Association between the size of myocardial infarction measured by gated-SPECT and adverse left ventricular remodeling

Abstract

Introduction: Increased ventricular volumes after acute myocardial infarction (AMI) is associated with increased mortality and heart failure. The discovery of methods that allow to predict an adverse left ventricular remodeling (ALVR) would favour the identification of a population in higher risk. Objective: To evaluate the association between infarct size (IS) measured by gated-SPECT, and ALRV in the follow-up of patients with AMI. Material and methods: Patients with ST-segment elevation MI evaluated with rest SPECT (with IS measurement) and echocardiogram (ECHO) during hospitalization and between 6 to 18 months of follow-up were analyzed. ALVR was defined as an increase in end diastolic diameter (EDD) by ECHO greater than or equal to 20% in follow-up. The association of IS measured by gated-SPECT and other variables with ALVR was evaluated. Results: There were 151 patients, with an average age of 61 years (±10); 80% male, 13% diabetics. The median IS by SPECT was 17% (3-29) and ALVR was found in 7% (n=10). IS was correlated with EDD in follow-up, finding a linear ascending association between both (r=0.4; p=0.0001; R2=0.15). In extensive infarction (≥31%), a higher percentage of ALVR was observed (16% [3-27] vs 43% [29-52], p: 0.0001). A multivariate analysis was performed, finding statistical significance only with IS measured by gated-SPECT (OR: 1.08, 95% CI: 1-1.17, p: 0.04). Conclusion: A significant association was found between the IS measured in the acute phase by cardiac gated-SPECT and the ALVR evaluated by echocardiogram in follow-up.