Cardiovascular disease in peritoneal dialysis patients

Patients on peritoneal dialysis have a high level of morbidity and mortality associated with atherosclerotic cardiovascular disease and they also have an increased risk of sudden death. The atherosclerosis seen in peritoneal dialysis patients is associated with both traditional cardiovascular risk factors such as low levels of physical activity, hyperlipidemia, hypertension, diabetes and smoking as well as non-traditional risk factors such as elevated oxidative stress and inflammation. The atherosclerosis may be preceded by endothelial dysfunction and increased arterial stiffness. Measures of arterial stiffness such as aortic pulse wave velocity predict morbidity and mortality. Numerous studies have reported that the elevated levels of oxidative stress and inflammation in this population are associated with arterial stiffness and in turn with the development of cardiovascular disease. A number of studies have reported that peritoneal dialysis is associated with lower levels of oxidative stress and inflammation compared to haemodialysis. A small number of trials have extended this work to determine associations between oxidative stress and inflammation with vascular or myocardial structure and function with equivocal results. The decision to undergo either peritoneal or haemodialysis is based on many factors which include the differential damage the renal replacement therapy may have on the cardiovascular system. Current evidence suggests this may vary over time. Previous randomised controlled trials and many other observational studies have produced conflicting results as to which therapy may have a cardiovascular advantage. Some registry data suggests peritoneal dialysis is associated with a lower mortality than haemodialysis in the first one-two years but thereafter may be higher on peritoneal dialysis than haemodialysis. Other registry data do not support this. Further long-term studies assessing surrogate and hard endpoint cardiovascular outcomes in peritoneal dialysis are required.