Prevalence of and predictors of bicuspid aortic valves in patients with dilated aortic roots

Diagnostic accuracy study of routine echocardiography for bicuspid aortic valve: a retrospective study and meta-analysis

BACKGROUND

Transthoracic echocardiography (TTE) is the standard procedure to distinguish tricuspid aortic valve (TAV) from bicuspid aortic valve (BAV). Published studies assessed the accuracy of TTE for BAV under ideal conditions. Conversely, we aimed at assessing accuracy of TTE for BAV under routine conditions.

METHODS

This retrospective, cross-sectional study of 216 adults included 132 men aged 62±14 years. Of these, 108 had BAV and 108 were age-matched individuals with TAV. All diagnoses were confirmed at surgery. We assessed TTE in two patient groups. First, in the (I) group of all 216 individuals, where we assessed accuracy for BAV according to the original diagnoses as documented by the primary investigators during original TTE examination. Second, we assessed accuracy for BAV according to expert re-evaluation in (II) all 158 TTE with availability of original recordings. Third, we performed a meta-analysis of published results on the accuracy of TTE for BAV according to PRISMA standards.

RESULTS

Sensitivity, specificity and accuracy of (I) primary investigators was 46.3%, 97.2, and 71.8% as compared to (II) expert re-evaluation with 59.7%, 93%, and 77.8%, respectively. Sensitivity was significantly higher at re-evaluation (P<0.001). TTE at a non-tertiary care center (P=0.012), presence of aortic aneurysm (P=0.001) and presence of severe aortic valve calcification (P=0.003) predicted an inaccurate diagnosis of BAV. Conversely, meta-analysis of published TTE studies identified a pooled sensitivity of 87.7% and a pooled specificity of 88.3% for BAV.

CONCLUSIONS

The current study shows that TTE yields almost ideal diagnostic accuracy when ideal investigators examine ideal patients. However, the study also shows that TTE yields suboptimal diagnostic accuracy under routine conditions. TTE in non-tertiary care settings, concomitant aortic aneurysm, and presence of severe aortic valve calcification predict an inaccurate diagnosis of BAV.

Association between leaflet fusion pattern and thoracic aorta morphology in patients with bicuspid aortic valve

PURPOSE

To determine if patients with certain bicuspid aortic valve (BAV) phenotypes are predisposed to particular morphological abnormalities of the thoracic aorta.

MATERIALS AND METHODS

One hundred ninety-two patients with BAV who underwent magnetic resonance angiography between January 2007 and July 2010 were retrospectively identified. Aortic morphology was examined through measurements of aortic size index at nine levels along the thoracic aorta, three-dimensional volume of the ascending aorta, vessel asymmetry, and assessment of aortic root morphology.

RESULTS

We found 140 patients (73%) with right and left coronary cusps (R-L) fusion, 46 patients (24%) with R-N fusion, and 6 patients (3%) with left and noncoronary cusps (L-N) fusion. Mean aortic volume in the proximal ascending aorta was significantly greater in R-L patients (0.93 versus 0.60 cm(3)/m(2); P < 0.01). R-N patients possessed greater aortic size index at the distal ascending aorta and proximal aortic arch, and were also significantly more likely to have Type 2 patterns of aortic dilatation.

CONCLUSION

Our results suggest that BAV with R-L fusion is associated with increased dimensions of the aortic root, while BAV with R-N fusion is associated with increased dimensions of the distal ascending aorta and proximal arch. Our findings illustrate the morphological heterogeneity that exists among BAV phenotypes.

Aortic disease in the young: genetic aneurysm syndromes, connective tissue disorders, and familial aortic aneurysms and dissections

There are many genetic syndromes associated with the aortic aneurysmal disease which include Marfan syndrome (MFS), Ehlers-Danlos syndrome (EDS), Loeys-Dietz syndrome (LDS), familial thoracic aortic aneurysms and dissections (TAAD), bicuspid aortic valve disease (BAV), and autosomal dominant polycystic kidney disease (ADPKD). In the absence of familial history and other clinical findings, the proportion of thoracic and abdominal aortic aneurysms and dissections resulting from a genetic predisposition is still unknown. In this study, we propose the review of the current genetic knowledge in the aortic disease, observing, in the results that the causative genes and molecular pathways involved in the pathophysiology of aortic aneurysm disease remain undiscovered and continue to be an area of intensive research.

