Left Ventricular Scar Burden Research Articles

Abstract Tu141: Effect of Epicardial Application of Oxygenated Hydrogel on Scar Burden in a Rat Model of Myocardial Infarction

Background: Epicardial application of a bioadhesive at the time of experimental myocardial infarction (MI) has been shown to reduce ventricular scar burden in mice. This study assessed the impact of an oxygenated hydrogel (O 2 -hydrogel) on post-infarct cardiac function and scar burden in rats. Method: Experimental MI was performed in Lewis rats (age 12-15 weeks) by permanent ligation of the anterior interventricular artery. There were 3 cohorts in this study: 1. MI followed by epicardial application of hydrogel, 2. MI followed by epicardial application of O 2 -hydrogel, and 3. MI with no treatment. Left ventricular (LV) function was evaluated by transthoracic echocardiography (TTE) at baseline, immediately post-MI, and 3 weeks post-MI. LV scar burden was evaluated with histopathology performed 3 weeks post-MI. Result: Twenty-four rats were analyzed (hydrogel, n= 8; O 2 -hydrogel, n= 9; untreated, n=7). LV fractional shortening (FS) measured by TTE 3 weeks post-MI was significantly reduced compared with baseline in untreated rats (44.6±12.4 to 22.3±4.9, P=0.043; Figure 1) and hydrogel treated rats (32.4±6.0 to 14.9±5.2, P=0.018). No significant change in FS was observed in the O 2 -hydrogel treatment cohort (39.0±13.9 to 38.1±12.6, P=0.859). LV scar burden in the O 2 -hydrogel cohort was significantly lower than in the hydrogel alone and untreated cohorts (11.9% vs 39.9% and 36.2%, respectively; Figure 2). Conclusion: In this rat model, epicardial application of O 2 -hydrogel at the time of experimental MI is associated with greater preservation of LV function and significantly lower scar burden than application of hydrogel alone or no treatment.

Non-invasive electrocardiographic assessment of arrhythmic risk in ischaemic cardiomyopathy patients undergoing revasularisation

Abstract Background Ventricular arrhythmias are a leading cause of death in patients with ischaemic cardiomyopathy (ICM). Ischaemia is thought to increase arrhythmic risk and coronary revascularisation is frequently undertaken to reduce this risk, although the recent REVIVED-BCIS2 trial did not show a difference in the incidence of death, device therapies or sustained arrhythmias in patients assigned to have percutaneous coronary intervention (PCI) compared to optimal medical therapy alone(1). Purpose We assessed the mechanistic effects of revascularisation on arrhythmic risk in patients with ICM using non-invasive electrocardiographic imaging (ECGi). Methods Patients were eligible if they had a left ventricular ejection fraction (LVEF) <40%, extensive coronary disease (BCIS Jeopardy Score≥6) and were scheduled to undergo revascularisation with coronary artery bypass grafting or PCI. ECGi assessment was performed using a 252-electrode vest with anatomical co-registration using a CT thorax. Patients underwent stress perfusion cardiac magnetic resonance (CMR) imaging; both ECGi and CMR were conducted at baseline and 3 months post revascularisation(Figure 1). The primary outcome measure was dispersion of repolarisation measured using global activation recovery interval (ARI) dispersion. Secondary outcome measures included repolarisation time (RT) dispersion, mean ARI and LV ARI dispersion. We also assessed the relationship between ARI dispersion, revascularisation and left ventricular scar burden. Data are presented as mean ± SD or median [IQR]. Results Thirty patients were recruited between 2020-2023; age 67±11 years, 90% male, BMI 28±5 and baseline LVEF was 29±8%. Twelve patients underwent CABG, 18 (60%) had PCI. The BCIS jeopardy score was 10 [9-11] at enrolment and decreased to 2 [0-4] after revascularisation. The LV scar burden at baseline was 15.1±6.5% and the change at 3 months was -0.5±5% (p=0.70). ARI dispersion and LV ARI dispersion were correlated with LV scar burden (r=0.62,p=0.01 and 0.71,p=0.002 respectively). No differences were seen in ARI dispersion (44.5 vs 44.1, p=0.86) or secondary outcome measures before and after revascularisation (RT dispersion: 45.5 vs 44.7, p=0.49; Mean ARI: 281.3 vs 282.6, p=0.74; ARI dispersion: 44.5 vs 44.1, p=0.86; LV ARI dispersion: 38.4 vs 36.7, p=0.39)(Figure 2). The LVEF change on CMR at 3 months was +6.9±10%; no relationship was seen between change in LVEF and ARI dispersion. Conclusion Arrhythmic risk assessed by non-invasive ECGi was not altered by coronary revascularisation. LV ARI dispersion was highly correlated with scar burden, which is not altered by revascularisation. Future work includes analysis of perfusion data. Our results support the findings of the REVIVED arrhythmia study that revascularisation does not reduce arrhythmic risk in patients with ICM(1). ECGi derived LV ARI dispersion correlates with scar and may represent a non-invasive arrhythmic risk assessment tool.Figure 1Figure 2

