Natural history of mild congenital aortic stenosis elucidated by serial hemodynamic studies

There is a paucity of information on the natural history of congenital aortic stenosis. This report analyzes serial clinical and hemodynamic data obtained prospectively from 15 initially asymptomatic children with congenital aortic stenosis. The first hemodynamic study was performed at an average age of 8.5, and the follow-up study at an average age of 15.1 years. The cardiac index was consistently normal in all patients. The peak pressure difference across the left ventricular outflow tract increased between initial and final studies in 12 of the 15 patients. The gradient ranged from 5 to 45 mm Hg (mean 26) during the first study, and from 15 to 81 mm Hg (mean 44) at follow-up examination. Severe obstruction (gradient > 50 mm Hg, normal cardiac output; or calculated aortic valve orifice <0.7 cm²/m² body surface area) developed in 6 of the 15 patients. In general, there was a poor correlation between the presence of symptoms, the electrocardiographic and radiographic findings and the severity of obstruction in any individual patient. The results of this study indicate that congenital aortic stenosis may be a progressive disorder, even early in life, in a significant fraction of patients presenting initially with mild obstruction.     

Natural history of moderate aortic stenosis

The natural history of severe, symptomatic aortic stenosis has been well documented. However, the natural history of moderate aortic stenosis remains poorly understood. Therefore, a group of 66 patients was identified who had a diagnosis of moderate aortic stenosis at the time of cardiac catheterization (aortic valve area 0.7 to 1.2 cm2) and who did not have surgical therapy during the 1st 180 days after cardiac catheterization. During a mean follow-up period of 35 months, 14 patients died of causes attributed to aortic stenosis and 21 underwent aortic valve replacement. The estimated probability for remaining free of any complication of aortic stenosis at the end of the first 4 years was 59%. Symptomatic patients with decreased ejection fraction or hemodynamic evidence of left ventricular decompensation were at greater risk for these complications. It is concluded that patients with moderate aortic stenosis are at significant risk for the development of complications.     

Natural history of supravalvular aortic stenosis and pulmonary artery stenosis

Data from 35 patients with supravalvular aortic stenosis or pulmonary artery stenosis, or both, undergoing cardiac catheterization between 1973 and 1989 were analyzed retrospectively. Twenty-seven patients had supravalvular aortic stenosis: 11 required surgery after the first investigation and 8 (80%) of 10 others undergoing serial investigation showed an increase in the left ventricle to aorta pressure gradient. Angiographic measurements showed that the increase in the aortic pressure gradient was related to failure of normal growth of the ascending aorta lumen. Nineteen patients had pulmonary artery stenosis, with a right ventricular pressure greater than 33 mm Hg. At restudy, right ventricular pressure had decreased in 9 (82%) of 11 patients. This decrease in right ventricular pressure was associated with an increase in the systolic distensibility of the proximal pulmonary arteries, although there was no increase in the diastolic diameters. One patient had a rapid early increase in right ventricular pressure and no pulmonary artery growth. In two patients, multiple peripheral pulmonary artery stenoses became evident with time and produced persistent right ventricular hypertension. Supravalvular aortic stenosis is usually a progressive lesion, with an increase in left ventricular outflow tract pressure gradient related to poor growth of the ascending aorta. Pulmonary artery stenosis usually improves and only rarely limits prognosis.     

Balloon dilatation of the aortic valve for congenital aortic stenosis in childhood

