Second natural history study of congenital heart defects. Results of treatment of patients with pulmonary valvar stenosis.

Abstract

From 1958 to 1969, 592 patients (mostly children) with pulmonary stenosis were admitted to the First Natural History Study of Congenital Heart Defects (NHS-1) after cardiac catheterization. Most with gradients < 50 mm Hg were managed medically; most with gradients > or = 80 mm Hg had pulmonary valvotomy. Among these with gradients of 50-79 mm Hg, some were managed medically, and some were managed surgically. Most had a second cardiac catheterization at conclusion of NHS-1. More than 15 years had elapsed since NHS-1, and most of the cohort are adults. This report (Second Natural History Study) addresses the long-term results of medical and surgical management. Of the original cohort of 592 patients, 580 were alive at completion of NHS-1. New data were obtained on 464 (78.4%) of the original cohort. Probability of 25-year survival was 95.7%. Probability of survival was less (80%) in a subgroup of patients entering NHS-1 > 12 years old with cardiomegaly. Less than 20% of patients managed medically during NHS-1 subsequently required a valvotomy. Only 4% of operated patients required a second operation. Bacterial endocarditis occurred rarely. Ninety-seven percent were in New York Heart Association class I. There was a small but higher-than-normal prevalence of serious arrhythmias. Most patients, whether medically or surgically managed, had low Doppler maximum gradients. Final clinical status was excellent or good in 83%. Probability of survival is similar to that of the general population, and the vast majority of patients are asymptomatic. If valvotomy or valvuloplasty is required in a child, reoperation is rarely necessary. Patients with gradients < 25 mm Hg do not experience an increase in gradient. Patients with a gradient > or = 50 mm Hg should have valvotomy or valvuloplasty. Choice of management of patients with gradients of 40-49 mm Hg remains debatable.