Aortic stenosis: the spectrum of practice

Abstract

There is significant variation in practice patterns in managing congenital aortic valve stenosis. Review of medical literature reveals no significant information regarding the current practice methods in the treatment of a simple lesion such as aortic stenosis (AS). Therefore, this survey-based study was conducted in an attempt to better understand the uniformity or heterogeneity of practice in treating AS. A questionnaire was prepared to evaluate the style of management of AS. This survey was designed to assess the practice of follow-up visitations, type and frequency of investigative studies, pharmacological therapy, and exercise recommendations. Questions about therapeutic intervention included those of timing and type of intervention. Questionnaires were sent to all academic pediatric cardiology programs in the United States (48 program) and selected international programs from Europe, Asia, and Australasia (19 program). The total number of surveys sent out was 67, and the total number of respondents was 25 (37%), 15 (31%) from the United States and 9 (53%) from outside the United States. The definition of moderate AS varied among respondents. The range provided for mild AS was identified as that with a peak-to-peak pressure gradient of < 25-30 mmHg, peak instantaneous Doppler gradient of < 36-50 mmHg, or mean Doppler gradient of < 25-40 mmHg. On the other hand, severe AS was defined as that with a peak-to-peak gradient of > 50-60 mmHg, peak instantaneous Doppler gradient of > 64-80 mmHg, or mean Doppler gradient of > 45-64 mmHg. In assessing follow-up patterns, 84% of respondents recommended seeing patients with mild AS annually, the longest time of follow-up listed in the questionnaire, whereas 20% suggested follow-up every 6 months. There was no consensus among survey centers regarding follow-up of patients with moderate AS. For severe AS, 16% recommend immediate intervention, 16% arrange follow-up every 6 months, and 56 and 28% recommend follow-up in 3 and 1 month(s), respectively. In making the decision to proceed with biventricular versus univentricular repair in patients with AS in the neonatal period, many factors were considered. Ninety-two percent of respondents rely on mitral valve z score, 84% on aortic valve z score, 52% on left ventricle length, 48% on the presence of antegrade ascending aorta flow, and only 32% considered significant endocardial fibroelastosis as a factor. Rhodes score was used by 20% of respondents in decision making regarding the approach to management of this subset of AS. This study shows that there is consensus in the management of mild and severe forms of AS. As expected, disagreement is present in the definition, evaluation, and therapy of moderate aortic valve stenosis. There is a tendency for catheter intervention except in the presence of dysplastic aortic valve or moderate to severe aortic regurgitation. There is also disagreement regarding methods used to determine biventricular versus univentricular repair of a borderline hypoplastic left heart.