Assessment of the fate of myocardial necrosis by serial myocardial perfusion imaging

BACKGROUND: Myocardial necrosis after myocardial infarction (MI) is common; extent and severity are however variable. The pattern is recognized by myocardial perfusion imaging (MPI) as fixed perfusion defects (FPD). The fate of such FPD is not well appraised. This study addressed this important issue in a large number of patients undergoing serial MPI in relation to type of intervening therapy. METHODS: Patients with prior MI or MPI-evidence of myocardial necrosis undergoing serial MPI without intervening acute coronary syndromes were included. The fate of necrosis by MPI on per-patient and per-region analysis was analyzed, factoring also the impact of intervening coronary revascularization (CR). RESULTS: A total of 3691 patients with 25,837 regions were identified, including 1413 (38.3%) subjects with 3358 (13.0%) regions exhibiting necrosis. Serial MPI after 29±21 months confirmed the persistent presence of myocardial necrosis FPD in the vast majority of patients and regions (86%); the consistency was even higher in the presence of moderate or severe necrosis (99%). Neither type nor site of CR significantly impacted on the presence and extent of myocardial necrosis at multivariable analysis. CONCLUSIONS: The finding of myocardial necrosis by MPI remains highly consistent over time, and is not significantly altered by CR.