Adjustments in ß-Adrenergic Signaling Contribute to the Amelioration of Cardiac Dysfunction by Exercise Training in Supravalvular Aortic Stenosis.

BACKGROUND/AIMS: Aortic stenosis-induced chronic pressure overload leads to cardiac dysfunction and congestive heart failure. The pathophysiological mechanisms of the myocardial impairment are multifactorial and include maladaptive ß-adrenergic signaling. Exercise training (ET) has been used as a non-pharmacological therapy for heart failure management. The present study tested the hypothesis that exercise training attenuates diastolic dysfunction through ß-adrenergic signaling preservation. METHODS: Wistar rats were submitted to ascending aortic stenosis (AS) surgery, and after 18 weeks, a moderate aerobic exercise training protocol was performed for ten weeks. RESULTS: ET attenuated diastolic dysfunction, evaluated by echocardiogram and isolated papillary muscle (IPM) assay. Also, ET reduced features of heart failure, cross-sectional cardiomyocyte area, and exercise intolerance, assessed by treadmill exercise testing. The ß2 adrenergic receptor protein expression was increased in AS rats independently of exercise. Interestingly, ET restored the protein levels of phosphorylated phospholamban at Serine 16 and preserved the ß-adrenergic receptor responsiveness as visualized by the lower myocardial compliance decline and time to 50% tension development and relaxation during ß-adrenergic stimulation in the IPM than untrained rats. Additionally, AS rats presented higher levels of TNFα and iNOS, which were attenuated by ET. CONCLUSION: Moderate ET improves exercise tolerance, reduces heart failure features, and attenuates diastolic dysfunction. In the myocardium, ET decreases the cross-sectional area of the cardiomyocyte and preserves the ß-adrenergic responsiveness, which reveals that the adjustments in ß-adrenergic signaling contribute to the amelioration of cardiac dysfunction by mild exercise training in aortic stenosis rats.

Balloon valvuloplasty in a dog with congenital bicuspid aortic valve and supravalvar aortic stenosis (atypical Shone's complex).

An 8-month-old intact female pug was presented for evaluation and possible balloon valvuloplasty (BV) for severe aortic stenosis. A bicuspid, severely stenotic aortic valve of type 3 morphology with a supravalvar stenosis component was diagnosed, consistent with the diagnosis of atypical Shone's complex. There was severe concentric hypertrophy of the left ventricle, with increased echogenicity of the myocardium nearest to the endocardial border. Mild left atrial enlargement was observed. Selective angiography and transesophageal echocardiography revealed an enlarged and relatively tortuous ascending aorta. The changes to the ascending aorta and the anatomy of the lesion made retrograde access to the left ventricle challenging. Ultimately, BV was successful using a pediatric valvuloplasty balloon catheter and rapid right ventricular pacing, and the pressure gradient across the aortic valve was decreased by more than 50% compared with preoperative measurements. Although valvar aortic stenosis is rare in veterinary medicine, this report highlights the potential challenges and feasibility of BV for this disease.

[Reintervention with percutaneous balloon angioplasty in patients with congenital heart disease with left-sided obstructions]. / Reintervención con angioplastía percutánea con balón en enfermos con cardiopatías congénitas con obstrucciones izquierdas.

BACKGROUND: Left-sided cardiac obstructions represent 15% of congenital heart disease (CHD). The treatment in adults is surgical; however, balloon dilation by interventional catheterization can alleviate the symptoms in pediatric patients to allow them to reach the target height. The aim was to determine the survival and the factors associated with reintervention in patients with CHD with left-sided obstruction treated with balloon angioplasty. METHODS: A cohort study was conducted in patients aged 4 to 17 years with left-sided heart obstruction (valvular stenosis [VS], supravalvular aortic stenosis [SAS], coarctation of the aorta [CA]) successfully treated with balloon angioplasty. The follow-up was of 10 years and the outcome variable was the restenosis with reintervention criteria. Pediatric stage at the time of the procedure, nutritional status, residual gradient, and presence of genetic syndromes were considered prognostic variables. For statistical analysis, measures of central tendency and dispersion were used. Chi squared was employed in qualitative variables and Kruskal-Wallis in quantitative variables. RESULTS: We had a total of 110 patients: 40% had CA, 35% VS, and 25% SAS. 39% required reintervention: 80% in SAS, 35% in CA, and 14% in VS. CONCLUSION: The intervention balloon is a stopgap measure that allows patients with left-sided obstructions to reach the target height.

