Serial Alterations and Prognostic Implications of Myocardial Perfusion and Fatty Acid Metabolism in Patients With Acute Myocardial Infarction

Abstract

Impaired fatty acid metabolism the myocardial infarction (MI)-related area has prognostic value, but can alter over time. The aim of this study was to correlate alterations in myocardial fatty acid uptake and perfusion assessed by serial imaging with future outcomes in post-MI patients. Following 2 imaging procedures using 15-4-iodophenyl-3-(R,S)-methylpentadecanoic acid (BMIPP) and perfusion tracers at an 11-month interval, 97 patients with acute MI were followed up for 33 months with respect to the primary endpoints of death, non-fatal MI and heart failure. Regional tracer uptake was semi-quantified for both the MI-related and remote coronary territories. A large BMIPP defect relative to a perfusion defect appeared on MI-related coronary territories. Thirteen patients with cardiac events had a greater prevalence of large BMIPP and perfusion defect scores for the MI-related areas on the first scan, previous MI, diabetes mellitus, and worsening of perfusion tracer uptake in the MI-related area than those without cardiac events. Multivariate analysis identified worsening perfusion in the MI-related area on the second scan, a large BMIPP defect in the same area on the first scan and previous MI as significant predictors with chi-square values of 3.48, 6.41 and 6.84, respectively. A combination of 3 predictors significantly (p<0.05) increased the global chi-square value to 15.45 compared with each chi-square value. The size of the infarct-related risk area assessed by early cardiac BMIPP imaging and deterioration of perfusion tracer uptake in the compromised area for the first 12 months following acute MI are related to future cardiac events, indicating a rationale for identifying metabolically damaged but viable myocardium for further risk stratification of post-MI patients.