Validation of echocardiographic two-dimensional speckle tracking longitudinal strain imaging for viability assessment in patients with chronic ischemic left ventricular dysfunction and comparison with contrast-enhanced magnetic resonance imaging.

The purpose of the present study was to compare longitudinal strain assessed by two-dimensional speckle tracking with scar tissue on contrast-enhanced magnetic resonance imaging (MRI) in patients with chronic ischemic left ventricular (LV) dysfunction. The aim was also to define a cutoff value for regional strain to discriminate between viable myocardium and transmural scar. Ninety patients with chronic ischemic LV dysfunction underwent transthoracic echocardiography to measure global and segmental (regional) longitudinal LV strain using two-dimensional speckle tracking and cine MRI followed by contrast-enhanced MRI to assess segmental LV function and the segmental/global (transmural) extent of scar tissue. The optimal cutoff value for regional strain to discriminate between segments with viable myocardium and segments with transmural scar was also determined. A good correlation was found between global LV strain and the global extent of scar tissue on contrast-enhanced MRI (R = 0.62, p <0.001). The mean segmental strain in segments without scar tissue was -10.4% +/- 5.2% compared with 0.6% +/- 4.9% in segments with transmural scar tissue (p <0.001). A strain value of -4.5% discriminated between segments with viable myocardium and segments with transmural scar tissue on contrast-enhanced MRI with a sensitivity of 81.2% and specificity of 81.6%. In conclusion, global and regional longitudinal strain measured with two-dimensional speckle tracking is associated with the global and regional (transmural) extent of scar tissue on contrast-enhanced MRI. A cutoff value of -4.5% for regional strain discriminated between segments with viable myocardium and those with transmural scar tissue on contrast-enhanced MRI with a sensitivity of 81.2% and specificity of 81.6%.