Bicuspid aortic valve and aortic root disease

Bicuspid aortic valve (BAV) is the most common form of congenital heart disease, with frequent and premature occurrence of cardiac events, dominated by significant valvular dysfunction. BAV has a high prevalence of aortic wall abnormalities such as ascending aortic dilatation. Because more rapid aortic dilatation can occur, once the ascending aorta reaches 40 mm, annual imaging with echocardiography or other imaging techniques is indicated. The most feared complication is aortic dissection. However, the actual incidence of this complication is low (4%). Although limited data exist regarding prophylactic intervention, it is suggested that elective surgical repair of BAV-associated aortic dilatation should be more aggressively recommended. In patients with BAV, the decision to indicate surgical treatment in aortic diameters between 50 and 55 mm should be based on patient age, body size, comorbidities, type of surgery, and the presence of additional risk factors.

The influence of operative techniques on the outcomes of bicuspid aortic valve disease and aortic dilatation

BACKGROUND

Bicuspid aortic valve is associated with aortic aneurysm formation that may extend beyond the ascending aorta.

METHODS

Between 1979 and 1997, 143 bicuspid aortic valve patients had aortic valve operations with replacement of an aneurysmal ascending aorta: 93 (65%) underwent full root replacement and 50 (35%) underwent separate valve and graft replacement. Distal aortic anastomosis was open in 42 patients (29%) and closed in 101 (71%). Late survival and complications were compared by surgical technique.

RESULTS

Patients undergoing full root replacement tended to be younger (mean age 46 +/- 16 vs 59 +/- 13, p < 0.001) and presented with more aortic insufficiency (80% vs 35%, p < 0.001). Three (2.1%) hospital deaths occurred. Event-free survival was 82% (95% confidence interval, 75% to 88%) at 10 years and 41% (95% confidence interval, 11% to 71%) at 20 years. At a median follow-up of 11.5 years, the incidence of new aneurysms and late aortic complications were not significantly different among the procedure groups. Age at the time of operation was the only predictor of late survival (hazard ratio, 1.07; p = 0.007).

CONCLUSIONS

Aortic root replacement with distal aortic reconstruction can be achieved with very low operative mortality and excellent long-term outcomes in patients with bicuspid aortic valve and dilated ascending aorta. The type of surgical procedure done in the aortic root and in the distal ascending aorta does not influence late survival, subsequent operation, or aortic complications. This is likely influenced by our patient-specific strategy when replacing the aortic root and distal ascending aorta.

Standardizing the method of measuring by echocardiogram the diameter of the ascending aorta in patients with a bicuspid aortic valve

Serial echocardiographic follow-up of patients with a bicuspid aortic valve (BAV), in addition to providing assessment of valve dysfunction, can help identify those at risk of aortic complications. However, currently there is no standardized echocardiographic method for measuring the ascending aorta. We examined the echocardiograms of 45 patients with a BAV and 45 matched controls to understand the effects of the measurement location (1, 2, and 3 cm above the sinotubular junction) and the point in the cardiac cycle (end-diastole, mid-systole, and end-systole) at which the ascending aortic measurements are made. A greater length of aorta could be measured in end-systole than in end-diastole, presumably because of aortic recoil. Using the control data for comparison, we found that more dilated ascending aortas were detected by measuring 3 cm above the sinotubular junction in the patients with a BAV (56%) than at 1 cm (42%). The increases in size between 1 and 2 cm were greater than those between 2 and 3 cm. In conclusion, we propose that all transthoracic echocardiograms should include the proximal aorta at least 2 cm and preferably 3 cm above the sinotubular junction and suggest that for standardization and optimal visualization the measurements be done at end-systole in all patients.

