Border Zone Mass Research Articles

Cardiac magnetic resonance to predict appropriate therapies in secondary prevention

Abstract Introduction Implantable cardioverter-defibrillator (ICD) therapy plays a pivotal role in the management of patient’s survivors of life-threatening ventricular arrhythmias (secondary prevention). Risk of recurrence may be related to presence of myocardial scar and its components (including core mass, border zone (BZ) mass, and BZ channels) assessed with late gadolinium enhancement cardiac magnetic resonance (LGE-CMR). Purpose Our study aims to analyze the role of imaging in predicting the risk of recurrent ventricular arrhythmias and improving the risk stratification for appropriate ICD therapy in patients receiving an ICD for secondary prevention. Methods From 2015 to 2020, a total of 111 patients with LGE-CMR before ICD implantation for secondary prevention. Scar tissue including core, BZ and BZ channels were automatically detected by specialized investigational software in patients with LGE-CMR. Patients were followed until a new event was detected. Results The mean age was 65.4 ± 11.4 years; 87% were men; 55% had ischemic cardiomyopathy. The mean left ventricular ejection fraction was 37.8 % ± 14.31%. Patients were followed for a median of 3.26 years (IQR 1.4-4.9). Within the first year of follow-up 22% of patients had received an appropriate therapy, 39% within 3 years and 53% within 6 years. Chronic kidney disease and New York Heart Association (NYHA) class were associated with the primary endpoint [HR 1.94(1.06-3.55), P-value 0.032)] and [HR 1.86 (1.19-2.91), P-value 0.006)], respectively. Regarding CMR characteristics, BZ percentage was also associated with appropriate ICD therapy in the follow up [HR 1.04(1-1.08), P-value 0.048)]. Other CMR parameter, such as BZ mass, BZ core %, BZ core mass and core mass showed a trend to predict ICD therapies during follow-up. ROC curve analysis with Youden’s index defined an optimal BZ percentage cutoff value for recurrence prediction of 9.5% [HR 0.49 (0.28-0.85)]. Conclusion In patients receiving an ICD for secondary prevention, chronic kidney disease, NYHA class and BZ percentage analyzed by LGE-CMR were predictors of recurrent ventricular arrhythmia. A cutoff of BZ of 9.5% could be used to select patients with high risk of recurrence.

Antiarrhythmic and Anti-Inflammatory Effects of Sacubitril/Valsartan on Post-Myocardial Infarction Scar.

Sacubitril/valsartan (Sac/Val) is superior to angiotensin-converting enzyme inhibitors in reducing the risk of heart failure hospitalization and cardiovascular death, but its mechanistic data on myocardial scar after myocardial infarction (MI) are lacking. The objective of this work was to assess the effects of Sac/Val on inflammation, fibrosis, electrophysiological properties, and ventricular tachycardia inducibility in post-MI scar remodeling in swine. After MI, 22 pigs were randomized to receive β-blocker (BB; control, n=8) or BB+Sac/Val (Sac/Val, n=9). The systemic immune response was monitored. Cardiac magnetic resonance data were acquired at 2-day and 29-day post MI to assess ventricular remodeling. Programmed electrical stimulation and high-density mapping were performed at 30-day post MI to assess ventricular tachycardia inducibility. Myocardial samples were collected for histological analysis. Compared with BB, BB+Sac/Val reduced acute circulating leukocytes (P=0.009) and interleukin-12 levels (P=0.024) at 2-day post MI, decreased C-C chemokine receptor type 2 expression in monocytes (P=0.047) at 15-day post MI, and reduced scar mass (P=0.046) and border zone mass (P=0.043). It also lowered the number and mass of border zone corridors (P=0.009 and P=0.026, respectively), scar collagen I content (P=0.049), and collagen I/III ratio (P=0.040). Sac/Val reduced ventricular tachycardia inducibility (P=0.034) and the number of deceleration zones (P=0.016). After MI, compared with BB, BB+Sac/Val was associated with reduced acute systemic inflammatory markers, reduced total scar and border zone mass on late gadolinium-enhanced magnetic resonance imaging, and lower ventricular tachycardia inducibility.

Non-invasive detection of slow conduction with cardiac magnetic resonance imaging for ventricular tachycardia ablation.

Non-invasive myocardial scar characterization with cardiac magnetic resonance (CMR) has been shown to accurately identify conduction channels and can be an important aid for ventricular tachycardia (VT) ablation. A new mapping method based on targeting deceleration zones (DZs) has become one of the most commonly used strategies for VT ablation procedures. The aim of the study was to analyse the capability of CMR to identify DZs and to find predictors of arrhythmogenicity in CMR channels. Forty-four consecutive patients with structural heart disease and VT undergoing ablation after CMR at a single centre (October 2018 to July 2021) were included (mean age, 64.8 ± 11.6 years; 95.5% male; 70.5% with ischaemic heart disease; a mean ejection fraction of 32.3 ± 7.8%). The characteristics of CMR channels were analysed, and correlations with DZs detected during isochronal late activation mapping in both baseline maps and remaps were determined. Overall, 109 automatically detected CMR channels were analysed (2.48 ± 1.15 per patient; length, 57.91 ± 63.07 mm; conducting channel mass, 2.06 ± 2.67 g; protectedness, 21.44 ± 25.39 mm). Overall, 76.1% of CMR channels were associated with a DZ. A univariate analysis showed that channels associated with DZs were longer [67.81 ± 68.45 vs. 26.31 ± 21.25 mm, odds ratio (OR) 1.03, P = 0.010], with a higher border zone (BZ) mass (2.41 ± 2.91 vs. 0.87 ± 0.86 g, OR 2.46, P = 0.011) and greater protectedness (24.97 ± 27.72 vs. 10.19 ± 9.52 mm, OR 1.08, P = 0.021). Non-invasive detection of targets for VT ablation is possible with CMR. Deceleration zones found during electroanatomical mapping accurately correlate with CMR channels, especially those with increased length, BZ mass, and protectedness.