Introducción: las obstrucciones izquierdas representan 15% de las cardiopatías congénitas (CC). El tratamiento en la edad adulta es quirúrgico; no obstante, la dilatación con balón puede paliar los síntomas en edad pediátrica para permitir que alcancen la talla diana. El objetivo fue determinar la sobrevida y los factores asociados a la reintervención en enfermos con CC con obstrucción izquierda tratados con plastía con balón. Métodos: se realizó un estudio de cohorte en pacientes entre 4 y 17 años con cardiopatías de obstrucción izquierda (estenosis valvular, supravalvular y coartación aórtica) tratados con angioplastía con balón exitosa. El seguimiento fue de 10 años y la variable de desenlace fue la reestenosis con criterios para reintervención. Se consideraron variables pronósticas la etapa pediátrica al momento del procedimiento, el estado nutricional, el gradiente residual y la presencia de síndromes genéticos. Se usaron medidas de tendencia central y dispersión. Se usó chi cuadrada en variables cualitativas y Kruskal-Wallis en variables cuantitativas. Resultados: fueron 110 pacientes; 40% presentó coartación aórtica, 35% estenosis valvular y 25% estenosis supravalvular aórtica. El 39% requirió reintervención y la frecuencia fue la siguiente: 80% en estenosis supravalvular, 35% en coartación aórtica y 14% en estenosis valvular aórtica. Conclusión: la intervención con balón es una medida paliativa que permite a los enfermos con obstrucciones izquierdas alcanzar la talla diana.

High-pressure balloon dilation in a dog with supravalvular aortic stenosis.

A 6-month-old female intact Goldendoodle was presented for diagnostic work up of a grade IV/VI left basilar systolic heart murmur. An echocardiogram was performed and revealed a ridge of tissue distal to the aortic valve leaflets at the sinotubular junction causing an instantaneous pressure gradient of 62 mmHg across the supravalvular aortic stenosis and moderate concentric hypertrophy of the left ventricle. Intervention with a high-pressure balloon dilation catheter was pursued and significantly decreased the pressure gradient to 34 mmHg. No complications were encountered. The patient returned in 5 months for re-evaluation and static long-term reduction in the pressure gradient was noted.

Integrin ß3 inhibition is a therapeutic strategy for supravalvular aortic stenosis.

The aorta is the largest artery in the body, yet processes underlying aortic pathology are poorly understood. The arterial media consists of circumferential layers of elastic lamellae and smooth muscle cells (SMCs), and many arterial diseases are characterized by defective lamellae and excess SMCs; however, a mechanism linking these pathological features is lacking. In this study, we use lineage and genetic analysis, pharmacological inhibition, explant cultures, and induced pluripotent stem cells (iPSCs) to investigate supravalvular aortic stenosis (SVAS) patients and/or elastin mutant mice that model SVAS. These experiments demonstrate that multiple preexisting SMCs give rise to excess aortic SMCs in elastin mutants, and these SMCs are hyperproliferative and dedifferentiated. In addition, SVAS iPSC-derived SMCs and the aortic media of elastin mutant mice and SVAS patients have enhanced integrin ß3 levels, activation, and downstream signaling, resulting in SMC misalignment and hyperproliferation. Reduced ß3 gene dosage in elastin-null mice mitigates pathological aortic muscularization, SMC misorientation, and lumen loss and extends survival, which is unprecedented. Finally, pharmacological ß3 inhibition in elastin mutant mice and explants attenuates aortic hypermuscularization and stenosis. Thus, integrin ß3-mediated signaling in SMCs links elastin deficiency and pathological stenosis, and inhibiting this pathway is an attractive therapeutic strategy for SVAS.

Severe left main coronary artery stenosis with abnormal branching pattern in a patient with mild supravalvar aortic stenosis and Williams-Beuren syndrome.