Morphology and function of the bicuspid aortic valve with and without coarctation of the aorta in the young

This study sought to determine the morphology and function of bicuspid aortic valves (BAVs) with and without coarctation of the aorta (CoA) in a young population. The transthoracic echocardiograms of 117 patients with BAVs and 62 patients with CoA were retrospectively reviewed and compared with normal transthoracic echocardiographic results. In each patient, the area subtended by the aortic cusps and valve and the diameters of the aortic root at different levels were measured, and additionally in each BAV, the type of cusp fusion and the presence and degree of aortic stenosis and/or regurgitation were evaluated. The median age of patients with BAVs was 4 years (range 0 days to 34 years), and the median age of patients with CoA was 1.9 years (range 0 days to 16.5 years). BAVs with right and left coronary cusp fusion were significantly associated with CoA (p <0.0001) and cardiac anomalies (p <0.0001), whereas BAVs with noncoronary and right coronary cusp fusion were affected by valvar dysfunction (p <0.001). Compared with normal tricuspid aortic valves, BAVs had aortic root dilation, even in patients with no hemodynamic disturbance, particularly at the level of the ascending aorta (p <0.0001); the difference was still significant comparing BAVs and CoA with tricuspid aortic valves and CoA (p <0.0001). In conclusion, different morphologies of BAVs are associated with different cardiac abnormalities, valvar function, and aortic root dilation. Although detectable early in life, valvar dysfunction and aortic root dilation progress with age.

Progression rate of ascending aortic dilation in patients with normally functioning bicuspid and tricuspid aortic valves

Dilation of the ascending aorta (AA), which is disproportionate to associated valvular lesions, is a relatively well-recognized phenomenon in patients with a bicuspid aortic valve (BAV). The aim of this study was to evaluate the rate of changes in the AA dimensions and the outcome in patients with AA dilation and BAVs compared with patients with AA dilation and tricuspid aortic valves (TAVs). Serial transesophageal echocardiograms (>12 months apart) were performed in 113 consecutive patients (BAV, n=27 and TAV, n=86) with AA diameters of >or=40 and <or=60 mm, respectively, without associated significant aortic valve stenosis or regurgitation. Baseline diameters at the sinuses of Valsalva (SV), the sinotubular junction (STJ), and the tubular tract (TT) were similar in both groups (41.3+/-5.3 vs 42.3+/-6.3 mm, p=NS, 37.8+/-5.2 vs 38.7+/-5.5 mm, p=NS, and 47.3+/-5.3 vs 45.9+/-5.1, p=NS, respectively). During an average 3-year follow-up, the rate of AA diameter progression was similar for the BAV and TAV groups (0.86+/-0.81 vs 0.82+/-1.1 mm/year, p=NS for the SV; 1.06+/-1.6 vs 0.63+/-1.1 mm/year, p=NS for the STJ; and 0.81+/-1.1 vs 0.75+/-1.1 mm/year, p=NS for the TT, respectively). Three patients in the TAV group experienced cardiac death (2 died suddenly and 1 after emergency surgery for AA dissection); there was no occurrence of cardiac death in the BAV group. In conclusion, the rate of progression of AA aneurysms was similar in patients with BAVs and in those with TAVs. Furthermore, patients with BAVs did not have increased rates of AA related complications compared with patients with TAVs.

Aortic dilatation in patients with bicuspid aortic valve

The association of a bicuspid aortic valve (BAV) with abnormalities of the proximal thoracic aorta, including dilatation, aneurysm and dissection, has been previously described, leading to the hypothesis of a common underlying developmental defect involving the aortic valve and the aortic wall. Consequently, any patient with BAV should receive a careful assessment not only of the valve function, but also of the aortic root and the ascending aorta. Dilatation of the proximal thoracic aorta is a common finding in patients with BAV and is believed to be related to aortic rupture and dissection. Because progressive dilatation can occur, careful long-term surveillance of the aortic dimensions is required. Prophylactic surgical repair of the dilated aorta should be recommended more aggressively for patients with BAV than for those with a tricuspid aortic valve. However, the optimal timing of aortic surgery in BAV patients remains uncertain because of the limited data available on the natural history of asymptomatic aortic dilatation.

