International Practice Heterogeneity in Pediatric Left Heart Disease Related Pulmonary Hypertension

Abstract

<h3>Purpose</h3> Elevated pulmonary vascular resistance (PVR) in left heart disease contributes to poor outcomes after pediatric heart transplant (HT). Medical management of high PVR pre-HT is controversial and insufficiently described. <h3>Methods</h3> We sought to characterize practice internationally by surveying physicians at pediatric HT centers via ISHLT and other networks. <h3>Results</h3> We received 49 complete responses from 39 centers in 16 countries. The majority of respondents were pediatric cardiologists (90%) practicing at centers offering pediatric heart (86%) and lung (55%) transplant. In patients with left heart failure and elevated baseline PVR, most centers (88%) perform acute vasoreactivity testing (AVT) during catheterization. Only half (51%) have established a maximum PVR for transplant eligibility, with most citing 6 WU*m² or lower (80%) [range 4-8 WU], obtained after AVT (84%). The highest post-AVT PVR ever listed ranged from 4-14.4, median 6 WU*m² (Figure). Pre-HT, phosphodiesterase 5 inhibitors are most frequently used to treat high PVR (65%); however, 31% never use pulmonary vasodilators. Implantation of a left ventricular assist device (LVAD) increases likelihood of medical therapy for PVR, though timing of initiation (pre- vs post-HT) and duration of therapy varies. Case scenarios demonstrate HT listing with post-transplant pulmonary vasodilator therapy is the favored approach for restrictive cardiomyopathy and elevated PVR, whereas LVAD +/- pulmonary vasodilators is favored for patients with dilated cardiomyopathy or postop LV dysfunction and high PVR, regardless of vasoreactivity. Most continue vasodilator therapy until PVR normalizes or short term (<6 months) post-transplant. <h3>Conclusion</h3> Practice regarding medical management of elevated PVR in children awaiting HT is heterogenous, with variable use of pulmonary vasodilators and a wide range of acceptable PVR cutoffs. Evidence-based guidelines are needed to ensure standardized care and equitable organ allocation.