Angiotensin-converting enzyme inhibitors reduce hemoglobin concentrations, hematocrit, and serum erythropoietin levels in renal transplant recipients without posttransplant erythrocytosis

Angiotensin-converting enzyme inhibitors slow recovery from anemia following cardiac surgery

OBJECTIVES

Angiotensin-converting enzyme (ACE) inhibitors, which are frequently administered in patients with heart disease, have a known inhibitory effect on erythropoiesis. The aim of this study was to detect whether early ACE inhibitor administration slows recovery from anemia following recent cardiac surgery.

METHODS AND RESULTS

Forty male patients with anemia (hemoglobin < 12 g/dL) an average of 9 days after cardiac surgery were randomized to receive enalapril (ACE inhibitor group) or not. All of the patients received ferrous sulfate, 525 mg, in addition to standard therapy. Patients with anemia due to other causes were excluded. Blood samples were obtained at baseline, and after 8 days, 16 days, and 60 days. A 6-min walking test and echocardioscan were performed at baseline, and after 16 days and 60 days of treatment, and a chest radiograph was obtained at baseline and after 60 days. The ACE inhibitor group showed a statistically significant lower increase in hemoglobin and RBC values. The peak between-group differences of 1 g/dL of hemoglobin (p = 0.012) and 444 RBCs per milliliter (p = 0.017) were observed on day 16.

CONCLUSIONS

Early enalapril maleate administration in anemic patients after heart surgery significantly inhibits erythropoiesis. This unfavorable effect on anemia should be considered when prescribing ACE inhibitors for such patients.

Angiotensin II receptor type 1 expression in erythroid progenitors: implications for the pathogenesis of postrenal transplant erythrocytosis

Under normal physiological conditions red blood cell production is controlled primarily by erythropoietin, although multiple additional stimulatory factors are likely to be involved. One of these factors, angiotensin II, can modulate erythropoiesis directly via its type 1 receptor, as well as indirectly through multiple secondary mediators. We propose that angiotensin II exerts its stimulatory effect during the early stages of erythropoiesis, and that this effect serves as an important compensatory mechanism if erythropoietin production is chronically inadequate. We speculate that if this compensatory stimulation continues to be abnormally high after restoration of erythropoietin production following renal transplantation, erythrocytosis ensues.

Use of recombinant human erythropoietin in kidney transplant patients with stable graft function

The purpose of this work was to determine the necessity for rhuEPO for 50 kidney transplant patients with stable graft function. We analyzed the red cell series, blood pressure, renal function, anthropometric data of the donor and recipient, proteinuria, and relationship with other factors, including immunosuppressants, angiotensin converting enzyme (ACE) inhibitors and angiotensin receptor blockers (ARB). The patients were divided into three groups depending on renal function: group A (with plasma creatinine <150 micromol/L), group B (151-250 micromol/L), and group C (>250 micromol/L). All patients were studied for 1 year. Erythropoietin use did not affect renal function, proteinuria or number of antihypertensive drugs group. The degree of renal dysfunction determined the time necessary to reach an adequate hemoglobin level (>12 g/L) and and the mean dose of weekly rhuEPO needed. The use of ACE inhibitors or ARBs increased the rhuEPO requirements in each group.

Congestive heart failure in patients with chronic kidney disease and on dialysis

CHF is highly prevalent in ESRD and is a leading cause of death in such patients. Hypertension, renal anemia, and comorbid conditions such as coronary artery disease are particularly important risk factors for CHF in ESRD. Dialysis hypotension may be a marker of poor prognosis in such persons. Recent studies suggest that lipid peroxidation and L-carnitine deficiency may contribute to CHF in some patients with ESRD. All forms of renal replacement therapy are capable of ameliorating symptoms of CHF, but their effect on cardiovascular mortality has not been firmly established. Drug therapy, particularly angiotensin-converting enzyme inhibitors and beta-adrenergic receptor blockers, is under-used in patients with ESRD and CHF. Heart/kidney transplantation may be a viable option for some patients with advanced CHF and ESRD.