Using the 3D architecture of scar to predict life-threatening ventricular arrhythmias, still a long way to go

Abstract Background Late gadolinium enhancement (LGE) has been proposed as an independent predictor of ventricular arrhythmias. Purpose The purpose of this study was to assess if myocardial scar characterization could enhance the risk stratification for life-threatening arrhythmias and sudden cardiac death (SCD). Methods We included patients with an indication for ICD or CRT-D implantation who underwent cardiac magnetic resonance for clinical proposes since February/2018 and in whom a 3D-LGE dataset was obtained. Patients with channelopathies (n=2) or inappropriate imaging quality (imaging artifacts; n=7) were excluded. Scar characterization using ADAS software was performed in 3D-LGE datasets in all but 16 patients, where 2D datasets were used. The primary endpoint was the composite of appropriate ICD therapy (classified as ATP or shock), sustained ventricular tachycardia or SCD. Results A total of 116 patients were analysed (mean age 66 ± 14 years; 81% male; mean LVEF 34 ± 14%; 74 patients with ischemic and 42 with non-ischemic cardiomyopathy; 40 patients received a device in the setting of secondary prevention). During a median follow-up of 2.3 years (IQR 1.3 – 3.3 years) there were 23 events (18 appropriate ICD therapies [9 shocks and 9 ATP], 3 episodes of VT under the threshold for ICD therapy and 2 SCD). No statistically significant differences were found between patients with or without events in terms of scar mass, border zone (BZ) mass, BZ channels (BZC), BZC mass, number of channels detected, and scar heterogeneity (BZ mass / scar mass ratio) - all p values > 0.2 – Figure. Restricting the analysis to only primary prevention cases yielded similar results. Overall, 26 patients did not show any channel. Four of these (all with non-ischemic LGE) experienced an arrhythmic event, yielding a negative predictive value of 83% (95% CI 64-93%) for the absence of channels. Conclusion In this cohort with still relatively limited follow-up duration, no single parameter reflecting scar tissue characterization was able to predict appropriate device therapies or sudden cardiac death.

Myocardial scar characteristics by 3D-LGE cannot fully explain different arrhythmic event rates in primary and secondary prevention of sudden cardiac death

Abstract Background There is a noticeable difference in the incidence of ventricular arrhythmias among patients receiving defibrillator devices (ICD or CRT-D) for primary vs. secondary prevention of sudden cardiac death (SCD). The underlying reasons for this difference remain to be fully explained. Purpose To assess for differences in myocardial scar characteristics between patients who had defibrillator devices implanted in primary vs. secondary prevention scenarios, and their correlation with arrhythmic events. Methods In this single center retrospective study, patients who underwent late gadolinium enhancement (LGE) cardiac MRI for clinical purposes before the implantation of an ICD or CRT-D were included. Patients with channelopathies (n=2) or inappropriate imaging quality (n=7) were excluded. We used ADAS software to perform myocardial scar characterization in 3D-LGE datasets in all but 16 patients, in which 2D datasets were used. The primary endpoint was a composite of appropriate ICD therapy (appropriate shock or ATP), sustained ventricular tachycardia or SCD. Results A total of 116 patients (mean age 66±14 years, 81% male) were included, 40 (35%) with devices implanted in secondary prevention. During a median follow-up of 28 months (IQR 16-24), 23 events were identified (18 appropriate ICD therapy, 9 shocks and 9 ATP; 2 SCD; 3 sustained VT), 7 of which (30.4%) in the primary prevention group, and 16 (69.6%) in the secondary prevention group. The event rate was significantly higher in the secondary prevention setting (15.0 events per 100 persons-year [95% CI 7.7 – 22.4] vs. 4.1 events per 100 persons-year [95% CI 1.1 – 7.1]; p < 0.001). Despite a higher LVEF in the secondary prevention group (41 ± 14% vs. 30 ± 13%; p-value < 0.001), no statistically significant differences were found regarding scar tissue characteristics, namely scar and borderzone (BZ) mass, total channel mass, largest channel mass, number of channels and scar heterogeneity (BZ mass / scar mass ratio) – Table. Conclusion Despite the higher event rate in patients receiving defibrillator devices in secondary vs. prevention, no differences in myocardial scar characteristics were found between both groups. These findings suggest that arrhythmic risk is unlikely to be explained solely by the anatomical substrate, and support a greater role for the interplay between substrate and transient triggers.

Myocardial scarring and recurrence of ventricular arrhythmia in patients surviving an out-of-hospital cardiac arrest.

Prediction of recurrent ventricular arrhythmia (VA) in survivors of an out-of-hospital cardiac arrest (OHCA) is important, but currently difficult. Risk of recurrence may be related to presence of myocardial scarring assessed with late gadolinium enhancement cardiac magnetic resonance (LGE-CMR). Our study aims to characterize myocardial scarring as defined by LGE-CMR in survivors of a VA-OHCA and investigate its potential role in the risk of new VA events. Between 2015 and 2022, a total of 230 VA-OHCA patients without ST-segment elevation myocardial infarction had CMR before implantable cardioverter-defibrillator implantation for secondary prevention at Copenhagen University Hospital, Rigshospitalet, and Hospital Clínic, University of Barcelona, of which n = 170 patients had a conventional (no LGE protocol) CMR and n = 60 patients had LGE-CMR (including LGE protocol). Scar tissue including core, border zone (BZ) and BZ channels were automatically detected by specialized investigational software in patients with LGE-CMR. The primary endpoint was recurrent VA. After exclusion, n = 52 VA-OHCA patients with LGE-CMR and a mean left ventricular ejection fraction of 49 ± 16% were included, of which 18 (32%) patients reached the primary endpoint of VA. Patients with recurrent VA in exhibited greater scar mass, core mass, BZ mass, and presence of BZ channels compared with patients without recurrent VA. The presence of BZ channels identified patients with recurrent VA with 67% sensitivity and 85% specificity (area under the ROC curve (AUC) 0.76; 95% CI: 0.63-0.89; p < .001) and was the strongest predictor of the primary endpoint. The presence of BZ channels was the strongest predictor of recurrent VA in patients with an out of-hospital cardiac arrest and LGE-CMR.

