Aortic valve replacement is indicated in all patients with symptomatic severe aortic stenosis.

True. The 5 year survival of symptomatic patients with angina is 50% and the 3 year survival for those presented with syncope is also 50%. Only 50% patients with exertional dyspnea will survive in two years if left untreated. Overall, the overall 3 year mortality for all symptomatic patients is around 75%. The near normal postoperative survival makes treatment strategy straightforward in this group of patients.

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Aortic valve replacement is also indicated in all patients with asymptomatic severe aortic stenosis.

False. The prognosis for asymptomatic patients is good. The overall risk of sudden death is around 2%. However, one needs to be aware of the pitfall of "asymptomatic" in patients with sedentary life style. Although strenuous exercise is contraindicated in patients with severe aortic stenosis, it has been advocated by some authorities that asymptomatic patients should undergo a cautious treadmill exercise test by cardiologists to evaluate their exercise tolerance and symptoms. In one study, it was found that 40% of these "asymptomatic" patients were found to be symptomatic during the treadmill test. This group of patients will probably benefit from aortic valve replacement.

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Aortic valve replacement in patients with severe aortic stenosis with good left ventricular function carries a good prognosis.

True. In good surgical center, aortic valve replacement in this group of patients offers excellent postoperative prognosis.

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Aortic valve replacement in patients with severe aortic stenosis with reduced left ventricular function is contraindicated.

False. The prognosis in this group of patients depends on the cause of the left ventricular dysfunction. If the decrease in left ventricular ejection fraction is due to afterload mismatch in relation to the aortic valve stenosis, the left ventricular performance would usually improve after the relieve of the obstruction. The gradient across the aortic valve by echocardiography is usually high in this group. However, the prognosis of surgery for those patients with a low gradient and a low left ventricular ejection fraction is much worse. In one study, the operative risk is 21% with a 4 year survival after surgery of 50% only. Careful evaluation by specialists in echocardiography using dobutamine or vasodilator stimulation may be useful to select patients with better prognosis for surgery.

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Aortic valve replacement for severe aortic stenosis is contraindicated in octogenarians.

False. In general, there should be no age limit for aortic valve replacement in elderly patients with severe aortic stenosis, provided that there are no significant co-morbid conditions. However, the risk and benefit ratio of surgery should be assessed individually in patients with other significant medical conditions such as renal or pulmonary impairment.

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References:

1. Blase A. Carabello. Evaluation and management of patients with aortic stenosis. Circulation. 2002;105:1746-50.
2. Otto CM et al. A prospective study of asymptomatic valvular stenosis: clinical, echocardiographic and exercise predictors of outcome. Circulation. 1997, 95:2262-70.
3. Connolly HM et al. Severe aortic stenosis with low transvalvular gradient and severe left ventricular dysfunction: result of aortic valve replacement in 52 patients. Circulation. 2000, 101:1940-46.

What is the most likely diagnosis?

The most likely diagnosis is ichthyosis vulgaris. Ichthyosis refers to a group of dermatoses due to disorder of epidermal cornification and is clinically characterised by a widespread, persistent, non-inflammatory scaling of the skin surface. Ichthyosis vulgaris is the commonest form of ichthyosis. In most cases, it is inherited in an autosomal dominant manner. Affected individual has symmetric skin scaling commonly affecting extremities sparing flexural areas. The affected skin feels dry and rough especially during winter time. Clinical features are not usually evident at birth but appeared during early childhood.

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What biochemical or molecular abnormality is thought to occur?

thought to occur? It is thought that a diminished or absent expression of profilaggrin in epidermis. Profilaggrin, a major component of keratohyalin granule, is a precursor of filaggrin. It is synthesized in the granular layer of the epidermis. Profilaggrin undergoes modifications to become filaggrin. Filaggrin plays an important role as water-binders in the upper stratum corneum.

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What are the differential diagnoses?

The differential diagnoses include other forms of ichthyosis such as acquired ichthyosis, X-linked ichthyosis and other ichthyosiform syndrome. Acquired ichthyosis usually appears for the first time in adulthood and is associated with systemic disease including malignancy.

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What associations have been reported with this condition?

Associations with ichthyosis vulgaris include keratosis pilaris, eczema, hay fever and asthma.

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What are the treatments?

Although ichthyosis vulgaris is a chronic disorder, many patients experience improvement with age. Liberal use of moisturisers such as aqueous cream, emulsifying ointment and urea cream help hydrating the skin and make the skin more supple. Alpha-hydroxy acids help disaggregation of corneocytes and improve skin hydration. Topical salicylic acid aids removal of scales while topical tretinoin reduces cohesiveness of epithelial cells and suppresses keratin synthesis.

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