Deep learning for automatic volumetric segmentation of left ventricular myocardium and ischaemic scar from multi-slice late gadolinium enhancement cardiovascular magnetic resonance.

This study details application of deep learning for automatic volumetric segmentation of left ventricular (LV) myocardium and scar and automated quantification of myocardial ischaemic scar burden from late gadolinium enhancement cardiovascular magnetic resonance (LGE-CMR). We included 501 images and manual segmentations of short-axis LGE-CMR from over 20 multinational sites, from which 377 studies were used for training and 124 studies from unique participants for internal validation. A third test set of 52 images was used for external evaluation. Three models, U-Net, Cascaded U-Net, and U-Net++, were trained with a novel adaptive weighted categorical cross-entropy loss function. Model performance was evaluated using concordance correlation coefficients (CCCs) for LV mass and per cent myocardial scar burden. Cascaded U-Net was found to be the best model for the quantification of LV mass and scar percentage. The model exhibited a mean difference of -5 ± 23 g for LV mass, -0.4 ± 11.2 g for scar mass, and -0.8 ± 7% for per cent scar. CCC were 0.87, 0.77, and 0.78 for LV mass, scar mass, and per cent scar burden, respectively, in the internal validation set and 0.75, 0.71, and 0.69, respectively, in the external test set. For segmental scar mass, CCC was 0.74 for apical scar, 0.91 for mid-ventricular scar, and 0.73 for basal scar, demonstrating moderate to strong agreement. We successfully trained a convolutional neural network for volumetric segmentation and analysis of LV scar burden from LGE-CMR images in a large, multinational cohort of participants with ischaemic scar.

Scar characterisation to predict arrhythmia and death in ischaemic cardiomyopathy: insights from the REVIVED trial