Using the 3D architecture of scar to predict life-threatening ventricular arrythmias - still a long way to go

Abstract Funding Acknowledgements Type of funding sources: None. Background Late gadolinium enhancement (LGE) has been proposed as an independent predictor of ventricular arrhythmias. Purpose The purpose of this study was to assess if myocardial scar characterization could enhance the risk stratification for life-threatening arrhythmias and sudden cardiac death (SCD). Methods We included patients with an indication for ICD or CRT-D implantation who underwent cardiac magnetic resonance for clinical proposes since February/2018 and in whom a 3D-LGE dataset was obtained. Patients with channelopathies (n=2) or inappropriate imaging quality (imaging artifacts; n=7) were excluded. Scar characterization using ADAS software was performed in 3D-LGE datasets in all but 5 patients, where 2D datasets were used. The primary endpoint was the composite of appropriate ICD therapy (classified as ATP or shock) or SCD. Results A total of 75 patients were analysed (mean age 63 ± 13 years; 83% male; mean LVEF 31 ± 13%; 50 patients with ischemic and 25 with non-ischemic cardiomyopathy; 14 patients received a device in the setting of secondary prevention). During a median follow-up of 1.4 years (IQR 0.7 – 2.4 years) there were 15 events (12 appropriate ICD therapies [8 shocks and 4 ATP] and 3 SCD). No statistically significant differences were found between patients with or without events in terms of scar mass, border zone (BZ) mass, BZ channels (BZC), BZC mass, number of channels detected, and scar heterogeneity (BZ mass / scar mass ratio) - all p values &amp;gt; 0.2 – Figure. Restricting the analysis to only primary prevention cases yielded similar results. Overall, 11 patients did not show any channel. Two of these experienced an arrhythmic event, yielding a negative predictive value of 80% (95% CI 75-83%) for the absence of channels. Conclusion In this cohort with still relatively limited follow-up duration, no single parameter reflecting scar tissue characterization was able to predict appropriate device therapies or sudden cardiac death.

Impact of cardiac magnetic resonance channels to localize deceleration zones during VT ablation

Abstract Funding Acknowledgements Type of funding sources: None. Background Cardiac magnetic resonance has demonstrated to accurately identify voltage conduction channels and it is nowadays an important tool to analyze the arrhythmic substrate, to predict ventricular tachycardia (VT) events and to aid VT ablation. The characteristics of CMR channels (CMR-CCs) that predicts the presence of deceleration zone (DZ) have not been explored. Methods Forty-four consecutive patients with scar-related VT undergoing ablation after CMR (October 2018-July 2021) were included (medium age 64.8±11.6 years; 95.5% male; 70.5% ischemic heart disease, mean ejection fraction of 32.3±7.8). Characteristics of CMR-CCs were analyzed and correlation with DZs both in baseline maps and remaps were performed. Patients were prospectively followed for VT recurrence for one year. Results Overall, 129 automatically detected CMR-CCs were analyzed (2.89±1.83 per patient; length: 52.72±65.44mm (0.18–376.73), CC mass: 1.76±2.46grams (0.01–14.59); protectedness 19.02±24.51% (0.01–143.51)). Overall, 73.6% of CMR-CCs were associated with a DZ: 58.1% CMR-CCs in baseline map and 15.5% with a DZs not observed initially but in remaps. The univariate analysis showed that channels associated with DZs were longer (61.83±73.43 vs. 29.96±32.55, OR 1.01, p0.004), with higher border zone mass (2.02±2.75 vs. 1.09±1.44, OR 1.28, p0.031) and more protectedness (21.90±27.23 vs. 11.46±14.20, OR1.02, p0.036). VT recurrence after one-year follow up was 21.95%. Conclusions Pre ablation CMR can accurately identify channels that correlates with DZs that could be targets for ablation, especially those CMR-CCs with higher length, border zone mass and protectedness. Additionally, some channels not related with DZ in the first map have a clear DZ after abolishing the first region of slow conduction, suggesting a very useful role of CMR to detect potential DZs.

PO-03-107 MYOCARDIAL SCAR CHARACTERISTICS BY 3D-LGE CANNOT FULLY EXPLAIN DIFFERENT ARRHYTHMIC EVENT RATES IN PRIMARY AND SECONDARY PREVENTION OF SUDDEN CARDIAC DEATH

