Cardiovascular SSC investigators have published a study on cardiovascular disease in pediatric chronic dialysis patients which appears in the August 2002 issue of Kidney International (volume 62:648-653). This work highlights one major research focus of the Cardiovascular SSC, cardiovascular disease in pediatric ESRD patients. This study identified 1,454 children (ages 0 to 19 years) who were incident dialysis patients from 1991 to 1996 identified in the U.S. Renal Data System database. Study endpoints include the development of arrhythmia, valvular heart disease, cardiomyopathy, cardiac arrest, or all-cause and cardiac related death.

  Of the 1,454 children that were identified are in the study, 452 (31.1%) developed a cardiac related event. Arrhythmia was the most common event (19.6%), followed by valvular heart disease (11.7%), cardiomyopathy (9.6%), and cardiac arrest (3%). One important finding in this study is the increased incidence of cardiomyopathy in black children and a trend towards increased incidence in girls. The adjusted annual cardiomyopathy rate has increased from 42.0 events per thousand patient years in 1991 to 84.8 events per thousand patient years in 1996. In this study, death occurred in 107 patients and 41 (38%) were attributed to cardiac causes.

  The authors conclude that cardiovascular disease is a significant cause of morbidity and mortality in pediatric chronic dialysis patients. The incidence of cardiomyopathy appears to be increasing. Black  female children and adolescents have an increased risk for cardiovascular disease.

  The Cardiovascular Special Study Center is pleased to announce the creation of a message board on the Cardiovascular SSC portion of the USRDS website. The purpose of this message board is to provide an open forum for discussion of issues related to cardiovascular disease and chronic kidney disease.  It is anticipated that topics of specific interests may be posed for the forum audience for discussion.

In March 2002 an important milestone was reached by the Cardiovascular Special Studies Center, the publication of its first major research project. The paper “Long-term survival of dialysis patients in the U.S. with prosthetic heart valves: should ACC/AHA practice guidelines and valve selection be modified” is the first USRDS paper to ever appear in the Journal Circulation.

  Current practice guidelines of the American College of Cardiology/American Heart Association task force on the management of patients with valvular heart disease proscribed the use of bioprosthetic (tissue) valves in hemodialysis patients. In this paper (Circulation 2002:105:1336-1341) dialysis patients hospitalized for heart valve replacement surgery from 1978-1998 were retrospectively identified from the USRDS database. The in hospital mortality of 5,858 dialysis patients undergoing heart valve surgery was 20.7%. Aortic valve replacement was performed in 3,415 patients (58%), mitral valve replacement in 1,848 patients (32%), and combined aortic and mitral valve replacement in 562 (10%). Tissue valves were used in 881 patients.  There was no significant difference of survival related to the type of prosthetic heart valve used for surgery. The estimated 2-year survival rate was 39.7± 3.5% with tissue valves versus 39.7± 1.4% for non-tissue valves. Compared with non-tissue prosthetic valves, the use of tissue valves was not predictive of death (relative risk 0.98; 95% confidence interval, 0.90 to 1.07).

  In the current task ACC/AHA task force recommendations the use of bioprosthetic valves in hemodialysis patients is classified as a class III indication (“conditions for which there is evidence and/or general agreement that the procedure/treatment is not useful and in some cases may be harmful”). This task force recommendation was based on a widely held opinion that the risk of bioprosthetic valve failure mandates the use of mechanical prosthetic valves in hemodialysis patients, in part arising from concerns regarding rapid calcification of bioprosthetic valves in dialysis patients. This paper by the Cardiovascular SSC investigators challenges the designation of valve replacement with bioprostheses as a class III indication in patients on hemodialysis. The article concludes that current recommendations regarding the proscription of bioprosthetic heart valves in hemodialysis patients should be rescinded.

  The interested reader is also referred to topics of related interest at the Circulation website www.circulationaha.org. Other websites, which would also be of interest, are the American Heart Association www.americanheart.org, and the American College of Cardiology www.acc.org.