Transmural Extent Of Late Gadolinium Enhancement Research Articles

Impact of Myocardial Viability on Long-term Outcomes after Surgical Revascularization.

This study was conducted to evaluate whether myocardial viability assessed with cardiac magnetic resonance (CMR) affected long-term clinical outcomes after coronary artery bypass grafting (CABG) in patients with ischemic cardiomyopathy (ICMP). Preoperative CMR with late gadolinium enhancement (LGE) was performed in 103 patients (64.9 ± 10.1 years, male:female = 82:21) with 3-vessel disease and left ventricular dysfunction (ejection fraction ≤ 0.35). Transmural extent of LGE was evaluated on a 16-segment model, and transmurality was graded on a 5-point scale: grades-0, absence; 1, 1 to 25%; 2, 26 to 50%; 3, 51 to 75%; 4, 76 to 100%. Median follow-up duration was 65.5 months (interquartile range = 27.5-95.3 months). Primary endpoint was the composite of all-cause mortality or hospitalization for congestive heart failure. Operative mortality was 1.9%. During the follow-up, all-cause mortality and readmission for congestive heart failure occurred in 29 and 8 patients, respectively. The cumulative incidence of the primary endpoint was 31.3 and 46.8% at 5 and 10 years, respectively. Multivariable analysis demonstrated that the number of segments with LGE grade 4 was a significant risk factor (hazard ratio 1.42, 95% confidence interval 1.10-1.83, p = 0.007) for the primary endpoint among the variables assessed by CMR. Other risk factors included age, dialysis, chronic obstructive pulmonary disease, and EuroSCORE II. The number of myocardial segments with transmurality of LGE >75% might be a prognostic factor associated with the composite of all-cause mortality or hospitalization for congestive heart failure after CABG in patients with 3-vessel disease and ICMP.

Association Between Myocardial Scar Burden and Left Ventricular Ejection Fraction in Ischemic Cardiomyopathy.

BackgroundThis study was conducted to assess the relationship between scar burden (extent and severity) and the follow-up left ventricular ejection fraction (LVEF).MethodsPatients were referred for viability assessment with late gadolinium enhancement (LGE) on cardiovascular magnetic resonance imaging. To measure the transmural extent of LGE in each segment (scar score), we used a five-point scale system. Baseline ejection fraction (EF) and at follow-up were recorded. LVEF classified as non-severe and severely depressed.ResultsThe study included 178 patients (males: 88.8%; mean age: 57.1±10.02 years; mean baseline LVEF: 28.61±10.39). In patients with severe baseline LVEF, the mean scar percentage was higher than that in patients who had non-severe LVEF (38.8±19.41 vs. 24.61±21.21; p˂0.001). On linear regression analysis, aldosterone antagonist and total scar score significantly predicted follow-up ejection fraction (EF) (B=-7.083, p˂0.001 and B=-3.038, p=0.038, respectively). Left anterior descending artery (LAD) territory viability and baseline EF significantly predicted change in EF in patients with LVEF ≤ 35% (B=5.389, p=0.009 and B=-0.581, p˂0.001, respectively). On binary regression analysis for the prediction of at least 5% improvement in EF in patients with baseline EF ≤ 35%, baseline EF and LAD viability were significant (B=-0.15, p=0.014 and B=1.042 and p=0.054, respectively).ConclusionsThe extent of myocardial scar and viability of LAD territory are identified as the important and independent parameters for the predictions of improvement in EF even after adjustment for demographics and baseline EF and following the standards of care medication.

Cardiac Function by Magnetic Resonance Imaging in Coronary Artery Occlusions After Kawasaki Disease.

To clarify ventricular function in patients with asymptomatic coronary artery occlusion (ACAO) after Kawasaki disease (KD).Methods and Results:We enrolled 65 patients with coronary artery lesions who had undergone cardiac magnetic resonance (CMR). Median age at CMR was 29 years. CMR was performed to evaluate only the transmural extent of late gadolinium enhancement (LGE) and ejection fraction (EF). Based on the depth of LGE, it was classified into 5 groups: 0% (G0), 1-25% (G1), 26-50% (G2), 51-75% (G3), and 76-100% (G4). We investigated the relationship of the degree of LGE and EF. Further, we also evaluated the EF among 3 groups [ACAO, myocardial infarction (MI), and noncoronary artery occlusion (Non-CO)]. The grade of LGE and the LVEF (mean±SD, %) were as follows: G0 (n=24, 52.6±4.8), G1 (n=13, 50.8±4.4), G2 (n=15, 49.1±5.6), G3 (n=9, 30.9±9.1), and G4 (n=9, 27.7±6.8). LVEF in patients with G3 and G4 was significantly low (P<0.05). LVEF (%) in patients with ACAO, MI, and Non-CO were 50.5±4.8 (n=38), 33.6±10.8 (n=17), and 53.0±5.7 (n=10), respectively. LVEF in the MI group was significantly low (P<0.0001). LGE >50% can lead to LV dysfunction. The transmural extent of LGE in most of the study patients with ACAO was ≤50% and they had subendocardial infarction, with preserved LV function.