Williams-Beuren syndrome (WBS) is a multisystem genetic disorder comprising of craniofacial, developmental, and cardiac malformations. The most common cardiac defects found are supravalvar aortic stenosis and peripheral pulmonary stenosis. However, WBS should be regarded as a general arteriopathy consisting of stenoses of medium- and large-sized arteries including the coronary arteries. Cardiac manifestations are often the initial reason for referral and careful cardiovascular assessment is important as coronary artery involvement confers a significant anesthetic risk and may be associated with ischemia and resultant ventricular dysfunction. Here we review the literature and describe a 2-year-old boy with evolving clinical features of WBS. He presented to our pediatric cardiology department for a routine assessment of peripheral pulmonary branch stenosis. A 12-lead electrocardiogram showed changes consistent with left ventricular ischemia and a two-dimensional echocardiogram showed reduced left ventricular function and mild supravalvar aortic stenosis. Subsequent cardiac catheterization diagnosed severe left main coronary artery stenosis. Deteriorating ventricular function secondary to acute ischemia postcatheterization required intensive care treatment from which the patient did not recover. This case report highlights the necessity of careful cardiology assessment without delay in patients with a suspicion of WBS. Isolated coronary stenosis though rare in WBS should be considered in the presence of ischemia or reduced ventricular function. Larger case series are needed to further characterize the correlation between WBS and acute coronary events.

Outcomes after primary transcatheter therapy in infants and young children with severe bilateral peripheral pulmonary artery stenosis.

BACKGROUND: Angioplasty and stent implantation have become accepted therapies for isolated peripheral pulmonary stenosis, and have been shown to increase vessel diameter and reduce right ventricular (RV) pressure acutely in patients with pulmonary artery (PA) stenosis. The purpose of this study was to assess long-term outcomes after primary transcatheter therapy for peripheral pulmonary stenosis. METHODS AND RESULTS: We studied 69 patients who underwent primary transcatheter intervention for severe isolated peripheral pulmonary stenosis at ≤ 5 years of age. Genetic/syndromic diagnoses included Williams syndrome (n=23), non-Williams familial arteriopathy (n=12), and Alagille syndrome (n=3). At the initial PA intervention, median RV:aortic pressure ratio decreased from 1.00 to 0.88 (median decrease, 0.18; P<0.001). Patients with a higher preintervention RV:aortic pressure ratio had a greater reduction (P<0.001). During follow-up (median, 8.5 years), 10 patients died, 5 from complications of PA catheterization (all before 1998). Thirteen patients underwent surgical PA intervention, most within 1 year and along with repair of supravalvar aortic stenosis. Freedom from any PA reintervention was 38 ± 6% at 1 year and 22 ± 6% at 5 years. The median RV:aortic pressure ratio decreased from 1.0 at baseline to 0.53 at the most recent catheterization (P<0.001), and 82% of patients with available clinical follow-up were asymptomatic. CONCLUSIONS: Transcatheter therapy for infants with severe peripheral pulmonary stenosis has become safer, regardless of genetic condition. Coupled with reintervention and surgical relief in selected cases, RV:aortic pressure ratios decrease substantially and most patients are asymptomatic at late follow-up.

Cardiac outcomes in adults with supravalvar aortic stenosis.

