The natural history of congenital subaortic stenosis.

BACKGROUND

Congenital subaortic stenosis (SAS) has a high recurrence rate after surgical correction. Aortic valve disease frequently coexists with SAS, being its occurrence and progression unpredictable. We aimed to assess predictors of SAS recurrence and aortic valve disease occurrence and progression.

METHODS

Retrospective analysis of 51 patients with SAS followed in a congenital heart disease clinic of a tertiary care hospital from July 1982 to October 2009.

RESULTS

The mean age at SAS diagnosis was 15 years and 28 patients (54.9%) were men. Aortic regurgitation was present in 23 (45.1%) patients. Thirty-four (66.7%) patients were submitted to SAS surgical correction, six (17.6%) of them also with aortic valve repair/replacement. Eighteen (52.9%) patients had SAS recurrence and eight patients (23.5%) underwent reoperation. A shorter time from diagnosis to surgery (odds ratio [OR] 0.98 [95% confidence interval, CI 0.96-1.00]; P= 0.04) and a left ventricular outflow tract (LVOT) peak pressure gradient at diagnosis > 50 mm Hg (OR 2.63 [95% CI 1.52-4.53]; P= 0.05) were independent predictors of SAS recurrence. At the end of follow-up, 37 patients (72.5%) had some form of aortic valve disease and 24 patients (47.1%) had progression for or of the aortic valve disease. Higher LVOT peak pressure gradient at diagnosis (OR 1.10 [95% CI 1.01-1.21]; P= 0.05) and higher left ventricular mass (OR 1.04 [95% CI 1.01-1.07]; P= 0.014) were independent predictors of aortic valve disease. Predictors of aortic valve disease progression were not found.

CONCLUSIONS

SAS recurrence occurred mainly in patients operated sooner and with a high LVOT peak pressure gradients, suggesting a more severe form of disease. A more turbulent systolic jet at LVOT was probably one of the main causes of aortic valve damage. Aortic valve disease progression occurred independently of surgery and SAS recurrence. All LVOT morphological anomalies should be detected and corrected in order to prevent SAS recurrence and aortic valve disease.