVI being used for other pathologies and populations such as bicuspid AS. Recently, the diagnosis and classification of bicuspid aortic valve based on multidetector computed tomography (MDCT) assessment has been proposed, which may have an impact of outcomes after TAVI. This review article describes the advancements in diagnosis and outcomes of bicuspid AS.

Clinical Characteristics of Korean Patients with Bicuspid Aortic Valve Who Underwent Aortic Valve Surgery

Background and Objectives

Clinical data for Korean patients with bicuspid aortic valve (BAV) that underwent aortic valve (AV) surgery are currently limited.

Methods

Data for 1,160 consecutive adult BAV patients who underwent AV surgery from 2000 to 2014 in 4 tertiary referral centers were retrospectively analyzed. A standard case report form was used for clinical and echocardiographic parameters.

Results

Mean age at the time of AV surgery was 59±13 years. The most common cause of AV surgery was aortic stenosis (AS, 892 [77%]), followed by aortic regurgitation (AR, 199 [17%]), and infective endocarditis (69 [6%]). AS showed a skewed peak in the aged population and was the predominant cause of AV surgery (87%) in patients ≥50 years of age, whereas AR (46%) and active infective endocarditis (19%) were more common in younger patients (p<0.001). Echocardiographic determination of the BAV phenotype revealed that fusion of the right coronary cusp (RCC) and left coronary cusp (LCC) was most common (622 [53%]), followed by fusion of RCC and non-coronary cusp (NCC) (313 [27%]), and fusion of LCC and NCC (42 [4%]); the BAV phenotype could not be determined in the remaining 183 patients (16%). Fusion of RCC and LCC was more commonly observed in patients with AR than in those with AS (74% vs. 49%; p<0.001).

Conclusion

BAV patients were characterized by distinct surgical indications according to their age. Possible associations between BAV phenotypes and surgical indications with potential impacts of ethnicity need to be tested in further studies.

Valve-sparing aortic root replacement in a bicuspid aortic valve with papillary fibroelastoma

We present our surgical strategy in a patient with a bicuspid aortic valve Type I (R/N), aortic root aneurysm and papillary fibroelastoma on the aortic valve's cusp. He underwent valve-sparing aortic root replacement (David V Procedure); we also removed the papillary fibroelastoma from the fused right- and non-coronary cusp. In this case, we used a 34-mm straight Dacron graft for root replacement and an aortic annulus downsized to 30 mm. We use Hegar dilatators for the intraoperative measurement of the aortic annulus. The subvalvular sutures are pledged U-sutures and our usual technique in bicuspid aortic valve is to take 2 on each commissure and 5 on each side so that we end up with 12. For the reimplantation of the aortic rim, we prefer a semi-circumferential suture with a small needle. We plicate the non-fused left cusp, which is our reference for the later reconstruction of the common right- and non-coronary cusp. The key strategy of our bicuspid valve reconstruction is aiming at a 180° non-fused commissure orientation and cusp plication. The coronary ostia and aortic root are marked intraoperatively with a radiopaque marker to facilitate postoperative diagnostics and any future interventions including later catheter-based valve interventions.

Aortic Dilatation Associated With Bicuspid Aortic Valve: Relation to Sex, Hemodynamics, and Valve Morphology (the National Heart Lung and Blood Institute-Sponsored National Registry of Genetically Triggered Thoracic Aortic Aneurysms and Cardiovascular Conditions)

This study analyzed the impact of sex, hemodynamic profile, and valve fusion pattern on aortopathy associated with bicuspid aortic valve (BAV). The National Heart Lung and Blood Institute-sponsored National Registry of Genetically Triggered Thoracic Aortic Aneurysms and Cardiovascular Conditions (GenTAC) provided comprehensive information on a large population of well-characterized patients with BAV. Of 969 enrolled patients with BAV, 551 (57%, 77% male) had already undergone valvular and/or aortic surgery. Echocardiographic imaging data were available on 339 unoperated or preoperative participants who formed the basis of this study. BAV function was normal in 45 (14%), with a predominant aortic regurgitation (AR) in 127 (41%) and a predominant aortic stenosis (AS) in 76 (22%). Moderate-severe AR was associated with larger sinus of Valsalva (SOV) diameters compared with normal function and AS (all p <0.01). Moderate-severe AS was associated with a larger ascending aortic (AscAo) diameter compared with normal function (p = 0.003) but not with AR. The SOV diameter was larger in men than in women (3.7 ± 0.7 vs 3.3 ± 0.6 cm, p <0.0001), whereas AscAo diameters were comparable (3.9 ± 0.9 vs 3.7 ± 0.9 cm, p = 0.08). Right-left commissural fusion was associated with a larger SOV diameter (3.7 ± 0.7 vs 3.3 ± 0.6 cm, p <0.0001) compared with a right-noncoronary fusion pattern. Predominant AR was more common in men (45% vs 27%, p = 0.004), whereas AS was more common in women (29% vs 18%, p = 0.04). In conclusion, in the GenTAC Registry, AR was associated with diffuse (annular, SOV, and AscAo) enlargement, whereas moderate-severe AS was only associated with AscAo enlargement. Male sex and right-left cusp pattern of cusp fusion were associated with larger SOV diameters and a greater likelihood of AR, whereas women had a higher prevalence of AS.

Clinical outcomes and prognostic factors of transcatheter aortic valve implantation in bicuspid aortic valve patients

BACKGROUND

The purpose of this study was to evaluate the outcomes of transcatheter aortic valve replacement (TAVR) in patients with bicuspid aortic valve stenosis (AS).

