Immediate- and medium-term effects of balloon pulmonary valvuloplasty in infants with critical pulmonary stenoses during the first year of life: A prospective single center study.

BACKGROUND

Balloon pulmonary valvuloplasty (BPV) represents the standard of management for all patients with severe pulmonary stenosis (PS) irrespective of their age. Nevertheless neonates and infants with critical PS represent a high-risk group that needs to be studied.

METHODS

The study population included 72 infants with severe congenital valvular PS and four infants with imperforate pulmonary valve (PV) who were subjected to detailed history taking, full clinical examination, resting 12-lead ECG, Chest roentgenogram and transthoracic echocardiography. BPV was attempted in all infants with a peak-to-peak gradient across the PV of 50 mmHg or greater at catheterization-laboratory. Full echocardiographic evaluation was done 24 hours after the procedure as well as 3 and 6 months later.

RESULTS

Seventy-six infants with severe PS or imperforate PV with a mean age of 5.63 ± 2.99 months were subjected to BPV with or without wire perforation. Immediately after the procedure patients had a significant reduction of the right ventricular systolic pressure (RVSP) (104.69 ± 24.98 mm Hg Vs 43.6 ± 13 mm Hg, p < 0.001) and RV-PA systolic pressure gradient (PG) (82.5 ± 23.76 mm Hg Vs 17.35 ± 8.96 mm Hg, p < 0.001). The immediate success rate defined as the drop in the RVSP to less than or equal to 50% of the baseline measurement was achieved in 85% of the cases. There was a progressive drop in the PG across the PV by Doppler echocardiogram throughout a follow-up period of six months from a mean of 93.3 ± 28.2 mm Hg to a mean of 17.4 ± 10.42 mm Hg (p < 0.001). There was a significant increase of the mean PV annulus diameter after balloon dilatation (p < 0.001). There was also a highly significant inverse correlation between the growth of the pulmonary annulus and the annular size at the baseline before dilatation (r = -0.74, p value <0.001). The incidence of PR significantly increased immediately after BPV to 64% followed by a progressive decline over a 6 months period of follow-up to 20%. There was a significant decrease in the incidence of tricuspid regurgitation (TR) over the same period of follow-up (from 55.6% at baseline to less than 20% at follow-up).

CONCLUSION

BPV is safe and effective to relieve critical PS in infants during the first year of life. The balloon promotes advantageous changes in both, pulmonary annulus and PG across the RVOT. In addition, the Doppler gradient observations during the follow-up support the expectation that BPV is a "curative" therapy.