Abstract Background Ischaemic cardiomyopathy continues to have unacceptably high mortality despite contemporary medical and device therapy (1). Ventricular arrhythmias are a leading cause of both death and morbidity in this population. Current guidelines recommend implantable cardioverter defibrillator (ICD) implantation in patients with a left ventricular ejection fraction (LVEF) below 35% but many who meet criteria never receive a therapy and there is a persistent sudden cardiac death risk in those who do not. Scar characteristics are not currently included in risk stratification algorithms, however both volume and entropy, a measure of myocardial heterogeneity, have been linked to arrhythmic risk. Purpose To assess whether left ventricular scar burden and morphology predicts fatal and non-fatal arrhythmia, independent of LVEF in severe ischaemic cardiomyopathy. Methods REVIVED-BCIS2 was a prospective, randomized controlled trial, which recruited 700 patients from 40 centres across the United Kingdom (1). Trial eligibility required the presence of ≥4 dysfunctional but viable myocardial segments; the majority of patients had viability assessed by cardiac magnetic resonance imaging (CMR). Semi-quantitative CMR scar burden was determined through consensus by two CMR experts in a blinded core laboratory. Scar morphology was further characterised by left ventricular entropy measured using novel dedicated software (TexRAD Ltd., Feedback plc, UK). The primary outcome was the composite of all-cause death and aborted sudden death (in turn, defined as appropriate ICD therapy or resuscitated cardiac arrest). Cox proportional hazard models were used to determine the effect of scar burden and entropy on clinical outcomes, adjusted for baseline LVEF, extent of coronary disease, type of implantable device and randomized treatment. Results Four hundred and ninety one patients underwent viability assessment by CMR and 478 were included in this analysis (Figure 1). Mean age was 69 ± 9; median follow up duration was 3.3 [2.3-4.9] years. By the end of trial follow up, 257/478 had a device in situ (CRT-D 99, ICD 147, CRT-P 11). The primary outcome occurred in 182 patients (38.1%). Each 10% increase in scar volume was associated with a 24% increase in the incidence of the primary outcome (adjusted HR per 10% 1.24, 95% CI: 1.11 to 1.39, p = 0.0002)(Figure 2). LVEF at baseline was not predictive (adjusted HR per 5% increase 0.94, 95% CI 0.86 – 1.02, p = 0.13). The relationship between LV entropy and outcomes will be presented at ESC. Conclusions In patients with severe ischaemic cardiomyopathy, scar volume was predictive of death and potentially fatal arrhythmias. Left ventricular ejection fraction was not a significant predictor in this cohort. Scar characteristics should form an integral part of risk stratification.Consort diagramPrimary outcome by scar burden

Impact of left ventricular scar burden on response to two different modalities of conduction system CRT

Abstract Funding Acknowledgements Type of funding sources: Foundation. Main funding source(s): British Heart Foundation Introduction Cardiac resynchronisation therapy (CRT) in the form of His bundle CRT and left bundle area CRT can be more effective than the gold standard, biventricular pacing (BVP). In BVP scar burden is known to predict response whether this is true for these novel modalities is not known. Purpose The purpose of this study was to determine whether left ventricular scar burden assessed using cardiac MRI can be used to predict the electrical and acute haemodynamic response to two novel CRT modalities. Methods Patients with standard CRT indications were recruited. They underwent a pre-procedure cardiac MRI, with late gadolinium enhancement (LGE) to quantify scar. His bundle CRT (His CRT) and left bundle area CRT (LBA CRT) were attempted. The electrical response was measured using high precision non-invasive mapping ECGi (CardioInsight, Medtronic). The haemodynamic response was measured with a high precision protocol. We investigated the impact of scar and baseline electrical characteristic on ECGi and haemodynamic response. Results 26 patients were recruited (85% male, mean age 69 ± 10, with ischaemic cardiomyopathy in 35%). LGE was observed in 96% of cases and the mean (range 1-39%). We found a significant correlation between scar extent and the electrical response with both modalities. There was a significant correlation between a lower scar burden and better electrical response. For His CRT the reduction in left ventricular activation time was better with lower scar burden (R= 0.77, p < 0.01, Picture 1), for LBA CRT for reduction in left ventricular activation was also better with lower scar burden (R = 0.53, p = 0.05, Picture 2). With His CRT there was also a significant correlation between lower scar extent and better acute haemodynamic response ( R = 0.6, p = 0.002) but this was not observed with LBA CRT (R = 0.07, p = 0.77). Conclusion Left ventricular myocardial scar can be used to predict the electrical response to two different conduction system CRT modalities.

Left ventricular mechanical dispersion in ischaemic cardiomyopathy: association with myocardial scar burden and prognostic implications.