METHODS

From April 2012 and December 2016, 108 patients with bicuspid AS underwent TAVR using the Sapien XT (34 patients) and Sapien 3 (74 patients) valves. Procedural and clinical outcomes were assessed according to VARC-2 criteria and compared between the two devices.

RESULTS

In the overall cohort, the majority of patients were male (71.3%) with an intermediate surgical risk and a mean Society of Thoracic Surgeons (STS) score of 5.2%. Compared to the Sapien XT group, the Sapien 3 group had a significantly lower STS score (3.3%±2.0% vs. 6.7%±3.6%; P=0.001). Compared to the Sapien XT group, the Sapien 3 group had a significantly lower rate of moderate or severe paravalvular leak (2.7% vs. 14.7%; P=0.03) and higher device success (97.3% vs. 82.4%; P=0.006). There were no significant differences between the two groups in terms of 30-day all-cause mortality, stroke, life-threatening bleeding, major vascular complication and acute kidney injury (stage 2 or 3). Cumulative all-cause mortality at 1-year follow-up was 6.9%. There were no significant differences in cumulative event rates for all-cause mortality at 1-year follow-up between the two groups (9.4% vs. 4.6%; log-rank P=0.47). By univariate analysis, major vascular complication was significantly associated with overall all-cause mortality [hazard ratios (HR): 7.57; 95% confidence interval (CI): 1.51-37.86; P=0.014].

CONCLUSIONS

TAVR using the balloon-expandable valves provided acceptable procedural and clinical outcomes in patients with bicuspid AS. The new-generation Sapien 3 valves showed improved procedural outcomes compared to the early-generation Sapien XT valves.

Anatomical and clinical predictors of valve dysfunction and aortic dilation in bicuspid aortic valve disease

Objective

Bicuspid aortic valve (BAV) is associated with early valvular dysfunction and proximal aorta dilation with high heterogeneity. This study aimed to assess the determinants of these complications.

Methods

Eight hundred and fifty-two consecutive adults diagnosed of BAV referred from cardiac outpatient clinics to eight echocardiographic laboratories of tertiary hospitals were prospectively recruited. Exclusion criteria were aortic coarctation, other congenital disorders or intervention. BAV morphotype, significant valve dysfunction and aorta dilation (≥2 Z-score) at sinuses and ascending aorta were established.

Results

Three BAV morphotypes were identified: right–left coronary cusp fusion (RL) in 72.9%, right–non-coronary (RN) in 24.1% and left–non-coronary (LN) in 3.0%. BAV without raphe was observed in 18.3%. Multivariate analysis showed aortic regurgitation (23%) to be related to male sex (OR: 2.80, p<0.0001) and valve prolapse (OR: 5.16, p<0.0001), and aortic stenosis (22%) to BAV-RN (OR: 2.09, p<0.001), the presence of raphe (OR: 2.75, p<0.001), age (OR: 1.03; p<0.001), dyslipidaemia (OR: 1.77, p<0.01) and smoking (OR: 1.63, p<0.05). Ascending aorta was dilated in 76% without differences among morphotypes and associated with significant valvular dysfunction. By contrast, aortic root was dilated in 34% and related to male sex and aortic regurgitation but was less frequent in aortic stenosis and BAV-RN.

Conclusions

Normofunctional valves are more prevalent in BAV without raphe. Aortic stenosis is more frequent in BAV-RN and associated with some cardiovascular risk factors, whereas aortic regurgitation (AR) is associated with male sex and sigmoid prolapse. Although ascending aorta is the most commonly dilated segment, aortic root dilation is present in one-third of patients and associated with AR. Remarkably, BAV-RL increases the risk for dilation of the proximal aorta, whereas BAV-RN spares this area.

Association between flow skewness and aortic dilatation in patients with aortic stenosis

We investigated association between hemodynamic characteristics and aortic dilatation in patients with severe aortic stenosis (AS). Eighty patients with severe AS (mean age, 67.2 ± 12.5 years) who underwent multi-detector computed tomography and phase-contrast magnetic resonance imaging at the ascending aorta were retrospectively analyzed. Patients with an ascending aorta diameter >4 cm had a significantly higher forward flow rate at systole (28.5 ± 6.0 vs. 36.2 ± 8.6 L min, P < 0.001), and retrograde flow rate at systole (11.3 ± 4.2 vs. 18.8 ± 5.8 L min, P < 0.001), fractional reverse ratio (a ratio of retrograde flow rate to forward flow rate; 34.1 ± 11.9% vs. 43.5 ± 18.0%, P = 0.014), flow skewness R_skewness (a ratio of sum of forward and retrograde systole flow to net systole flow rate; 2.4 ± 0.7 vs. 3.2 ± 1.0, P < 0.001). The presence of bicuspid aortic valve (BAV; odds ratio [OR] 72.01, 95% confidence interval [CI] 10.57-490.46, P < 0.001), Left ventricular mass index (LVMI; OR 1.02 /g/m²; CI 1.00-1.04, P = 0.043) and R_skewness (OR 5.6 per 1, 95% CI 1.8-17.1, P = 0.001) were associated with aortic dilatation. BAV, LVMI, and increased R_skewness in the ascending aorta are associated with aortic dilatation in patients with AS.

