The utility of global longitudinal strain in the identification of prior myocardial infarction in patients with preserved left ventricular ejection fraction

Prior myocardial infarction (MI) is associated with increased mortality and is prevalent in certain high risk patient groups. Electrocardiogram may be used in diagnosis, however, sensitivity is limited, thus non-invasive imaging techniques may improve diagnosis. We investigated whether global longitudinal strain (GLS) and longitudinal strain parameters are reduced in patients with prior MI but preserved left ventricular ejection fraction (LVEF). The study included 40 clinical patients with prior MI occurring >3 months previously (defined as subendocardial hyperenhancement on late Gadolinium enhancement imaging) with LVEF ≥ 55% and 40 controls matched for age and LVEF. GLS, global longitudinal strain rate (GLSR) and early diastolic longitudinal strain rate (GLSRe) were measured from cine imaging feature tracking analysis. Presence of wall motion abnormality (WMA) and minimum systolic wall thickening (SWT) were calculated from cine imaging. GLS was -17.3 ± 3.7% in prior MI versus -19.3 ± 1.9% in controls (p = 0.012). GLSR was -88.0 ± 33.7%/s in prior MI versus -103.3 ± 26.5%/s in controls (p = 0.005). GLSRe was 76.4 ± 28.4%/s in prior MI versus 95.5 ± 26.0%/s in controls (p = 0.001). GLS accurately identified prior MI AUC 0.662 (95% CI 0.54-0.785) p = 0.012 whereas WMA AUC 0.500 (95% CI 0.386-0.614) p = 1.0 and minimum SWT AUC 0.609 (95% CI 0.483-0.735) p = 0.093 did not. GLS, GLSR and GLSRe are reduced in prior MI with preserved LVEF. Normal LVEF and lack of WMA cannot exclude prior MI. Prior MI should be considered when reduced GLS, GLSR or GLSRe are detected by non-invasive imaging.