Left ventricular (LV) mechanical dispersion (MD) may result from heterogeneous electrical conduction and is associated with adverse events. The present study investigated (i) the association between LV MD and the extent of LV scar as assessed with contrast-enhanced cardiac magnetic resonance (CMR) and (ii) the prognostic implications of LV MD in patients after ST-segment elevation myocardial infarction. LV MD was calculated by echocardiography and myocardial scar was analysed on CMR data retrospectively. Infarct core and border zone were defined as ≥50% and 35-50% of maximal signal intensity, respectively. Patients were followed for the occurrence of the combined endpoint (all-cause mortality and appropriate implantable cardioverter-defibrillator therapy). In total, 96 patients (87% male, 57 ± 10 years) were included. Median LV MD was 53.5 ms [interquartile range (IQR) 43.4-62.8]. On CMR, total scar burden was 11.4% (IQR 3.8-17.1%), infarct core tissue 6.2% (IQR 2.0-12.7%), and border zone was 3.5% (IQR 1.5-5.7%). Correlations were observed between LV MD and infarct core (r = 0.517, P < 0.001), total scar burden (r = 0.497, P < 0.001), and border zone (r = 0.298, P = 0.003). In total, 14 patients (15%) reached the combined endpoint. Patients with LV MD >53.5 ms showed higher event rates as compared to their counterparts. Finally, LV MD showed the highest area under the curve for the prediction of the combined endpoint. LV MD is correlated with LV scar burden. In addition, patients with prolonged LV MD showed higher event rates. Finally, LV MD provided the highest predictive value for the combined endpoint when compared with other parameters.

Gelatin Methacryloyl Bioadhesive Improves Survival and Reduces Scar Burden in a Mouse Model of Myocardial Infarction.

BackgroundDelivery of hydrogels to the heart is a promising strategy for mitigating the detrimental impact of myocardial infarction (MI). Challenges associated with the in vivo delivery of currently available hydrogels have limited clinical translation of this technology. Gelatin methacryloyl (GelMA) bioadhesive hydrogel could address many of the limitations of available hydrogels. The goal of this proof‐of‐concept study was to evaluate the cardioprotective potential of GelMA in a mouse model of MI.Methods and ResultsThe physical properties of GelMA bioadhesive hydrogel were optimized in vitro. Impact of GelMA bioadhesive hydrogel on post‐MI recovery was then assessed in vivo. In 20 mice, GelMA bioadhesive hydrogel was applied to the epicardial surface of the heart at the time of experimental MI. An additional 20 mice underwent MI but received no GelMA bioadhesive hydrogel. Survival rates were compared for GelMA‐treated and untreated mice. Left ventricular function was assessed 3 weeks after experimental MI with transthoracic echocardiography. Left ventricular scar burden was measured with postmortem morphometric analysis. Survival rates at 3 weeks post‐MI were 89% for GelMA‐treated mice and 50% for untreated mice (P=0.011). Left ventricular contractile function was better in GelMA‐treated than untreated mice (fractional shortening 37% versus 26%, P<0.001). Average scar burden in GelMA‐treated mice was lower than in untreated mice (6% versus 22%, P=0.017).ConclusionsEpicardial GelMA bioadhesive application at the time of experimental MI was performed safely and was associated with significantly improved post‐MI survival compared with control animals. In addition, GelMA treatment was associated with significantly better preservation of left ventricular function and reduced scar burden.

ECG score to predict ICD therapies in patients with nonischemic cardiomyopathy and primary prophylactic CRT-D