There is a noticeable difference in the incidence of ventricular arrythmias among patients receiving defibrillator devices (ICD or CRT-D) for primary vs. secondary prevention of sudden cardiac death (SCD). The underlying reasons for this difference remain to be fully explained. To assess for differences in myocardial scar characteristics between patients who had defibrillator devices implanted in primary vs. secondary prevention scenarios, and their correlation with arrhythmic events. In this single center retrospective study, patients who underwent late gadolinium enhancement (LGE) cardiac MRI for clinical purposes before the implantation of an ICD or CRT-D were included. Patients with channelopathies (n=2) or inappropriate imaging quality (n=7) were excluded. We used ADAS software to perform myocardial scar characterization in 3D-LGE datasets in all but 16 patients, in which 2D datasets were used. The primary endpoint was a composite of appropriate ICD therapy (appropriate shock or ATP), sustained ventricular tachycardia or SCD. A total of 116 patients (mean age 66±14 years, 81% male) were included, 40 (35%) with devices implanted in secondary prevention. During a median follow-up of 28 months (IQR 16-24), 23 events were identified (18 appropriate ICD therapy, 9 shocks and 9 ATP; 2 SCD; 3 sustained VT), 7 of which (30.4%) in the primary prevention group, and 16 (69.6%) in the secondary prevention group. The event rate was significantly higher in the secondary prevention setting (15.0 events per 100 persons-year [95% CI 7.7 – 22.4] vs. 4.1 events per 100 persons-year [95% CI 1.1 – 7.1]; p < 0.001). Despite a higher LVEF in the secondary prevention group (41 ± 14% vs. 30 ± 13%; p-value < 0.001), no statistically significant differences were found regarding scar tissue characteristics, namely scar and borderzone (BZ) mass, total channel mass, largest channel mass, number of channels and scar heterogeneity (BZ mass / scar mass ratio) – Table. Despite the higher event rate in patients receiving defibrillator devices in secondary vs. prevention, no differences in myocardial scar characteristics were found between both groups. These findings suggest that arrhythmic risk is unlikely to be explained solely by the anatomical substrate, and support a greater role for the interplay between substrate and transient triggers.Tabled 1Primary PreventionSecondary Preventionp-valueScar + BZ mass (g)26.2 (IQR 13.3 - 35.0)23.7 (IQR 11.4 - 33.4)p = 0.322Scar + BZ percentage (%)18.0 (IQR 11.0 – 27.0)17.0 (IQR 9.0 - 26.0)p = 0.545BZ mass (g)17.7 (IQR 11.1 - 24.2)14.8 (IQR 8.8 - 22.0)p = 0.350BZ percentage (%)13.0 (IQR 8.0 - 18.0)11.0 (IQR 6.0 - 17.0)p = 0.677Scar mass (g)6.6 (IQR 3.4 - 11.0)6.9 (IQR 2.0 - 10.3)p = 0.693Scar percentage (%)4.0 (IQR 2.0 - 9.0)5.0 (IQR 1.0 - 8.0)p = 0.695Scar heterogeneity2.4 (IQR 1.7 - 3.9)2.7 (IQR 1.5 - 4.4)p = 0.797Total channels mass (g)3.0 (IQR 0.7 - 4.9)1.8 (IQR 0.0 - 5.0)p = 0.215Biggest channel mass (g)1.4 (IQR 0.5 - 2.5)0.8 (IQR 0.0 - 3.0)p = 0.163Number of channels3.0 (IQR 1.0 - 5.0)3.0 (IQR 0.0 - 5.0)p = 0.520BZ, Borderzone Open table in a new tab

PO-03-086 USING THE 3D ARCHITECTURE OF SCAR TO PREDICT LIFE-THREATENING VENTRICULAR ARRHYTHMIAS – STILL A LONG WAY TO GO

Late gadolinium enhancement (LGE) has been proposed as an independent predictor of ventricular arrhythmias. The purpose of this study was to assess if myocardial scar characterization could enhance the risk stratification for life-threatening arrhythmias and sudden cardiac death (SCD). We included patients with an indication for ICD or CRT-D implantation who underwent cardiac magnetic resonance for clinical proposes since February/2018 and in whom a 3D-LGE dataset was obtained. Patients with channelopathies (n=2) or inappropriate imaging quality (imaging artifacts; n=7) were excluded. Scar characterization using ADAS software was performed in 3D-LGE datasets in all but 16 patients, where 2D datasets were used. The primary endpoint was the composite of appropriate ICD therapy (classified as ATP or shock), sustained ventricular tachycardia or SCD. A total of 116 patients were analysed (mean age 66 ± 14 years; 81% male; mean LVEF 34 ± 14%; 74 patients with ischemic and 42 with non-ischemic cardiomyopathy; 40 patients received a device in the setting of secondary prevention). During a median follow-up of 2.3 years (IQR 1.3 – 3.3 years) there were 23 events (18 appropriate ICD therapies [9 shocks and 9 ATP], 3 episodes of VT under the threshold for ICD therapy and 2 SCD). No statistically significant differences were found between patients with or without events in terms of scar mass, border zone (BZ) mass, BZ channels (BZC), BZC mass, number of channels detected, and scar heterogeneity (BZ mass / scar mass ratio) - all p values > 0.2 – Figure. Restricting the analysis to only primary prevention cases yielded similar results. Overall, 26 patients did not show any channel. Four of these (all with non-ischemic LGE) experienced an arrhythmic event, yielding a negative predictive value of 83% (95% CI 64-93%) for the absence of channels. In this cohort with still relatively limited follow-up duration, no single parameter reflecting scar tissue characterization was able to predict appropriate device therapies or sudden cardiac death.

