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Potential Prediction of Myocardial Viability Using Strain/Strain Rate at Low-Dobutamine Stress Echocardiography on a Segment-by-segment Basis

Background: It is crucial to determine if the myocardium with highly impaired function is irreversibly harmed or reversibly dysfunctional in acute myocardial infarction. Although dobutamine-induced wall motion improvement is suitable for assessing viability, it is vulnerable to significant inter- and intra-observer variability because it is subjective. Objectives: It was determined whether peak longitudinal strain (PLS) and peak longitudinal strain rate (PLSR) in individual myocardial segments with low dose dobutamine stress echocardiography (LDDSE) could diagnose myocardial viability in patients with acute ST segment elevation myocardial infarction using delayed contrast-enhanced cardiac magnetic resonance (DE-CMR) as a reference (STEMI). Patients and Methods: This study included 60 individuals who had been in the hospital for at least three months after acute myocardial infarction. LDDSE with delayed contrast-enhanced cardiac magnetic resonance and offline deformation indices analysis was performed on all patients. Results: There were 268 segments having significant resting wall motion anomalies available for the final analysis. Dobutamine-induced peak longitudinal strain was greater in viable than non-viable segments in all investigated individual myocardial segments (< 0.001 for mid inferoseptum, p=0.001 for mid inferolateral, and < 0.001 for all other segments). Furthermore, dobutamine-induced peak longitudinal strain rate was significantly lower in non-viable segments compared to viable segments within the studied individual myocardial segments (p< 0.001 for basal antro-septum, < 0.001 for apical inferior, <0.001 for mid inferolateral, < 0.001 for mid antrolateral, <0.001 for mid inferoseptum, <0.001 basal anterior, <0.001 for basal inferolateral, <0.001 basal inferoseptum, and < 0.001 for all other segments). Conclusion: Dobutamine-induced peak longitudinal strain and strain rate could predict myocardial viability segment by segment in those suffering from acute ST segment elevation myocardial infarction. The study used delayed contrast-enhanced cardiac magnetic resonance (DE-CMR) as a reference to determine whether LDDSE can detect myocardial viability in those suffering from acute ST segment elevation