Scar Burden Research Articles

Feasibility of gray-blood late gadolinium enhancement evaluation in young patients with congenital and acquired heart disease.

Late gadolinium enhancement (LGE) sequences have become common in pediatric cardiovascular magnetic resonance (CMR) to assess for myocardial fibrosis. Bright-blood late gadolinium enhancement (BB-LGE) by conventional phase-sensitive inversion recovery (PSIR) is commonly utilized, but similar inversion time (TI) value of fibrosis and left ventricular (LV) blood pool can make subendocardial areas difficult to assess. A gray-blood LGE (GB-LGE) technique has been described, targeting nulling of the LV blood pool and demonstrating improvement in ischemic scar detection over BB-LGE in adult patients. We sought to evaluate the feasibility of the GB-LGE technique in a young population with congenital and acquired heart disease and compare its ability to detect subendocardial scar to conventional BB-LGE. Seventy-six consecutive patients referred for clinical CMR underwent both BB-LGE and GB-LGE on 1.5 T and 3 T scanners. Conventional PSIR sequences were obtained with TI to null the myocardium (BB-LGE) in short-axis and horizontal long-axis stacks. Same PSIR stacks were immediately repeated with TI to null the blood pool (GB-LGE). Both sequences were reviewed separately a week apart by two readers, blinded to the initial clinical interpretation. Studies were analyzed for overall image quality, confidence in scar detection, confidence in detection of LGE, LGE class, inter- and intra-observer agreement for the presence of scar, and intraclass correlation coefficient (ICC) for total scar burden. Overall confidence in myocardial scar detection by BB-LGE or GB-LGE as well as grading of image quality were not statistically different [(p = 1 and p = 1) and (p = 0.53, p = 0.18), respectively]. There was very good inter-observer agreement for the presence of scar on BB-LGE (K = 0.88, 95% CI 0.77-0.99) and GB-LGE (K = 0.84, 95% CI 0.7-0.96), as well as excellent intra-observer agreement for both readers (K = 0.93, 95% CI 0.87-0.99; and K = 0.81, 95% CI 0.69-0.95). Interclass correlation coefficient for total scar burden was excellent for BB-LGE (ICC = 0.98, 95% CI 0.96-0.99) and GB-LGE (ICC = 0.94, 95% CI 0.91-0.97). The GB-LGE technique is feasible in the pediatric population with congenital and acquired heart disease. It can detect subendocardial/ischemic scar similar to conventional bright-blood PSIR sequences in the pediatric population.

A Safe and Simple Method of Augmentation Mastopexy

Introduction: Combining breast augmentation with mastopexy has historically been considered challenging, with concerns about complications and suboptimal aesthetic outcomes. However, recent data suggest that the combined procedure can be performed safely and effectively. Materials and Method: This article presents a technique for augmentation mastopexy that aims to minimize complications and is safe to perform. The technique focuses on preserving a robust blood supply, minimizing lower breast contour bottoming out, maintaining upper pole fullness, reducing the risk of recurrent ptosis, minimizing scar burden, and avoiding periareolar scar widening. Precise preoperative and intraoperative markings are crucial for achieving long-lasting results. The use of tailor tacking and marking the vertical excess with the patient in an upright position provides a reliable method for determining the amount of soft tissue resection required. Results: The results are shown in the postoperative photographs at 10 days, 1 month, and 3 months, respectively. These are compared with the preoperative photographs of the patient’s features. Discussion: The technique incorporates the use of an implant placed in the dual-plane subpectoral pocket to address upper pole flatness and provide structural support in the lower pole. The article emphasizes the importance of preserving Cooper’s ligaments during skin resection to maintain the supportive role of the skin. Vertical wedge resection of the lower pole is employed to reconstruct the breast cone and create a strong vertical fibrous band, which contributes to the long-term shape and support of the breast. The article also discusses techniques to mitigate nipple-areolar complex widening and emphasizes the importance of patient selection based on specific criteria. Conclusion: Overall, the authors present a safe and simple technique for augmentation mastopexy that aims to achieve long-lasting results with minimal complications. The authors advocate for careful patient selection and adherence to their methodology, which incorporates principles of preserving blood supply, maintaining breast contours, and minimizing scar burden.

The influence of arm positions on mechanical dyssynchrony measured by gated myocardial perfusion imaging.

In routine procedures, patient's arms are positioned above their heads to avoid potential attenuation artifacts and reduced image quality during gated myocardial perfusion imaging (G-MPI). However, it is difficult to achieve this action in the acute period following pacemaker implantation. This study aimed to explore the influence of arm positioning on myocardial perfusion imaging (MPI) in different types of heart disease. This study was conducted retrospectively. A total of 123 patients were enrolled and underwent resting G-MPI using a standard protocol with arms positioned above their heads and again with their arms at their sides. All individuals were divided into 3 groups: the normal group, the obstructive coronary artery disease (O-CAD) group, and the dilated cardiomyopathy (DCM) group. The G-MPI data were measured by QGS software and Emory Reconstruction Toolbox, including left ventricular ejection fraction (LVEF), end-diastolic volume (EDV), end-systolic volume (ESV), extent, total perfusion deficit (TPD), summed rest score (SRS), scar burden, phase standard deviation (SD), and phase histogram bandwidth (BW). In total, extent, TPD, EDV, ESV, LVEF, systolic SD, systolic BW, diastolic SD, and diastolic BW were all significantly different between the 2 arm positions (all P<0.01). On the Bland-Altman analysis, both EDV and ESV with the arm-down position were significantly underestimated (P<0.001). Meanwhile, TPD, extent, and LVEF with the arm-down position were significantly overestimated (P<0.05). Systolic SD, systolic BW, diastolic SD, and diastolic BW were systematically overestimated (P<0.001). In the DCM group (n=52), EDV, ESV, systolic SD, systolic BW, diastolic SD, and diastolic BW were identified as significantly different by the paired t-test between the 2 arm positions (P<0.05). In the O-CAD group (n=32), scar burden, ESV, LVEF, and diastolic BW were significantly different between the 2 arm positions (P<0.05). Systolic and diastolic dyssynchrony parameters and most left ventricular (LV) functional parameters were significantly influenced by arm position in both normal individuals and patients with heart failure (HF) with different pathophysiologies. More attention should be given to LV dyssynchrony data during clinical evaluation of cardiac resynchronization therapy (CRT) implantation procedure.

