Effect of renin-angiotensin system inhibitors on survival in kidney transplant recipients: A systematic review and meta-analysis

Renin-angiotensin system inhibitors, specifically angiotensin II converting enzyme inhibitors (ACEI) and angiotensin II receptor blockers (ARB), have confirmed renoprotective benefits in patients with proteinuria and hypertension. However, it remains controversial whether these agents are beneficial to kidney recipients. We conducted this meta-analysis to evaluate the effects of ACEI/ARB treatment on patient and allograft survival after kidney transplant. The PubMed, Embase and Cochrane Library databases were searched for eligible articles from before May 2016, and we included 24 articles (9 randomised controlled trials [RCTs] and 15 cohort studies with 54,096 patients), in which patient or graft survival was compared between an ACEI/ARB treatment arm and a control arm. Pooled results showed that ACEI/ARB was associated with decreased risks of patient death (relative risk [RR] = 0.64; 95% confidence interval [CI]:0.49-0.84) and graft loss (RR = 0.59; 95%CI:0.47-0.74). Subgroup analysis of the cohorts revealed significantly reduced patient death (RR = 0.61; 95%CI:0.50-0.74) and graft loss (RR = 0.58; 95%CI:0.46-0.73), but this was not seen in RCTs (patient survival: RR = 0.84, 95%CI:0.39-1.81; graft survival: RR = 0.70, 95%CI:0.17-2.79). Significantly less graft loss was noted among patients with biopsy-proved chronic allograft nephropathy (CAN) (RR = 0.26, 95%CI:0.16-0.44). Furthermore, the benefit of ACEI/ARB on patient survival (RR = 0.62; 95%CI:0.47-0.83) and graft survival (RR = 0.58, 95%CI:0.47-0.71) was limited to those with ≥3years' follow-up. ACEI/ARB decreased proteinuria (P < 0.001) and lowered haemoglobin (P = 0.002), but the haemoglobin change requires no additional treatment (from 119-131 g/L to 107-123 g/L). We therefore concluded that ACEI/ARB treatment may reduce patient death and graft loss, but additional well-designed prospective studies are needed to validate these findings.

Renin-angiotensin-aldosterone system inhibitors lower hemoglobin and hematocrit only in renal transplant recipients with initially higher levels

AIM

We have analyzed the effects of renin-angiotensin-aldosterone system (RAAS) inhibitors on evolution of hemoglobin (Hb) and hematocrit (Htc) levels as well as on the evaluation of kidney graft function in stable renal transplant recipients (RTRs) in respect with initially higher or lower Hb and Htc values.

METHODS

The study group comprised of 270 RTRs with stable graft function. Besides other prescribed antihypertensive therapy, 169 of them have been taking RAAS inhibitors.

RESULTS

We wanted to analyze the effect of the use of RAAS inhibitors on Hb and Htc in patients with initially higher or lower Hb/Htc values. For this analysis, only RTRs that were taking RAAS inhibitors were stratified into two groups: one with higher Hb and Htc (initial Hb≥150g/L and Htc≥45%) and another one with lower Hb and Htc (initial Hb<150g/L and Htc<45%) values. Thirty-four RTRs with initially higher Hb and 41 RTRs with initially higher Htc had a statistically significant decrease in Hb (p=0.006) and Htc (p<0.0001) levels after 12-months of follow-up. In the group of patients with initially lower Hb (135 RTRs) and Htc (128 RTRs) there was a significant increase in Hb (p=0.0001) and Htc (p=0.004) levels through the observed period. The use of RAAS inhibitors has been associated with a trend of slowing renal insufficiency in RTRs (p=0.03).

CONCLUSION

RAAS inhibitors lower Hb and Htc only in RTRs with initially higher levels. In patients with initially lower Hb and Htc levels, the use of these drugs is followed by beneficial impact on erythropoiesis and kidney graft function.

Understanding medical care of transplant recipients through integrated registry and pharmacy claims data

BACKGROUND

Limited data exist on medication use aside from immunosuppression among large samples of kidney transplant recipients.

METHODS

We examined a novel database wherein Organ Procurement and Transplantation Network (OPTN) registry data were linked to records from a US pharmaceutical claims clearinghouse (2005-2010 claims) to examine pharmaceutical care at the first transplant anniversary (n = 16,157). We quantified the use of the following medication types within ±60 days of the first-year OPTN report according to estimated glomerular filtration rate (eGFR): antihypertensives, lipid-lowering, bone and mineral, and anemia treatments. Adjusted associations of medication use with eGFR and other clinical factors were quantified by multivariate logistic regression.

