Risk factors for ≥moderate pulmonary regurgitation
Among the 193 patients who had follow-up echocardiography results, PR occurred in 186 patients, including 110 with mild PR and 76 with moderate to severe PR.
Univariate analysis results demonstrated that patients with ≥moderate PR during follow-up had a younger age, shorter height, lower weight, and smaller body surface area at the time of initial PBPV (P <0.05). Moreover, patients in this group were inclined to have a smaller pulmonary annulus diameter at baseline, higher RV-PA PSEG, and increased RV/systemic pressure ratio (P <0.05). Severe PVS will more likely result in ≥moderate PR (P <0.05), while no significant difference was observed between the balloon and annulus ratio (1.20 (IQR: 1.20–1.25) and 1.24 (IQR: 1.20–1.30), P >0.05). Of the 76 patients with ≥moderate PR, 11 (14.5%) presented with pulmonary artery valve dysplasia or abnormal valve morphology, of whom 7 had pulmonary valves with two lobes and 4 had pulmonary valves with dysplasia. (Table 4).
Multivariate analysis results illustrated that low weight (OR: 0.668, 95% CI: 0.518–0.862) and higher initial RV-PA PSEG (OR: 1.017, 95% CI: 1.003–1.031) were independent risk factors for ≥moderate PR (P <0.05) (Table 5).
Residual stenosis and re-stenosis during follow-up
Among 193 patients with follow-up data, 32 (16.6%) had residual stenosis following initial PBPV or re-stenosis during follow-up, of whom 9 required re-intervention. The other 9 children underwent re-intervention including 7 who underwent repeat PBPV at an average of 2.12 years (range: 6 months to 5 years) after initial PBPV, and 2 children underwent surgical intervention at 6 months and 1.33 years after initial PBPV (Figure 2).