Value of genotyping and scar-phenotyping for VT ablation procedures in patients with nonischemic left ventricular cardiomyopathies.

Variants of cardiomyopathy genes in patients with nonischemic cardiomyopathy (NICM) generate various phenotypes of cardiac scar and delayed enhancement cardiac magnetic resonance (DE-CMR) imaging which may impact ventricular tachycardia (VT) management. The objective was to compare the findings of cardiomyopathy genetic testing on DE-CMR imaging and long-term outcomes among patients with NICM undergoing VT ablation procedures. Image phenotyping and genotyping were performed in a consecutive series of patients referred for VT ablation and correlated to survival free of VT. Scar depth index (SDI) (% of scar at 0-3 mm, 3-5 mm and >5 mm projected on the closest endocardial surface) was determined. Forty-three patients were included (11 women, 55 ± 14 years, ejection fraction (EF) 45 ± 16%) and were followed for 3.4 ± 2.9 years. Pathogenic variants (PV) were identified in 16 patients (37%) in the following genes: LMNA (n = 5), TTN (n = 5), DSP (n = 2), AMLS1 (n = 1), MYBPC3 (n = 1), PLN (n = 1), and SCN5A (n = 1). A ring-like septal scar (RLSS) pattern was more often seen in patients with pathogenic variants (66% vs 15%, p = .001). RLSS was associated with deeper seated scars (SDI >5 mm 30.6 ± 22.6% vs 12.4 ± 16.2%, p = .005), and increased VT recurrence (HR 5.7 95% CI[1.8-18.4], p = .003). After adjustment for age, sex, EF, and total scar burden, the presence of a PV remained independently associated with worse outcomes (HR 4.7 95% CI[1.22-18.0], p = .02). Preprocedural genotyping and scar phenotyping is beneficial to identify patients with a favorable procedural outcome. Some PVs are associated with an intramural, deeper seated scar phenotype and have an increase of VT recurrence after ablation.

Impact of cardiac history and myocardial scar on increase of myocardial perfusion after revascularization

PurposeWe sought to assess the impact of coronary revascularization on myocardial perfusion and fractional flow reserve (FFR) in patients without a cardiac history, with prior myocardial infarction (MI) or non-MI percutaneous coronary intervention (PCI). Furthermore, we studied the impact of scar tissue.MethodsSymptomatic patients underwent [15O]H2O positron emission tomography (PET) and FFR before and after revascularization. Patients with prior CAD, defined as prior MI or PCI, underwent scar quantification by magnetic resonance imaging late gadolinium enhancement.ResultsAmong 137 patients (87% male, age 62.2 ± 9.5 years) 84 (61%) had a prior MI or PCI. The increase in FFR and hyperemic myocardial blood flow (hMBF) was less in patients with prior MI or non-MI PCI compared to those without a cardiac history (FFR: 0.23 ± 0.14 vs. 0.20 ± 0.12 vs. 0.31 ± 0.18, p = 0.02; hMBF: 0.54 ± 0.75 vs. 0.62 ± 0.97 vs. 0.91 ± 0.96 ml/min/g, p = 0.04). Post-revascularization FFR and hMBF were similar across patients without a cardiac history or with prior MI or non-MI PCI. An increase in FFR was strongly associated to hMBF increase in patients without a cardiac history or with prior MI/non-MI PCI (r = 0.60 and r = 0.60, p < 0.01 for both). Similar results were found for coronary flow reserve. In patients with prior MI scar was negatively correlated to hMBF increase and independently predictive of an attenuated CFR increase.ConclusionsPost revascularization FFR and perfusion were similar among patients without a cardiac history, with prior MI or non-MI PCI. In patients with prior MI scar burden was associated to an attenuated perfusion increase.

