Assessment of viable myocardium by nitrate-augmented technetium-99m sestamibi myocardial perfusion imaging

Abstract

Objective The aim of this study was to assess the role of nitrate-augmented technetium-99m (99mTc) sestamibi imaging in the evaluation of viable myocardium in patients who had ischemic heart disease with depressed left ventricle (LV) systolic function. Background In the setting of acute myocardial infarction, stunning can occur, which is the persistent LV dysfunction following opening of the occluded coronary artery; recovery of function occurs usually within months. In the setting of chronic LV dysfunction, the pathophysiology underlying the dysfunction is referred to as myocardial hibernation. Various imaging techniques have been introduced to detect viability and discriminate this from scar tissue. Patients and methods Between November 2015 and November 2016, 100 patients with a history of myocardial infarction 'functional class II and III' or/and LV dysfunction were included in this multicenter prospective study. All patients underwent 99mTc sestamibi myocardial perfusion imaging under both rest and rest with nitrate conditions. Results Nitrates improved viability detection by myocardial perfusion imaging in patients with depressed LV systolic function. There was significant decrease in the total perfusion defect in rest with nitrate study in comparison with the rest study (P = 0.006). Conclusion In patients with chronic ischemic heart disease with depressed LV systolic function, the use of nitrate-augmented Tc-99m sestamibi protocol in cardiac single photon emission computed tomography imaging results in improved detection of viable but hypoperfused segments. It is a good indicator for differentiating viable tissues from the scar.