Strategies to prevent ischemic heart disease after kidney transplantation

Clinical diagnosis of metabolic syndrome: predicting new-onset diabetes, coronary heart disease, and allograft failure late after kidney transplant

Metabolic syndrome is associated with coronary heart disease (CHD) and new-onset diabetes after kidney transplant (NODAT). Using data collected from transplant centers worldwide for the Patient Outcomes in Renal Transplantation study, we examined associations of metabolic syndrome (n = 2253 excluding recipients with diabetes pretransplant), CHD (n = 2253), and NODAT (n = 1840 further excluding recipients with diabetes in the first year post-transplant), with the primary outcome of allograft failure. We assessed risk factors associated with secondary outcomes of metabolic syndrome, NODAT, and CHD after adjusting for type of baseline immunosuppression and transplant center effects. Metabolic syndrome prevalence was 39.8% at 12-24 months post-transplant and 35.4% at 36-48 months. Metabolic syndrome was independently associated with NODAT (hazard ratio 3.46, 95% confidence interval 2.40-4.98, P < 0.0001), CHD (2.03, 1.16-3.52, P = 0.013), and allograft failure (1.36, 1.03-1.79, P = 0.028). Allograft failure occurred in 218 patients (14.6%). After adjustment for metabolic syndrome, NODAT (1.63, 1.18-2.24, P = 0.003) and CHD (5.48, 3.27-9.20, P < 0.0001) remained strongly associated with increased risk of allograft failure. Metabolic syndrome, NODAT, and CHD are risk factors for allograft failure. NODAT and CHD are risk factors for allograft failure, independent of metabolic syndrome.

Trends in kidney transplantation over the past decade

Kidney transplantation offers patients with end-stage renal disease the greatest potential for increased longevity and enhanced quality of life; however, the demand for kidneys far exceeds the available supply. This has led to an increase in the number of people on waiting lists and an increase in waiting time. In the US, the overall median wait time was 2.85 years in 2004. The projected median waiting time for adult patients awaiting a deceased donor kidney in 2006 is 4.58 years. The renal transplant community has pursued multiple avenues in an attempt to increase the donor pool, but this remains a major challenge. In the last decade, the number of live donor kidney transplants performed in the US and Canada has doubled and represents just over 40% of all donor kidneys. Among deceased donor kidneys, the largest percentage increases were seen in expanded criteria donor and donation after cardiac death kidneys. In the last decade, the age distribution among donors, and among patients on waiting lists or receiving a renal transplant, has shifted towards older age groups. There have been dramatic shifts in baseline immunosuppression with increased usage of induction agents and the nearly universal replacement of azathioprine by mycophenolate. Additionally, tacrolimus use has increased from 13% to 79% at discharge, while ciclosporin (cyclosporine) use has fallen from 76% to 15%. Although 1-year graft survival rates are excellent, only modest improvements have been observed in long-term graft survival rates in the last decade. Thus, efforts have shifted from improving early graft outcomes to altering the natural course of late graft failure. Death of transplant recipients from cardiovascular disease, infection and cancer remains an important limitation in kidney transplantation. Continued success in kidney transplantation will require increased numbers of donors, both living and deceased, as well as reduction in the primary causes of late transplant loss, namely premature patient death with a functioning graft and chronic allograft nephropathy.