Summed thickening score by myocardial perfusion imaging: A risk factor of left ventricular remodeling in patients with myocardial infarction

Abstract

BackgroundLeft ventricular (LV) remodeling has adverse effects on the prognosis of patients with myocardial infarction (MI). The aim of this study is to identify the risk factors of LV remodeling in MI patients by radionuclide myocardial imaging. Methods and ResultsThis retrospective study consisted of 92 patients who had a history of definite prior MI on ECG and underwent both resting gated single photon emission computed tomography (SPECT) myocardial perfusion imaging (MPI) and positron emission tomography (PET) myocardial metabolism imaging. LV remodeling was defined as > mean + 2SD of LV end-diastolic volume index (LVEDVi) in the normal database. LV enlargement, cardiac dysfunction, wall thickening abnormalities expressed as summed thickening score (STS) were more severe in the old MI patients as compared to those with subacute MI. STS (Odds ratio, 1.296; P = .004) and the proportion of segments with reduced wall thickening in segments with normal perfusion (Odds ratio, 1.110; P = .001) were identified as the independent factors of LV remodeling in subacute and old MI patients in the multivariate binary regression model. Total perfusion deficit (TPD), viable myocardium, scar, and the proportion of segments with reduced wall thickening in segments with decreased perfusion showed strong correlation with LV remodeling in the univariate regression model as well. ConclusionsLV remodeling in old MI patients is more extensive and severe than that in subacute MI patients. LV wall thickening abnormalities as expressed by STS and the proportion of segments with reduced wall thickening in segments with normal perfusion are the independent risk factors of LV remodeling in MI patients.