Variations in cardiac transplantation: comparisons between the United Kingdom and the United States

Background: International practice variations have been documented in various health care specialties. This study compares cardiac transplantation in the UK with practice in the US. UK data were from an ongoing multi-center prospective study, the UK Cardiothoracic Transplant Audit. The UK population comprised 620 listings and 463 transplants. US data were obtained from UNOS and comprised 3946 listings and 4704 transplants. There was a mean of 14 transplants per center per year in the US compared with 34 in the UK. Notable differences in practice include rarity of listing in the UK of patients > 65 years (0.2% vs 4.1% in US) and patients with previous transplants (UK 0.9%, US 3.2%). Patients listed in the US were more likely to be on ventricular assist devices (odds ratio 8.0, 95% CI 3.0–21.7) or inotropes (odds ratio 4.9, 95% CI 3.7–6.4). Living donor (domino) transplants, although comprising 7% of transplants in the UK, are virtually non-existent in the US (1 domino in 4704 transplants). Heterotopic transplants were more common in the UK (4.4% vs 0.5%). Indications for transplant were similar (except retransplantation). The donor age was >35 years in 43% of UK donors vs 33% of US donors. This study reveals substantial practice differences between the UK and US. Further studies are required to examine the reasons for these practice differences, the influence on transplant outcome, and their ethical and economic implications.