PO-04-122 IMPACT OF CARDIAC MAGNETIC RESONANCE CHANNELS TO LOCALIZE DECELERATION ZONES DURING VT ABLATION

Cardiac magnetic resonance has demonstrated to accurately identify voltage conduction channels and it is nowadays an important tool to analyze the arrhythmic substrate, to predict ventricular tachycardia (VT) events and to aid VT ablation. The characteristics of CMR channels (CMR-CCs) that predicts the presence of deceleration zone (DZ) have not been explored. To analyze the correlation between CMR-CCs and deceleration zones in isochronal late activation maps. Forty-four consecutive patients with scar-related VT undergoing ablation after CMR (October 2018-July 2021) were included (medium age 64.8±11.6 years; 95.5% male; 70.5% ischemic heart disease, mean ejection fraction of 32.3±7.8). Characteristics of CMR-CCs were analyzed and correlation with DZs both in baseline maps and remaps were performed. Patients were prospectively followed for VT recurrence for one year. Overall, 129 automatically detected CMR-CCs were analyzed (2.89±1.83 per patient; length: 52.72±65.44mm (0.18–376.73), CC mass: 1.76±2.46grams (0.01–14.59); protectedness 19.02±24.51% (0.01–143.51)). Overall, 73.6% of CMR-CCs were associated with a DZ: 58.1% CMR-CCs in baseline map and 15.5% with a DZs not observed initially but in remaps. The univariate analysis showed that channels associated with DZs were longer (61.83±73.43 vs. 29.96±32.55, OR 1.01, p0.004), with higher border zone mass (2.02±2.75 vs. 1.09±1.44, OR 1.28, p0.031) and more protectedness (21.90±27.23 vs. 11.46±14.20, OR1.02, p0.036). VT recurrence after one-year follow up was 21.95%. Pre ablation CMR can accurately identify channels that correlates with DZs that could be targets for ablation, especially those CMR-CCs with higher length, border zone mass and protectedness. Additionally, some channels not related with DZ in the first map have a clear DZ after abolishing the first region of slow conduction, suggesting a very useful role of CMR to detect potential DZs.Tabled 1Univariate analysis of channels characteristics and the primary endpoint (slow conduction properties) (PO-04-122)Total (n=129)Slow conduction (n=95)Non-slow conduction (n=34)ORpLength per channel (mm)52.72±65.44 (0.18–376.73)61.83±73.4329.96±32.551.01 (1-1.03)0.004Mass per channel (grams)1.76±2.46 (0.01–14.59)2.02±2.751.09±1.441.28 (0.97-1.7)0.031Width per channel (mm)4.94±1.91 (0.01–9.34)4.97±1.894.67±2.041.08 (0.88-1.31)0.465Protectedness per channel (mm)19.02±24.51 (0.01–143.51)21.90±27.2311.46±14.201.02 (1-1.05)0.036Layers:- Endocardium- Mesocardium- Epicardium- Endo/Meso- Meso/Epi- Transmural.48 (37.2%)7 (5.4%)26 (20.2%)21 (16.3%)8 (6.2%)19 (14.7%).3052215717.1824612.0.41 (0.18-0.91)0.89 (0.16-4.81)2.26 (0.72-7.12)0.88 (0.31-2.48)2.63 (0.31-22.16)3.49 (0.76-15.97).0.030.890.160.360.360.09Number of layers per channel3.05±2.32 (1–9)3.32±2.462.50±1.801.16 (0.96-1.4)0.104Number of AHA segments per channel2.28±1.20 (1–8)2.47±1.361.85±1.031.56 (1.01-2.4)0.028 Open table in a new tab

Myocardial scarring and recurrence of ventricular arrhythmia in patients surviving a ventricular fibrillation out of hospital cardiac arrest

Abstract Introduction Prediction of ventricular arrhythmia recurrence in survivors of ventricular fibrillation out of hospital cardiac arrest (VF-OHCA) is important, but currently difficult. Risk of recurrence may be related to presence of myocardial scarring and dedicated late gadolinium enhancement cardiac magnetic resonance (LGE-CMR) software allows for characterization of left ventricular scarring, including differentiation between core, border zone (BZ) and BZ channels that represent potential electrical circuits of slow conductivity responsible for ventricular arrhythmic events. Purpose Our study aims to characterize myocardial scarring as defined by LGE-CMR in survivors of a VF-OCHA and investigate its potential role for the risk of new ventricular arrhythmia. Methods Between 2018 and 2021, a total of 130 VF-OHCA patients had CMR, of which we included 28 patients with LGE-CMR before ICD implantation for secondary prevention. A total of 15 (54%) patients had signs of acute or chronic ischemic heart disease (IHD); and 13 (46%) patients had arrhythmogenic cardiomyopathy (ACM). Scar tissue including core, BZ and BZ channels were automatically detected by specialized investigational software. To differentiate BZ from healthy tissue and BZ from core, thresholds of 40% ± 5% and 60% ± 5% of the maximum signal intensity were applied. A BZ channel in the LGE-CMR reconstruction was defined as a continuous corridor of BZ between 2 core areas or between a core area and a valve annulus (Figure 1A+B). Results The median age was 56 years; 86% were men and the median left ventricular ejection fraction was 50±11%. A total of 16 (57%) patients had an inferior scar on LGE-CMR, and 8 (29%) patients with IHD were incompletely revascularized. After a median follow-up of 98 days, 9 (32%) patients (6/9 with IHD, including 5/6 incompletely revascularized; 3/9 with ACM) had recurrence of ventricular arrhythmia (6/9 monomorphic ventricular tachycardia (VT)). A significantly higher number of patients with BZ channels had recurrence of ventricular arrhythmia compared with patients without BZ channels (7/11 vs. 2/17; P=0.01) (Figure 2). The number of BZ channels (3±1 vs. 2±1; P=0.13); scar mass (21±8g vs. 14±11g; P=0.21); core mass (7±4g vs. 4±5g; P=0.14); and BZ mass (11±5g vs. 9±7g; P=0.42) were insignificantly higher in patients with recurrent ventricular arrhythmia compared with patients without. Conclusion Borderzone channels analyzed by LGE-CMR were associated with subsequent recurrence of ventricular arrhythmia in patients with out of hospital cardiac arrest caused by ventricular fibrillation. Funding Acknowledgement Type of funding sources: None.

Predicting arrhythmia recurrence following catheter ablation for ventricular tachycardia using late gadolinium enhancement magnetic resonance imaging: Implications of varying scar ranges.