Factors Determining Aortic Valve Dysfunction in Korean Subjects With a Bicuspid Aortic Valve

Bicuspid aortic valve (BAV) disease has a male predominance of approximately 3:1 and shows diverse presentations about aortic valve dysfunction. This study aimed to find independent determinants for significant aortic stenosis (AS) or significant aortic regurgitation (AR) in adults with BAV. We retrospectively investigated the medical records of 1,073 subjects (773 men, mean age 55 ± 14 years) who were first diagnosed with BAV disease by transthoracic echocardiography. We excluded 52 subjects with both significant AS and significant AR. Of the remaining 1,021 subjects, 418 (41%) presented with significant AS, 249 (24%) showed significant AR, and the rest of the subjects were grouped into a normal functioning BAV (n = 354, 35%). BAV morphology was classified into the following 4 types according to position and pattern of raphe and cusps: (1) fusion of the right and left coronary cusps (type 1), (2) fusion of the right and noncoronary cusps (type 2), (3) fusion of the left and noncoronary (type 3), and (4) no raphe (type 0). Patients with significant AS were older, more likely to be women than men, and had a higher prevalence of type 0 BAV. Patients with significant AR were younger and were more likely to be men. In multivariate logistic regression analysis, women, older age, and type 0 or type 3 BAV were associated with significant AS. In contrast, men, hypertension, and chronic kidney disease were correlated with significant AR. Significant valve dysfunction in adults with first diagnosed BAV was closely associated with age, gender, and BAV morphology.

Elevated oxidative stress in the aortic media of patients with bicuspid aortic valve

OBJECTIVE

Congenital bicuspid aortic valve (BAV) is distinctly associated with the development of ascending aortopathy in adulthood, portending risk of both ascending aortic aneurysm and dissection. Our previous work implicated deficiency in oxidative stress response as a mediator of the BAV-associated aortopathy. We hypothesize that reactive oxygen species generation invokes elevated local oxidative tissue damage in ascending aorta of patients with BAV.

METHODS

Ascending aortic specimens were obtained from patients undergoing elective aortic replacement and/or aortic valve replacement and during heart transplant operations. Levels of superoxide anion were measured via high-pressure liquid chromatography-based detection of 2-hydroxyethidium in aortic specimens. Lipid peroxidation and enzymatic activity of superoxide dismutase and peroxidase were quantified in aortic specimens.

RESULTS

Superoxide anion production was elevated in aortic specimens from patients with nonaneurysmal BAV (n = 59) compared with specimens from patients with the morphologically normal tricuspid aortic valve (TAV, n = 38). Total superoxide dismutase activity was similar among aortic specimens from patients with TAV versus BAV (n = 27 and 26, respectively), whereas peroxidase activity was increased in aortic specimens from patients with BAV compared with specimens from patients with TAV (n = 14 for both groups). Lipid peroxidation was elevated in aortic specimens from BAV patients compared with TAV patients (n = 14 and 11, respectively).

CONCLUSIONS

Superoxide anion accumulation and increased lipid peroxidation demonstrate that, despite increased peroxidase activity, the ascending aortopathy of patients with BAV involves oxidative stress. In addition, the absence of increased superoxide dismutase activity in BAV specimens indicates a deficiency in antioxidant defense. This suggests that the characteristic smooth muscle cell loss observed in BAV aortopathy may be a consequence of superoxide-mediated cell damage.

Bicuspid aortic valve syndrome: a multidisciplinary approach for a complex entity

Bicuspid aortic valve (BAV) or bicuspid aortopathy is the most common congenital heart disease. It can be clinically silent and it is often identified as an incidental finding in otherwise healthy, asymptomatic patients. However, it can be dysfunctioning at birth, even requiring neonatal intervention, or, in time, lead to aortic stenosis, aortic insufficiency, and endocarditis, and also be associated with aortic aneurysm and aortic dissection. Given its prevalence and significant complications, it is estimated that BAV is responsible for more deaths and morbidity than the combined effects of all the other congenital heart defects. Pathology of BAV is still not well known and many questions are unresolved. In this manuscript we review some aspects on bicuspid aortopathy, a heterogeneous and frequent disease in which like some authors have previously described, complex gene environment are present. Further investigations and, what is more, multidisciplinary teams are needed to improve our knowledge on this really fascinating disease.

Outcomes in Transcatheter Aortic Valve Replacement for Bicuspid Versus Tricuspid Aortic Valve Stenosis

BACKGROUND

Transcatheter aortic valve replacement (TAVR) is being increasingly performed in patients with bicuspid aortic valve stenosis (AS).

OBJECTIVES

This study sought to compare the procedural and clinical outcomes in patients with bicuspid versus tricuspid AS from the Bicuspid AS TAVR multicenter registry.

METHODS

Outcomes of 561 patients with bicuspid AS and 4,546 patients with tricuspid AS were compared after propensity score matching, assembling 546 pairs of patients with similar baseline characteristics. Procedural and clinical outcomes were recorded according to Valve Academic Research Consortium-2 criteria.

RESULTS

Compared with patients with tricuspid AS, patients with bicuspid AS had more frequent conversion to surgery (2.0% vs. 0.2%; p = 0.006) and a significantly lower device success rate (85.3% vs. 91.4%; p = 0.002). Early-generation devices were implanted in 320 patients with bicuspid and 321 patients with tricuspid AS, whereas new-generation devices were implanted in 226 and 225 patients with bicuspid and tricuspid AS, respectively. Within the group receiving early-generation devices, bicuspid AS had more frequent aortic root injury (4.5% vs. 0.0%; p = 0.015) when receiving the balloon-expanding device, and moderate-to-severe paravalvular leak (19.4% vs. 10.5%; p = 0.02) when receiving the self-expanding device. Among patients with new-generation devices, however, procedural results were comparable across different prostheses. The cumulative all-cause mortality rates at 2 years were comparable between bicuspid and tricuspid AS (17.2% vs. 19.4%; p = 0.28).

