The surgical treatment of aortic dissection in a patient with Turner's syndrome: report of a case

Aortic dilatation and dissection in Turner syndrome: what we know, what we are unclear about and what we should do in clinical practice?

Aortic dilatation and aortic dissection are increasingly recognised in patients with Turner syndrome (TS). Risk factors for aortic dissection include aortic dilatation, bicuspid aortic valves, coarctation of aorta and pregnancy. The risk of death due to aortic dissection in pregnancy in TS is 2%, which is approximately 100 times higher than the general population, as maternal mortality is extremely low. Ongoing cardiovascular monitoring is recommended, although there remain several unanswered questions in relation to cardiovascular imaging especially the choice of modality for detection of vascular, valvular abnormalities and measurements of aortic dimensions. Due to the relative short stature of patients with TS, aortic dimensions need to be defined by aortic measurements adjusted for body surface area, known as aortic sized index (ASI). The relationship of ASI and other risk factors with aortic dissection is only beginning to be clarified. Clinical management and monitoring of such patients should be delivered by a group of clinicians familiar with the issues unique to TS patients in a multidisciplinary fashion. All clinicians including the non-specialists need to have a low threshold of suspecting aortic dissection in these adolescents and young adults. This up to date review, including a summary of all 122 published cases of TS patients with aortic dissection, aims to provide a summary of recent publications on characteristics of aortic dissection and aortic dilatation in TS to highlight gaps in knowledge and propose possible clinical monitoring pathway of cardiovascular health in children and adults with TS. Cardiovascular assessment and risk counselling is especially crucial during the period of transition of adolescents with TS, although life long monitoring by expert cognizant to the issues specific in TS is essential.

Cardiovascular Disorders of Turner's Syndrome: A Review

A series of cardiovascular abnormalities may be associated with Turner's Syndrome (TS). Over 50% of the reported cardiovascular malformations have been bicuspid aortic valve or coarctation of the aorta alone. or in a combination, which may lead to a higher risk for infective endocarditis. Isolated dilation of the ascending aorta was often seen in TS, while aortic dissection has been increasingly observed in recent years. The aortic root dilation was found more likely to be due to a mesenchymal defect rather than atherosclerotic changes. Women with TS are often hypertensive as a result of aortic abnormality or renal vascular disorder. They have an increased risk of developing neoplasms, such as gonadoblastoma and dysgerminoma, and therefore they may require regular monitoring while receiving hormone therapy. In patients with gonadal dysgenesis, exogenous estrogen treatment poses a problem of connective tissue disorders of the great vessels. To resolve the contradiction between exogenous estrogen therapies and the hold-up of the progression of the connective tissue abnormality is a topic to be coped with. Careful clinical assessment is mandatory in the evaluation of patients with TS with cardiovascular abnormalities.

Dissection of the aorta in Turner syndrome: two cases and review of 85 cases in the literature

Patients with Turner syndrome (TS) are at risk for aortic dissection, but the clinical profile for those at risk is not well described. In addition to reporting two new cases, we performed an electronic search to identify all reported cases of aortic dissection associated with TS. In total, 85 cases of aortic dissection in TS were reported between 1961 and 2006. Dissection occurred at a young age, 30.7 (range 4-64) years, which is significantly earlier than its occurrence in the general female population (68 years). Importantly, in 11% of the cases, neither hypertension nor congenital heart disease were identified, suggesting that TS alone is an independent risk factor for aortic dissection; however, the cases where no risk factors were identified were very poorly documented. A TS aortic dissection registry has been established to determine the natural history and risk factors better (http://www.turnersyndrome.org/).