Usefulness of MRI in the follow-up of patients with repaired aortic coarctation and bicuspid aortic valve

BACKGROUND

The long-term outcome of repaired aortic coarctation may be complicated by dilatation of the ascending aorta notably in patients with bicuspid aortic valve. Magnetic resonance imaging was used to compare the size of the ascending aorta in patients with bicuspid or tricuspid aortic valve.

METHODS

In 50 patients with a repair of aortic coarctation, the size of the ascending aorta was measured in a bicuspid aortic valve group (n=11) and a tricuspid aortic valve group (n=39). The aortic diameter was measured at the level of the sinus of Valsalva and at the widest part of the ascending aorta using magnetic resonance imaging.

RESULTS

The mean age of patients at surgical repair was respectively 2.2+/-3.3 years for the bicuspid aortic valve group and 2.5+/-3.5 years for the tricuspid aortic valve group (p=NS) and the mean age at the time of the magnetic resonance imaging was 10.2+/-4.7 years and 9.3+/-5.9 years (p=NS) respectively. A significant difference in the aortic diameter was found between the bicuspid aortic valve group and the tricuspid aortic group both at the level of sinus of Valsalva (34.8+/-8.2 mm, 19.5+/-4.4 mm, respectively, p<0.01) and at the level of the ascending aorta (36.8+/-7.2 mm, 16.9+/-3.4 mm, respectively, p<0.01).

CONCLUSIONS

The occurrence of ascending aortic dilatation is significantly associated with the presence of a bicuspid aortic valve. This requires long-term follow-up, which can be effectively performed by magnetic resonance imaging.

Heritable Disorders Predisposing to Aortic Dissection

Heritable disorders of connective tissue often predispose patients to aortic pathology and in particular aortic dissection. The Marfan syndrome, vascular Ehlers-Danlos syndrome, familial forms of thoracic aortic aneurysms or aortic dissection, and bicuspid aortic valve are all examples of heritable disorders that have associated defects affecting the integrity of the aortic wall, posing a risk of both aneurysmal dilation and dissection. The purpose of this review was to outline the phenotypes of the heritable syndromes that predispose to aortic dissection, present a guideline to their management and surveillance, and to offer insight into some of the surgical pitfalls that occur when repairing ascending aortic dissections in these types of patients.

Management of the Valve and Ascending Aorta in Adults with Bicuspid Aortic Valve Disease

Bicuspid aortic valve (BAV) disease is the most common congenital cardiac malformation, being present in 1% to 2% of the population. It is heritable and is three to four times more likely to occur in men. The pathogenesis of BAV disease is unknown. Bicuspid valves progress to aortic stenosis or insufficiency in the majority of patients. BAV disease is associated with several anomalies of the aorta including coarctation, aneurysm formation, and dissection. Several lines of evidence suggest that aortic complications are caused by the same underlying factor that causes BAV disease, rather than being a consequence of turbulent blood flow through a stenotic valve. Several different surgical options exist for patients with BAV disease depending on the age of presentation and the size and appearance of the aorta. We herein describe our surgical management of the aortic valve and ascending aorta in patients with BAV disease.

Aortic valve morphology definition with transthoracic combined with transesophageal echocardiography in a population with high prevalence of bicuspid aortic valve

OBJECTIVE

To assess the utility of transthoracic echocardiography (TTE) with second harmonic combined with transesophageal echocardiography (TEE) in defining aortic valve morphology in a subset of patients with a high prevalence of bicuspid aortic valve.

METHODS AND MATERIALS

Patients (n = 174) with dilated aortic root were consecutively evaluated using, initially, TTE. The aortic valve structure was assigned as tricuspid, bicuspid or undefined. In those assigned as bicuspid or undefined, TEE was performed. Other factors that could affect valve morphology assignment were recorded and evaluated in multivariate analysis.

