Association Between Abnormal Myocardial Fatty Acid Metabolism and Cardiac-Derived Death Among Patients Undergoing Hemodialysis: Results From a Cohort Study in Japan

Background: Detecting myocardial ischemia in hemodialysis patients is crucial given the high incidence of silent ischemia and the high cardiovascular mortality rates. Abnormal myocardial fatty acid metabolism as determined by imaging with I-123-labeled BMIPP (beta-methyl iodophenyl-pentadecanoic acid) might be associated with cardiac-derived death in hemodialysis patients. Study Design: Prospective observational study. Setting & Participants: Asymptomatic hemodialysis patients with one or more cardiovascular risk factors, but without known coronary artery disease, were followed up for 3 years at 48 Japanese hospitals (406 men, 271 women; mean age, 64 years). Predictor: Baseline BMIPP summed scores semiquantified using a 17-segment 5-point system (normal, 0; absent, 4). Outcomes: Cardiac-derived death, including cardiac and sudden death. Measurements: HRs were estimated using a Cox model for associations between BMIPP summed scores and cardiac-derived death, adjusting for potential confounders of age, sex, body mass index, dialysis duration, and cardiovascular risk factors. Results: Rates of all-cause mortality and cardiac-derived death were 18.5% and 6.8%, respectively. Cardiac-derived death (acute myocardial infarction [n = 10], congestive heart failure [n = 13], arrhythmia [n = 2], valvular heart disease [n = 1], and sudden death [n = 20]) accounted for 36.8% of all-cause deaths. Cardiac-derived death (n = 46) was associated with age, history of heart failure, and BMIPP summed scores of 4 or higher (HR, 2.9; P < 0.001). Three-year cardiac-derived death-free survival rates were 95.7%, 90.6%, and 78.8% when BMIPP summed scores were 3 or lower, 4-8, and 9 or higher, respectively. BMIPP summed score also was a predictor of all-cause death (HR, 1.6; P = 0.009). Limitations: Sudden death of unknown cause was considered to have been cardiac derived, although a coronary origin was not confirmed. Conclusions: Abnormal myocardial fatty acid metabolism is associated with cardiac-derived death in hemodialysis patients. BMIPP single-proton emission computed tomography appears clinically useful for predicting cardiac-derived death in this population. Am J Kidney Dis. 61(3):466-475. (C) 2013 by the National Kidney Foundation, Inc.