Dissection of the aorta in Turner syndrome: two cases and review of 85 cases in the literature

Girls and women with Turner syndrome are at risk for catastrophic aortic dissection and rupture, but the clinical profile for those at risk is not well described. In addition to reporting two new cases, we performed an electronic search to identify all reported cases of aortic dissection associated with Turner syndrome. Particular attention was paid to the reporting of systemic hypertension (HTN) and congenital heart disease (CHD) which are known risk factors for aortic disease in the general population. In total, 85 cases of aortic dissection in TS were reported between 1961 and 2006. Dissection occurred at a young age, 30.7 (range 4-64) years, which is significantly earlier than its occurrence in the general female population (68 years). Of the cases for which HTN and CHD were explicitly assessed, 15% had HTN alone, 30% had CHD alone and 34% had both. Importantly, in 11% of the cases, neither HTN nor CHD were identified, suggesting that TS alone is an independent risk factor for aortic dissection; however, the cases where no risk factors were identified were very poorly documented. Dissection in women with TS undergoing assisted reproductive techniques (ART) frequently resulted in death. The literature on aortic dissection in TS is sparse and most cases are poorly documented, making it difficult to establish firm guidelines regarding monitoring and treatment. A TS aortic dissection registry has been established to better determine the natural history and risk factors (http://www.tssus.org/readweb.asp?wid = 3092).

Sudden death of a young woman due to aortic dissection caused by Turner's syndrome

A 24-year-old woman was found dead in her bed. There had been an episode of fainting with cervicodynia 1 day before death but no significant past medical history, except for menstrual irregularities. Post-mortem examination revealed that death was due to hemopericardium caused by rupture of the ascending aorta by thoracic aortic dissection (Stanford type A). Microscopically, weakness of the aorta was due to cystic medial necrosis. On external examination, short stature, a short neck and multiple pigmented nevi were observed, while internal examination revealed coarctation of the aorta and funicular ovaries. Examination of the X chromatin showed a decrease in numbers of Barr bodies in the tissues, and a 45,X/46,XX mosaicism was suspected. It is concluded that the cause of death was aortic dissection due to Turner's syndrome.

Mapping a locus for familial thoracic aortic aneurysms and dissections (TAAD2) to 3p24-25

BACKGROUND

Familial thoracic aortic aneurysms and dissections (TAAD) occur as part of known syndromes such as Marfan syndrome but can also be inherited in families in an autosomal dominant manner as an isolated condition. Previous studies have mapped genes causing nonsyndromic familial TAAD to 5q13-15 (TAAD1) and 11q23.2-q24 (FAA1). Further genetic heterogeneity for the condition was evident by the presence of TAAD in some families not linked to these known loci.

METHODS AND RESULTS

A 4-generation family with dominant mode of inheritance of TAAD was studied. Affected status was determined by dilation of the ascending aorta, surgical repair of an aneurysm or dissection, or death as the result of aortic dissection. None of the family members evaluated met the diagnostic criteria for Marfan syndrome. After exclusion of known loci for familial TAAD, a genome-wide scan was carried out to map the defective gene causing the disease in the family. A locus was mapped to a 25-cM region on 3p24-25 with a maximum multipoint logarithm of the odds score of 4.28.

CONCLUSIONS

A third locus for nonsyndromic TAAD was mapped to 3p24-25 and termed the TAAD2 locus. This locus overlaps a previously mapped second locus for Marfan syndrome, termed the MFS2 locus. Future characterization of the TAAD2 gene will determine if TAAD2 is allelic to MFS2. In addition, identification of the TAAD2 gene will improve the presymptomatic diagnosis of individuals with this life-threatening genetic syndrome and provide information concerning the pathogenesis of the disease.

Turner syndrome and the heart: cardiovascular complications and treatment strategies

