Predictors of successful pulmonary balloon valvuloplasty: 10-year experience.

At our institution, 55 infants and children (ages 0.3-21 yr, median 2.5 yr) underwent pulmonary balloon valvuloplasty between August 1983 and May 1993. Systolic pressure gradients fell acutely following balloon valvuloplasty from 63.5 +/- 24.8 mmHg (mean +/- standard deviation) to 26.7 +/- 12.9 mmHg (P < 0.001) with a decrease in systolic pressure ratio from 0.81 +/- 0.25 to 0.42 +/- 0.12 (P < 0.0001). Fifty of the 55 patients had long-term echocardiographic evaluation performed > 2 yr following balloon valvuloplasty. Thirty-four of the 50 patients (Group A; 68%) were classified as having successful (residual systolic gradients < 25 mmHg, ventricular systolic pressure ratios < 0.6) long-term outcomes. Their peak systolic gradients fell acutely from 58.8 +/- 16.6 mmHg to 22.7 +/- 11.2 mmHg (P < 0.001). At 4.6 +/- 2.3 yr postvalvuloplasty, peak instantaneous pressure gradients were 17.8 +/- 5.7 mmHg (P = ns vs. acute postvalvuloplasty). Fifteen of the 50 patients (Group B; 30%) had unsuccessful (residual systolic gradients > or = 25 mmHg and/or ventricular systolic pressure ratios > 0.6) long-term outcomes. Their peak instantaneous systolic gradients fell acutely from 76.5 +/- 33.1 mmHg to 36.6 +/- 11.4 mmHg (P < 0.05). At 3.8 +/- 1.7 yr postvalvuloplasty, peak instantaneous pressure gradients were 35.1 +/- 9.1 mmHg (P = ns vs. acute postvalvuloplasty). One 3-yr-old patient (Group C, 2%) required repeat balloon valvuloplasty on two separate occasions for recurrent stenosis. There was no significant prevalvuloplasty difference between Groups A and B with regard to age, weight, or Z scores of the pulmonary annuli or balloon/annulus ratio; however, patients in Group A had significantly lower prevalvuloplasty gradients and lower systolic pressure ratios than patients in Group B. Total systolic gradient reduction between patients with successful and unsuccessful outcomes was not significantly different (Group A: 36.1 +/- 16.6 mmHg; Group B: 41 +/- 22.3 mmHg). At long-term follow-up, patients in Group A had fewer symptoms and a significantly lower rate of electrocardiographic right ventricular hypertrophy than Group B patients. Successful outcomes defined by our criteria following balloon valvuloplasty were achieved in 68% of patients with greatest long-term success in patients with prevalvuloplasty systolic gradients < 60 mmHg and systolic pressure ratios < 0.8. Intervention at lesser systolic gradients (40-60 mmHg) appears indicated to achieve lower long-term gradients and fewer symptoms as total systolic gradient reduction by this technique is limited.