Radiomics of Late Gadolinium Enhancement Reveals Prognostic Value of Myocardial Scar Heterogeneity in Hypertrophic Cardiomyopathy

BackgroundLate gadolinium enhancement (LGE) scar burden by cardiac magnetic resonance is a major risk factor for sudden cardiac death (SCD) in hypertrophic cardiomyopathy (HCM). However, there is currently limited data on the incremental prognostic value of integrating myocardial LGE radiomics (ie, shape and texture features) into SCD risk stratification models. ObjectivesThe purpose of this study was to investigate the incremental prognostic value of myocardial LGE radiomics beyond current European Society of Cardiology (ESC) and American College of Cardiology (ACC)/American Heart Association (AHA) models for SCD risk prediction in HCM. MethodsA total of 1,229 HCM patients (62% men; age 52 ± 16 years) from 3 medical centers were included. Left ventricular myocardial radiomic features were calculated from LGE images. Principal component analysis was used to reduce the radiomic features and calculate 3 principal radiomics (PrinRads). Cox and logistic regression analyses were then used to evaluate the significance of the extracted PrinRads of LGE images, alone or in combination with ESC or ACC/AHA models, to predict SCD risk. The ACC/AHA risk markers include LGE burden using a dichotomized 15% threshold of LV scar. ResultsSCD events occurred in 30 (2.4%) patients over a follow-up period of 49 ± 28 months. Risk prediction using PrinRads resulted in higher c-statistics than the ESC (0.69 vs 0.57; P = 0.02) and the ACC/AHA (0.69 vs 0.67; P = 0.75) models. Risk predictions were improved by combining the 3 PrinRads with ESC (0.73 vs 0.57; P < 0.01) or ACC/AHA (0.76 vs 0.67; P < 0.01) risk scores. The net reclassification index was improved by combining the PrinRads with ESC (0.25 [95% CI: 0.08-0.43]; P = 0.005) or ACC/AHA (0.05 [95% CI: −0.07 to 0.16]; P = 0.42) models. One PrinRad was a significant predictor of SCD risk (HR: 0.57 [95% CI: 0.39-0.84]; P = 0.01). LGE heterogeneity was a major component of PrinRads and a significant predictor of SCD risk (HR: 0.07 [95% CI: 0.01-0.75]; P = 0.03). ConclusionsMyocardial LGE radiomics are strongly associated with SCD risk in HCM and provide incremental risk stratification beyond current ESC or AHA/ACC risk models. Our proof-of-concept study warrants further validation.

Global myocardial ischaemia in severe aortic stenosis reverses early after aortic valve replacement

Abstract Funding Acknowledgements Type of funding sources: Foundation. Main funding source(s): British Heart Foundation Background Myocardial ischaemia is common in aortic stenosis (AS) and is associated with exercise capacity, onset of symptoms and adverse myocardial remodelling. Positron emission tomography and invasive coronary studies have evaluated myocardial blood flow before and after aortic valve replacement (AVR), but these have been limited by imaging resolution, or by assessment of flow in a single coronary territory rather than the extent of the myocardium. Cardiovascular magnetic resonance (CMR) can determine myocardial function, remodelling and scar burden, and can also quantify pixel-wise stress myocardial blood flow (MBF). Using AI-based segmentation, global and regional stress and rest MBF can be determined inline with high precision and reproducibility. Purpose We aimed to evaluate the early effects of AVR on myocardial ischaemia in patients with severe symptomatic AS without flow limiting coronary disease. Methods Patients with severe symptomatic AS, without flow limiting coronary stenosis (by CT or invasive angiography), undergoing either surgical or transcatheter AVR were prospectively recruited. Patients underwent baseline echocardiography, paired cardiovascular magnetic resonance (CMR) with adenosine stress (140mcg/kg/min for 4 minutes) pre-operatively and a median[IQR] of 62 [40–83] days post-operatively. Results 26 patients (median [IQR] age 71 [66–75], 73% male) were included (3 patients only had rest perfusion due to safety concerns). The median [IQR] peak aortic velocity by echocardiography (Vmax) was 4.3 [4.1–4.5]m/s and AVA 0.8 [0.6–0.9]cm2. At a median 62 days post-AVR [IQR 40–83 days], the Vmax improved to median [IQR] 2.5 [2.0–2.9]m/s and the LV mass by CMR regressed from median [IQR] 83 [76–92]g/m2 to 72 [66–88]g/m2 (13% reduction), p = 0.001. Stress myocardial blood flow (MBF) increased 21% from median [IQR] 1.63 [1.38–2.21]ml/g/min to 1.97 [1.68–2.52]ml/g/min, p&amp;lt;0.001. Resting MBF did not change (0.88 vs 0.84, p = 0.32). Both epicardial and endocardial stress MBF improved after AVR, but the improvement in global stress MBF was mostly driven by a 40% improvement in endocardial MBF from median [IQR] 1.26 [1.18–1.78] to 1.77 [1.62–2.32]ml/g/min. Likewise there was an improvement in the endocardial to epicardial ratio from median [IQR] 0.73 [0.67–0.81] to 0.85 [0.80–0.97], p&amp;lt;0.001. Conclusions Severe AS results in marked subendocardial ischaemia which may be a substrate for myocardial fibrosis and adverse cardiac events, but is highly and rapidly reversible by valve intervention. The improvement in myocardial blood flow is driven by 40% increase in subendocardial blood flow. This effect is seen despite only modest early LV mass regression. Larger studies with histological correlation are required to determine the relative contributions of afterload and structural capillary rarefaction to ischaemia in these patients.