Turner syndrome is a condition usually associated with reduced final height, gonadal dysgenesis, and thus insufficient circulating levels of female sex steroids, and infertility. A number of other signs and symptoms are seen more frequently with the syndrome. With respect to cardiac function, congenital malformations of the heart and the great vessels, hypertension and ischemic heart disease, and increased risk of aortic dissection are all conditions that the pediatrician or the physician caring for females with Turner syndrome should keep in mind. Many girls and adolescents with Turner syndrome receive growth hormone (GH) treatment, which has so far been an effective and well-tolerated therapy. Nevertheless, because of the experience from acromegaly, the physician should monitor blood pressure and perform echocardiography, together with clinical examinations by a cardiologist at regular intervals. During adulthood most women with Turner syndrome are faced with premature menopause and the need for female hormone replacement therapy (HRT). During clinical evaluation of girls and women with Turner syndrome, these conditions and complications should be kept under surveillance. Here the cardiovascular complications of Turner syndrome are reviewed. The risk of congenital heart defects such as bicuspid aortic valves, aortic coarctation, other valve abnormalities, and septal defect is increased. Likewise, the risk of aortic dissection at a young age is increased, as is the risk of hypertension, ischemic heart disease, and stroke. GH therapy does not seem to adversely affect the heart, although longer-term follow-up studies are needed. In short-term studies, HRT lowers blood pressure, while any effect on the risk of ischemic heart disease has not been evaluated. Treatment with GH and HRT are discussed in relation to the heart and great vessels. Presently, the pathophysiology of the congenital cardiovascular malformation in Turner syndrome is unexplained, although different theories exist. Recommendations for clinical practice are given, including life-long surveillance of cardiac function, aortic diameter and blood pressure.

Further delineation of aortic dilation, dissection, and rupture in patients with Turner syndrome

OBJECTIVE

Although cardiovascular malformations (CVMs) are well-recognized congenital anomalies in Turner syndrome, aortic dilation and dissection are less common and less familiar. Most of the relevant literature is limited to single cases reports or small series. We sought to increase the information available about the frequency and characteristics of aortic dilation in patients with Turner syndrome.

DESIGN

A 1-page survey of cardiac abnormalities, including aortic dilation, was mailed to approximately 1000 (1040 verified) members of the Turner Syndrome Society as an enclosure in the June 1997 newsletter. We also conducted a literature review.

PARTICIPANTS

A total of 245 patients or families of patient members of the Turner Syndrome Society responded to the survey ( approximately 24% response rate).

RESULTS

A CVM was reported in 120 of 232 (52%) respondents to this questionnaire. Obstructive lesions of the left side of the heart predominated and included bicuspid aortic valve (38%) and coarctation (41%). Aortic dilation was reported in at least 15 of 237 respondents (6.3%; 95% confidence interval: 3.6%-10.3%); 2 of 15 (13%) had dissection. Twelve of 15 (80%) patients had an associated risk factor for aortic dilation such as a CVM or hypertension. The 3 (20%) patients who did not have a CVM or hypertension were all younger than 21 years. In the entire group with aortic dilation, 10 of 15 (67%) patients were younger than 21 years. All patients with aortic dilation had involvement of the ascending aorta, and 2 had additional involvement of the descending aorta distal to a repaired coarctation. An update of the literature revealed 68 patients with aortic dilation, dissection, or rupture. An associated CVM or hypertension was reported in 53 of 59 (90%) informative patients. At least 6 (10%) had no predisposing risk factor (information was inadequate for 9 of 68 patients). The following patterns of aortic involvement were identified: ascending +/- descending aorta with coarctation (14); ascending +/- descending aorta without coarctation (39); descending aorta with coarctation (3); descending thoracic or abdominal aorta without coarctation (4); and unspecified (8). Dissection or rupture was reported in 42/68 (62%). Two reported patients died suddenly from aortic dissection in the third trimester of assisted pregnancy. At least 20 (29%) patients were younger than 21 years. One of the 6 (17%) patients with isolated aortic dilation was in this younger group.

CONCLUSIONS

More information is needed about the frequency and natural history of aortic dilation in Turner syndrome. This work contributes new patient data and increases the literature review. Despite the well-recognized limitations of self-reporting, this survey detected aortic dilation with or without dissection in approximately 6% of patients with Turner syndrome. Although rare, this is a potentially catastrophic occurrence, warranting greater awareness among health professionals. In this study and the literature, the vast majority of patients with aortic dilation have an associated risk factor such as a CVM, typically bicuspid aortic valve or coarctation, or systemic hypertension. These patients represent a higher risk group that should be followed appropriately, usually under the direction of a cardiologist. Patients undergoing assisted pregnancy also should be evaluated closely. It is generally accepted that at the time of diagnosis of Turner syndrome, all patients should have a complete cardiology evaluation including echocardiography. The small number of patients with aortic dilation without a CVM, who would not be under the long-term care of a cardiologist, makes it prudent to screen all patients with Turner syndrome for this potentially lethal abnormality. The specific timing for this screening is controversial. Our recommendations for prospective imaging do not represent a rigid standard of care.

