Type 3 mucopolysaccharidosis: report of a case with severe mitral valve involvement

Outcome of Combined Mitral and Aortic Valve Replacement in Adults With Mucopolysaccharidosis (the Hurler Syndrome)

We describe 2 adult sisters with type I mucopolysaccharidosis (MPS) who underwent combined mitral and aortic valve replacement for mitral and aortic valve stenosis. One died early postoperatively and the other survived but had a repeat double-valve replacement 1 month after the first. We analyzed previously reported patients with MPS and valve replacement to learn of their outcomes. The study of our 2 patients and those previously reported suggests that valve replacement in patients with MPS should be viewed with extreme caution.

Metabolic cardiomyopathies

The energy needed by cardiac muscle to maintain proper function is supplied by adenosine Ariphosphate primarily (ATP) production through breakdown of fatty acids. Metabolic cardiomyopathies can be caused by disturbances in metabolism, for example diabetes mellitus, hypertrophy and heart failure or alcoholic cardiomyopathy. Deficiency in enzymes of the mitochondrial beta-oxidation show a varying degree of cardiac manifestation. Aberrations of mitochondrial DNA lead to a wide variety of cardiac disorders, without any obvious correlation between genotype and phenotype. A completely different pathogenetic model comprises cardiac manifestation of systemic metabolic diseases caused by deficiencies of various enzymes in a variety of metabolic pathways. Examples of these disorders are glycogen storage diseases (e.g. glycogenosis type II and III), lysosomal storage diseases (e.g. Niemann-Pick disease, Gaucher disease, I-cell disease, various types of mucopolysaccharidoses, GM1 gangliosidosis, galactosialidosis, carbohydrate-deficient glycoprotein syndromes and Sandhoff's disease). There are some systemic diseases which can also affect the heart, for example triosephosphate isomerase deficiency, hereditary haemochromatosis, CD 36 defect or propionic acidaemia.

Combined aortic and mitral valve replacement in an adult with mucopolysaccharidosis (Maroteaux-Lamy syndrome)

A 41-year-old man with aortic stenosis, mitral stenosis, and tricuspid regurgitation due to Maroteaux-Lamy syndrome underwent aortic and mitral valve replacement with tricuspid annuloplasty. The annular diameter of the aortic and mitral valves was extremely small. The valve prostheses were 19 mm in diameter in the aortic position and 25 mm in the mitral position. Histologically, the valves showed thickening and hyalinization of the collagen fibers, and the presence of foamy cells that contained a large quantity of pure acid mucopolysaccharide. On an echocardiographic examination performed 2 years after the surgery, the peak systolic gradient of the trans-aortic valve was 18 mmHg at rest, and 26 mmHg during exercise. Careful observation of the residual pressure gradient will be needed. The patient's present New York Heart Association (NYHA) status is grade I and he has returned to work.

Severe mitral insufficiency in mucopolysaccharidosis type III-B (Sanfilippo syndrome)

A 6-year-old girl with mucopolysaccharidosis (MPS) III-B (Sanfilippo syndrome) who developed severe mitral regurgitation and congestive heart failure requiring surgery (valvuloplasty) is reported. One year after surgery the patient remains well, with marked improvement in her physical activity, and without signs of heart failure. This is only the second report of severe mitral regurgitation in MPS III, and is the first report of a successful repair (valvuloplasty) of a dysplastic mitral valve in the MPS. Mitral valvuloplasty should be considered instead of valve replacement in any MPS patient with mitral valve regurgitation requiring surgery.

Mitral stenosis in the Maroteaux-Lamy syndrome: a treatable cause of dyspnoea

The case is reported of a young woman with the Maroteaux-Lamy syndrome (mucopolysaccharidosis type VI) who presented with rapidly progressive dyspnoea due to mitral stenosis. Mitral valve replacement was performed and the appearance of the valve was typical of mucopolysaccharide infiltration. Dyspnoea in patients with the Maroteaux-Lamy syndrome may be due primarily to cardiac valve involvement, and in this setting, valve surgery is safe and effective.

Valvular heart disease in four patients with Maroteaux-Lamy syndrome

BACKGROUND

Maroteaux-Lamy syndrome is a lysosomal storage disease of mucopolysaccharide metabolism (MPS type VI) that may involve the mitral and aortic valves. Affected patients have other skeletal and oropharyngeal malformations that complicate anesthetic and surgical management.

METHODS AND RESULTS

The present report describes the clinical, echocardiographic, and pathological findings in four patients with Maroteaux-Lamy syndrome. Two of three siblings underwent successful double-valve replacement for aortic and mitral valve stenoses. The third sibling, whose aortic and mitral valves were thick and fibrotic, died from septicemia after hip surgery. A fourth, unrelated patient also had successful double-valve replacement.

CONCLUSIONS

Our experience emphasizes the potential difficulties in preoperative assessment and surgical treatment as well as the unique problems related to airway management in patients with this syndrome.

Severe aortic stenosis in systemic lupus erythematosus and mucopolysaccharidosis type II (Hunter's syndrome)

Cardiac manifestations of the mucopolysaccharidoses often include valvular regurgitation, but stenotic lesions are quite rare. This report describes a 30-year-old man with mucopolysaccharidosis type II (Hunter's syndrome) and systemic lupus erythematosus who developed severe progressive aortic stenosis and died. Autopsy examination revealed evidence of various cardiac mucopolysaccharide disease including valvular leaflets thickened and distorted with fibrocalcific nodules. A brief review of previously reported valvular disease in Hunter's syndrome and other mucopolysaccharidoses is presented. This is also the first report of a patient with both systemic lupus and a mucopolysaccharidosis.

Echocardiographic abnormalities in the mucopolysaccharide storage diseases

The mucopolysaccharide storage diseases express themselves clinically with a wide variety of abnormalities, including growth and mental retardation, skeletal abnormalities, clouded corneas, nerve compression syndromes, upper airway obstruction and cardiovascular involvement, to name the most common. In most cases the cause of early death is cardiorespiratory failure secondary to cardiovascular involvement and upper airway obstruction. The findings of cardiac ultrasound examination in 29 children, adolescents and young adults are presented. In addition to the previously well-described abnormalities of the mitral and aortic valves in several types of mucopolysaccharide storage disease, we report patchy involvement in some cases, 3 instances of asymmetric septal hypertrophy not previously reported in mucopolysaccharide storage diseases, cardiac involvement in half of our patients with Sanfilippo syndrome and a lack of age-related severity of cardiac involvement even within the specific syndromes.