CONCLUSIONS

Compared with tricuspid AS, TAVR in bicuspid AS was associated with a similar prognosis, but lower device success rate. Procedural differences were observed in patients treated with the early-generation devices, whereas no differences were observed with the new-generation devices.

Computational comparison of regional stress and deformation characteristics in tricuspid and bicuspid aortic valve leaflets

The bicuspid aortic valve (BAV) is the most common congenital valvular defect and a major risk factor for secondary calcific aortic valve disease. While hemodynamics is presumed to be a potential contributor to this complication, the validation of this theory has been hampered by the limited knowledge of the mechanical stress abnormalities experienced by BAV leaflets and their dependence on the heterogeneous BAV fusion patterns. The objective of this study was to compare computationally the regional and temporal fluid wall shear stress (WSS) and structural deformation characteristics in tricuspid aortic valve (TAV), type-0, and type-I BAV leaflets. Arbitrary Lagrangian-Eulerian fluid-structure interaction models were designed to simulate the flow and leaflet dynamics in idealized TAV, type-0, and type-I BAV geometries subjected to physiologic transvalvular pressure. The regional leaflet mechanics was quantified in terms of temporal shear magnitude (TSM), oscillatory shear index (OSI), temporal shear gradient (TSG), and stretch. The simulations identified regions of WSS overloads and increased WSS bidirectionality (174% increase in temporal shear magnitude, 0.10 increase in OSI on type-0 leaflets) in BAV leaflets relative to TAV leaflets. BAV leaflets also experienced larger radial deformations than TAV leaflets (4% increase in type-0 BAV leaflets). Type-I BAV leaflets exhibited contrasted WSS environments marked by WSS overloads on the non-coronary leaflet and sub-physiologic WSS levels on the fused leaflet. This study provides important insights into the mechanical characteristics of BAV leaflets, which may further our understanding of the role played by hemodynamic forces in BAV disease. Copyright © 2016 John Wiley & Sons, Ltd.

Morphotype-Dependent Flow Characteristics in Bicuspid Aortic Valve Ascending Aortas: A Benchtop Particle Image Velocimetry Study

The bicuspid aortic valve (BAV) is a major risk factor for secondary aortopathy such as aortic dilation. The heterogeneous BAV morphotypes [left-right-coronary cusp fusion (LR), right-non-coronary cusp fusion (RN), and left-non-coronary cusp fusion (LN)] are associated with different dilation patterns, suggesting a role for hemodynamics in BAV aortopathogenesis. However, assessment of this theory is still hampered by the limited knowledge of the hemodynamic abnormalities generated by the distinct BAV morphotypes. The objective of this study was to compare experimentally the hemodynamics of a normal (i.e., non-dilated) ascending aorta (AA) subjected to tricuspid aortic valve (TAV), LR-BAV, RN-BAV, and NL-BAV flow. Tissue BAVs reconstructed from porcine TAVs were subjected to physiologic pulsatile flow conditions in a left-heart simulator featuring a realistic aortic root and compliant aorta. Phase-locked particle image velocimetry experiments were carried out to characterize the flow in the aortic root and in the tubular AA in terms of jet skewness and displacement, as well as mean velocity, viscous shear stress and Reynolds shear stress fields. While all three BAVs generated skewed and asymmetrical orifice jets (up to 1.7- and 4.0-fold increase in flow angle and displacement, respectively, relative to the TAV at the sinotubular junction), the RN-BAV jet was out of the plane of observation. The LR- and NL-BAV exhibited a 71% increase in peak-systolic orifice jet velocity relative to the TAV, suggesting an inherent degree of stenosis in BAVs. While these two BAV morphotypes subjected the convexity of the aortic wall to viscous shear stress overloads (1.7-fold increase in maximum peak-systolic viscous shear stress relative to the TAV-AA), the affected sites were morphotype-dependent (LR-BAV: proximal AA, NL-BAV: distal AA). Lastly, the LR- and NL-BAV generated high degrees of turbulence in the AA (up to 2.3-fold increase in peak-systolic Reynolds shear stress relative to the TAV) that were sustained from peak systole throughout the deceleration phase. This in vitro study reveals substantial flow abnormalities (increased jet skewness, asymmetry, jet velocity, turbulence, and shear stress overloads) in non-dilated BAV aortas, which differ from those observed in dilated aortas but still coincide with aortic wall regions prone to dilation.

Radiofrequency Ablation of a Nonsustained Ventricular Tachycardia Arising from the Left Coronary Cusp of a Bicuspid Aortic Valve: A Case Report

Radiofrequency ablation is the therapy of choice for the suppression of medically intractable symptomatic ventricular arrhythmias. Here we present the case report of a 50-year-old woman with bicuspid aortic valve (BAV) and symptomatic nonsustained ventricular tachycardia arising from the left ventricular outflow tract (LVOT). The origin of the ventricular arrhythmia was confirmed in the left coronary cusp (LCC) of the BAV. The patient underwent a successful radiofrequency ablation. LCC of a tricuspid aortic valve is a common origin of idiopathic LVOT tachycardia; however, little is known for these types of arrhythmias when located in the cusps of a BAV.

Morphologic and Functional Markers of Aortopathy in Patients With Bicuspid Aortic Valve Insufficiency Versus Stenosis

BACKGROUND

Bicuspid aortic valve (BAV)-associated aortopathy is heterogeneous and still insufficiently defined. We prospectively analyzed the morphologic and functional variables of aortopathy in patients undergoing operations for BAV insufficiency (BAV-AI) vs stenosis (BAV-AS).