Serial cardiac magnetic resonance imaging after surgical coronary revascularization for left ventricular dysfunction

ObjectivesSerial changes in segmental myocardial function after surgical myocardial revascularization have not been well demonstrated. This study was conducted to evaluate improvements in segmental myocardial function after coronary artery bypass grafting in patients with left ventricular dysfunction. MethodsSerial cardiac magnetic resonance with late gadolinium enhancement (LGE) was performed in 67 patients with left ventricular ejection fraction ≤0.35, preoperatively and at 3 months and 1 year after surgery. The wall motion score and transmural extent of LGE were evaluated on a 16-segment model. Changes in segmental myocardial function were evaluated according to the transmurality of LGE (5-point scale: grade 0 = absence of LGE, 1 = LGE 1%-25%, 2 = LGE 26%-50%, 3 = LGE 51%-75%, and 4 = LGE 76%-100%). ResultsOf 908 segments in which 1-year graft patency was confirmed, 657 dysfunctional segments (378 hypokinesia, 275 akinesia, 2 dyskinesia, and 2 aneurysm) were evaluated. The LGE grades were 0, 1, 2, 3, and 4 in 235, 187, 127, 59, and 49 segments, respectively. Segmental myocardial function improved in 56.5% (371 out of 657 segments) and 58.9% (387 out of 657 segments) of dysfunctional segments at 3 months and 1 year, respectively. Of LGE grades 0, 1, 2, 3, and 4 segments, improved wall motion was observed with an inverse correlation in 71.1% (167 out of 235 segments), 55.1% (103 out of 187 segments), 49.6% (63 out of 127 segments), 40.7% (24 out of 59 segments), and 28.6% (14 out of 49 segments) at 3 months and in 74.0% (174 out of 235 segments), 57.2% (107 out of 187 segments), 52.8% (67 out of 127 segments), 44.1% (26 out of 59 segments), and 26.5% (13 out of 49 segments) at 1 year, respectively. ConclusionsOne third of segments with a transmural extent of LGE >50% still had a chance for improvement after revascularization, although an inverse correlation was seen between the LGE grade and improvement of segmental myocardial function.

125 Myocardial Extracellular Volume Estimation by Cardiovascular Magnetic Resonance Predicts Functional Recovery Following Acute Myocardial Infarction

Background The transmural extent of myocardial infarction (MI) assessed by late gadolinium enhancement (LGE) cardiovascular magnetic resonance (CMR) is a reference standard for prediction of functional recovery. In acute MI (AMI), myocardial oedema and effects of reperfusion therapy reduce the predictive accuracy of LGE. LGE assesses tissue dichotomously as “viable” or “non-viable”, but does not consider severity of tissue damage within the hyperenhanced infarct zone. Extracellular volume (ECV) estimation, using native and post-contrast T1 mapping CMR, allows for quantitative assessment of severity of myocardial damage. We aimed to assess if CMR measurement of infarct ECV offers additional predictive value over LGE extent for contractile recovery in reperfused AMI. Methods 35 patients with first ST-segment elevation AMI treated by primary percutaneous coronary intervention underwent acute (day 2) and convalescent (3 months) CMR at 3 Tesla. Cine imaging, tissue tagging, modified Look-Locker inversion T1 mapping (3–3–5 acquisition with 3x R-R interval recovery epochs) natively and 15 min post gadolinium-contrast administration and LGE imaging at 20 min were performed. The ability of acute infarct ECV and acute transmural extent of LGE to predict convalescent wall motion, ejection fraction (EF) and strain were compared. A per-patient analysis was performed using a region of interest corresponding to the core of the infarct, excluding any microvascular obstruction (MO). Segmental analysis was also performed and evaluated using a multilevel linear mixed-effects model to account for non-independence of segmental data. Results Per-patient, ECV and transmural extent of LGE correlated with convalescent wall motion score (r = 0.43, p Conclusions Acute infarct ECV in reperfused AMI predicts LV functional recovery, and is both independent of and more accurate than transmural extent by LGE. There is clinical utility for ECV mapping post-AMI.