Balloon dilatation of the aortic valve was attempted in 34 consecutive children aged 16 months to 17 years (median 7 years), weight range 9-60 (median 22) kg. Previous surgical valvotomy had been performed in two patients (twice in one of them). The valve was not crossed in one patient. In the remaining 33 patients the pressure difference between the left ventricle and the ascending aorta during systole was reduced from 71 (30) to 28 (19) mm Hg. In 24 patients recatheterisation 2-19 (mean 9) months later showed gradients that were similar to those immediately after balloon dilatation (35 (20) v 31 (20) mm Hg). The two patients with the highest residual gradients immediately after balloon dilatation showed a spontaneous reduction in gradient at repeat catheterisation, whereas the patient who had twice had previous surgical valvotomy showed an increase in gradient from 37 to 99 mm Hg over nine months and required aortic root replacement. Balloon dilatation was repeated in two patients and this caused a further reduction in gradient. New aortic regurgitation occurred in nine (27%) patients (grade I, 8; grade II, 1) and aortic regurgitation was exacerbated (grade I to II) in two of the nine with pre-existing aortic regurgitation. External iliac artery avulsion occurred in one (3%) patient and two (6%) required intravenous streptokinase because the femoral artery became occluded. There were no other complications. Open valvotomy was performed in the child in whom the valve was not crossed, but no other child required aortic valve operation. Balloon dilatation of the aortic valve gave reasonable short term palliation and was well tolerated. It is an alternative to surgical valvotomy for initial palliation of congenital aortic stenosis in many children.     

Serial hemodynamic observations in congenital valvular and subvalvular aortic stenosis.

The present study is an attempt to clarify the natural history of valvular and subvalvular aortic stenosis. Twenty-eight patients with isolated and uncomplicated congenital aortic stenosis who had serial hemodynamic evaluation without intervening surgery were selected. They were divided into three groups according to the severity of the peak systolic pressure gradient. At the initial study, 16 of the 28 patients had mild stenosis, 11 patients had moderate stenosis, and one patient had severe stenosis. On restudy, there were only 9 patients with mild stenosis, 12 patients with moderate stenosis, and 7 patients with severe stenosis. The cardiac index and right-sided hemodynamics were normal. The electrocardiographic and radiographic findings in relation to severity of the lesion were also observed. It is our feeling that both valvular and subvalvular aortic stenosis are progressive lesions, the subvalvular being more so than the valvular.     

Balloon dilatation of the aortic valve for congenital aortic stenosis in childhood.

Balloon dilatation of the aortic valve was attempted in 34 consecutive children aged 16 months to 17 years (median 7 years), weight range 9-60 (median 22) kg. Previous surgical valvotomy had been performed in two patients (twice in one of them). The valve was not crossed in one patient. In the remaining 33 patients the pressure difference between the left ventricle and the ascending aorta during systole was reduced from 71 (30) to 28 (19) mm Hg. In 24 patients recatheterisation 2-19 (mean 9) months later showed gradients that were similar to those immediately after balloon dilatation (35 (20) v 31 (20) mm Hg). The two patients with the highest residual gradients immediately after balloon dilatation showed a spontaneous reduction in gradient at repeat catheterisation, whereas the patient who had twice had previous surgical valvotomy showed an increase in gradient from 37 to 99 mm Hg over nine months and required aortic root replacement. Balloon dilatation was repeated in two patients and this caused a further reduction in gradient. New aortic regurgitation occurred in nine (27%) patients (grade I, 8; grade II, 1) and aortic regurgitation was exacerbated (grade I to II) in two of the nine with pre-existing aortic regurgitation. External iliac artery avulsion occurred in one (3%) patient and two (6%) required intravenous streptokinase because the femoral artery became occluded. There were no other complications. Open valvotomy was performed in the child in whom the valve was not crossed, but no other child required aortic valve operation. Balloon dilatation of the aortic valve gave reasonable short term palliation and was well tolerated. It is an alternative to surgical valvotomy for initial palliation of congenital aortic stenosis in many children.     

Natural history and outcome of aortic stenosis diagnosed prenatally.

