Risk factors for residual stenosis or re-stenosis
All study participants with follow-up echocardiography were classified into two groups. The first group (83.4%) included patients with a residual stenosis of <40 mmHg after initial PBPV. The other group (16.6%) included patients with residual stenosis after initial PBPV or re-stenosis of ≥40 mmHg during follow-up, and some of them underwent repeat intervention.
Univariate analysis results showed that the group with residual stenosis or re-stenosis had younger age, lower weight, and smaller body surface area at the time of initial PBPV. Moreover, patients in that group had small pulmonary annulus diameter at baseline, higher RV-PA PSEG, and increased RV/systemic pressure ratio (P <0.05). Critical PVS was statistically associated with residual stenosis or repeat intervention, while BAR had no significant association. (Table 6).
Multivariate analysis results showed that higher initial RV-PA PSEG (OR: 1.056, 95% CI: 1.035–1.078) was a significant independent risk factor for residual stenosis after initial PBPV or re-stenosis of ≥40 mmHg during follow-up (P <0.05) (Table 7).