Recently published results of the DANISH study raise concerns, if primary prophylactic ICD implantations in patients with nonischemic cardiomyopathy (NICM) and severe reduced left ventricular ejection fraction (LVEF) should be performed without further risk stratification. There was no significant difference in the overall mortality of patients with or without ICD and CRT defibrillator (CRT-D) or CRT pacemaker (CRT-P), respectively. Clinical risk scores to identify patients with ischemic cardiomyopathy (ICM) who benefit most from an ICD have been recommended. The need for risk stratification systems concerning patients with NICM has been emphasized. A retrospective study of 434 consecutive patients with CRT-D implantation was performed. Patients with no regular follow-up at our institution (n= 132), secondary prophylactic ICD indication (n= 61), and upgrade to CRT (n= 95) were excluded. The occurrence of an adequate ICD therapy was defined as the endpoint. Left ventricular ejection fraction (LVEF), genesis of the cardiomyopathy as well as the modified Selvester ECG score (MSES) for evaluation of the left ventricular scar burden were documented among other characteristics. Within a median follow-up of 605 days, 24% of the patients experienced an adequate ICD therapy. These patients had significantly lower LVEF (20% vs. 23%), and the MSES was higher (7 vs. 3points). There was no significant difference in patients suffering from ICM vs NICM. Areceiver-operating-characteristic (ROC) analysis revealed asensitivity of 0.914 and aspecifity of 0.586 for MSES ≥4 to predict the occurrence of an ICD therapy. None of 35patients suffering from NICM with MSES <4 experienced an ICD therapy. The evaluation of the left ventricular scar burden using MSES can be useful for the decision between CRT-D and CRT-P in patients suffering from NICM.

Left ventricular scar impact on left ventricular synchronization parameters and outcomes of cardiac resynchronization therapy

BackgroundLeft ventricular scar, including global scar and lateral wall, plays an important role in predicting response to cardiac resynchronization therapy (CRT). Materials and methodsThirty patients underwent CRT implantation. Assessment of left ventricular (LV) dyssynchrony was done through Gated SPECT LV phase analysis. Pre-implantation cardiac magnetic resonance (CMR) with late gadolinium enhancement technique to examine LV scar burden. Echocardiographic examination of LV end-systolic volume (LVES) prior to CRT and 6 months later. ResultsThirty patients received CRT (mean age 58.7±9.0, 24 males). Reverse LV remodeling (decline ≥15% from baseline VES) was documented in 19 patients. Temporal changes in LV dyssynchrony parameters were correlated to LV reverse remodeling. Applying ROC for predicting CRT non-response showed a cutoff 36.5% of global LV scar burden had a sensitivity of 81.8% and specificity of 68.4%. A cutoff for lateral wall scar burden 40.5% of whole lateral wall had a sensitivity of 72.7% and specificity of 68.4%. ConclusionReverse LV remodeling is associated with temporal improvements in LV dyssynchrony parameters. LV scar had an unfavorable impact on CRT response. Both global and lateral wall scar burden could predict CRT nonresponse status.

The Relationship between Time from Myocardial Infarction, Left Ventricular Dyssynchrony, and the Risk for Ventricular Arrhythmia: Speckle-Tracking Echocardiographic Analysis

Differences in arrhythmogenic substrate may explain the variable efficacy of implantable cardioverter-defibrillators (ICDs) in primary sudden cardiac death prevention over time after myocardial infarction (MI). Speckle-tracking echocardiography allows the assessment left ventricular (LV) dyssynchrony, which may reflect the electromechanical heterogeneity of myocardial tissue. The aim of the present study was to evaluate the relationship among LV dyssynchrony, age of MI, and their association with the risk for ventricular tachycardia (VT) after MI. A total of 206 patients (median age, 67 years; 87% men) with prior MIs (median MI age, 6.2 years; interquartile range, 0.66-15 years) who underwent programmed electrical stimulation, speckle-tracking echocardiography, and ICD implantation were retrospectively evaluated. LV dyssynchrony was defined as the standard deviation of time to peak longitudinal systolic strain values using speckle-tracking strain echocardiography. LV scar burden was evaluated by the percentage of segments exhibiting scar (defined as an absolute longitudinal strain of magnitude < 4.5%). Patients were followed up for the occurrence of first monomorphic VT requiring ICD therapy (antitachycardia pacing or shock) for a median of 24 months. In total, 75 individuals experienced the primary end point of monomorphic VT. LV dyssynchrony was independently associated with the occurrence of VT at follow-up (hazard ratio per 10-msec increase, 1.12; 95% confidence interval, 1.07-1.18; P < .001), together with nonrevascularization of the infarct-related artery and VT inducibility. Patients with older (>180 months) MIs had a higher likelihood of VT inducibility (88% vs 63%, P = .003) and greater scar burden (14.7 ± 15.8% vs 10.7 ± 11.4%, P = .03) compared with patients with recent (<8 months) MIs. LV dyssynchrony is independently associated with the occurrence of VT after MI.