RESULTS

Requirements for multiple antihypertensive agents rose with lower eGFR, with β-blockers comprising the most commonly used antihypertensive agent. The adjusted likelihood of vitamin D (adjusted odds ratio (aOR) 2.07, 95% CI 1.19-3.59) and especially erythrocyte-stimulating agents (aOR 19.94, 95% CI 7.01-56.00) rose in a graded manner to peak with eGFR <15 versus >90, whereas statin use was most common with eGFR 30-59 ml/min/1.73 m(2). Black race was independently associated with increased use of all classes of antihypertensives and vitamin D, but lower adjusted statin use. Rapamycin-based immunosuppression was associated with increased use of statins and erythrocyte-stimulating agents.

CONCLUSIONS

Integrated registry and pharmacy fill data provide a novel tool for pharmacoepidemiologic investigations of delivered post-transplant care. Transplant recipients with reduced renal function have increased requirements for pharmaceutical care of comorbidities. Causes of racial variation in medication fills warrant further investigation.

Beta and angiotensin blockades are associated with improved 10-year survival in renal transplant recipients

Background

Mortality in allograft kidney transplant recipients is high, and cardiovascular disease is the leading cause of death in these patients. They have heightened activity of sympathetic and renin–angiotensin systems. We tested the hypothesis that blockade of sympathetic and renin–angiotensin systems in these patients may offer a survival benefit using a large cohort of patients with long‐term follow up.

Methods and Results

Medical records of 321 consecutive patients from our institution who had received renal transplantation between 1995 and 2003 were abstracted. Survival was analyzed as a function of pharmacological therapies adjusted for age, sex, and comorbidities. The characteristics of the 321 patients were as follows: age at transplant, 44±13 years; 40% male; 89% with hypertension; 36% with diabetes, and mean left ventricular ejection fraction of 60%. Over a follow‐up of 10±4 years, there were 119 deaths. Adjusted for age, sex, diabetes, and coronary artery disease, use of a beta‐blocker therapy (P=0.04) and angiotensin‐converting enzyme inhibitor or receptor blocker (P=0.03) was associated with better survival. This treatment effect was seen across all major clinical subgroups and was supported by propensity score analysis. The propensity score–adjusted 10‐year survival was 95% in those taking both groups of medications, 72% in those taking either of them, and 64% in those taking neither (P=0.004).

Conclusions

Use of beta‐blocker and angiotensin blocking therapies is associated with higher survival after renal transplantation, indicating their potential protective role in this high‐risk population.

Cardiovascular disease medications after renal transplantation: results from the Patient Outcomes in Renal Transplantation study

BACKGROUND

Cardiovascular disease (CVD) is the most common cause of death after kidney transplantation. Nevertheless, the use of potentially protective CVD medications has not been examined in a large international cohort of kidney transplant patients.

METHODS

Using the Patient Outcomes in Renal Transplantation database, we retrospectively examined CVD medication use in 14,236 kidney transplant patients from 10 centers worldwide at 4 and 12 months posttransplant.

RESULTS

Use of CVD medications posttransplant increased between 1990 to 1994 and 2000 to 2006, with a 12-fold increase in the use of statins (odds ratio [OR] 12.28, 95% confidence interval [CI] 10.18-14.80). Use of β-blockers also increased (OR 3.74, 95% CI 3.20-4.38), as did use of angiotensin converting enzyme inhibitors or angiotensin II receptor blockers (OR 3.68, 95% CI 3.07-4.40) and antiplatelet agents (OR 1.93, 95% CI 1.66-2.24). Use of most CVD medications was not higher in patients with diabetes than in patients without diabetes, despite a higher risk of CVD among patients with diabetes. Although use of several CVD medications was higher in patients with previous CVD events than in patients with no previous CVD, less than 75% of patients with previous CVD were using a statin or antiplatelet agent.

CONCLUSION

Although use of CVD medications after kidney transplant has increased in recent years, use of potentially cardioprotective medications may be suboptimal given the high CVD risk in kidney transplant patients.

[Medical care of chronic kidney disease after kidney transplantation]

Kidney transplantation is the treatment of choice to enhance survival, morbidity and quality of life perceived by the patient. Despite improvements in short-term outcomes, a gap persists comparing with health of general population. A stringent collaboration between the family physician, the community nephrologists, the transplant center and others specialists is required. Recent recommendations have been published in France.