Left ventricular shape index and eccentricity index assessed by gated PET/CT. Promising parameters for detection of left ventricular remodelling

Abstract Funding Acknowledgements Type of funding sources: Public Institution(s). Main funding source(s): University of Groningen/University Medical Center Groningen. Background Left ventricular (LV) remodelling has been described as the pathway that precedes heart failure. This process consists of changes in the shape, size, volume and function of the left ventricle; all of this directly associated to increased risk of major adverse cardiac events (MACEs). Different parameters are used to evaluate cardiac geometry in multiple cardiac imaging modalities. In nuclear medicine, LV geometry can be studied through shape index (SI) and eccentricity index (EI). These values examine the degree of sphericity (SI) and elongation (EI) of the left ventricle. However, in cardiac perfusion PET/CT, the LV remodelling has not been extensively studied with SI and EI values, and their role is yet to be elucidated. Purpose This project aim to describe the role of SI and EI values in patients examined by gated 13N-ammonia PET/CT in ischemic and infarction scenario. Methods We retrospectively randomly selected 140 patients referred to 13N-ammonia PET/CT between 2016 and 2022 for suspected or diagnosed CAD. The patients were classified in 4 groups of 35 patients according to the presence and burden of ischemia or infarction: normal=0% of scar burden and ischemic burden; mild ischemia=5–10% of ischemic burden; moderate-severe ischemia≥10% of ischemic burden and infarction≥5% of scar burden. We collected the information regarding myocardial flows (myocardial blood flow (MBF) at rest, hyperaemic MBF at stress and coronary flow reserve (CFR)) and left ventricular geometry (SI end-diastolic at rest and stress, SI end-systolic at rest and stress, and EI at rest and stress). All the variables were automatically processed with QPS/QGS software. We performed a multicomparison analysis for the mentioned variables with One way ANOVA variance and Dunnett’s Test as Post Hoc, stablishing as the control the infarction group. Results The study population consisted of 35.7% women, all patients over 36 years old, with no significant differences between groups regarding the presence of cardiac risk factors. The control group showed important changes in all SI and EI when compared to the rest of the groups. With a maximum change of 0.090 observed in SI end-systolic stress in the mild ischemia group, and a minimum change of −0.041 in EI rest in the moderate-severe ischemia group. Control subjects had statistically significant higher values of SI end-diastolic rest (p&amp;lt;0.001) and stress (p = 0.005), end-systolic rest (p = 0.001)and stress (p&amp;lt;0.001) and statistically significant lower values of EI rest (p&amp;lt;0.001) and stress (p&amp;lt;0.001) when compared with all the other groups. Additionally, all SI and EI values in stress follow a linear change proportional to the degree of myocardial extend (Figure 1 and 2). Conclusions(s) SI and EI by 13N-ammonia PET/CT are variables that seem clinically relevant for the early detection of LV remodeling. However, there is still research to do for establishing cut-off values and evaluating the prediction of MACEs.

Prognostic implications of left ventricular inward displacement assessed by cardiac magnetic resonance imaging in patients with myocardial infarction.

Risk stratification of patients with ischemic heart disease (IHD) still depends mainly on the left ventricular ejection fraction (LVEF). LV inward displacement (InD) is a novel parameter of LV systolic function, derived from feature tracking cardiac magnetic resonance (CMR) imaging. We aimed to investigate the prognostic impact of InD in patients with IHD and prior myocardial infarction. A total of 111 patients (mean age 57 ± 10, 86% male) with a history of myocardial infarction who underwent CMR were included. LV InD was quantified by measuring the displacement of endocardially tracked points towards the centreline of the LV during systole with feature tracking CMR. The endpoint was a composite of all-cause mortality, heart failure hospitalization and arrhythmic events. During a median follow-up of 142 (IQR 107-159) months, 31 (27.9%) combined events occurred. Kaplan-Meier analysis demonstrated that patients with LV InD below the study population median value (23.0%) had a significantly lower event-free survival (P < 0.001). LV InD remained independently associated with outcomes (HR 0.90, 95% CI 0.84-0.98, P = 0.010) on multivariate Cox regression analysis. InD also provided incremental prognostic value to LVEF, LV global radial strain and CMR scar burden. LV InD, measured with feature tracking CMR, was independently associated with outcomes in patients with IHD and prior myocardial infarction. LV InD also provided incremental prognostic value, in addition to LVEF and LV global radial strain. LV InD holds promise as a pragmatic imaging biomarker for post-infarct risk stratification.

Lesion formation following pulsed field ablation for pulmonary vein and posterior wall isolation.

Pulsed field ablation (PFA) results in unique lesion formation, but there is lack of in-vivo validation in terms of scar formation following atrial fibrillation (AF) ablation. We aimed to access atrial lesion formation based on late gadolinium enhancement (LGE) cardiovascular magnetic resonance imaging (CMR) following PFA for pulmonary vein (PV) and posterior wall isolation (PWI). AF ablation was performed in 10 patients using a 31mm pentaspline PFA catheter. After pulmonary vein isolation (PVI; n=8 PFA-applications/ PV; n=4 in basket and n=4 in flower configuration), another eight applications in flower configuration were conducted for concomitant PWI. Patients underwent LGE CMR 3 months after ablation aiming for quantification of left atrial (LA) scar. Acute procedural success was achieved in all patients. Mean procedure duration was 62±7min. and mean LA dwell time of the PFA catheter was 13±2min. Mean post ablation total LA scar burden was 8.1±2.1% and mean scar width was 12.8±2.1mm. At the posterior LA, 22.6±2.2% of the anatomical segment resulted in chronic scar tissue, concentrated at the PW. Postablation CMR found no evidence for PV stenosis or collateral damage of adjacent structures. At 7 months of follow-up, 9/10 patients (90%) were free from arrhythmia recurrence. PFA for AF resulted in durable and transmural atrial scar tissue at the PVs and PW. LGE CMR found a very homogeneous and contiguous lesion pattern with no signs for collateral damage.