METHODS

A total of 172 consecutive patients (71% male, 59 ± 10 years) underwent aortic valve replacement with or without proximal aortic operation for BAV-AS (n = 137), and BAV-AI (n = 35) from January 2012 through December 2014. All patients underwent preoperative cardiac magnetic resonance imaging to evaluate morphologic and functional variables of the aortic root. Magnetic resonance imaging data were used to guide sampling of aortic tissue intraoperatively (ie, from the area where flow jet impacts on the aortic wall [jet sample] and the opposite aortic wall [control sample]). Aortic wall lesions were graded based on the histologic sum score (range, 0 to 21). Expression and severity of aortopathy were quantified by means of proximal aortic phenotype, indexed aortic diameters, and a sum score.

RESULTS

Cross-sectional aortic diameters were significantly larger in the BAV-AI group vs the BAV-AS group (47 ± 8 mm vs 41 ± 8 mm, p = 0.001). Moreover, root dilatation phenotype was more frequent in the BAV-AI group (27% vs 6%, p = 0.01) and was associated with a significantly larger aortic annulus diameter (32 ± 3 mm vs 27 ± 3 mm, p < 0.001). The histologic sum score was significantly different between the study groups (3.7 ± 2.6 BAV-AI vs 2.5 ± 1.4 BAV-AS, p = 0.03). Logistic regression revealed a significant association between BAV-AI and indexed aortic diameter exceeding 22 mm/m² (odds ratio, 4.7; p = 0.007).

CONCLUSIONS

Our study demonstrates that BAV functional phenotype correlates significantly with the expression and severity of bicuspid aortopathy.

Bicuspid Aortic Valve: Unlocking the Morphogenetic Puzzle

Although bicuspid aortic valve is the most common congenital abnormality, it is perhaps erroneous to consider this disease one clinical entity. Rather, it may be useful to consider it a cluster of diseases incorporating different phenotypes, etiologies, and pathogenesis. Discussion of bicuspid aortic valve can be difficult because there is no clear consensus on a phenotypic description among authors, and many classification schemes have been proposed. The literature suggests that different phenotypes have different associations and clinical manifestations. In addition, recent studies suggest a genetic basis for the disease, yet few genes have so far been described. Furthermore, recent scientific literature has been focusing on the increased risk of aortic aneurysms, but the pathogenesis of bicuspid aortic valve aortopathy is still unclear. The aim of this paper is to review the current evidence about the unsolved issues around bicuspid aortic valve.

Hemodynamics through the congenitally bicuspid aortic valve: a computational fluid dynamics comparison of opening orifice area and leaflet orientation

A computational fluid dynamics model of a bicuspid aortic valve has been developed using idealised three-dimensional geometry. The aim was to compare how the orifice area and leaflet orientation affect the hemodynamics of a pure bicuspid valve. By applying physiologic material properties and boundary conditions, blood flow shear stresses were predicted during peak systole. A reduced orifice area altered blood velocity, the pressure drop across the valve and the wall shear stress through the valve. Bicuspid models predicted impaired blood flow similar to a stenotic valve, but the flow patterns were specific to leaflet orientation. Flow patterns developed in bicuspid aortic valves, such as helical flow, were sensitive to cusp orientation. In conclusion, the reduced opening area of a bicuspid aortic valve amplifies any impaired hemodynamics, but cusp orientation determines subsequent flow patterns which may determine the specific regions downstream from the valve most at risk of clinical complications.

Higher neutrophil to lymphocyte ratio is related to a lower ejectionfraction in bicuspid aortic valve patients

BACKGROUND/AIM

Inflammation plays an important role in the pathophysiology of vascular disease. In this study, we aimed to evaluate the associations of neutrophil to lymphocyte ratio (NLR; an indicator of inflammation) with left ventricular ejection fraction and ascending aorta diameter in patients with a bicuspid aortic valve (BAV).

MATERIALS AND METHODS

One hundred and thirty-nine consecutive patients with the diagnosis of BAV were enrolled in the study. Complete blood counts were analyzed for neutrophil and lymphocyte levels and NLR. The subjects were separated into two groups based on their ascending aorta diameter. The patients with ascending aorta diameter equal to or above 3.9 cm were included in group 1 whereas those with ascending aorta diameter below 3.9 cm were included in group 2.

RESULTS

When the results were compared, it was demonstrated that there was a positive correlation between NLR and ascending aorta diameter (r: 0.485, P = 0.026), whereas there was a negative correlation between NLR and left ventricular end-diastolic diameter (r: 0.475, P = 0.030), left ventricular end-systolic diameter (r: 0.482, P = 0.027), and left ventricular ejection fraction (r: -0.467, P = 0.033) in BAV patients with ascending aorta dilatation (group 1).

CONCLUSION

NLR is associated with ascending aorta diameter and left ventricular ejection fraction in BAV patients with ascending aorta dilatation.

Are normal-sized ascending aortas at risk of late aortic events after aortic valve replacement for bicuspid aortic valve disease?

OBJECTIVES

Bicuspid aortic valve (BAV)-associated aortopathy has been proposed to progress after isolated aortic valve replacement (AVR) surgery, which has been traditionally used as an argument against a TAVR procedure in this clinical subset. Still, more than half of BAV patients have a normal-sized proximal aorta at the time of AVR surgery. We aimed to analyse the long-term risk of adverse aortic events after isolated conventional AVR surgery for BAV and normal-sized proximal aorta.

