Right ventricle-pulmonary artery coupling in repaired tetralogy of Fallot with pulmonary regurgitation: Clinical implications

Abstract

Background: Right ventricle-pulmonary artery (RV-PA) coupling is a strong prognostic marker in several clinical settings, but few studies have focused on its role in repaired tetralogy of Fallot (rToF) with pulmonary regurgitation.

Aim: To assess whether differences exist in RV-PA coupling, estimated by echocardiography, between patients with rToF and pulmonary regurgitation with or without an indication for pulmonary valve replacement (PVR).

Methods: The study population included 40 patients with rToF, who were allocated to two groups: 20 with an indication for PVR (i-PVR group); and 20 without an indication for PVR (ni-PVR group). Forty healthy controls were also included. All subjects underwent echocardiography, and cardiac magnetic resonance (CMR) was available in 27/40 patients with rToF. RV-PA coupling was assessed by echocardiographic tricuspid annular plane systolic excursion/pulmonary arterial systolic pressure (TAPSE/PASP) and right ventricular stroke volume/right ventricular end-systolic volume (RVSV/RVESV) by CMR.

Results: TAPSE was similar in the i-PVR and ni-PVR groups (19.0±3.4 vs 18.8±2.7mm; P=0.97) whereas RV-PA coupling was significantly worse in the i-PVR group versus the ni-PVR group (TAPSE/PASP 0.8±0.3 vs 1.1±0.5mm/mmHg; P=0.001), and in the i-PVR group versus the control group (P=0.02); there was no difference between the ni-PVR and control groups (P=0.29). CMR data confirmed the echocardiography results, with a significant difference in RV-PA coupling between the i-PVR and ni-PVR groups (RVSV/RVESV 0.9±0.2 vs 1.2±0.3mL/min/mL; P=0.01).

Conclusions: This study demonstrates worse RV-PA coupling, despite normal RV systolic function, in patients with rToF with an indication for PVR. RV-PA coupling could be a sensitive marker of a progressive maladaptive RV response to long-standing volume overload in rToF before the onset of clinical symptoms and RV systolic dysfunction.

Keywords: Adult congenital heart disease; Cardiopathie congénitale des adultes; Echocardiography; Follow-up studies; Fuite valvulaire pulmonaire; Pulmonary valve regurgitation; Suivi à long terme; Tetralogy of Fallot; Tétralogie de Fallot; Échocardiographie.