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 &amp;lt; 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.

Predictive value of scar burden assessed by cardiac MRI on sudden cardiac death in cardiac resynchronization therapy patients: a systematic review and meta-analysis

Abstract Funding Acknowledgements Type of funding sources: Public grant(s) – National budget only. Main funding source(s): Ministry of Innovation and the National Research, project no. RRF-2.3.1-21-2022-00003 and Project no. RRF-2.3.1-21-2022-00004 (MILAB) has been implemented with the support provided by the European Union. Background Myocardial fibrosis (MF) is associated with a higher prevalence of ventricular arrhythmias (VA) and sudden cardiac death (SCD). Late gadolinium enhancement cardiovascular magnetic resonance (LGE-CMR) can accurately evaluate the extent of MF. Clinical evidence suggests that scar assessment may help the decision of adding an implantable cardioverter defibrillator (ICD) to cardiac resynchronization therapy (CRT) to reduce the risk of VA and SCD. Purpose In this systematic review and meta-analysis, we collected and analyzed evidence pertaining to the association between scar burden and the risk of VA and SCD, and we evaluated the impact of appropriate device choice for CRT. Methods We performed a systematic literature search on MEDLINE using the PubMed, Embase, Scopus and CENTRAL databases. The target population were adults with heart failure with reduced ejection fraction who underwent CRT. The primary outcome was the association between the incidence of VA and/or SCD and scar burden assessment. Meta-analyses were performed using the META and DMETAR packages in R, using a random-effects model. The risk of bias was assessed using RoB2and the quality of evidence was evaluated using the GRADE assessment. Results 6 eligible articles have been included in our study, with a total of 1548 patients, of whom 465, 696, and 387 have been implanted with an ICD, CRT-D, CRT-P respectively. Altogether 62,68 % of the total population were LGE-CMR positive. The proportion of appropriate ICD shock reached 15,65 % in the total population during the median follow-up time of 51,59 months. The risk of developing appropriate ICD shocks in the LGE positive population was almost 70% higher (Hazard ratio 1,69, 95% Confidence interval: 1,29- 2,21; p&amp;lt;0,001) compared to LGE negative patients. Conclusion In our meta-analysis, LGE-CMR was significantly associated with appropriate device therapy and can identify a subgroup of patients with an increased risk of life-threatening VA. Based on our results performing an MRI before device implantation might be important to select the high-risk patients for SCD in the elderly with ischaemic etiology and older age.

The last shall be the first: the role of combined QLV- and CMR-determined electromechanical concordance in predicting optimal left ventricular stimulation site in cardiac resynchronisation therapy

Abstract Funding Acknowledgements Type of funding sources: None. Background/introduction Optimisation of cardiac resynchronisation therapy (CRT) response still represents a significant challenge to cardiac electrophysiology. In this regard, perhaps the area of greatest uncertainty revolves around optimal left ventricular lead (LVL) position and in particular whether this should be directed at areas of latest electrical or mechanical activation given the equivocal evidence on their precise relationship in heart failure (HF) patients. Furthermore, while echocardiography has demonstrated that LVL aimed at regions of greatest mechanical delay maximises CRT response, cardiac magnetic resonance (CMR) with its greater spatial resolution and tissue definition is yet to demonstrate a role in doing so. Purpose To retrospectively evaluate concordance between latest electrical and CMR-determined mechanical activation in a CRT population and its relationship with reverse remodeling. Methods This is a retrospective single center analysis of 104 CRT patients. All patients had CMR and echocardiography performed before implantation. During implantation, coronary sinus angiogram was performed and electrical delay (QLV time with RV-LV time greater than 80 ms) was mapped on all veins suitable for lead implantation and LVL was positioned in the region of latest electrical activation programming LVL cathode accordingly. LVL cathode position was thus assumed to represent the region of latest electrical delay. A post-hoc analysis was then conducted by means of CART-Tech® software providing radial strain and scar maps on a 36-segment anatomical model. Patients were then stratified based on concordance between LVL cathode position (using 3D heart models superimposed on 2D angiography images) and most mechanically delayed segments (either the three most delayed segments or adjacent ones) or non concordance (one or more segments between LVL cathode and three most mechanically delayed segments). Data from patient follow-up was collected with echocardiography at least 3 months after implant date. CRT response was expressed as reduction in end-systolic volume (ESV) greater than 15%. Results A preliminary analysis of the first 30 patients of our cohort was conducted. Electromechanical concordance and non-concordance were present in 24 and 6 patients, respectively. Baseline patient characteristics including demographics, comorbidities, HF aetiology, ECG and echocardiography features were comparable between groups except for scar burden, which was higher in the non-concordance group. Response to CRT was 80% in the concordant vs. 20% in the non-concordant group. Conclusions While a confounding effect of scar burden cannot be excluded, these preliminary data suggest that electromechanical concordance in LVL cathode placement may represent a predictor of optimal CRT response. The full scope of this study will be fully appreciated in the coming month on completion of analysis of the entire patient cohort.

