Left Ventricular Outflow Tract Obstruction in Aortic Arch Anomalies With Ventricular Septal Defect.

BACKGROUND

The predictors of left ventricular outflow tract obstruction (LVOTO) after the repair of coarctation of the aorta or interruption of the aortic arch (CoA/IAA) with ventricular septal defect have been investigated. However, the predictors remain controversial.

METHODS

We performed primary repair of CoA/IAA with ventricular septal defect for 75 patients from 1996 to 2005. Four of the 75 patients died within 5 years after primary repair without relation to LVOTO. The morphology of the aortic valve of 71 survivors was bicuspid in 23 patients and tricuspid in 48 patients. The mean follow-up was 9.2 ± 2.6 years after primary repair.

RESULTS

There were 12 patients who showed LVOTO of 3.0 m/s or greater after primary repair. All of the 6 bicuspid patients demonstrated valvular aortic stenosis, and all of the 6 tricuspid patients showed discrete subvalvular LVOTO. In 5 of the 6 tricuspid patients, the aortic annular z-score before primary repair was -3.0 or less. A bicuspid aortic valve (p = 0.016) and the aortic annular z-score of -3.0 or less (p = 0.019) were significant risk factors for LVOTO after primary repair. At 10 years after primary repair, 82.6% and 95.6% of the bicuspid and tricuspid patients, respectively, were free from reoperation (p = 0.015).

CONCLUSIONS

The presence of a bicuspid aortic valve and an aortic valve annular z-score of -3.0 or less before primary repair are risk factors for LVOTO, and stenotic bicuspid valves and discrete subvalvular LVOTO are the main causes of LVOTO after primary repair of CoA/IAA with ventricular septal defect. The bicuspid patients more frequently required reoperation than the tricuspid patients.