METHODS

A total of 200 consecutive patients (mean age 56 ± 13 years, 73% men) with BAV disease and ascending aortic diameter of <40 mm underwent isolated conventional AVR from 1995 through 2008 and were identified from our institutional BAV database. Long-term follow-up data (a total of 1532 patient-years) were obtained for all hospital survivors. Composite adverse aortic/cardiovascular events were defined as the need for redo aortic surgery, the occurrence of aortic dissection/rupture, or sudden cardiac death during follow-up.

RESULTS

A total of 25 (13%) patients died after a mean follow-up of 8.5 ± 5 years post-AVR surgery, which resulted in an overall survival rate of 75 ± 6 and 87 ± 7% at 15 years postoperatively, for BAV-aortic stenosis and BAV-aortic regurgitation, respectively (P = 0.6). An adverse aortic event occurred in 1 (0.5%) study patient, while 5 (2.5%) further patients suffered sudden cardiac death. Only 1 patient required redo aortic surgery. No documented aortic dissection/rupture occurred. Redo AVR surgery due to endocarditis or structural valve degeneration was performed in 6 (3%) patients. The rate of freedom from composite adverse events was 92 ± 5 and 95 ± 4% at 15 years, for the AS and AR subgroups, respectively (P = 0.7).

CONCLUSIONS

BAV patients with aortic valve dysfunction and normal-sized ascending aorta are at considerably low risk of late adverse aortic events after isolated AVR.

Quadricuspid Aortic Valve

Background—

Quadricuspid aortic valve (QAV) is a rare congenital cardiac defect. This study sought to determine QAV frequency in a large echocardiography database, to characterize associated cardiovascular abnormalities, and to describe long-term outcomes.

Methods and Results—

Fifty patients (mean±SD age, 43.5±21.8 years at the time of the index diagnosis; female sex, 52%) received a diagnosis of QAV between January 1, 1975, and March 14, 2014 (frequency, 0.006%). The QAV was type A in 32% and type B in 32% (Hurwitz and Roberts classification). Aortic dilatation was present in 29% of the patients, and 26% had moderate or severe aortic valve regurgitation at the index diagnosis. Stenosis affected only 8% of the valves and was mild. Other findings, including abnormalities of other cardiac valves, septal defects, persistent left superior vena cava, and patent ductus arteriosus, were present in 32% of patients. During a mean±SD follow-up of 4.8±5.6 years, 8 patients underwent aortic valve surgery, with severe aortic valve regurgitation being the surgical indication in 7 patients. One patient with mild to moderate aortic valve regurgitation underwent aortic valve repair for obstruction of the left coronary ostium by the accessory cusp of QAV. No infective endocarditis or aortic dissection was found. Overall survival was 91.5% and 87.7% at 5 and 10 years.

Conclusions—

Aortic dilatation and other structural cardiac abnormalities were relatively common among patients with QAV. Aortic valve regurgitation was the predominant hemodynamic abnormality and the indication for aortic valve surgery in most patients who received surgery. Long-term survival was excellent.

Current topics on bicuspid aortic valve: clinical aspects and surgical management

Bicuspid aortic valve (BAV) has been identified as the most common heart valve anomaly and is considered to be a heritable disorder that affects various cardiovascular disorders, including aortopathy. Current topics regarding the clinical management of BAV including surgical strategies with or without concomitant aortic repair or replacement are attracting interest, in addition to the pathological and morphological aspects of BAV as well as aortopathy. However, surgical indications are still being debated and are dependent on current clinical guidelines and surgeons' preferences. Although clinical guidelines have already been established for the management of BAV with or without aortopathy, many studies on clinical management and surgical techniques involving various kinds of subjects have previously been published. Although a large number of studies concerning the clinical aspects of BAV have been reviewed in detail, controversy still surrounds the clinical and surgical management of BAV. Therefore, surgeons should carefully consider valve pathology when deciding whether to replace the ascending aorta. In this review, we summarized current topics on BAV and the surgical management of diseased BAV with or without aortopathy based on previous findings, including catheter-based interventional management.

Bicuspid valve-related aortic disease: flow assessment with conventional phase-contrast MRI

RATIONALE AND OBJECTIVES

Abnormal blood flow with bicuspid aortic valve (BAV) has been characterized with four-dimensional flow magnetic resonance imaging (MRI), but this approach is time consuming and requires technical expertise. We assess the relationship between different leaflets fusion patterns with BAV, eccentric systolic flow, and dilation patterns of the ascending aorta using two-dimensional (2D) phase-contrast (PC) MRI.

MATERIALS AND METHODS

Fifty-nine patients with BAV who underwent cardiac MRI were identified; 47 had right-left (RL) aortic leaflet fusion and 12 had right-noncoronary (RN) fusion. Flow displacement was calculated, and patients with abnormal displacement (>0.1) were classified as either rightward or leftward. Patterns of aortopathy were determined (0-3), and correlation between leaflet fusion, flow direction, aortopathy type, and other clinical parameters was performed with Pearson correlation, the Fisher exact test and chi-square analysis.

RESULTS

Normal systolic flow was seen in 24% of cases and was significantly correlated with normal aortas (P = .011). Abnormal flow displacement with RL fusion was strongly associated with rightward deviation (36 of 37 cases), whereas RN fusion skewed leftward (seven of eight cases; P < .01). In patients with aortopathy, RL fusion was strongly associated with type 2 aortopathy and RN with type 3 aortopathy (P < .01).

CONCLUSIONS

Conventional PC MRI can identify abnormal systolic flow and differences in jet orientation with BAV. RL leaflet fusion is associated with rightward flow deviation and type 2 aortopathy, whereas RN fusion is linked to leftward deviation and type 3 aortopathy. The presence and direction of eccentric flow jets may help risk stratify these patients for valve-related aortic disease.