Electrocardiographic left ventricular scar burden predicts clinical outcomes following infarct-related ventricular tachycardia ablation

Conducting channels within scars form the substrate for infarct-related ventricular tachycardia (VT) and are targeted during catheter ablation. Whether the amount of left ventricular scar (LVS) affects outcomes after VT ablation is not known. To test the hypothesis that increased LVS is associated with worsened clinical outcomes and reduced survival after VT ablation. Patients with coronary artery disease and intrinsic AV nodal conduction undergoing infarct-related VT ablation were studied. A validated 32-point scoring system was used to measure LVS from 12-lead ECGs. Primary endpoint was all-cause mortality or transplantation. Secondary endpoint was a composite of death, transplantation, or readmission due to VT recurrence within 1 year of discharge. Of 356 patients undergoing 466 infarct-related VT ablations screened, 192 (84% male, age 66 ± 11 years, 52% prior coronary artery bypass graft, ejection fraction 28% ± 11%) who underwent 245 procedures for VT (2.4 ± 1.5 VTs per patient, 31% with VT storm, refractory to 2.7 ± 1.2 antiarrhythmic drugs) between 1999 and 2009 were included. During mapping, all patients had low-voltage areas. Mean LVS was 21.4% ± 15.0%. Over 3.4 ± 3.1 years, 78 patients (41%) reached the primary endpoint (73 deaths, 5 transplants). In the first year after discharge, the secondary endpoint was reached in 56 subjects (29%). In a multivariate model, larger LVS (hazard ratio [HR] 1.03 for every 3% increase in LVS, P < .01), renal dysfunction (HR 2.66, P <.01), and increased age (HR 1.05 per year, P < .01) predicted mortality, whereas noninducibility of any VT was protective. (HR 0.36, P < .01) Larger LVS and renal dysfunction were associated with worsened 1-year outcomes, whereas noninducibility was protective. LVS burden derived from 12-lead ECGs is a significant and independent predictor of mortality and clinical outcomes in subjects with infarct-related VT.

Predictors of response to cardiac resynchronization therapy on pre-implantation cardiovascular magnetic resonance imaging

Background Cardiac resynchronization therapy (CRT) is an established treatment for severe heart failure. However, up to 40% of patients do not respond. While regional scar distribution has received focused attention, the predictive utility of global markers of remodeling and irreversible injury has not been well explored. Methods Sixty-eight patients receiving CRT underwent pre-implant cardiovascular MRI followed by serial echocardiography at 3 and 6 months. Blinded measurement of Left Ventricular (LV) and Right Ventricular (RV) chamber dimensions, volumes and mass were performed from short axis cine datasets. LV dysynchrony was measured by septal to lateral wall delay. Total LV scar burden was determined from Late Gadolinium Enhancement (LGE) images using manual contour tracing of endocardial and epicardial borders with application of a signal threshold ≥5SD above reference myocardium. Response to CRT was defined as a reduction in LV end-systolic volume (ESV) ≥15% at 6 months. Results The mean age was 66.3 ± 8.9 years with a mean LV Ejection fraction (EF) of 25.2 ± 7.2%. Overall, 47 patients (69%) responded. Among all baseline measures LVEDV (p=0.03), LVESV (p=0.045), RV EF (p=0.0349) and total scar burden (p=0.018) were the only significant predictors of CRT response. Multivariate analysis showed total scar burden to be the only independent predictor of CRT response (p=0.015). Conclusions Pre-implantation MRI offers markers for the prediction of response to CRT. Of these, total scar burden appears to be an independent predictor of response and may be of assistance in the selection of optimal candidates. Funding None

