Timing of Pulmonary Valve Replacement: How Much Can the Right Ventricle Dilate Before it Looses Its Remodeling Potential?

Congenital heart disease patients that develop secondary pulmonary regurgitation require a pulmonary valve replacement (PVR) in their follow-up. The indications for PVR in asymptomatic patients are debated. Most guidelines consider a RV end-diastolic volume (RVEDV) over 150 ml/m(2) as an indication for PVR. We analyzed clinical, echocardiographic and MRI variables of patients that underwent a surgical PVR between September 2006 and February 2013. The included patients were asymptomatic, without pulmonary stenosis and with both pre- and post-surgery MRI. Thirty-five patients (74.3 % males) were included. Mean age at PVR was 25.8 years (SD = 7.18), and weight was 64.5 Kg (SD = 12.03). The main diagnosis was tetralogy of Fallot (n = 28), pulmonary atresia (n = 2), primary pulmonary regurgitation (n = 2) and pulmonary regurgitation after percutaneous treatment (n = 2). The maximal RVEDV pre-PVR was 267 ml/m(2), and right ventricular end-systolic volume (RVESV) was 183 ml/m(2). RV size and function were established by MRI: Pre-PVR Post-PVR p RVEDV (ml/m(2)) 162 (SD = 39.1) 94 (SD = 23.6) <0.001 RVESV (ml/m(2)) 87 (SD = 28.9) 44 (SD = 15.7) <0.001 RVEF 44.8 % (SD = 8.17) 52 % (SD = 9.9) <0.001 Patients with a RVEDV under 170 ml/m(2) combined with a RVESV under 90 ml/m(2) had a favorable RV remodeling, defined as RVEDV under 110 ml/m(2) (sensitivity 87.5 %), RVESV under 55 ml/m(2) (sensitivity 100 %) and RVEF over 50 % (sensitivity 100 %). When deciding the optimal PVR timing in asymptomatic patients, both RVEDV and RVESV should be considered. Our results suggest that higher volumes than used in the clinical practice can achieve a good remodeling. Therefore, PVR could be performed later in the follow-up reducing the number of cardiac interventions.