Prediction of Cardiac Death in Hemodialysis Patients by Myocardial Fatty Acid Imaging

Abstract

The aim was to evaluate the potential of single-photon emission computed tomography (SPECT) to predict cardiac death in chronic hemodialysis patients using the iodinated fatty acid analogue iodine-123 123I-beta-methyl iodophenyl-pentadecanoic acid (BMIPP). We previously reported that BMIPP SPECT could detect asymptomatic coronary artery disease with high sensitivity in hemodialysis patients. We prospectively enrolled 375 asymptomatic hemodialysis patients who had undergone dual SPECT using 123I-BMIPP and 201thallium (Tl) chloride. Patients who had a clinical history of myocardial infarction and/or coronary revascularization were excluded from the study. Uptake on SPECT images was graded in 17 segments on a 5-point scale (0 normal, 4 absent) and assessed as summed BMIPP or Tl scores. During a 3.6 +/- 1.0-year follow-up, 57 patients who had undergone coronary revascularization within 60 days of SPECT were excluded from the analysis. Among the remaining 318 patients (male/female: 170/148; 64 +/- 12 years of age), 50 died of cardiac events (acute myocardial infarction 22, congestive heart failure 17, cardiac sudden death 11). Stepwise Cox hazard analysis associated cardiac death with age (> or =70 years) and with severely abnormal BMIPP SPECT images (BMIPP summed scores > or =12: hazard ratio 21.894; p < 0.0001). Kaplan-Meier analysis showed that the cardiac death-free survival rates at 3 years were 61% and 98% in patients with BMIPP summed scores of > or =12 and <12, respectively. Severely impaired myocardial fatty acid metabolism, which might mainly reflect repetitive myocardial ischemia, can identify a high-risk group of cardiac death among hemodialysis patients.