Aortic dissection and Turner's syndrome: case report and review of the literature

Cardiovascular abnormalities are frequently encountered in patients with Turner's syndrome. These include coarctation of the aorta, aortic root dilatation, bicuspid aortic valve, atrial and ventricular septal defects. Aortic dissection is a rare but devastating complication of Turner's syndrome that usually occurs in adulthood. We report a case of Turner's syndrome with coarctation of the aorta and chronic aortic dissection, and review the relevant literature. There have been 21 prior reported cases of aortic dissection in patients with Turner's syndrome. Possible etiologic factors contributing to the occurrence of aortic dissection in this syndrome are protean. They include the presence of cystic medial necrosis, coarctation of the aorta, bicuspid aortic valve, aortic root dilatation, and hypertension, although cases of aortic dissection and Turner's syndrome have been described in patients without any risk factors. As our knowledge of the natural history of congenital heart defects and risk factors for aortic dissection in Turner's syndrome is limited, periodic cardiac evaluation of these patients may be warranted. Early recognition and treatment of this potentially lethal complication of Turner's syndrome is essential.

Cardiovascular malformations and complications in Turner syndrome

BACKGROUND

Turner syndrome (gonadal dysgenesis with sex chromosome abnormalities) is recognized to be a disorder in which cardiovascular malformations are common. The prevalence and natural history of these findings, the risk for aortic dissection, and the occurrence of cardiovascular disease have all been the subject of debate, as have been the American Academy of Pediatrics recommendations for cardiac screening of patients with Turner syndrome.

OBJECTIVE

To evaluate a large population of patients both cross-sectionally and longitudinally to determine the prevalence of cardiovascular malformations, the risk for dissection of the aorta, to determine whether there are phenotype:karyotype correlations that can allow for specific recommendations, and to devise an appropriate screening protocol.

DESIGN AND METHODS

Data have been collected for patients with Turner syndrome. These individuals have been seen in an ongoing clinic established for the study of the natural history of Turner syndrome. Data from physical examinations, evaluations by cardiologists, echocardiography results, medical and surgical complications, medical records, and causes of death were analyzed. A total of 244 of 462 individuals in this population with karyotype-proven Turner syndrome could be evaluated because echocardiograms had been obtained. In addition, the medical literature was reviewed for occurrences of aortic dissection in patients with Turner syndrome.

RESULTS

A total of 136 (56%) of 244 of these patients had cardiovascular abnormalities, 96 (71%) were structural, 40 (29%) were functional, including hypertension (HBP), mitral valve prolapse and conduction defects. Coarctation of the aorta and bicuspid aortic valve, alone or in combination, comprised >50% of the cardiac malformations. Bicuspid valve was often not detected by examination, but only by echocardiography. Aortic dissection occurred in three of the patients. In one, it was traumatic; in a second, it occurred at the site of coarctation repair. The third patient had long-standing HBP with malignant obesity. In the literature, there have been 42 case reports of aortic dissection in Turner syndrome. In all except 5, predisposing risk factors of coarctation, bicuspid aortic valve, and/or HBP were present. Of these 5, sufficient information regarding predisposing risk factors was provided for only 2. No phenotype:karyotype correlations could be drawn with any certainty.

CONCLUSIONS

When the diagnosis of Turner syndrome is made, a screening echocardiogram should be obtained. Referral to a cardiologist first may be appropriate, but physical examination does not substitute for visualization. Individuals with and without evidence of structural cardiac malformations should be monitored for HBP on a lifelong basis. In the absence of structural cardiac malformations or HBP, the risk for aortic dissection appears small, and repeated echocardiography or magnetic resonance imaging to follow aortic root diameters does not appear to be warranted based on data currently available. Protocols for following patients with structural malformations need to be individualized, and wholesale recommendations have little merit. A longitudinal study using magnetic resonance imaging or cardiac echocardiography to establish normal parameters for aortic root diameters and to follow aortic root changes is needed.