Delayed enhancement and myocardial velocity mapping CMR reveal differences in regional left ventricular function with varying levels of scar

Background Delayed enhancement (DE) CMR is the gold standard for detecting irreversibly damaged myocardial tissue (scar). Yet, direct impact of scar on regional systolic and diastolic left ventricular (LV) function is not well understood. Standard tools for LV velocities (Tissue Doppler Imaging) are limited by poor reproducibility and incomplete assessment of all regions and motion directions. Myocardial CMR velocity mapping (MVM) is reproducible, non-invasive, and allows direct measure of myocardial velocities of all LV motion components in all regions. Here, we analyze effects of LV scar burden on myocardial motion.

Impact of left ventricular scar burden and cardiac synchrony on CRT efficacy: a single-centre retrospective observational study

BackgroundWhether left ventricular scar burden and cardiac synchrony could impact CRT efficacy has not been well described.ObjectiveThis study was to assess the impact of left ventricular scar burden and cardiac...

User-dependence of myocardial infarct identification using semi-automated thresholding techniques: implications for CRT response predictions based on scar burden

Background Semi-automatic segmentation of infarcted tissue in late gadolinium-enhanced (LGE) MR images is usually done using a thresholding technique. In the threshold technique, an observer identifies a region of remote “normal” myocardium. Based on the distribution of pixel intensities within this “normal” region, pixels that lay more than two standard deviations outside the mean of this distribution are classified as infarcted myocardium. Having a left ventricular scar burden greater than 33% has previously been used as a cut-off for predicting nonresponse to cardiac resynchronization therapy (CRT) (Chalil et al. Europace, 2007). We hypothesized that the user-defined region of “normal” myocardium would have a significant effect on the classification of patients as non-responders to CRT (>33% LV scar burden).

Abstract 3098: Left Ventricular Delayed Hyper-enhancement Further Risk Stratifies Patients with Severe Systolic Dysfunction Regardless of the Presence of Coronary Artery Disease: A Cardiac MRI Study

Background: Patients with severe systolic left ventricular (LV) dysfunction have poor survival. Delayed hyperenhancement magnetic resonance imaging (DHE-MRI) accurately measures myocardial scar. In patients with severe systolic LV dysfunction, it is unclear if presence of scar further impacts survival. We sought to determine if presence of LV scar further risk-stratifies patients with severe LV dysfunction. Methods: We studied 199 consecutive patients with LV systolic dysfunction who underwent DHE-MRI (Siemens 1.5 T scanner, Erlangen, Germany) from 2005– 6. The percentage of myocardial scar was determined semi-quantitatively on DHE-MR images, in a standard 17-segment model using custom software (Siemens Research), and defined as intensity &gt;2 standard deviation above viable myocardium. Transmurality score was recorded in all segments as follows: 0 = no scar, 1 = 1–25% scar, 2 = 26 –50 %, 3 = 51–75% and 4 = &gt; 75%. Global LV scar burden was calculated as total transmurality score for all segments/17. LV ejection fraction (EF) and end-diastolic diameter (EDD) were recorded from echocardiography. Presence of coronary artery disease (CAD) and all-cause mortality were recorded. Results: In a median follow up of 1.6 years [1, 1.9], 26 (13 %) patients died. Characteristics of survivors vs. non-survivors are detailed in Table . Survival in patients with any amount of LV scar had significantly worse 1-year survival compared to those without (log-rank p = 0.03). Median global LV scar burden was 1.8 [1, 2.5]. On receiver operating characteristic curve analysis, global scar burden &gt; 1.8 was predictive of death (area under curve 0.61, p = 0.05). Patients with scar burden &gt; 1.8 also had significantly worse 1-year survival compared to those with scar burden ≤ 1.8 (log rank p = 0.03). Conclusions: In patients with severe systolic LV dysfunction, higher LV myocardial scar burden, detected on DHE-MRI is associated with worse survival, despite similar LVEF, LVEDD, and prevalence of CAD. Table