Association between pulse pressure and cardiovascular disease in renal transplant patients.

Elevated pulse pressure in general population has been shown to be associated with cardiovascular disease, which is the main cause of death in renal transplant patients. We investigated the effect that a wider pulse pressure range may have on cardiovascular disease after renal transplantation in 532 transplant patients with functioning graft for more than 1 year. Patients were classified into two groups depending on 1-year pulse pressure (< or >/=65 mmHg) and we analyzed patient and graft survival, post-transplant cardiovascular disease and main causes of death. Higher pulse pressure was associated with older recipient age (40.8 +/- 10.8 vs. 50 +/- 11.3), higher systolic blood pressure (132.7 +/- 16.1 vs. 164.5 +/- 16), lower blood diastolic pressure (84.5 +/- 11.6 vs. 84.4 +/- 11.2), higher prevalence of diabetes (12% vs. 23%) and total cardiovascular disease (20.9% vs. 33.6%). Five- and 10-year patient survivals were lower in the group with higher pulse pressure, being vascular disease the main cause of death in both groups. In a Cox regression model increased pulse pressure was associated with higher cardiovascular disease (RR = 1.73, 95% CI: 1.13-2.32 p < 0.01). In conclusion, pulse pressure was an independent risk factor for increased cardiovascular morbidity and mortality in renal transplant patients.

Creatinine reduction ratio on post-transplant day two as criterion in defining delayed graft function.

Delayed graft function (DGF) is a common complication after renal transplant, affecting its outcome. A common definition of DGF is the need for dialysis within the first week of transplantation, but this criterion has its drawbacks. We tried to validate an earlier and better defined parameter of DGF based on the creatinine reduction ratio on post-transplant day 2 (CRR2). We analyzed the clinical charts of 291 cadaver kidney recipients to compare the outcome of patients with immediate graft function (IGF), dialyzed patients (D-DGF) and nondialyzed CRR2-defined DGF patients (ND-DGF) and to identify risk factors for D-DGF and ND-DGF. Creatinine reduction ratio on post-transplant day 2 correlates significantly with renal function during the first year. Patients with IGF have significantly better renal function throughout the first year and better graft survival than patients with D-DGF and ND-DGF, while we found no differences either in renal function from days 30-365 or in graft survival between D-DGF and ND-DGF patients. Defining DGF by CRR2 allows an objective and quantitative diagnosis after transplantation and can help to improve post-transplant management. Creatinine reduction ratio on post-transplant day 2 correlates with renal function throughout the first year. The worse survival in the ND-DGF group is an important finding and a major advantage of the CRR2 criterion.

The risk of cardiovascular disease associated with proteinuria in renal transplant patients.

Proteinuria in the general population has been shown to be associated with cardiovascular disease, which is the main cause of death in renal transplantation. We investigated the effect of proteinuria on cardiovascular disease after renal transplantation in 532 renal transplant patients with functioning grafts for more than 1 year. Patients were classified into two groups depending on the presence of persistent proteinuria. We analyzed graft and patient survival, posttransplantation cardiovascular disease, and main causes of graft loss and death. Five- and 10-year graft and patient survival rates were lower in the group with proteinuria. The main cause of death was vascular disease in both groups. The presence of posttransplantation cardiovascular disease was higher in the group with proteinuria. Persistent proteinuria was associated with graft loss (RR=4.18), patient death (RR=1.92), and cardiovascular disease (RR=2.45). In conclusion, persistent proteinuria was an independent risk factor for increased cardiovascular morbidity and mortality in renal transplant patients.

Measurement of renal function in pre-ESRD patients.

The measurement of renal function in pre-dialysis patients is important in order to determine the appropriate time to begin renal replacement therapy, to forecast the start, and to compare, in groups of patients, the efficiency of different treatments that limit renal disease progression. The most reliable methods, such as inulin clearance or measurement by radioisotopes, are too awkward for the usual clinical follow-up of patients. Although much simpler and almost as reliable, the use of iohexol radiologic contrast does not allow the frequent monitoring of the patient either. The determinations of the plasmatic creatinine and its clearance or the estimate of the glomerular filtration rate by means of equations derived from the creatinine are the methods most often used in order to measure renal function, although not without problems in pre-dialysis. In order to try to overcome such problems, more precise equations and procedures, including the measurement of averaged urea-creatinine clearance or creatinine clearance with cimetidine, have been designed that better estimate the glomerular filtration rate. However, none of these methods is totally reliable in pre-dialysis. A new endogen marker, cystatin C, has advantages over creatinine, though more studies are needed in pre-dialysis in order to ascertain its use. The initial proposal of the National Kidney Foundation's Kidney Disease Outcome Quality Initiative (DOQI) guidelines to use weekly Kt/V and nutritional parameters to determine the time for starting renal replacement therapy has widened the prospects of the debate on the measurement of renal function in pre-dialysis, but further work is required to define their role in pre-dialysis patients' follow-up.

Return to dialysis after renal transplantation. Which would be the best way?

The exact moment to return to dialysis when a graft fails has not clearly been established. Furthermore, there is no agreement with respect to whether the guidelines accepted for patients entering dialysis for the first time are adequate for this subgroup of patients with advanced renal failure, due to the special characteristics of these patients, derived from the immunosuppressive medications they are taking among other accompanying factors. We reviewed a group of renal transplant patients who returned to dialysis and compared them with a group of patients entering dialysis for the first time. Patients with chronic renal failure due to graft failure had a poorer renal function at the time entering dialysis and a more profound anemia. Additionally, complications considered such as the number of hospital admissions during the first year after initiation of dialysis were considerably higher in the group of transplanted patients. We advocate for an earlier referral to the dialysis unit, a more aggressive erythropoietin therapy in the phase of advanced renal failure due to chronic allograft nephropathy, and in selected cases retransplantation before definitive graft loss.