Pulmonary vascular resistance index and mortality after paediatric heart transplant

Although some prior studies have provided evidence to question the historical belief that pulmonary vascular resistance index ⩾6 Wood Units×m2 should be a contraindication to heart transplantation in children, no national analyses specific to the modern area have addressed this question.

Data were analysed for paediatric heart transplant recipients from 1 January, 2002 to 1 September, 2012 (n=699). The relationship between pulmonary vascular resistance and all-cause 30-day mortality was evaluated using univariate and multivariate analyses.

The 30-day mortality included 10 patients (1.43%), which is lower than in the previous analyses. Receiver operating curve analysis of pulmonary vascular resistance index as a predictor of mortality yielded a cut-off value of 3.37 Wood Units×m2, but the area under the curve and specificity of this threshold was weaker than in previous analyses. Whereas pulmonary vascular resistance index treated as a dichotomised variable was a significant predictor of mortality in univariate (odds ratio 4.92, 95% confidence interval 1.04-23.33, p=0.045) and multivariate (odds ratio 5.26, 95% confidence interval 1.07-25.80, p=0.041) analyses, pulmonary vascular resistance index treated as a continuous variable was not a significant predictor of mortality in univariate (p=0.12) or multivariate (p=0.11) analyses.

The relationship between pulmonary vascular resistance and post-heart transplant mortality in children is less convincing in this analysis of a comprehensive, contemporary database than in previous series. This suggests the possibility that modern improvements in the management of post-transplant right ventricular dysfunction have mitigated the contribution of pulmonary hypertension to early mortality.