The Association Between Aortic Valve Leaflet Morphology and Patterns of Aortic Dilation in Patients With Bicuspid Aortic Valves

BACKGROUND

Dilation of the aorta is a frequent complication in patients with bicuspid aortic valves. The aim of this study was to determine the relationship between the subtype of leaflet fusion, right and noncoronary leaflet (R/N) fusion versus right and left leaflet (R/L) fusion, and the patterns of aortic dilation and valve dysfunction in young patients with bicuspid aortic valves.

METHODS

We performed a retrospective review of 642 patients who presented with bicuspid aortic valves between 1994 and 2014. Of these patients, 210 (33%) had aortic dilation (z score >3) by echocardiogram. For each patient, the most recent study or the last study before intervention was reviewed.

RESULTS

Median patient age was 15 years (range, 0 to 40 years) with patients with R/N fusion being younger. The most prevalent subtype was R/N fusion (R/N, n = 114, 54% versus R/L, n = 96, 46%). Dilation of the ascending aorta was seen more often in patients with R/N fusion (R/N, 88% versus R/L, 68%; p = 0.004), whereas the prevalence of dilation of the sinuses of Valsalva was significantly higher in patients with R/L fusion (R/L, 46% versus R/N, 20%; p = 0.01). The magnitude of dilation differed as well. The z value of the sinuses of Valsalva was significantly higher in patients with R/L fusion (R/L, 2.03 versus R/N, 1.2; p = 0.003), whereas the z values of the ascending aorta and sinotubular junction were similar between the groups. Patients with R/N fusion were more likely to have aortic stenosis, and within the R/N group, patients with aortic insufficiency had a greater degree of ascending aorta dilation (p = 0.04).

CONCLUSIONS

Our study suggests that in young patients with bicuspid aortic valves and aortic dilation, aortic valve morphology may be associated with the patterns of aortic dilation and valve dysfunction. Patients with R/N fusion were more likely to have ascending aorta dilation, whereas patients with R/L fusion were more likely to have dilation of the aortic root. In addition, patients with R/N fusion presented at a younger age and were more likely to have aortic stenosis. Recognition of these differences may eventually be helpful for patient counseling and the planning of follow-up.

Structure and function of the tricuspid and bicuspid regurgitant aortic valve: an echocardiographic study

OBJECTIVES

The emerging new treatment options for aortic valve disease call for more sophisticated diagnostics. We aimed to describe the echocardiographic pathophysiology and characteristics of the purely regurgitant aortic valve in detail.

METHODS

Twenty-nine men, with chronic aortic regurgitation without concomitant heart disease referred for aortic valve intervention, underwent 2D transoesophageal echocardiographic (TEE) examination prior to surgery according to a previously published matrix. Measurements of the aortic valve apparatus in long and short axis view were made in systole and diastole and analysed off-line. The aortic valves were grouped as tricuspid (TAV) or bicuspid (BAV), and classified by regurgitation mechanism.

RESULTS

Twenty-four examinations were eligible for analysis of which 13 presented TAV and 11 BAV. The regurgitation mechanism was classified as dilatation of the aorta in 6 cases, as prolapse in 11 cases and as poor cusp tissue quality or quantity in 7 cases. The ventriculo-aortic junction (VAJ) and valve opening were closely related (TAV r = 0.5, BAV r = 0.73) but no correlation was found between the VAJ and the maximal sinus diameter (maxSiD) or the sinotubular junction (STJ). However, the STJ and maxSiD were significantly related (TAV vs BAV: systole r = 0.9, r = 0.8; diastole r = 0.9, r = 0.7), forming an entity. The conjoined BAV cusps were shorter than the anterior cusps when closed (P = 0.002); the inter-commissural distances of the cusps in the BAV group were significantly different (P = 0.001 resp. 0.03) in both systole and diastole.

CONCLUSIONS

The VAJ was independent of other aortic dimensions and should thereby be considered as a separate entity with influence on valve opening. The detailed 2D TEE measurements of this study add further important information to our knowledge about the function and echocardiographic anatomy of the pathological aortic valve and root either as a stand-alone examination or as a benchmark and complement to 3D echocardiography. This may have an impact on decisions regarding repairability of the native aortic valve.

Aortic valve reconstruction with use of pericardial leaflets in adults with bicuspid aortic valve disease: early and midterm outcomes

In this study, we retrospectively analyzed the outcomes of adults with bicuspid aortic valve (BAV) disease who underwent aortic valve reconstructive surgery (AVRS), consisting of replacement of the diseased BAV with 2 or 3 pericardial leaflets plus fixation of the sinotubular junction for accurate and constant leaflet coaptation. From December 2007 through April 2013, 135 consecutive patients (mean age, 49.2 ± 13.1 yr; 73.3% men) with symptomatic BAV disease underwent AVRS. Raphe was observed in 84 patients (62.2%), and the remaining 51 patients had pure BAV without raphe. A total of 122 patients (90.4%) underwent 3-leaflet reconstruction, and 13 (9.6%) underwent 2-leaflet reconstruction. Concomitant aortic wrapping with an artificial graft was performed in 63 patients (46.7%). There were no in-hospital deaths and 2 late deaths (1.5%); 6 patients (4.4%) needed valve-related reoperation. The 5-year cumulative survival rate was 98% ± 1.5%, and freedom from valve-related reoperation at 5 years was 92.7% ± 3.6%. In the last available echocardiograms, aortic regurgitation was absent or trivial in 116 patients (85.9%), mild in 16 (11.9%), moderate in 2 (1.5%), and severe in one (0.7%). The mean aortic valve gradient was 10.2 ± 4.5 mmHg, and the mean aortic valve orifice area index was 1.3 ± 0.3 cm(2)/m(2). The 3-leaflet technique resulted in lower valve gradients and greater valve areas than did the 2-leaflet technique. Thus, in patients with BAV, AVRS yielded satisfactory early and midterm results with low mortality rates and low reoperation risk after the initial procedure.