Preinterventional quantification of dense scar or borderline zone in patients undergoing ventricular tachycardia ablation

Abstract Funding Acknowledgements Type of funding sources: None. Introduction This study sought to examine the prognostic role of quantifying areas of interest in preinterventional cardiac magnetic resonance (CMR) in patients with structural heart disease (SHD) referred for ablation of ventricular tachycardia (VT). Background The role of preinterventional CMR for the identification of scar areas, borderline zones and reentry channels in the ventricles has been well established. Whether the burden of dense scar or borderline tissue has a prognostic impact on the acute and the long-term ablation outcome in SHD patients is disputed. Methods and results We investigated 185 patients with SHD undergoing preinterventional CMR prior to VT-ablation. 38 patients were excluded because of poor imaging quality, leaving a cohort of 147 patients with positive late enhancement (LGE) imaging (mean age 62 years, 47% non-ischemic cardiomyopathy, mean left ventricle ejection fraction 38%, 96% with implanted ICD). The cohort was divided in ischemic (ICM) and non-ischemic (NICM) cardiomyopathy group and the results regarding burden of overall scar tissue, dense scar, borderline zone, as well as clinical and procedural characteristics, acute and long-term results of the two groups were compared. The ICM patients had more advanced NYHA stadium (p = 0.046), reduced left ventricular ejection fraction (LV-EF, p &amp;lt;0.001) and higher left ventricular enddiastolic volume (LVEDV, p &amp;lt;0.001). The NICM patients were more often under antiarrhythmic therapy (p = 0.005) and underwent more frequently epicardial ablation (p &amp;lt;0.001). Although the overall scar burden war higher in ICM patients (p &amp;lt;0.001), the groups showed no significant difference in borderline zone burden (p = 0.580). Furthermore, the two groups had similar results in number of inducible VTs (p = 0.054) and VT inducibility at the end of the procedure (p = 0.121). Nevertheless, the NICM group underwent overall more ablation procedures during the 19-month follow up (p = 0.023). Both groups showed similar results regarding assist device implantation, heart transplantation or death until the end of the follow up (p = 0.192). Conclusion While quantification of the scar tissue and the borderline zone is feasible in ICD patients with SHD, the scar or the borderline zone burden were not predictive of the VT ablation outcome.

MAgnetic resonance imaging based DUal lead cardiac Resynchronization therapy: A prospectIve Left Bundle Branch Pacing study (MADURAI LBBP study)

Cardiac resynchronization therapy(CRT) is a class-I indication for LVEF≤35%, and heart failure(HF). LBBB associated nonischemic-cardiomyopathy (LB-NICM) with minimal or no scar by cardiac-magnetic-resonance(CMR) imaging may be associated with excellent prognosis following CRT. Left-bundle-branch-pacing(LBBP) can achieve excellent resynchronization in LBBB patients. Aim of our study was to prospectively assess feasibility and efficacy of LBBP with or without a defibrillator in patients with LB-NICM and LVEF ≤35%, risk stratified by CMR. Pts with LB-NICM, LVEF≤35% and HF were prospectively enrolled from 2019 to 2022. If the scar burden<10% by CMR, LBBP only (Group-I) and if ≥10%, LBBP+ICD(Group-II) was performed. Primary endpoints-1.Echocardiographic-response(ER)- ΔLVEF ≥15% at 6 months; 2.Composite of time to death, HFH or sustained VT/VF. Secondary endpoints-1.Echocardiographic-hyper-response(EHR-LVEF≥50%orΔLVEF ≥20%) at 6 and 12 months; 2.Indication for ICD-upgradation(persistent LVEF<35% at 12 months or sustained VT/VF) RESULTS: 120 patients were enrolled. CMR showed <10% scar-burden in 109 patients(90.8%). 4 patients opted for LBBP+ICD and withdrew. LBBP optimized-dual-chamber-pacemaker(LOT-DDD-P) was done in 101 patients and LOT-CRT-P in 4 patients(Group-I,n=105). Scar-burden ≥10% in 11 pts who underwent LBBP+ICD(Group-II). During mean-follow-up 21±12 months, primary endpoint of ER observed in 80%(68/85 pts) in Group-I vs 27%(3/11 pts) in Group-II(p-0.0001). Primary composite-endpoint of death,HFH or VT/VF occurred in 3.8% in group-I vs 33.3% in Group-II(p<0.0001). Secondary endpoint of EHR(LVEF≥50%) observed in 39.5%vs0%, 61.2%vs9.1% and 80%vs33.3% at 3, 6 and 12 months in group-I and group-II respectively. CMR guided CRT using LOT-DDD-P appears to be a safe and feasible approach in LB-NICM and has the potential to reduce healthcare cost.

PO-02-075 ASSOCIATIONS OF DEMOGRAPHICS AND COMORBIDITIES WITH LEFT ATRIAL SCAR BURDEN IN PATIENTS WITH PERSISTENT ATRIAL FIBRILLATION UNDERGOING CATHETER ABLATION FROM THE REAL-AF REGISTRY