OBJECTIVE: To document the growth of the left heart structures and outcome of fetuses with aortic stenosis. DESIGN: Retrospective echocardiographic and clinical study. SETTING: Tertiary centre for fetal cardiology. PATIENTS: 27 consecutive fetuses with aortic stenosis. MAIN OUTCOME MEASURES: Survival of affected fetuses. Measurement of left ventricular end diastolic volume (LVEDV), aortic root diameter, and ejection fraction. RESULTS: Before 25 weeks' gestation, the LVEDV was normal or increased in all cases. In six of eight fetuses studied sequentially, the LVEDV fell across normal centiles. Initial ejection fraction was reduced in 23 fetuses (88%). Before 28 weeks' gestation, the aortic root was normal in all but one case, but after 29 weeks, 11 of 13 fetuses had values below the 50th centile. In two fetuses prenatal aortic valvoplasty was attempted, 10 babies had postnatal interventions, and there were six survivors. Biventricular repair was attempted in eight cases, of whom five survived. A first stage Norwood operation was performed in three babies, of whom one survived. The four fetuses with the highest aortic root z scores had successful biventricular repair. The two fetuses with initially normal ejection fractions survived. Successful biventricular repair was achieved even where the LVEDV was below the 5th centile. CONCLUSIONS: In aortic stenosis diagnosed prenatally, failure of growth of the left ventricle and aortic root often occurs. The outcome of affected fetuses is better than previously reported. Prenatal echocardiography may assist selection of suitable candidates for biventricular versus Norwood repair.     

Valvuloplasty of congenital aortic stenosis

While percutaneous transluminal valvuloplasty has largely replaced open commissurotomy for congenital pulmonary valve stenosis, the experience with valvuloplasty for congenital aortic stenosis is limited. Between August, 1984 and June, 1987, a total of 27 valvuloplasties were carried out in 25 patients with congenital aortic stenosis; nine infants and 16 patients ranging in age from four to 25 years (mean age 13 +/- 6 years). The indication for valvuloplasty was established on the basis of congestive heart failure or severe stenosis in infants and in the presence of a pressure gradient in excess of 60 mm Hg in those older than one year of age. In eight infants, valvuloplasty reduced the transvalvular pressure gradient from 73 +/- 5 to 36 +/- 9 mm Hg (p less than 0.01; Figure 1). In the 16 patients older than one year of age, the pressure gradient was reduced from 93 +/- 25 to 49 +/- 15 mm Hg (p less than 0.01; Figure 2). The size of the balloon chosen was based on two-dimensional echocardiographic measurements of the aortic ring diameter from inner edge to inner edge. In infants, coronary artery dilating catheters and balloon catheters with an inflated diameter of 4.2 to 8 mm were employed; in children, the balloon diameter selected was 1 to 3 mm less than that of the valve ring diameter, in 15 cases a single-balloon catheter and in one a trefoil catheter. After puncture of the femoral artery and retrograde advancement of a guide-wire into the left ventricle, the balloon catheter was positioned via the guide-wire across the aortic valve.(ABSTRACT TRUNCATED AT 250 WORDS)     

Percutaneous aortic valvoplasty in congenital aortic valvar stenosis

OBJECTIVE: To evaluate immediate and midterm results with percutaneous aortic valvoplasty. Material and METHODS: We reviewed the records of 141 patients undergoing percutaneous aortic valvopasty over a period of 13 years. RESULTS: The patients were aged from 2 months to 40 years, with a mean of 10.9 +/- 9.9 years. Of the total, 90 (63+/%) were male. The initial systolic peak-to-peak gradient decreased from 163 +/- 52 mmHg to 32 +/- 18 mmHg (p < 0.01) after valvoplasty in all 141 patients, while the proportional reduction ranged from 0 to 100%, with a mean of 72 +/- 27%. The index of the size of the balloon to the diameter of the valvar orifice was 0.88 +/- 0.19 in 128 patients. The follow-up ranged from 6 to 168 months, with a mean 51 +/- 48 months in 70 patients. A significant difference was found in those failing after dilation when the initial evaluation was compared to the final evaluation of patients with follow-up. In those failing, the number of patients rose from 12 (17%) to 21 (30%) (p < 0.01). In contrast, in those in whom we achieved success, there was not such a great difference between the initial and final evaluation: 58 (83%) versus 49 (70%) (p < 0.1). The actuarial freedom curve of patients not needing new percutaneous aortic valvoplasty or surgery, by 182 months, was at 87% and 82% respectively. CONCLUSION: We have reviewed the largest series of patients in Latin-America reported thus far after undergoing percutaneous aortic valvoplasty, concentrating on mid term follow-up and limitations. New prospective and multicentric studies are needed from our region.