Thresholding-based analysis of late gadolinium enhancement cardiac magnetic resonance (LGE-CMR) can create scar maps and identify corridors that might provide a reentrant substrate for ventricular tachycardia (VT). Current recommendations use a full-width-at-half-maximum approach, effectively classifying areas with a pixel signal intensity (PSI) >40% as border zone (BZ) and >60% as core. The purpose of this study was to investigate the impact of 4 different threshold settings on scar and corridor quantification and to correlate this with postablation VT recurrence. Twenty-seven patients with ischemic cardiomyopathy who had undergone catheter ablation for VT were included for retrospective analysis. LGE-CMR images were analyzed using ADAS3D LV. Scar maps were created for 4 PSI thresholds (40-60, 35-65, 30-70, and 45-55), and the extent of variation in BZ and core, as well as the number and weight of conduction corridors, were quantified. Three-dimensional representations were reconstructed from exported segmentations and used to quantify the surface area between healthy myocardium and scar (BZ + core), and between BZ and core. A wider PSI threshold was associated with an increase in BZ mass and decrease in scar (P <.001). No significant differences were observed for the total number of corridors and their mass with increasing PSI threshold. The best correlation in predicting arrhythmia recurrence was observed for PSI 45-55 (area under the curve 0.807; P = .001). Varying PSI has a significant impact on quantification of LGE-CMR parameters and may have incremental clinical value in predicting arrhythmia recurrence. Further prospective investigation is warranted to clarify the functional implications of these findings for LGE-CMR-guided ventricular ablation.

Scar related border zone channels assessed with cardiac MRI are associated with ventricular arrhythmia in patients with ST-segment elevation myocardial infarction

Abstract Funding Acknowledgements Type of funding sources: None. Introduction Prediction of scar-related ventricular arrhythmia in ST-Segment Elevation Myocardial Infarction (STEMI) is important, but currently difficult. Late gadolinium enhancement cardiac magnetic resonance (LGE-CMR) permits characterization of left ventricular (LV) ischemic scars, including differentiation between core, border zone (BZ) and BZ channels. The latter represents potential electrical circuits of slow conductivity responsible for ventricular arrhythmic events. We hypothesized that detailed BZ channel characterization potentially serves as a risk marker for ventricular arrhythmia, therefore contributing to risk stratification following STEMI. Purpose The aim of this study was to assess scar-related arrhythmic BZ channels with advanced CMR in STEMI patients developing subsequent ventricular arrhythmia compared with controls. Methods This is a CMR sub-study of the DANAMI-3 STEMI multicenter trial (year 2011, n=1234) and Danegaptide phase II proof-of-concept clinical trial (year 2013, n=591). All patients were admitted for primary PCI in all primary PCI centers in Denmark. A total of 779 patients had a 3-month follow-up CMR. Of these, 21 patients subsequently experienced ventricular arrhythmia during 68 months of follow-up and were randomly matched 1:2 with 42 controls, who constituted the study population. Matching were based on left ventricular ejection fraction (LVEF), infarct location, culprit vessel, and revascularization status in patients with multivessel disease. Ischemic scar tissue including core, BZ and BZ channels were automatically detected by a specialized investigational software (1). To differentiate BZ from healthy tissue and BZ from core, thresholds of 40% ± 5% and 60% ± 5% of the maximum signal intensity were applied. A BZ channel in the LGE-CMR reconstruction was defined as a continuous corridor of BZ between 2 core areas or between a core area and a valve annulus (Figure 1). Results We included 63 patients (median age: 58.0 years; 84% men; median LVEF: 45 ± 10%), of whom 30 (48%) patients had an anterior located infarction, and 45 (71%) patients were completely revascularized. The median time from STEMI to a ventricular arrhythmic event was 3 ± 2 years. A significantly higher number of patients with ventricular arrhythmia had BZ channels (n=16 (76%) vs. n=18 (43%), P=0.02) including an increased number of BZ channels (2 ± 2 vs. 1 ± 1, P=0.02) compared with controls. Patients with subsequent ventricular arrhythmia had a larger scar mass (core mass + BZ mass) (27 ± 17g vs. 19 ± 11g; P=0.03), core mass (9 ± 8g vs. 6 ± 5g; P=0.06) and BZ mass (18 ± 10g vs. 13 ± 7g; P=0.01). Conclusion(s) Border zone channels visualized by LGE-CMR were associated with subsequent development of ventricular arrhythmia in patients with STEMI and may serve as risk stratification following STEMI.

PO-628-06 EFFECT OF ANGIOTENSIN RECEPTOR NEPRILYSIN INHIBITOR AND EMPAGLIFLOZINE ON ISCHEMIC VENTRICULAR TACHYCARDIA SUBSTRATE: A HIGH-DENSITY MAPPING AND MRI STUDY

Angiotensin receptor neprilysin inhibitor (ARNI) and empagliflozine reduce cardiovascular death in heart failure, but mechanistic data on this effect are scarce. To assess the effect of ARNI and empagliflozine on scar remodeling and ventricular tachycardia (VT) inducibility in a swine model of chronic myocardial infarction (MI). Left anterior descending artery MI was induced in 40 Landrace Large X White pigs. Thirty-one animals (78%) survived the MI induction procedure and were randomized to receive treatment with beta-blocker (BB) only (group 1, n=7), empagliflozine+BB (group 2, n=8), ARNI + BB (group 3, n=8) or empagliflozine + ARNI + BB (group 4, n=8). Contrast-enhanced (ce)-MRI were performed at 2-day (baseline) and 1-month post-MI and were post-processed with ADAS 3D; ventricular scar subtypes and borderzone (BZ) corridors volume were measured. EP study with endo-epicardial high-density mapping was performed 1-month post-MI. VT was inducible in 21/31 subjects (68%). Treatment with ARNI (groups 3 and 4) showed a significant reduction of VT inducibility (OR 0.15 [0.026-0.91], p=0.03) compared to non-ARNI groups (100%, 75%, 50% and 50% for groups 1, 2, 3 and 4, respectively), representing a 30% relative risk reduction. Treatment with empagliflozine (group 2) did not reduce VT inducibility (p=0.704). Baseline ceMRI data showed a mean core and BZ scar mass of 5.4±3.1 and 6.1±3.1 grams, respectively, without significant differences in the percentage of core scar. The mean number of corridors was 2.1±1.2 with a mean mass of 1.3±1.0, without significant differences across groups. Treatment with ARNI and empagliflozine significantly reduced the number (+1.0, -1.1, -1.2 and -1.7 corridors for groups 1, 2, 3 and 4, respectively; p=0.021) and mass of corridors (+0.3, -1.6, -0.8 and -0.4 grams for groups 1, 2, 3 and 4, respectively; p=0.012) at the follow-up ceMRI. ARNI and empagliflozine groups tended to reduce overall BZ mass compared to the control group (reduction of the BZ percentage -1.2±4, -4.9±2, -5.6±2, -3.8±4; p=0.102). Treatment with ARNI reduced VT inducibility by 30% after MI, likely driven by a significant reduction of the number and mass of BZ corridors. Empagliflozine reduced the number and mass of BZ corridors, without impact on VT inducibility.View Large Image Figure ViewerDownload Hi-res image Download (PPT)

