Obesity and cardiac risk after kidney transplantation: experience at one center and comprehensive literature review.

BACKGROUND: The cardiac implications of obesity in kidney transplant recipients are not well-described. METHODS: We examined associations of body mass index (BMI) at transplant with posttransplant cardiac risk among 1102 renal allograft recipients at a single center in 1991 to 2004. Cumulative posttransplant incidences of congestive heart failure (CHF), atrial fibrillation (AF), myocardial infarction, and a composite of these cardiac diagnoses were estimated by the Kaplan-Meier method. Bivariate (hazards ratio) and covariate (adjusted hazards ratio) relationships of BMI increments with cardiac risk were modeled by Cox's regression. We also systematically reviewed the literature on BMI and cardiac events after transplant. RESULTS: In the local data, 5-year cumulative incidence of any cardiac diagnosis rose from 8.67% to 29.35% across the lowest to highest BMI quartiles (P=0.02), driven primarily by increases in CHF and AF. In contrast, the rate of myocardial infarction did not differ by BMI quartile (P=0.56). Each 5 U BMI increase predicted 25% higher risk of the cardiac composite (hazards ratio 1.25, 95% CI 1.07-1.47, P=0.005), a relationship that persisted with significance after covariate adjustment (adjusted hazards ratio 1.19, 95% CI 1.00-1.43, P=0.049). BMI independently predicted cardiac risk in subcohorts with pretransplant heart disease and with nondiabetic renal failure. Data from 26 original articles support BMI as a risk factor for posttransplant CHF and AF, whereas findings for coronary/ischemic outcomes are inconsistent and predominantly negative. CONCLUSIONS: High BMI at transplant predicts increased cardiac risk, especially of CHF and AF. Further research should examine whether obesity treatment modifies cardiac risk after kidney transplantation.

Post-coronarography application of continuous veno-venous hemofiltration in the prevention of contrast nephropathy in patients with complex multisystem deficiency.

BACKGROUND: An increased admission of high-risk patients to diagnostic and interventional radiological procedures with contrast medium has resulted in an increase of contrast-induced nephropathy, which now represents the third main cause of hospital-acquired acute renal failure. The pathogenic mechanism of contrast-induced nephropathy (CN) is unclear, but there is much evidence which indicated an interaction between direct tubular cytotoxicity and osmotic/hemodynamic effects. Continuous veno-venous hemofiltration (CVVH) has shown possible benefits in preventing CN. It is not understood when and how prophylactic strategies should be used either in pharmacological therapies or in continous renal replacement therapy (CRRT) approaches. The aim of this study was to evaluate the efficiency of the CVVH technique in preventing CN secondary to emergency radiological procedures in very high-risk patients. PATIENTS AND METHODS: Twelve patients with severe chronic renal impairment (serum creatinine concentration >2 mg/dl with an estimated glomerular filtration rate (eGFR) <40 ml/min) in association with at least two severe comorbidities (such as previous acute myocardial infarction in hypertensive or diabetic patients obesity, cardiac failure with ejection fraction <40%, severe hypotension) were treated with CVVH after coronarography using an iso-osmolar contrast medium (Visipaque, Iodixanol), with or without percutaneous transluminal coronary angioplasty. Adverse events and their association with the interventional radiological procedure were investigated after hemofiltration. RESULTS: Statistically significant differences were observed for both eGFR and serum creatinine at different time points (pre-, post- and 7 days after the procedure) at p<0.05. Statistical analysis of all the variables related to the radiological procedure and the hemofiltration technique did not cause any modification of renal function between the pre- and post-procedure values. No patient showed signs of cardiovascular instability, nor were any episodes of marked hypotension reported during the dialysis session. No patient showed any adverse effects related to the interventional radiological procedure or to the CVVH technique. Renal function, according to serum creatinine concentration and the e-GFR calculation (Cockcroft), did not worsen but had improved when the patients left hospital, with function rates statistically significantly better compared to that on hospital admission, even 7 days after the radiological procedure. CONCLUSION: The present study suggests the efficiency of the CVVH technique in preventing CN in high-risk patients who need to undergo interventional radiological cardiovascular procedures involving the administration of an iodine-based contrast medium.

Variations in the risk for cerebrovascular events after kidney transplant compared with experience on the waiting list and after graft failure.

BACKGROUND AND OBJECTIVES: This study examined the risks, predictors, and mortality implications of cerebrovascular disease events after kidney transplantation in a national cohort. DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS: This analysis used United States Renal Data System registry data to study retrospectively Medicare-insured kidney transplant candidates (n = 51,504), recipients (n = 29,614), and recipients with allograft failure (n = 2954) in 1995 through 2002. New-onset cerebrovascular disease events including ischemic stroke, hemorrhagic stroke, and transient ischemic attacks were ascertained from billing records, and participants were followed until Medicare-end or December 31, 2002. Multivariable survival analysis was used to compare cerebrovascular disease event incidence and risk profiles among the study samples. RESULTS: The cumulative, 3-yr incidence of de novo cerebrovascular disease events after transplantation was 6.8% and was lower than adjusted 3-yr estimates of 11.8% on the waiting list and 11.2% after graft loss. In time-dependent regression, transplantation predicted a 34% reduction in subsequent, overall cerebrovascular disease events risk compared with remaining on the waiting list, whereas risk for cerebrovascular disease events increased >150% after graft failure. Similar relationships with transplantation and graft loss were observed for each type of cerebrovascular disease event. Smoking was a potentially preventable correlate of posttransplantation cerebrovascular disease events. Women were not protected. All forms of cerebrovascular disease event diagnoses after transplantation predicted increased mortality. CONCLUSIONS: Along with known benefits for cardiac complications, transplantation with sustained graft function seems to reduce risk for vascular disease events involving the cerebral circulation.