Does mild pulmonary stenosis progress during childhood? A study of its natural course

Background: Increase in the gradient in congenital pulmonary valvular stenosis during follow-up is a subject of controversy and could determine the need for treatment in pediatric patients. Hypothesis: It is postulated that a gradient <50 mmHg shows a stable or decreasing tendency at follow-up for congenital pulmonary valvular stenosis. Methods: Thirty-five patients with pulmonary stenosis, isolated and not treated, were followed for 7 years (interquartilic rank 5.7 years) at 1.5-year intervals. Clinical and complementary tests (electrocardiogram, x-ray, Doppler echocardiogram) were undertaken. The gradient was measured by Doppler and by using the clinical formula derived from the New England Study (Ellison). The changes observed from the initial to the final consultation were analyzed by means of the Student's t-test, paired Wilcoxon, and Pearson correlation coefficient. Results: No significant changes were noted on symptoms or physical examination. Signs of cardiac enlargement diminished on both ECG (R wave in V-1, p < 0.0001) and x-ray (cardiothoracic ratio, p < 0.0007), with a decreasing gradient trend during the follow-up period (p < 0.026) as well. Conclusions: The gradient trend confirms the stable nature of mild pulmonary stenosis. In our study, we found that patients aged > 6 months, whose gradients were below 40 mmHg at the time of diagnosis, remained stable and required no treatment. Furthermore, the follow-up control and clinical management of these patients may then be performed at intervals of 2 years or more.