The Role of Multimodality Cardiac Imaging for the Assessment of Sports Eligibility in Patients with Bicuspid Aortic Valve

Bicuspid aortic valve (BAV) cannot be considered an innocent finding, but it is not necessarily a life-threatening condition. Athletes with BAV should undergo a thorough staging of the valve anatomy, taking into consideration hemodynamic factors, as well as aortic diameters and looking for other associated significant cardiovascular anomalies by use of a multimodality cardiac imaging approach. Furthermore an accurate follow-up is mandatory with serial cardiological controls in those allowed to continue sports.

Steady flow hemodynamic and energy loss measurements in normal and simulated calcified tricuspid and bicuspid aortic valves

The bicuspid aortic valve (BAV), which forms with two leaflets instead of three as in the normal tricuspid aortic valve (TAV), is associated with a spectrum of secondary valvulopathies and aortopathies potentially triggered by hemodynamic abnormalities. While studies have demonstrated an intrinsic degree of stenosis and the existence of a skewed orifice jet in the BAV, the impact of those abnormalities on BAV hemodynamic performance and energy loss has not been examined. This steady-flow study presents the comparative in vitro assessment of the flow field and energy loss in a TAV and type-I BAV under normal and simulated calcified states. Particle-image velocimetry (PIV) measurements were performed to quantify velocity, vorticity, viscous, and Reynolds shear stress fields in normal and simulated calcified porcine TAV and BAV models at six flow rates spanning the systolic phase. The BAV model was created by suturing the two coronary leaflets of a porcine TAV. Calcification was simulated via deposition of glue beads in the base of the leaflets. Valvular performance was characterized in terms of geometric orifice area (GOA), pressure drop, effective orifice area (EOA), energy loss (EL), and energy loss index (ELI). The BAV generated an elliptical orifice and a jet skewed toward the noncoronary leaflet. In contrast, the TAV featured a circular orifice and a jet aligned along the valve long axis. While the BAV exhibited an intrinsic degree of stenosis (18% increase in maximum jet velocity and 7% decrease in EOA relative to the TAV at the maximum flow rate), it generated only a 3% increase in EL and its average ELI (2.10 cm2/m2) remained above the clinical threshold characterizing severe aortic stenosis. The presence of simulated calcific lesions normalized the alignment of the BAV jet and resulted in the loss of jet axisymmetry in the TAV. It also amplified the degree of stenosis in the TAV and BAV, as indicated by the 342% and 404% increase in EL, 70% and 51% reduction in ELI and 48% and 51% decrease in EOA, respectively, relative to the nontreated valve models at the maximum flow rate. This study indicates the ability of the BAV to function as a TAV despite its intrinsic degree of stenosis and suggests the weak dependence of pressure drop on orifice area in calcified valves.

Fused aortic valve without an elliptical-shaped systolic orifice in patients with severe aortic stenosis: cardiac computed tomography is useful for differentiation between bicuspid aortic valve with raphe and tricuspid aortic valve with commissural fusion

OBJECTIVE

The objective is to determine cardiac computed tomography (CCT) features capable of differentiating between bicuspid aortic valve (BAV) and tricuspid aortic valve (TAV) in severe aortic stenosis (AS) patients with fused cusp and without elliptical-shaped systolic orifices.

METHODS

We retrospectively enrolled 53 patients who had severe AS with fused cusps and without an elliptical-shaped systolic orifice on CCT and who had undergone surgery. CCT features were analyzed using: 1) aortic valve findings including cusp size, cusp area, opening shape, midline calcification, fusion length, calcium volume score, and calcium grade; 2) diameters of ascending and descending aorta, and main pulmonary artery; and 3) rheumatic mitral valve findings. The variables were evaluated using univariate and multivariate logistic regression analyses.

RESULTS

At surgery, 19 patients had BAV and 34 had TAV. CCT features including uneven cusp size, uneven cusp area, round-shaped systolic orifice, longer cusp fusion, and dilatation of ascending aorta were significantly associated with BAV (P < 0.05). In particular, fusion length (OR, 1.76; P = 0.001), uneven cusp area (OR, 10.46; P = 0.012), and midline calcification (OR, 0.08; P = 0.013) were strongly associated with BAV.

CONCLUSION

CCT provides diagnostic clues that helps differentiate between BAV with raphe and TAV with commissural fusion in patients with severe AS.

KEY POINTS

• Accurate morphologic assessment of the aortic valve is important for treatment planning. • It is difficult to differentiate BAV from TAV with a fused cusp. • CCT provides diagnostic clues for the differentiation of BAV and TAV.

Multi-detector CT angiography of the aortic valve-Part 2: disease specific findings

The aortic valve and adjacent structures should be routinely evaluated on all thoracic cross-sectional imaging studies. Echocardiography and magnetic resonance imaging (MRI) are the main imaging techniques used for assessment of the aortic valve and related pathology but multi-detector computed tomography (MDCT) can offer valuable complimentary information in some clinical scenarios. MDCT is the definite means of assessing aortic valvular calcification, acute aortic syndrome and for non-invasive assessment of the coronary arteries. MDCT also has an emerging role in the planning and follow-up of trans-catheter aortic valve replacement. This article reviews the spectrum of aortic valve disease highlighting the key MDCT imaging features.