Effects of an Angiotensin-Converting Enzyme Inhibitor on Residual Renal Function in Patients Receiving Peritoneal Dialysis

A Randomized, Controlled Study

15 July 2003 | Volume 139 Issue 2 | Pages 105-112

Background: Residual renal function is an important determinant of mortality and morbidity in patients receiving peritoneal dialysis. However, few studies have evaluated therapeutic approaches for preserving residual renal function after the initiation of dialysis.

Objective: To test the hypothesis that the angiotensin-converting enzyme (ACE) inhibitor ramipril slows the decline in residual renal function in patients with end-stage renal failure treated with peritoneal dialysis.

Design: Randomized, open-label, controlled trial.

Setting: Single-center study in the dialysis unit of a university teaching hospital.

Patients: 60 patients receiving peritoneal dialysis.

Measurements: Patients were randomly assigned to ramipril (5 mg daily) or no treatment. The target blood pressure was 135/85 mm Hg or less. Rate of decline in residual glomerular filtration rate (GFR) and development of complete anuria were compared among groups.

Results: Over 12 months, average residual GFR declined by 2.07 mL/min per 1.73 m² in the ramipril group versus 3.00 mL/min per 1.73 m² in the control group (P = 0.03). The difference between the average changes in residual GFR in the ramipril and control groups from baseline to 12 months was 0.93 mL/min per 1.73 m² (95% CI, 0.09 to 1.78 mL/min per 1.73 m²). At 12 months, 14 patients in the ramipril group and 22 in the control group developed anuria. With intention-to-treat multivariable analysis using the Cox model, it was estimated that at 3, 6, and 9 months, patients assigned to ramipril had a higher adjusted hazard of complete anuria than did patients assigned to no treatment. Of the 25 patients who still did not have complete anuria at 12 months, those assigned to ramipril had a better prognosis than did those assigned to no treatment (adjusted hazard ratio, 0.58 [CI, 0.36 to 0.94]). The rates of death from any cause, duration of hospitalization, and cardiovascular events did not differ significantly between groups.

Conclusions: Although the trial was small and had a limited ability to exclude effects of potential confounding factors, the angiotensin-converting enzyme inhibitor ramipril may reduce the rate of decline of residual renal function in patients with end-stage renal failure treated with peritoneal dialysis.

Editors' Notes Context Few studies assess preservation of residual renal function after initiation of dialysis. Contribution This open-label randomized trial in patients receiving peritoneal dialysis showed that ramipril reduced declines in glomerular filtration rate and decreased the hazard rate of anuria at 1 year. Five of 30 patients stopped taking ramipril because of dizziness or cough; none withdrew as a result of hyperkalemia. Cautions The trial did not use a placebo comparison group, involved patients from a single university teaching hospital, and was not powered to detect differences in health care utilization or morbidity or mortality. –The Editors

 

Author and Article Information

From Prince of Wales Hospital, The Chinese University of Hong Kong, Shatin, Hong Kong.

The preliminary results of this study were presented at the 35th Annual Meeting of the American Society of Nephrology, 30 October–4 November 2002, Philadelphia, Pennsylvania.

Acknowledgment: The authors thank Ms. Wendy Tang for her clerical assistance and the nursing staff of Renal Unit, Prince of Wales Hospital, Shatin, Hong Kong, for their help in data collection.

Grant Support: In part by research accounts 6901031 and 6900570 from the Chinese University of Hong Kong and in part by Aventis Pharmaceuticals Limited.

Potential Financial Conflicts of Interest: None disclosed.

Requests for Single Reprints: Philip K.-T. Li, FRCP, Department of Medicine and Therapeutics, Prince of Wales Hospital, The Chinese University of Hong Kong, Shatin, Hong Kong; e-mail, philipli{at}cuhk.edu.hk.

Current Author Addresses: Drs. Li, Chow, Wong, Leung, and Szeto: Department of Medicine and Therapeutics, Prince of Wales Hospital, The Chinese University of Hong Kong, Ngan Shing Street, Shatin, Hong Kong, China.

Author Contributions: Conception and design: P.K.-T. Li.

Analysis and interpretation of the data: K.-M. Chow, C.-B. Leung, C.-C. Szeto.

Drafting of the article: C.-C. Szeto.

Critical revision of the article for important intellectual content: P.K.-T. Li.

Final approval of the article: P.K.-T. Li, T. Y.-H. Wong.

Provision of study materials or patients: P.K.-T. Li.

Statistical expertise: C.-C. Szeto.

Obtaining of funding: P.K.-T. Li.

Administrative, technical, or logistic support: P.K.-T. Li.

Collection and assembly of data: K.-M. Chow, T. Y.-H. Wong, C.-B. Leung, C.-C. Szeto.