Heart-Lung - Professor Richard Kirk 2023

Multi-Organ Transplant
Introduction	Heart-Lung	Heart or Lung plus Kidney	Heart or Lung plus Liver

Heart-Lung

Indications

The primary indication for heart and lung transplantation (HLTx) is pulmonary arterial hypertension (PAH), either due to congenital heart disease or idiopathic pulmonary arterial hypertension (iPAH) or PAH consequent upon severe lung disease.
Pulmonary indications included cystic fibrosis and interstitial fibrosis, however in recent years bilateral sequential lung transplants have been preferred over HLTx for these diseases as LTx has better outcomes than HLTx.

Assessment

Assessment should follow the same principles as for heart transplantation.

When the primary indication is cardiac, then the principle determinant as to whether a heart transplant alone or whether a HLTx is required, is the pulmonary vascular resistance (PVR). Listing criteria guidelines (Mehra 2006) suggest the PVR (indexed PVR) upper limit for adults is >5 WU (>6 WU) however it is recognised that successful transplants can occur when the PVR is more than 6 WU, especially when the PVR is not "fixed" as determined by using vaso-active testing (e.g. nitric oxide) in the cath lab. There is no data for pediatric patients but clinical practice is very variable (Hopper et al 2023). Due to the inferior outcomes of HLTx compared to HTx alone, every effort should be made to enusre the PVR is truly prohibitive of a successful HTx alone.
When the primary indication is iPAH or severe lung disease associated with PAH then right ventricular function is a major consideration - will it improve after transplant or will it continue to fail? It is now recognised that most will recover after lung transplant alone, although it may be required to be supported by ECMO in the immediate post transplant period. Again the judgement is critical as LTx alone has a much better outcome than HLTx.

Management

There is no consensus on the use of induction or long term immunosuppression in HLTx (Kovac 2020). Currently it is reasonable to use the same protocols used for isolated lung transplants. Graft surveillance should utilize both cardiac and lung protocols but it should be noted that the lung graft appears to reduce the incidence of cardiac rejection and allograft vasculopathy. Despite this long term outcomes from HLTx are inferior to both isolated cardiac or lung transplant alone, with 50% survival at 5 years at best, but may be significantly less depending on the indication.