Increased Risk of Systolic Cardiac Dysfunction in Renal Failure Patients

An often asymptomatic condition—systolic dysfunction, or decreased pumping of the heart—poses an increased risk of death for patients on kidney transplant waiting lists, according to a study appearing in the June 2008 issue of the Journal of the American Society Nephrology (JASN). The findings reveal that a clinical indicator beyond well-known risk factors for cardiovascular mortality should be considered when caring for patients waiting for kidney donations. The study also suggests that changes in organ allocation policies may be warranted.

Previous research has shown that patients with chronic kidney disease face an elevated risk of dying from heart conditions, such as cardiac ischemia, which occurs when the heart receives an insufficient supply of blood and oxygen. However, ischemic events do not account for most of the cardiac deaths that have been reported in these patients.

To determine what other heart effects may be playing a role in the deaths of patients with chronic kidney disease, Dr. Angelo M. de Mattos, an associate professor of nephrology at the University of California, Davis, School of Medicine and Medical Center in Sacramento, Calif., and colleagues at the University of Alabama at Birmingham analyzed the records for 2,718 kidney transplant candidates, noting the causes of death in those who died. During the study, 681 patients died during follow-up, which was conducted for a median of 27 months.

The investigators discovered that patients with systolic dysfunction were nearly twice as likely to die as those without this condition. This higher rate of mortality was similar to that seen in patients with cardiac ischemia, the most well-known risk factor for cardiovascular death in patients with chronic kidney disease.

Dr. de Mattos and his team found that death rates for patients with systolic dysfunction who were waiting for kidney transplants were almost six-fold higher than the reported mortality for individuals with systolic dysfunction in the general population.

A weakness in ATP utilization in the kidney may portend poor ATP function in other organs. The study “identifies a subset of the chronic kidney disease population (those with systolic dysfunction, with or without ischemia) at significantly higher mortality risk while awaiting transplantation” the authors write. Widely available and minimally invasive testing could be used to help identify those patients with chronic kidney disease who have this mostly asymptomatic, yet life-threatening, condition.

Editors note: May we suggest that patients with multiple disease states of unknown etiology, suffer from an underlying mitochondrial dysfunction, causing ATP deficiency which effects all organ function.

The American Society of Nephrology (ASN) is a not-for-profit organization of 11,000 physicians and scientists dedicated to the study of nephrology and committed to providing a forum for the promulgation of information regarding the latest research and clinical findings on kidney diseases. ASN publishes the Journal of the American Society of Nephrology (JASN), the Clinical Journal of the American Society of Nephrology (CJASN), and the Nephrology Self-Assessment Program (NephSAP). In January 2009, ASN will launch a newsmagazine.

Abstract

Individuals waiting for a renal transplant experience excessive cardiovascular mortality, which is not fully explained by the prevalence of ischemic heart disease in this population. Overt heart failure is known to increase the mortality of patients with ESRD, but the impact of lesser degrees of ventricular systolic dysfunction is unknown. For examination of the association between left ventricular ejection fraction (LVEF) and mortality of renal transplant candidates, the records of 2718 patients evaluated for transplantation at one institution were reviewed. During 6355 patient-years (median 27 mo) of follow-up, 681 deaths occurred. Patients with systolic dysfunction (LVEF 0.40) had significantly lower survival than those with higher systolic function (median 49 ± 3.1 versus 72 ± 4.0 mo; P < 0.001) but had similar survival to patients with ischemia (48 ± 2.5 mo). Multivariate modeling showed that those with systolic dysfunction were nearly twice as likely to die as those with normal systolic function, adjusted for risk factors including diabetes, left ventricular hypertrophy, and ischemia (adjusted hazard ratio 1.7; 95% confidence interval 1.43 to 2.07). In addition, a graded, reverse association between LVEF and mortality was identified. In conclusion, systolic dysfunction is strongly associated with mortality, in a graded manner, in renal transplant candidates.

Reference:

Angelo M. de Mattos, Andrew Siedlecki, et.al. Systolic Dysfunction Portends Increased Mortality among Those Waiting for Renal Transplant. J. Am. Soc. Nephrol. 0: ASN.2007040503v1.

American Society of Nephrology (ASN) Released: Thu 15-May-2008

Key concepts: kidney /renal failure, heart disease, systolic dysfunction