Factors Can Predict Sudden Cardiac Death in Dialysis Patients
VANCOUVER, B.C.—A German team is gathering information to create a tool to accurately predict which dialysis patients are most likely to succumb to sudden cardiac death.
Sudden cardiac death is responsible for 26% of deaths among diabetic patients on dialysis, Christoph Wanner, MD, told attendees at the 20112 World Congress of Nephrology.
Previous research has shown that when estimated glomerular filtration rate falls below 30 mL/min/1.73 m2, a form of cardiovascular pathology distinct from atherosclerosis emerges, said Dr. Wanner, Professor of Nephrology at University Clinic, Würzburg, Germany. This is characterized by vascular stiffness, structural heart disease and sympathetic overactivity. These lead to an increased risk of arrhythmia, heart failure and sudden death.
In an analysis of follow-up results of 1,255 type 2 diabetes patients on dialysis who took part in the 4D study, levels of N-terminal pro b-type natriuretic peptide (NT-pro-BNP), hemoglobin A1c (HbA1c) and albumin were the only three biomarkers significantly associated with sudden cardiac death, Dr. Wanner explained (Circulation. 2009;120:2421-2428; Eur Heart J. 2008;29:2092-2099). 4D was a randomized, controlled trial of atorvastatin versus placebo (N Engl J Med. 2005; 353:238-248).
“We deduced that NT-pro-BNP can be helpful in borderline cases, enabling further distinction of those patients into groups of high versus low risk of sudden cardiac death,” Dr. Wanner told listeners. The combination of NT-pro-BNP with albumin and HbA1c is highly predictive of sudden cardiac death, he said.
His team is developing a score to identify patients who are at high versus low risk of sudden cardiac death based on these and other easily obtainable prognostic indicators in patients' history and laboratory values.
Among the other indicators uncovered by research conducted by Dr. Wanner and his collaborators as well as other investigators are severe wasting, poor glycemic control (Circulation 2009;120:2421-2428), vitamin D deficiency (Eur Heart J. 2010;31:2253-2261; Nephrol Dial Transplant 2011;26:1024-1032), and a concurrent decrease in level of parathyroid hormone and body mass index (Nephrol Dial Transplant. 2011;26:1340-1346).
Dr. Wanner described an analysis he has undertaken to pinpoint the prognostic value of various indicators. Elements of patient history shown to be associated with sudden cardiac death in 4D subjects are the presence of coronary artery disease and peripheral vascular disease. Biomarkers predictive of sudden death include elevated HbA1c, hypoalbuminuria, and elevated NT-pro-BNP. Their overall discriminative ability is 0.72, which is highly statistically significant, said Dr. Wanner.
“This was a good talk because it gave statistical weight to what we know clinically,” said Anna Maria Ukdahl, MD, a nephrologist at Ornskoldsvik Hospital in Ornskoldsvik, Sweden, who attended Dr. Wanner's presentation.