Cardiovascular outcomes of ACE inhibitors and angiotensin receptor blockers in kidney transplant recipients: a meta-analysis of randomized trials

Introduction Cardiovascular disease is a leading cause of morbidity and mortality among kidney transplant recipients, a high-risk population with complex cardiovascular–renal interactions. Although blockade of the renin–angiotensin system is widely used for blood pressure control and nephroprotection, its impact on hard clinical outcomes in the transplant population remains uncertain. Purpose The objective of this systematic review and meta-analysis was to evaluate all-cause mortality, graft loss, and hemodynamic control (systolic and diastolic blood pressure) associated with the use of angiotensin-converting enzyme inhibitors (ACEi) or angiotensin receptor blockers (ARBs) compared to placebo or control in kidney transplant recipients. Methods A systematic review and meta-analysis of randomized controlled trials was conducted using PubMed and the Cochrane Library, including adult kidney transplant recipients. Statistical analysis was performed using Review Manager (RevMan 5.4.1). Odds ratios were used for dichotomous outcomes and mean differences for continuous variables. Random-effects models were applied. Results Seven randomized controlled trials including 1,190 patients were analyzed. No statistically significant differences were observed between treatment and control groups for all-cause mortality (OR 1.02; 95% CI 0.57–1.85; p=0.94) or graft loss (OR 0.64; 95% CI 0.34–1.22; p=0.17). Treatment with ACEi or ARBs was associated with significant reductions in systolic blood pressure (MD −6.81 mmHg; 95% CI −10.93 to −2.68; p<0.001) and diastolic blood pressure (MD −5.29 mmHg; 95% CI −6.41 to −4.18; p<0.00001). As secondary safety outcomes, a significant reduction in hemoglobin levels was observed in the intervention group (MD −0.75 g/dL; 95% CI −1.30 to −0.20; p=0.008) , whereas doubling of serum creatinine levels showed no significant difference between groups (OR 0.66; 95% CI 0.36–1.22; p=0.19). Conclusions In kidney transplant recipients, a population at high cardiovascular risk, the use of angiotensin-converting enzyme inhibitors or angiotensin receptor blockers is associated with significant improvements in blood pressure control. However, these hemodynamic benefits did not translate into statistically significant reductions in all-cause mortality or graft loss. The observed reduction in hemoglobin levels highlights the need for careful hematological and renal function monitoring in this population.