Previous research has shown that women are more likely to suffer significant complications of atrial fibrillation (AF). Scar burden at catheter ablation (CA) may indicate substrate and disease progression, but data are conflicting from small studies. Issues with voltage data include choice of mapping catheter, rhythm mapping was performed in, voltage cut-off used, and how truly representative low voltage is of scar. To examine the relationship of LA scar to demographics and patient comorbidities in a large registry of patients undergoing first-time radiofrequency AF ablation for persistent AF (PsAF). The Real-world Experience of Catheter Ablation for the Treatment of Symptomatic Paroxysmal AF and PsAF Using Novel Contact Force Technologies registry (Real-AF) is a prospective, observational, multicenter registry of over 5,000 patients undergoing CA with follow-up at 6 and 12 months. We evaluated 1,431 eligible patients among this cohort by using independent sample t and chi square testing to identify associations of demographics and comorbidities with degree of LA scar burden >= 5%, calculated from CARTO as total % LA area < 0.50mV bipolar. Mapping was performed using the Pentaray catheter and subgroup analysis was prespecified in those mapped during sinus. Mean age was greater among patients with LA scar burden ≥ 5% (66 vs 72 years, p<0.001). Women were more likely than men to have LA scar (55% vs 31%, p <0.001). Congestive heart failure (CHF) was associated with greater LA scar burden as well (46% vs 37%, p = <0.001). CHADSVASc was also greater in patients with LA scar (2.8 vs 3.6, p<0.001). Patients with scar were more likely to undergo substrate modification (SM) during ablation (85% vs 47%, p = <0.001). Among a subgroup of patients presenting in sinus (n=344), all above associations remained significant other than that of CHF and increased LA scar (46% vs 37%, p = 0.12). In early outcome data, LA scar was not predictive of increased AF recurrence 12 months following ablation compared to scar burden < 5% (24% vs 17%, p = 0.075). Increased LA scar burden was associated with female sex, greater age, CHADSVASc and CHF. As a categorical variable, there was no significant correlation between scar burden at time of first ablation and AF recurrence at 12 months, but further data is pending. This is the largest study to our knowledge to investigate correlation of patient characteristics and AF recurrence with degree of LA scarring in patients with persistent AF.

PO-05-192 LOCAL HETEROGENEITY OF LATE GADOLINIUM ENHANCEMENT PREDICTS VENTRICULAR ARRHYTHMIA IN HYPERTROPHIC CARDIOMYOPATHY

Hypertrophic cardiomyopathy (HCM) is the most common cause of sudden cardiac death in young people. Despite recent advances in risk stratification using cardiac magnetic resonance (CMR) imaging, risk prediction remains suboptimal. Improved risk stratification is therefore warranted. Whether local heterogeneity of Late Gadolinium Enhancement (LGE) signal is associated with ventricular arrhythmia remains unknown. To determine whether local heterogeneity of LGE signal on CMR predicts ventricular arrhythmia and appropriate shocks after implantable cardioverter defibrillator (ICD) implantation in patients with HCM. Local heterogeneity was quantified by LGE-CMR signal dispersion score and compared with cardiovascular outcomes in 179 HCM patients who underwent ICD implantation. The primary outcome was appropriate ICD shocks. During a median follow-up time of 7.3 years the event rate was 0.015 per person year. History of ventricular arrhythmia (HR 9.413, p<0.001) and sudden cardiac death (HR 13.82, p<0.001) were associated with receiving an appropriate ICD shock in both univariable and multivariable analyses. History of syncope, family history of sudden cardiac death, non-sustained ventricular tachycardia, left ventricular wall thickness and presence of LGE were not associated with the primary outcome. When compared to patients without ICD shock, patients who received ICD shocks had higher burden of LGE gray zone (16.8±7.5% vs 25.8±3.5% p<0.001) and scar (10.5±6.7% vs 18.7±4.3% p<0.001) on CMR. Importantly, patients with ICD shocks had a higher dispersion score (1.20 vs 0.97, respectively), signifying higher degree of LGE signal heterogeneity (p=0.047). Dispersion score, a marker of local LGE signal heterogeneity of scar and gray zone was associated with a higher burden of ICD shocks in HCM patients who received ICDs. Mechanistically, local LGE signal heterogeneity could represent complex scar. These results may contribute to improved risk stratification for ventricular arrhythmia in HCM patients.

PO-02-020 CHARACTERIZING PREDICTORS AND OUTCOMES OF LATE RESPONDERS TO CARDIAC RESYNCHRONIZATION THERAPY

Typically, response to cardiac resynchronization therapy (CRT) is evaluated at 6 months. There is a subset of patients who do not fully respond to CRT at this point, however, do demonstrate improvement at 12 months. Characterizing these patients and their outcomes has not been widely explored. We examined in the MORE-CRT MPP study, the predictors of patients who do not demonstrate a reduction in left ventricular end-systolic volume (LVESV) >15% at 6 months, who however do reach that endpoint at 12 months. The MORE-CRT MPP study is a prospective, randomized, multicenter study. All patients (n = 5803) initially received conventional biventricular (BiV) CRT for 6 months. At this stage, echocardiographic non-responders were randomised to either continued conventional BiV pacing, or MultiPoint pacing. This post-hoc analysis evaluated the BiV pacing group only. This group was split into: i) non-responders (<15% reduction in LVESV at 6 and 12 months), ii) early responders (>15% reduction in LVESV at 6 months), and iii) delayed responders (<15% reduction in LVESV at 6 months, but >15% improvement at 12 months). Logistic regression models were used to assess the baseline characteristics of delayed responders. Heart failure hospitalization was the clinical endpoint. Of the 2,920 patients in the analysis 16.7% (n=486) were non-responders, 78% were early responders (n=2263), and 5.8% (n=171) were delayed responders. On multivariable analysis, only patients with ischaemic aetiology and a reduced QRS duration/left ventricular end-diastolic volume (LVEDV) ratio at baseline were statistically significant for predicting delayed response (see table). Freedom from heart failure hospitalization was similar in the early and late CRT responders, and significantly worse in the non-responder group. Patients with increased scar burden and those with a lower QRS/LVEDV ratio (i.e., reduced relative degree of dyssynchrony) were likely to be delayed responders to conventional BiV CRT. Early and delayed CRT responders have a similar risk of heart failure hospitalization despite the slower echo remodelling.Tabled 1Univariate and multivariate Cox regression model to predict likelihood of delayed response to cardiac resynchronization therapy (CRT).ParameterUnivariate AnalysisMultivariate AnalysisOR [95% CI]p-valueSample SizeOR [95% CI]p-valueAge1.004 [0.990, 1.019]0.5724351.01 [0.99, 1.02]0.46COPD (Yes vs No)0.804 [0.466, 1.388]0.432436Diabetes (Yes vs No)1.106 [0.795, 1.539]0.552436Hypercholesterolaemia (Yes vs No)1.099 [0.800, 1.509]0.562436Hypertension (Yes vs No)0.857 [0.624, 1.176]0.342436Ischaemic vs Non-Ischaemic1.638 [1.198, 2.240]0.00224361.64 [1.13, 2.37]0.009LBBB vs Non-LBBB0.650 [0.448, 0.944]0.02418640.75 [0.51, 1.10]0.14LVEF0.983 [0.961, 1.006]0.152436NYHA I/II vs NYA III/IV1.066 [0.779, 1.459]0.692427QRS duration/LVEDV ratio1.000 [0.993, 1.006]0.9320670.47 [0.22, 0.99]0.047Renal disease (Yes vs No)1.244 [0.799, 1.937]0.332436Female vs Male0.786 [0.555, 1.112]0.1724360.96 [0.63, 1.46]0.84 Open table in a new tab