Cardiovascular magnetic resonance determinants of ventricular arrhythmic events after myocardial infarction.

To non-invasively characterize, by means of late gadolinium enhancement cardiac magnetic resonance (LGE-CMR), scar differences, and potential variables associated with ventricular tachycardia (VT) occurrence in chronic post-myocardial infarction (MI) patients. A case-control study was designed through retrospective LGE-CMR data analysis of chronic post-MI patients (i) consecutively referred for VT substrate ablation after a first VT episode (n = 66) and (ii) from a control group (n = 84) with no arrhythmia evidence. The myocardium was characterized differentiating core, border zone (BZ), and BZ channels (BZCs) using the ADAS 3D post-processing imaging platform. Clinical and scar characteristics, including a novel parameter, the BZC mass, were compared between both groups. One hundred and fifty post-MI patients were included. Four multivariable Cox proportional hazards regression models were created for total scar mass, BZ mass, core mass, and BZC mass, adjusting them by age, sex, and left ventricular ejection fraction (LVEF). A cut-off of 5.15 g of BZC mass identified the cases with 92.4% sensitivity and 86.9% specificity [area under the ROC curve (AUC) 0.93 (0.89-0.97); P < 0.001], with a significant increase in the AUC compared to other scar parameters (P < 0.001 for all pairwise comparisons). Adding BZC mass to LVEF allowed to reclassify 33.3% of the cases and 39.3% of the controls [net reclassification improvement = 0.73 (0.71-0.74)]. The mass of BZC is the strongest independent variable associated with the occurrence of sustained monomorphic ventricular tachycardia in post-MI patients after adjustment for age, sex, and LVEF. Border zone channel mass measurement could permit a more accurate VT risk stratification than LVEF in chronic post-MI patients.

Myocardial Scar Characterization and Future Ventricular Arrhythmia in Patients With Ischemic Cardiomyopathy and an Implantable Cardioverter-Defibrillator.

Background: Implantable cardioverter-defibrillator (ICD) therapy is associated with several deleterious effects, which can be reduced by antiarrhythmic drugs or catheter ablation. However, it is largely unknown which patients might benefit from these therapies. Therefore, this study aimed to investigate whether myocardial scar characterization improves risk stratification for ventricular arrhythmia (VA) occurrence in patients with ischemic cardiomyopathy and an ICD.Methods: In this study, 82 patients with ischemic cardiomyopathy who received an ICD were enrolled retrospectively. Late gadolinium enhancement cardiac magnetic resonance (LGE-CMR) images were analyzed using an investigational software tool to obtain quantitative data regarding the total scar, core, and border zone (BZ). Data regarding the QRS complex was obtained from electrocardiography (ECG). The primary endpoint was appropriate ICD therapy.Results: During a median follow-up duration of 3.98 years [interquartile range (IQR) 2.89–5.14 years], appropriate therapy occurred in 24 (29.3%) patients. Patients with appropriate ICD therapy had a significantly larger total scar mass [60.0 (IQR 41.2–73.4) vs. 43.3 (IQR 31.2–61.2) g; P = 0.009] and BZ mass [32.9 (IQR 26.9–42.4) vs. 24.5 (IQR 18.8–32.5) g; P = 0.001] than those without appropriate therapy. In multivariable Cox regression analyses, total scar mass [hazard ratio (HR) 1.02 [95% confidence interval (CI) 1.00–1.04]; P = 0.014] and BZ mass (HR 1.04 [95% CI 1.01–1.07]; P = 0.009) independently predicted appropriate ICD therapy. Core mass and the QRS complex, however, were not significantly associated with the primary endpoint.Conclusion: LGE-CMR-based, but not ECG-based myocardial scar characterization improves risk stratification for VA occurrence in patients with ischemic cardiomyopathy who received an ICD.

Effect of adipose graft transposition procedure (AGTP) on the ischemic arrhythmogenic substrate: an MRI study in a swine model of chronic myocardial infraction

