Global Cardiovascular Risk Under Early Corticosteroid Cessation Decreases Progressively in the First Year Following Renal Transplantation

Initial experience of dual maintenance immunosuppression with steroid withdrawal in vascular composite tissue allotransplantation

Current immunosuppression in VCA is largely based on the experience in solid organ transplantation. It remains unclear if steroids can be reduced safely in VCA recipients. We report on five VCA recipients who were weaned off maintenance steroids after a median of 2 months (mean: 4.8 months, range 2-12 months). Patients were kept subsequently on a low dose, dual maintenance consisting of tacrolimus and mycophenolate mofetil/mycophenloic acid with a mean follow-up of 43.6 months (median = 40 months, range 34-64 months). Early and late acute rejections responded well to temporarily augmented maintenance, topical immunosuppression, and/or steroid bolus treatment. One late steroid-resistant acute rejection required treatment with thymoglobulin. All patients have been gradually weaned off steroids subsequent to the treatment of acute rejections. Low levels of tacrolimus (<5 ng/mL) appeared as a risk for acute rejections. Although further experience and a cautious approach are warranted, dual-steroid free maintenance immunosuppression appears feasible in a series of five VCA recipients.

Validity of cardiovascular risk prediction models in kidney transplant recipients

Background. Predicting cardiovascular risk is of great interest in renal transplant recipients since cardiovascular disease is the leading cause of mortality. Objective. To conduct a systematic review to assess the validity of cardiovascular risk prediction models in this population. Methods. Five databases were searched (MEDLINE, EMBASE, SCOPUS, CINAHL, and Web of Science) and cohort studies with at least one year of follow-up were included. Variables that described population characteristics, study design, and prognostic performance were extracted. The Quality in Prognostic Studies (QUIPS) tool was used to evaluate bias. Results. Seven studies met the criteria for inclusion, of which, five investigated the Framingham risk score and three used a transplant-specific model. Sample sizes ranged from 344 to 23,575, and three studies lacked sufficient event rates to confidently reach conclusion. Four studies reported discrimination (as measured by c-statistic), which ranged from 0.701 to 0.75, while only one risk model was both internally and externally validated. Conclusion. The Framingham has underestimated cardiovascular events in renal transplant recipients, but these studies have not been robust. A risk prediction model has been externally validated at least on one occasion, but comprehensive validation in multiple cohorts and impact analysis are recommended before widespread clinical application is advocated.

The external validation of the cardiovascular risk equation for renal transplant recipients: applications to BENEFIT and BENEFIT-EXT trials

BACKGROUND

Renal transplant recipients (RTRs) have increased cardiovascular disease risk. Recently, major adverse cardiac event (MACE) and mortality risk calculators for prevalent RTRs were developed. We aimed to externally validate these risk equations in an international transplant database and subsequently demonstrate application to 2 clinical trials: Belatacept Evaluation of Nephroprotection and Efficacy as First-line Immunosuppression Trial (BENEFIT) and Belatacept Evaluation of Nephroprotection and Efficacy as First-line Immunosuppression Trial-EXTended criteria donors (BENEFIT-EXT).

METHODS

The 7-year risk calculators were developed using data from the ALERT trial and validated for discrimination and calibration in the Patient Outcomes in Renal Transplantation (PORT) study cohort. The outlier laboratory readings were trimmed to the 99th percentile observed in the PORT database. Diabetes mellitus, LDL-cholesterol, and serum creatinine values 3 years posttransplantation were used when applying the calculators to BENEFIT and BENEFIT-EXT trial treatment arms.

RESULTS

MACE could be predicted using a 7-variable model. The area under the ROC curve was 0.738 in ALERT and 0.740 in PORT, indicating preserved discrimination. In PORT, the calibration of the model indicated significant underestimation of risk in decile 5 and 9. Total mortality could be predicted using a 6-variable model. The area under the ROC curve was 0.734 in ALERT and 0.721 in PORT, indicating preserved discrimination. In PORT, the calibration of the model indicated significant underestimation of risk in decile 7 and significant overestimation in the highest risk decile. In BENEFIT and BENEFIT-EXT trial, the calculator estimated that belatacept use may result in reduction in MACE (>20%) and mortality (∼18%-30%).

CONCLUSION

The MACE and mortality risk calculators for prevalent RTRs have been externally validated and found suitable for generic risk stratification.

A cardiovascular risk calculator for renal transplant recipients

BACKGROUND

Renal transplant recipients (RTRs) have increased cardiovascular disease (CVD) risk. Standard CVD risk calculators are poorly predictive in RTRs; we therefore aimed to develop and validate an equation for CVD risk prediction in this population.

METHODS

We used data from the Assessment of Lescol in Renal Transplantation trial, which are randomly divided into an assessment sample and a test sample (67% and 33%, respectively, of the total population). For variable selection in the assessment sample, backward stepwise Cox regression was used. Using the regression coefficients and centralized prognostic index, risk was calculated for individual patients. The equation was then validated for calibration and discrimination using the test sample.

RESULTS

Major adverse cardiac events could be predicted using a seven-variable model including age, previous coronary heart disease, diabetes, low-density lipoprotein, creatinine, number of transplants, and smoking. The calibration of the model was good in the test sample with a Hosmer-Lemeshow chi-square value of 11.47 and a P value of 0.245. The areas under the receiver operating characteristic curve were 0.738 in the assessment sample and 0.740 in the test sample. Total mortality could be predicted using a six-variable model including age, coronary heart disease, diabetes, creatinine, total time on renal replacement therapy, and smoking. The calibration of the model was acceptable in the test sample with a Hosmer-Lemeshow chi-square value of 13.08 and a P value of 0.109. The areas under the receiver operating characteristic curve were 0.734 in the assessment sample and 0.720 in the test sample.

CONCLUSIONS

Using the Assessment of Lescol in Renal Transplantation trial population, a formula for 7-year CVD and mortality risk calculation for prevalent RTRs has been developed.

Cardiovascular risk, cardiovascular events, and metabolic syndrome in renal transplantation: comparison of early steroid withdrawal and chronic steroids

BACKGROUND

Cardiovascular disease (CVD) is the leading cause of death with a functioning graft in renal transplant recipients. The purpose of this study was to compare Framingham Risk Score (FRS), metabolic syndrome (MS), and cardiovascular events (CVE) in patients receiving early corticosteroid withdrawal (ECSWD), or chronic corticosteroid therapy (CCS).

METHODS

In all, 251 ECSWD and 146 CCS patients were evaluated. FRS and MS were identified at baseline, six, 12, and 24 months post-transplant. A total of 124 patients with diabetes mellitus prior to transplantation were excluded from MS analysis. CVE were defined as sudden-death, MI, angina, or CVA/TIA. Repeat-measure logistic regression was used for statistical analysis.

RESULTS

Fifty-four patients experienced 72 CVE. Mean follow-up was 755 +/- 312 d and time to CVE was 14.8 +/- 8.3 months. Demographics were similar between groups. FRS was not different between groups. CVE were significantly greater in CCS patients then ECSWD (20% vs. 10%, p = 0.024). New-onset MS occurred more frequently in patients receiving CCS then ECSWD (45% vs. 22%, p < 0.001) and was associated with more CVE (p < 0.015).

CONCLUSIONS

Patients receiving ECSWD regimens have significantly decreased CVE and new onset MS compared with CCS. MS is associated with increased CV risk and CVE.