Pulmonary vascular remodelling after heart transplantation in patients with cavopulmonary connection

OBJECTIVES: Pulmonary vascular resistance (PVR) after heart transplantation (HT) is an important predictor of postoperative outcomes. We hypothesize that PVR and pulmonary capillary wedge pressure (PCWP) will exhibit favourable pulmonary vascular remodelling in patients with failing cavopulmonary connection (CPC) after HT. METHODS: Retrospective analysis of patients with superior CPC (SCPC) and total CPC (TCPC) who have undergone HT was performed. Patient data, including age, underlying congenital heart defect, timing of CPC surgery and timing of HT, were reviewed. Right heart catheterization data, including PCWP (mmHg) and PVR indexed (PVRi, Woods Units) from preoperative, at 1 month, 6 months and 12 months after HT, were collected. Paired data were analysed using Student's t-test. RESULTS: Among 21 patients with failing CPC who underwent HT, 10 had SCPC and 11 had TCPC. Average age at HT was 13.3 +/- 8 years. Average time after CPC to HT was 8.5 +/- 6.2 years. PVRi was noted to trend down over time after HT (PVRi pre-HT versus 6 months after HT, 2.75 vs 2.06, P = 0.06 and pre-HT versus 12 months after HT, 2.79 vs 2.27, P = 0.09). There was a statistically significant decrease in PCWP at 6 months (pre-HT versus 6 months after HT, 12.6 vs 10.8, P = 0.01) and 12 months (pre-HT versus 12 months after HT, 12.9 vs 10.1, P = 0.01) after HT. CONCLUSIONS: Pulmonary vascular changes occur gradually after HT in patients with CPC similar to those shown after HT in patients with cardiomyopathy. However, larger studies are needed to investigate correlation between outcomes and the presence or absence of pulmonary vascular changes after HT in CPC patients.