Abstract Funding Acknowledgements Type of funding sources: Public grant(s) – National budget only. Main funding source(s): Instituto de Salud Carlos III BACKGROUND Cardiac regenerative therapy is a promising treatment for patients with myocardial infarction (MI) and heart failure. Nevertheless, previous ex-vivo studies have raised concern on the potential increased risk of arrhythmic events following certain cell therapies. Adipose graft transposition procedure (AGTP) is a cardiac reparative therapy consisting in transposing a vascularized adipose flap from the autologous pericardium and placing it over the epicardial scar area and has demonstrated to reduce infarct size and improve the left ventricular ejection fraction in preclinical and human studies. PURPOSE To assess the effect of the AGTP on the post-MI scar composition and image-based ventricular tachycardia (VT) corridors detection by means of late gadolinium enhanced cardiac magnetic resonance (LGE-CMR). METHODS A left circumflex artery (first marginal branch) MI was induced in 9 Landrace X Large White Pigs by delivering 1-3 coils. Two weeks post-MI, all subjects underwent a 3 Tesla LGE-CMR and randomized to the AGTP or sham group. LGE-CMR was repeated 30 days post-treatment (6 weeks post-MI). The arrhythmogenic substrate was characterized with an advanced image post-processing tool (ADAS 3D) and included quantification of dense scar and border zone (BZ) mass and detection of ventricular tachycardia (VT) corridors (including corridor scar mass). RESULTS The overall scar mass did not differ between scans in the overall population (7.6 ± 3.5 g vs 7.5 ± 2.2 g in the baseline and post-treatment scans, respectively; p = 0.9). Compared to the sham subjects, those receiving AGTP showed an absolute reduction of the total (-3.2 ± 1.4 g vs. +2.4 ± 1.7 g, p = 0.04) and dense scar (-0.9 ± 0.4 g vs. +0.7 ± 0.5 g, p = 0.03). BZ mass tended to decrease in the AGTP group (-2.2 vs 1.63 g; p = 0.06). The AGTP group showed a trend to reduce the number of VT corridors (-1 ± 0.7 vs. +0.4 ± 0.2, p = 0.078) and corridor scar mass (-0.3 ± 0.26 g vs. +0.1 ± 0.1 g, p = 0.11) (figure). CONCLUSIONS Cardiac reparative therapy of MI with AGTP reduced dense scar mass, compared to the increase observed in the sham group. The trend to reduce the BZ mass and the number/mass of VT corridors suggests a beneficial effect on the arrhythmic remodeling of the post-MI scar. Abstract Figure. Reduction in corridor"s number

Cardiovascular magnetic resonance determinants of ventricular arrhythmic events after myocardial infarction

Abstract Funding Acknowledgements Type of funding sources: None. Background Late gadolinium enhancement cardiac magnetic resonance (LGE-CMR) permits to identify the arrhythmogenic substrate in chronic post-myocardial infarction (MI) patients. It is unknown why a minority of chronic post-MI patients develop sustained ventricular tachycardias (VT) over follow-up, regardless of their left ventricular ejection fraction (LVEF). Objectives To noninvasively characterize scar differences and potential predictors of VT occurrence in chronic post-MI patients. Methods A case-control study was designed through retrospective LGE-CMR data analysis of chronic post-MI patients i) consecutively referred for VT substrate ablation after a first VT episode (n = 66), and ii) from a control group (n = 84) with no arrhythmia evidence. The myocardium was characterized differentiating core, border zone (BZ) and BZ channels (BZC) using the ADAS 3D post-processing imaging platform. Clinical and scar characteristics, including a novel parameter, the BZC mass, were compared between both groups. Results 150 post-MI patients were included for analysis. Four multivariate Cox proportional hazards regression models were created for total scar mass (model 1), BZ mass (model 2), core mass (model 3), and BZC mass (model 4, see table). All of them were adjusted by age, sex, and LVEF. In the corresponding models, only total scar mass, BZ mass, core mass, and BZC mass were independent variables associated with the development of VT. BZC mass showed the best performance: a cut-off of 5.15 g identified the cases with 92.4% sensitivity and 86.9% specificity [AUC 0.93 (0.89–0.97); p &amp;lt; 0.001], with a significant increase in the AUC compared to the other scar parameters (p &amp;lt; 0.001 for all pairwise comparisons using the De Long’s test). By using BZC mass as a risk stratification parameter together with LVEF, the net reclassification improvement (NRI) was 33.3% for the cases, and 39.3% for the controls. The net proportion of patients reclassified correctly was 36.7% Conclusions The mass of BZC, automatically obtained with a commercially available CMR post-processing software, is the strongest independent variable associated with the occurrence of clinical SMVT in post-MI patients after covariate adjustment for age, sex, and LVEF. The measurement of BZC mass could permit a more accurate arrhythmia risk stratification than LVEF in chronic post-MI patients (NRI 36.7%). Scar characteristics analyzed from LGE-CMR imaging should be taken into consideration to better stratify ventricular arrhythmia risk in chronic post-MI patients. Abstract Figure. ROC curves for predicting VT occurrence

Scar channels in cardiac magnetic resonance to predict appropriate therapies in primary prevention

Scar characteristics analyzed by late gadolinium enhancement cardiac magnetic resonance (LGE-CMR) are related with ventricular arrhythmias. Current guidelines are based only on the left ventricular ejection fraction to recommend an implantable cardioverter-defibrillator (ICD) in primary prevention. Our study aims to analyze the role of imaging to stratify arrhythmogenic risk in patients with ICD for primary prevention. From 2006 to 2017, we included 200 patients with LGE-CMR before ICD implantation for primary prevention. The scar, border zone, core, and conducting channels (CCs) were automatically measured by a dedicated software. The mean age was 60.9 ± 10.9 years; 81.5% (163) were men; 52% (104) had ischemic cardiomyopathy. The mean left ventricular ejection fraction was 29% ± 10.1%. After a follow-up of 4.6 ± 2 years, 46 patients (22%) reached the primary end point (appropriate ICD therapy). Scar mass (36.2 ± 19 g vs 21.7 ± 10 g; P < .001), border zone mass (26.4 ± 12.5 g vs 16.0 ± 9.5 g; P < .001), core mass (9.9 ± 8.6 g vs 5.5 ± 5.7 g; P < .001), and CC mass (3.0 ± 2.6 g vs 1.6 ± 2.3 g; P < .001) were associated with appropriate therapies. Scar mass > 10 g (25.31% vs 5.26%; hazard ratio 4.74; P = .034) and the presence of CCs (34.75% vs 8.93%; hazard ratio 4.07; P = .003) were also strongly associated with the primary end point. However, patients without channels and with scar mass < 10 g had a very low rate of appropriate therapies (2.8%). Scar characteristics analyzed by LGE-CMR are strong predictors of appropriate therapies in patients with ICD in primary prevention. The absence of channels and scar mass < 10 g can identify patients at a very low risk of ventricular arrhythmias in this population.