Patients with end-stage renal disease (ESRD) are at higher risk for infective endocarditis, according to a new study. Specific subgroups of ESRD patients are at particular risk.
Also known as bacterial endocarditis, infective endocarditis (IE) is the result of bacteria entering the bloodstream and settling in the endocardium, heart valve or blood vessel. IE is a serious complication for patients treated with renal replacement therapy (RRT), including those receiving hemodialysis, kidney transplantation or peritoneal dialysis.
The researchers used information gathered from the Danish National Registry on Regular Dialysis and Transplantation and the Danish National Patient registry. The results of the study were published online ahead of publication in the Clinical Journal of the American Society of Nephrology.
According to the data, 10,612 patients started renal replacement therapy in Denmark from 1996 to 2012. Of these, 7,233 patients were on hemodialysis (HD), 3,056 were on peritoneal dialysis (PD), and 323 received kidney transplants (KT). 36 percent of the study subjects were female; subjects had a mean age of 63 years.
The researchers, led by Dr. Mavish Safdar Chaudry from the Department of Cardiology at Gentofte Hospital, estimated the incidence of endocarditis for each RRT modality. They used multivariable Cox regression models to identify independent risk factors.
Of the 10,612 patients the researchers followed, 2.5 percent developed endocarditis and 31 required valve surgery. At that rate, IE would develop in 627 per 100,000 person-years among those receiving RRT.
This rate is at least 60 times higher than the rate of endocarditis in the general Danish population, which is a rate of approximately 8 to 10 per 100,000 per year. The rate of infective endocarditis in the U.S. is between 2 and 6 cases per 100,000 person-years, according to Cleveland Clinic's Center for Continuing Education.
Of the Danish subjects who developed infective endocarditis, 22 percent died in the hospital and 51 percent perished within one year.
Hemodialysis patients seemed to be the most prone to infective endocarditis. The researchers estimated the development of IE in 1,092 hemodialysis, 212 peritoneal dialysis and 85 kidney transplant patients per 100,000 person years.
Study subjects undergoing hemodialysis had a 5.5 times higher risk for infective endocarditis compared with PD patients; HD patients younger than 66 years were particularly vulnerable to developing IE. Kidney transplant patients had less than half the risk of hemodialysis patients.
Vascular access type affected infection rates. Among subjects receiving hemodialysis, those with central venous catheters had more than twice the rate of IE compared with those who had arteriovenous (AV) fistulas. Subjects with central venous catheters had nearly triple the rate of IE compared with those who had arteriovenous grafts. At 3,053 versus 2,099 per 100,000 person-years, IE rates were similar for cuffed and uncuffed catheters.
The team of scientists determined that certain factors could predict infective endocarditis. Recent initiation of renal replacement therapy is a factor, for example, as study participants were more likely to develop IE within the first six months of RRT than were those who had been undergoing therapy for more than 2.3 years. Other predictive factors included aortic valve disease and endocarditis prior to the initiation of renal replacement.
The authors of the study urge renewing efforts to identify infective endocarditis in patients undergoing renal replacement therapy.
"This strongly advocates frequent use of both transthoracic and transesophageal echocardiography in the case of bacteremia or unexplained fever episodes in these patients," says Chaudry.
