Pulmonary valve replacement in chronic pulmonary regurgitation in adults with congenital heart disease: impact of preoperative QRS-duration and NT-proBNP levels on postoperative right ventricular function.

BACKGROUND: Chronic severe pulmonary regurgitation (PR) causes progressive right ventricular (RV) dysfunction and heart failure. Parameters defining the optimal time point for surgery of chronic PR are lacking. The present study prospectively evaluated the impact of preoperative clinical parameters, cardiorespiratory function, QRS duration and NT-proBNP levels on post operative RV function and volumes assessed by cardiac magnetic resonance imaging (CMR) in patients with chronic severe PR undergoing pulmonary valve replacement.

METHODS AND RESULTS: CMR was performed pre- and 6 months postoperatively in 27 patients (23.6 ± 2.9 years, 15 women) with severe PR. Postoperatively, RV endsystolic (RVESVI) and enddiastolic volume indices (RVEDVI) decreased significantly (RVESVI pre 78.2 ± 20.4 ml/m² BSA vs. RVESVI post 52.2 ± 16.8 ml/m²BSA, p<0.001; RVEDVI pre 150.7 ± 27.7 ml/m²BSA vs. RVEDVI post 105.7 ± 26.7 ml/m²BSA; p<0,001). With increasing preoperative QRS-duration, postoperative RVEF decreased significantly (r=-0.57; p<0.005). Preoperative QRS-duration smaller than the median (156 ms) predicted an improved RVEF compared to QRS-duration≥ 156 ms (54.9% vs 46.8%, p<0.05). Multivariate analysis identified preoperative QRS duration as an independent predictor of postoperative RVEF (p<0.005). NT-proBNP levels correlated with changes in RVEDI (r=0.58 p<0,005) and RVESVI (r=0.63; p<0,0001). Multivariate analysis identified NT-proBNP levels prior to PVR as an independent predictor of volume changes (p<0.05).

CONCLUSION: Valve replacement in severe pulmonary regurgitation causes significant reduction of RV volumes. Both, preoperative NT-proBNP level elevation and QRS prolongation indicate patients with poorer outcome regarding RV function and volumes.