Improved Wall Motion of Late Gadolinium-Enhanced Myocardium After Complete Surgical Revascularization

Gadolinium-enhanced cardiac magnetic resonance (CMR) imaging suggests a low possibility of myocardial function improvement after revascularization if the transmural extent of late gadolinium enhancement (LGE) was over 50%. We evaluated myocardial wall motion in patients who underwent complete revascularization for left ventricular dysfunction. Thirty-three patients with left ventricular dysfunction (ejection fraction ≤ 0.35) underwent complete revascularization. Gadolinium-enhanced CMR was performed preoperatively and postoperatively (postoperative 24.1 ± 17.6 months). Postoperative coronary angiograms were also performed to confirm graft patency. Wall motion score and transmural extent of LGE were evaluated on a 16 segment model of short-axis images. Of 528 total segments, 373 dysfunctional segments (70.6%; 189 hypokinesia, 177 akinesia, 6 dyskinesia, and 1 aneurysm) were evaluated for postoperative changes. When LGE was graded on a 5 point scale (absence of LGE, grade 0; LGE of 1% to 25%, grade 1; 26% to 50%, grade 2; 51% to 75%, grade 3; and 76% to 100%, grade 4), LGE was found in 221 (59%) segments (grades 1, n = 80; 2, n = 55; 3, n = 37; and 4, n = 49). After revascularization, wall motion improved in 72.1% (269 of 373) of dysfunctional segments (128 of 189 hypokinesia versus 141 of 184 akinesia; p = 0.055). Improved wall motion was observed in 77.0% (117 of 152), 67.5% (54 of 80), 69.1% (38 of 55), 86.5% (32 of 37), and 57.1% (28 of 49) of grades 0, 1, 2, 3, and 4 segments, respectively. Improved motion of late gadolinium-enhanced myocardium, even in segments showing transmural LGE of 75% or greater and akinesia, was observed after complete revascularization. An inverse proportional correlation between the transmural extent of LGE and wall motion improvement was not observed.

Predictive power of late gadolinium enhancement for myocardial recovery in chronic ischaemic heart failure: a HEART sub-study.

The amount of myocardial scar measured by late gadolinium enhancement (LGE) cardiovascular magnetic resonance (CMR) imaging predicts regional recovery in wall motion following revascularization. Previous studies have been conducted in patients with a relatively recent myocardial insult and relatively preserved left ventricular (LV) function. In this sub-study of a clinical trial, the predictive value of LGE, and other CMR-derived data, for myocardial recovery in patients with chronic severe ischaemic cardiomyopathy was assessed. Twenty-two patients with severe LV impairment of ischaemic origin were enrolled as a sub-study of a trial that randomly assigned patients to revascularization or not in addition to guideline-indicated pharmacological therapy. Patients underwent a CMR study at baseline and 6 months. Scans were qualitatively and quantitatively assessed for wall motion, rest/stress myocardial perfusion, and LGE. The median duration of heart failure was 13 (inter-quartile range 5-21) months. Patients had severe LV dilatation [end-diastolic volume (EDV) 280 ± 77 mL] and reduction in LV ejection fraction (LVEF) (29 ± 10%). The percentage scar burden by LGE was 17 ± 9%. Patient characteristics of those undergoing revascularization (n = 7) or not (n = 14) were similar. Myocardial perfusion reserve index (MPRI) improved following revascularization (MPRI 1.17 vs. 1.57, P < 0.0001) but not following medical therapy (1.39 vs. 1.32, P = 0.54). However, LVEF improved in patients whether or not they had revascularization. In the revascularization group, 14% of dysfunctional segments with LGE <25% and 22% of dysfunctional segments with LGE <50% had improved contractile function. However, the transmural extent of LGE did not predict contractile recovery following revascularization or pharmacological therapy (P = 0.19, P = 0.42). LVEDV improved overall (280 ± 77 to 269 ± 83 mL, P = 0.05); improvement was associated with heart failure duration (P = 0.04). In patients with chronic severe LV impairment of ischaemic origin, duration of heart failure is a better predictor of recovery than transmural extent of LGE, following medical therapy or successful revascularization. This suggests that the extent of myocardial remodelling is more important for LV recovery than the presence and extent of prior infarction alone and that LGE should not be the sole determinant of treatment method in severe LV systolic dysfunction of ischaemic origin.

Myocardial Infarction Without Coronary Artery Stenosis Illustrated by Tc-99m Pyrophosphate Scan, Cardiac Magnetic Resonance Imaging, and Myocardial Perfusion Scintigraphy

A 42-year-old woman presented with chest pain and ECG changes suggestive of acute myocardial infarction. However, a coronary angiogram showed no significant epicardial coronary stenosis. Nonetheless, abnormal Tc-99m pyrophosphate activity accumulated within the inferolateral wall, consistent with acute necrosis. Cardiac magnetic resonance revealed near transmural extent of late gadolinium-enhancement with mild hypokinesis in the mid to basal inferolateral segments. Dipyridamole Tl-201 single photon emission computed tomography 6 months later demonstrated stress-induced ischemia in the corresponding area, with subendocardial scar in the mid level. Nuclear perfusion scintigraphy is needed for accurate assessment of infarct size and coronary flow after the acute stage of a myocardial infarction has passed.