PO-02-201 OUTCOMES OF RADIOFREQUENCY ABLATION OF ATRIAL FIBRILLATION IN OCTOGENARIANS IN A MULTICENTER REGISTRY (REAL-AF)

Catheter ablation for atrial fibrillation (AF) has significantly increased in prevalence, including in an elderly population. However, some studies suggest that outcomes of AF ablation may be inferior in elderly patients. Real-world, multi-center data is minimal and may provide more insight on this possibility. To compare the outcomes of octogenarians versus non-octogenarians undergoing catheter ablation of AF in high volume centers. Patients undergoing radiofrequency ablation of AF were prospectively enrolled in a multi-center registry (REAL-AF) from January 2018 to May 2021. The cohort was divided into 2 groups, patients ≥ 80 years old (octogenarians) and patients < 80 years old (non-octogenarians). Baseline characteristics and procedural data were collected prospectively on all patients. Routine ambulatory monitoring was performed at 6- and 12-months and additionally as needed based on symptoms. Efficacy was assessed at 12 months. The primary outcome was freedom from symptomatic atrial arrhythmias lasting greater than 30 seconds after a 90-day blanking period. 71 patients were included in the octogenarian group and 1,134 patients in the non-octogenarian group. The proportion of patients with persistent AF was similar between the groups. Octogenarians were more likely to have lower BMI, hypertension, prior bleeding, and left atrial scar as assessed by electro-anatomic mapping system (EAM). Left ventricular ejection fraction and left atrial volume as measured on EAM were also similar among the groups. There was a trend towards increased recurrence of atrial arrhythmias in octogenarians (table 1). At 12 months, octogenarians were more likely to be on anti-arrhythmic drugs as well. However, there was no difference in procedure-related complications between the groups. When controlled for left atrial scar burden, there was no difference in outcomes between the two groups. Octogenarians undergoing ablation of atrial fibrillation are more likely to have recurrent atrial arrhythmias than younger patient; this difference seems to be associated with an increased likelihood of abnormal left atrial voltage in the elderly patients. Although octogenarians are considered a frail population, AF ablation maintained similar safety profiles and arrhythmia related healthcare utilization rates when compared to a younger population.

A new method incorporating deep learning with shape priors for left ventricular segmentation in myocardial perfusion SPECT images

Accurate segmentation of the left ventricle (LV) is crucial for evaluating myocardial perfusion SPECT (MPS) and assessing LV functions. In this study, a novel method combining deep learning with shape priors was developed and validated to extract the LV myocardium and automatically measure LV functional parameters. The method integrates a three-dimensional (3D) V-Net with a shape deformation module that incorporates shape priors generated by a dynamic programming (DP) algorithm to guide its output during training. A retrospective analysis was performed on an MPS dataset comprising 31 subjects without or with mild ischemia, 32 subjects with moderate ischemia, and 12 subjects with severe ischemia. Myocardial contours were manually annotated as the ground truth. A 5-fold stratified cross-validation was used to train and validate the models. The clinical performance was evaluated by measuring LV end-systolic volume (ESV), end-diastolic volume (EDV), left ventricular ejection fraction (LVEF), and scar burden from the extracted myocardial contours. There were excellent agreements between segmentation results by our proposed model and those from the ground truth, with a Dice similarity coefficient (DSC) of 0.9573 ± 0.0244, 0.9821 ± 0.0137, and 0.9903 ± 0.0041, as well as Hausdorff distances (HD) of 6.7529 ± 2.7334 mm, 7.2507 ± 3.1952 mm, and 7.6121 ± 3.0134 mm in extracting the LV endocardium, myocardium, and epicardium, respectively. Furthermore, the correlation coefficients between LVEF, ESV, EDV, stress scar burden, and rest scar burden measured from our model results and the ground truth were 0.92, 0.958, 0.952, 0.972, and 0.958, respectively. The proposed method achieved a high accuracy in extracting LV myocardial contours and assessing LV functions.