AIMS: Supravalvar aortic stenosis is a rare form of left ventricular outflow tract obstruction that is often progressive in childhood. Little data are available on outcomes in the adult population. Our aim was to define cardiac outcomes in adults with supravalvar aortic stenosis. METHODS AND RESULTS: This is a multicentre retrospective study of cardiac outcomes in adults (≥18 years) with supravalvar aortic stenosis. We examined: (i) adverse cardiac events (cardiovascular death, myocardial infarction, stroke, heart failure, sustained arrhythmias, and infective endocarditis) and (ii) the need for cardiac surgery in adulthood. One hundred and thirteen adults (median age at first visit 19 years; 55% with Williams-Beuren syndrome; 67% with surgical repair in childhood) were identified. Adults without Williams-Beuren syndrome had more severe supravalvar aortic stenosis and more often associated left ventricular outflow tract obstructions (P < 0.001). In contrast, mitral valve regurgitation was more common in patients with Williams-Beuren syndrome. Eighty-five per cent of adults (96/113) had serial follow-up information (median follow-up 6.0 years). Of these patients, 13% (12/96) had an adverse cardiac event and 13% (12/96) had cardiac operations (7 valve repair or replacements, 4 supravalvar aortic stenosis repairs, 1 other). Cardiac surgery was more common in adults without Williams-Beuren syndrome (P = 0.007). Progression of supravalvar aortic stenosis during adulthood was rare. CONCLUSION: Adults with supravalvar aortic stenosis remain at risk for cardiac complications and reoperations, while progression of supravalvar aortic stenosis in adulthood is rare. Valve surgery is the most common indication for cardiac surgery in adulthood.

Congenital supravalvular aortic stenosis: defining surgical and nonsurgical outcomes.

BACKGROUND: Supravalvular aortic stenosis is a rare stenotic lesion of the left ventricular outflow tract (LVOT). We characterized the natural history of the disease and the effect of surgical intervention. METHODS: Ninety-five children diagnosed with supravalvular aortic stenosis between 1976 and 2006 were studied. Procedural and repeated echocardiography reports were analyzed. RESULTS: Stenosis morphology (localized, 82%; diffuse, 18%) was independent of Williams syndrome (n = 59, 62%). The risk of open operation (n = 47) was 46% +/- 6% at 10 years. Increased risk of operation was associated with higher baseline LVOT peak gradients (p < 0.001), smaller minimum LVOT z scores (p < 0.01; thresholds > 50 mm Hg and < -3, respectively), and the absence of Williams syndrome (p = 0.01). Patients who did not undergo operations had gradually reducing LVOT gradients and enlarging ascending aorta z scores over time. Persistently small minimum LVOT z scores and higher gradients were associated with children who required an operation. Operation resulted in persistent relief of LVOT obstruction and accelerated increases in ascending aorta dimensions. Overall survival was 94% +/- 3% and 85% +/- 7% at 10 and 15 years and was similar for surgical and nonsurgical groups. No independent risk factors for death were identified on univariate or multivariable analysis. CONCLUSIONS: Many children-particularly those with Williams syndrome-show regression of stenosis without intervention. Children who undergo operation have high LVOT gradients and smaller LVOT z scores that do not improve over time. Surgical intervention alters the natural history: LVOT obstruction is relieved and does not recur, and ascending aortic dimensions progressively enlarge towards normal values.

[The Williams-Beuren syndrome: reconstruction of the thoracic aorta combining surgery and endovascular treatment]. / Syndrome de Williams-Beuren: reconstruction étendue de l'aorte thoracique combinant chirurgie et traitement percutané

The Williams-Beuren syndrome is the association of elf-like facies, mental retardation with cardiovascular anomalies, the most common of which is supravalvular aortic stenosis. This lesion may be focal or associated with hypoplasia of the distal aorta. The treatment is surgical and the role of interventional cardiological treatment is poorly defined. The authors report the case of a child with typical Williams-Beuren syndrome. An initial, very localised surgical aortic repair was performed at 3 months of age for a discrete supravalvular aortic stenosis. Two months later, a second operation was required for a new stenosis of the distal anastomosis associated with marked hypoplasia of the aortic arch. The progressive constitution of an isthmic coarctation led to the percutaneous implantation of a stent followed by two balloon dilatations. Only the first two endoluminal procedures successfully reduced the transisthmic pressure gradient. An antihypertensive treatment was given and regular echocardiography allows monitoring of the adaptation of the left ventricle.

Fatal aortic rupture complicating stent plasty in a case of aortoarteritis.

Endovascular stenting has emerged as an effective alternative for unsuccessful angioplasty of the aorta in aortoarteritis. This is a single case report of fatal aortic rupture following balloon angioplasty of post-patch aortoplasty restenosis in aortoarteritis. We report a fatal aortic rupture during angioplasty of the primarily stented stenotic segment of the aorta in a case of aortoarteritis.