Despite a shift towards transplanting higher risk donors and recipients, medium and long term all-cause graft failure following first kidney transplants improved steadily between 1995 and 2014.
The findings, published in Nephrology Dialysis Transplantation [link here] support the already well documented improvement in short term outcomes.
Data from 10,871 adult transplants from the Australia and New Zealand Dialysis and Transplant (ANZDATA) Registry were compared across two decades in five-year time periods 1995-99, 2000-04, 2005-09 and 2010-14.
The study found all-cause graft failure rates for the entire cohort were 4.3%, 5.5%, 10.2% and 20.8%, at 1 year, 2 years, 5 years, and 10 years respectively.
It also found the primary outcome of all-cause 5-year graft failure improved with later time periods.
“Compared to 1995-1999 (reference), the adjusted hazard ratio for 5-year graft failure was 0.78 (95% CI 0.67-0.91), 0.70 (95% CI 0.59-0.83) and 0.60 (95% CI 0.50-0.73) for 2000-2004, 2005-2009, and 2010-2014, respectively,” the study authors said.
“Similar to all-cause 5-year graft failure, adjusted hazard ratio for all-cause 10-year graft failure reduced from 0.83 (95% CI 0.74-0.93) for 2000-04 to 0.78 (95% CI 0.68-0.89) for 2005-09 compared to 1995-99 (reference).”
The improved outcomes were set against a shift towards transplanting people at an older age (p<0.001), with more comorbidities – [diabetes (p<0.001), coronary artery disease (p<0.001), peripheral vascular disease (p<0.001)] – longer dialysis vintage (p<0.001), higher BMI (p<0.001), and more HLA mismatches (p<0.001).
The study investigators, including Director of Clinical Research at the Townsville University Hospital Professor Andrew Mallett, said the age of donors also increased over time (p <0.001).
Factors associated with shorter transplant survival included:
- recipient age greater than 45 year old,
- recipient BMI >30kg/m2
- acute rejection,
- dialysis vintage greater than 1 year prior to transplant,
- recipient smoking history,
- recipient diabetes,
- recipient coronary artery disease,
- donor age greater than 45 years,
- ischaemia time >18 hours,
- and absence of calcineurin inhibitor in the initial immunosuppression regimen.
“Living kidney donor, recipient male gender, and mycophenolate in the initial immunosuppression regimen was associated with superior all-cause 5-year graft failure risk.”
The investigators said improvements in kidney transplant medical care including increased utilisation of calcineurin inhibitors and mycophenolate, improved infection prophylaxis and advances in metabolic syndrome management, would all have contributed to improved transplant outcomes.
They said their findings were consistent with overseas data.
Death with functioning graft rates at 1-year, 2-year, 5-year and 10-year were 2.2%, 3.5%, 7.8% and 16.9%, respectively