Transplantation Express Report

Publication date: 2004-01-05

Cardiovascular Disease after Renal Transplantation

This report was reviewed for medical and scientific accuracy by David A. Laskow, MD, Chief, Kidney/Pancreas Transplant Service, Associate Professor of Surgery, University of Medicine & Dentistry of New Jersey—Robert Wood Johnson Medical School, New Brunswick, New Jersey

Introduction

The incidence of atherosclerotic cardiovascular disease is higher in patients with chronic kidney disease compared to the general population and results in significant morbidity and mortality.¹ Between 1997 and 1999, it was estimated that 41% of deaths among patients with chronic kidney disease (treated with hemodialysis, peritoneal dialysis or kidney transplantation) were due to coronary heart disease with another 6% to cerebrovascular disease.² Similarly, the prevalence of cardiovascular disease in renal transplant recipients is significantly higher than the general population and also results in significant morbidity and mortality.¹ Indeed, cardiovascular disease is the leading cause of death among renal transplant recipients with a functioning graft.³ More specifically, among renal transplant recipients with functioning grafts, 13% of deaths are attributable to myocardial infarction, 7.4% to cerebrovascular disease, and 25.3% to other cardiovascular causes. Recently, literature examining the relationship between renal function and cardiovascular disease demonstrated the importance of even minor alterations in renal function as it related to cardiovascular death.⁴ Therefore, reducing the risk of atherosclerotic cardiovascular disease among patients with chronic kidney disease and renal transplant recipients is an important clinical goal.

Epidemiology of Cardiovascular Disease in the Renal Patient

It is likely that, as in the general population, dyslipidemias play a major role in the development of atherosclerotic cardiovascular disease in patients with chronic kidney disease, including those who have undergone renal transplant surgery.⁵ Whereas no well-designed, prospective clinical trials have evaluated the relationship between dyslipidemias and atherosclerotic cardiovascular disease in these populations, results of several observational studies suggest that such a relationship exists. In one such study, the use of 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase inhibitors (“statins”) in patients with Stage 5 chronic kidney disease was independently associated with lower total mortality (relative risk 0.68, 95% Confidence Interval (CI), 0.54–0.87) and cardiovascular mortality (relative risk 0.64, 95% CI, 0.45–0.91).⁶ In the renal transplant population, associations between elevated total cholesterol,^7-9 low levels of high-density lipoprotein (HDL)-cholesterol,^10,11 and high levels of triglycerides^8,12 and atherosclerotic cardiovascular disease have been reported. Moreover, renal transplant recipients may also have non-traditional lipoprotein abnormalities that could theoretically contribute to atherosclerotic cardiovascular disease.^13-15 However, the role of these lipoprotein abnormalities in the pathogenesis of atherosclerotic cardiovascular disease in chronic kidney disease is unclear.

Additional cardiovascular risks have been described in the chronic kidney disease and renal transplant populations; however, less is known about these risks and their relative contribution to overall cardiovascular morbidity and mortality.¹⁶ Among renal transplant recipients, associations between diabetes, age at transplant, obesity, smoking, hyperuricemia, pre-transplantation vascular disease, number of previous acute rejection episodes, elevated hematocrit, with hypertension and atherosclerotic cardiovascular disease have been reported.

Dyslipidemias Among Renal Transplant Recipients

Dyslipidemias are common in the renal transplant population particularly in transplant recipients with underlying diabetes, the single leading cause