Myocardial viability assessment in patients with highly impaired left ventricular function: comparison of delayed enhancement, dobutamine stress MRI, end-diastolic wall thickness, and TI201-SPECT with functional recovery after revascularization

Abstract

This study compared different magnetic resonance imaging (MRI) methods with Tl(201) single photon emission computerized tomography (SPECT) and the "gold standard" for viability assessment, functional recovery after coronary artery bypass grafting (CABG). Twenty patients (64+/-7.3 years) with severely impaired left ventricular function (ejection fraction [EF] 28.6+/-8.7%) underwent MRI and SPECT before and 6 months after CABG. Wall-motion abnormalities were assessed by stress cine MRI using low-dose dobutamine. A segment with a nonreversible defect in Tl(201)-SPECT and a delayed enhancement (DE) in an area >50% of the entire segment, as well as an end-diastolic wall thickness <6 mm, was defined as nonviable. The mean postoperative EF (n=20) improved slightly from 28.6+/-8.7% to 32.2+/-12.4% (not significant). Using the Tl(201)-SPECT as the reference method, end-diastolic wall thickness, MRI-DE, and stress MRI showed high sensitivity of 94%, 93%, and 84%, respectively, but low specificities. Using the recovery of contractile function 6 months after CABG as the gold standard, MRI-DE showed an even higher sensitivity of 99%, end-diastolic wall thickness 96%, stress MRI 88%, and Tl(201)-SPECT 86%. MRI-DE showed advantages compared with the widely used Tl(201)-SPECT and all other MRI methods for predicting myocardial recovery after CABG.

Prevalence and functional impact of lipomatous metaplasia in scar tissue following myocardial infarction evaluated by MRI

“…Other locations were affected with decreasing frequency (number in parenthesis): the mid-cavity inferior and inferolateral segments (6), basal inferolateral and midcavity anterior (5), basal anteroseptal and anterolateral as well as mid-cavity anterolateral (4) segments. Less common locations were the basal anterior and inferior segments and the apex (3) itself, apical lateral and anterior (2). In one case LM could be found in the mid-cavity inferoseptal segment.…”

“…Functional and volumetric assessment of the heart The left ventricular (LV) ejection fraction (EF) and stroke volume (SV) were calculated by measuring the enddiastolic (EDV) and end-systolic volumes (ESV) using the Simpson's rule on short axis slices as previously described [2].…”

“…Post-MI healing with scar development has been considered to be completed after 6-8 weeks [1]. Necrosis and scar tissue can easily be visualised by magnetic resonance imaging (MRI) using the technique of late gadolinium-DTPA enhancement (LGE) [2]. Approximately 12 to 16 weeks post-MI wall thinning occurs as the end-stage of the remodelling process [3].…”

Magnetic Resonance Imaging of the Failing Heart

“…When assessing myocardial viability and in the prediction of pharmacological, interventional, and surgical treatmentt he combination of the three described CMr methods (cine, stress perfusion, and late enhancement) should be used (19)(20)(21). Assessment of aortic and pulmonary valve regurgitation with CMrisreliable and widely used to complement the observationswith echocardiography,especially in patients with corrected congenital heart disease (22).…”

Automated regional wall motion abnormality detection by combining rest and stress cardiac MRI: Correlation with contrast‐enhanced MRI

“…CE-MRI allows imaging of myocardial infarction, in which scar tissues appear hyperenhanced, and the extent of infarction is the main predictor for functional outcome after revascularization. Head-to-head comparisons for predicting functional improvement between rest-stress MR study with infarct transmurality from CE-MRI have been performed and they have been proven to be correlated (6)(7)(8).…”