RESULTS

TTE was able to characterise 89% of the tricuspid valves and 56% of the bicuspid. Bicuspid structure was the only variable that, in the multivariate analysis, was related to the inability to definitively assign aortic valve morphology (OR = 0.13). TEE was performed in 59 patients and the morphology was definitively assigned in 56 of them (95%). TEE diagnosed 15 bicuspid valves in addition to confirming the 17 identified by TTE. Overall, using TTE combined with TEE we were able to correctly assign valvular morphology in 98% of patients.

CONCLUSION

In a subset of patients with a high prevalence of bicuspid aortic valve, combination of TTE and TEE should be considered to define aortic valve morphology. TEE identifies an important number of patients with BAV.

Factors related to aortic regurgitation in the presence of a dilated aortic root

The relation among aortic regurgitation (AR) and aortic root diameter, anthropometric variables, and aortic valve morphology was assessed in 142 patients with dilated aortic roots. The diameter of the aortic root indexed for body surface area and aortic valve sclerosis were related to the presence and severity of AR.

Aortic dimensions in patients with bicuspid aortic valve without significant valve dysfunction

The dimensions of the entire aorta at different anatomic levels were measured by transthoracic 2-dimensional echocardiography in 162 consecutive patients with isolated bicuspid aortic valves (BAVs) without significant aortic valve dysfunction. Aortic dilation involved the aortic root and the ascending aorta but was not present in the descending and abdominal aorta. A significant increase in the dimensions of the aortic arch was found in patients with BAVs aged >40 years. Ascending aortic diameter and the extension of aortic dilation were significantly correlated with age, but no correlation was found between aortic dimensions and aortic valve morphology.

Dilated ascending aorta in a child with ring chromosome 21 syndrome

Ring chromosome 21 syndrome is a rare condition with a well-characterized phenotype. Affected individuals have recognizable dysmorphic features, developmental delays, growth retardation, and a predisposition for congenital malformations involving the neurologic, craniofacial, digestive, genitourinary, skeletal, and hematologic systems. Structural cardiac anomalies have also been described, but dilated ascending aorta has not been previously reported in association with ring 21 (r(21)). Although rarely seen in this syndrome, the presence of ectopia lentis, abdominal herniae, and dilated ascending aorta suggest an underlying connective tissue disorder. A possible explanation is haploinsufficiency of the COL6A1, COL6A2, and/or COL18A genes located on the distal portion of chromosome 21q, which are lost when the ring chromosome is formed. This article contains supplementary material, which may be viewed at the American Journal of Medical Genetics website at http://www.interscience.wiley.com/jpages/0148-7299/suppmat/index.html.

Aortic Valve Repair Using a Differentiated Surgical Strategy

BACKGROUND

Reconstruction of the aortic valve for aortic regurgitation (AR) remains challenging, in part because of not only cusp or root pathology but also a combination of both can be responsible for this valve dysfunction. We have systematically tailored the repair to the individual pathology of cusps and root.

METHODS

Between October 1995 and August 2003, aortic valve repair was performed in 282 of 493 patients undergoing surgery for AR and concomitant disease. Root dilatation was corrected by subcommissural plication (n=59), supracommissural aortic replacement (n=27), root remodeling (n=175), or valve reimplantation within a graft (n=24). Cusp prolapse was corrected by plication of the free margin (n=157) or triangular resection (n =36), cusp defects were closed with a pericardial patch (n=16). Additional procedures were arch replacement (n=114), coronary artery bypass graft (n=60) or mitral repair (n=24). All patients were followed-up (follow-up 99.6% complete), and cumulative follow-up was 8425 patient-months (mean, 33+/-27 months).Results- Eleven patients died in hospital (3.9%). Nine patients underwent reoperation for recurrent AR (3.3%). Actuarial freedom from AR grade > or =II at 5 years was 81% for isolated valve repair, 84% for isolated root replacement, and 94% for combination of both; actuarial freedom from reoperation at 5 years was 93%, 95%, and 98%, respectively. No thromboembolic events occurred, and there was 1 episode of endocarditis 4.5 years postoperatively.

CONCLUSIONS

Aortic valve repair is feasible even for complex mechanisms of AR with a systematic and individually tailored approach. Operative mortality is low and mid-term durability is encouraging. The incidence of valve-related morbidity is low compared with valve replacement.