Left Ventricular Scar Research Articles

Post-ST-Segment-Elevation Myocardial Infarction Platelet Reactivity Is Associated With the Extent of Microvascular Obstruction and Infarct Size as Determined by Cardiac Magnetic Resonance Imaging.

BackgroundDespite optimized medical management and techniques of primary percutaneous coronary intervention, a substantial proportion of patients with ST‐segment–elevation myocardial infarction (STEMI) display significant microvascular damage. Thrombotic microvascular obstruction (MVO) has been implicated in the pathogenesis of microvascular and subsequent myocardial damage attributed to distal embolization and microvascular platelet plugging. However, there are only scarce data regarding the effect of platelet reactivity on MVO.Methods and ResultsWe prospectively evaluated 105 patients in 2 distinct periods (2012–2013 and 2016–2018) who presented with first ST‐segment–elevation myocardial infarction and underwent primary percutaneous coronary intervention. All patients were treated with dual antiplatelet therapy (DAPT). Blood samples were analyzed for platelet reactivity, and cardiac magnetic resonance imaging scans were evaluated for late gadolinium enhancement and MVO. DAPT suboptimal response was defined as hyporesponsiveness to either aspirin or P2Y12 receptor inhibitor agents and demonstrated in 31 patients (29.5%) of the current cohort. Suboptimal platelet response to DAPT was associated with a significantly greater extent of MVO when expressed as a percentage of the left ventricular mass, left ventricular scar, and the number of myocardial left ventricular segments showing MVO (P<0.01 for each). Adjusted multivariable logistic regression model revealed that suboptimal response to DAPT is significantly associated with both greater late gadolinium enhancement (P<0.01) and MVO extent (odds ratio, 3.7 [95% CI, 1.3–10.5]; P=0.01). Patients with a greater extent of MVO were more likely to sustain major adverse cardiovascular events at a 1‐year follow‐up (37% versus 11%; P<0.01).ConclusionsIn patients undergoing primary percutaneous coronary intervention for ST‐segment–elevation myocardial infarction, platelet reactivity in response to DAPT is a key predictor of the extent of both myocardial and microvascular damage.

Role of Cardiac Magnetic Resonance Imaging in the Evaluation of Athletes with Premature Ventricular Beats.

Premature ventricular beats (PVBs) in athletes are not rare. The risk of PVBs depends on the presence of an underlying pathological myocardial substrate predisposing the subject to sudden cardiac death. The standard diagnostic work-up of athletes with PVBs includes an examination of family and personal history, resting electrocardiogram (ECG), 24 h ambulatory ECG (possibly with a 12-lead configuration and including a training session), maximal exercise testing and echocardiography. Despite its fundamental role in the diagnostic assessment of athletes with PVBs, echocardiography has very limited sensitivity in detecting the presence of non-ischemic left ventricular scars, which can be revealed only through more in-depth studies, particularly with the use of contrast-enhanced cardiac magnetic resonance (CMR) imaging. The morphology, complexity and exercise inducibility of PVBs can help estimate the probability of an underlying heart disease. Based on these features, CMR imaging may be indicated even when echocardiography is normal. This review focuses on interpreting PVBs, and on the indication and role of CMR imaging in the diagnostic evaluation of athletes, with a special focus on non-ischemic left ventricular scars that are an emerging substrate of cardiac arrest during sport.

368 Serial vs. single cardiovascular screening of adolescent athletes

Abstract The primary objective of preparticipation cardiovascular evaluation (PPCE) in young athletes is to detect asymptomatic individuals with cardiovascular disease (CVD) at risk of sudden cardiac death (SCD). The study population included a consecutive series of competitive athletes age 12–18 years who underwent PPCE, which according to Italian law is mandatory and based on yearly evaluations, at the Center for Sports Medicine of Treviso (Veneto region of Italy), from 2009 to 2019. The screening protocol included personal and family history questionnaire, physical examination, resting 12-lead ECG, and limited stress testing for evaluation of exertional ventricular arrhythmias. 2,3 This latter test was performed using a bicycle with constant-load increases (i.e. 2 W/kg in female participants and 3 W/kg in male participants) for 3 min for at least 85% or more of maximal heart rate was achieved, plus 3 min of postexercise monitoring. 3 Athletes with a positive medical history and abnormal physical examination, ECG, or stress test underwent further investigations. The diagnostic yield of the initial screening session was compared with that of repeat PPCEs. Athletes with a definitive diagnosis of CVD at risk of SCD were considered ineligible for competitive sports, although they received a tailored programme for leisure physical activity and were enrolled in a yearly follow-up programme. Outcome data of screened athletes, either eligible or ineligible to play competitive sports, were obtained from office visits, hospital records, or interrogation of the Registry of Juvenile SCD of the Veneto region. The study population included 15 127 consecutive athletes (64% male, 96% White) who underwent a total of 53 396 annual PPCEs (mean 3.7 per athlete) over the 11-year study period. The median age at first screening was 13 years [interquartile range (IQR): 12–14]. Sixty-three athletes (65% male) were diagnosed with a CVD at risk of SCD such as congenital heart disease (n = 17), ion channel disease (n = 11), inherited cardiomyopathy (n = 13), isolated nonischaemic left ventricular scar (NLVS) with ventricular arrhythmias (n = 18), or other (n = 4); 266 athletes had cardiac conditions not associated with SCD. Seventeen of the 63 athletes (27%) with atrisk CVD had a positive family history, symptoms, or abnormal physical examination, 38 (60%) had ECG abnormalities, and 32 (51%) developed arrhythmias on limited exercise testing. CVDs more frequently identified on repeat evaluation included inherited cardiomyopathies [7/11 (64%)], NLVS with ventricular arrhythmias [15/18 (83%)], and long QT syndrome [7/11 (64%)]. During a mean follow-up of 6.7 ± 3.5 years, 1 athlete with a negative PPCE experienced an episode of aborted SCD attributable to ventricular fibrillation that remained unexplained after a comprehensive diagnostic workup (event rate, 0.98/100 000 athletes per year). These results show that annual cardiovascular screening of adolescent athletes increased by three times the diagnostic yield of CVD at risk of SCD compared with a once-only (initial) evaluation. Inherited cardiomyopathies and isolated NLVS with ventricular arrhythmias were the CVDs more frequently identified on repeat evaluation.

Comparative assessment of the diagnostic value of echocardiography and magnetic resonance imaging in determining myocardial viability

Aim. To compare myocardial imaging methods in patients with complicated coronary artery disease with significantly decreased myocardial contractility.Material and methods. This single-center retrospective study included 109 patients with complicated coronary artery disease who underwent surgical treatment between 2014 and 2020. All patients had indications for delayed contrast-enhanced cardiac magnetic resonance imaging (MRI) in order to determine myocardial viability due to a pronounced decrease in left ventricular contractility according to echocardiography (ejection fraction (EF) ≤30%).Results. Impairment of local contractility according to MRI and echocardiography significantly correlates with depth of contrast accumulation (p=0,0000000018 and p=0,0000034, respectively). Delayed contrast-enhanced cardiac MRI with cine sequences allows to determine higher number of impaired contractility cases compared with echocardiography (p=0,000006).Conclusion. MRI with cine sequence allowed to determine higher number of impaired contractility cases compared with echocardiography. Delayed contrastenhanced MRI is a reliably more sensitive method than electrocardiography in detecting left ventricular scarring. The depth of contrast agent accumulation correlates with local contractility impairment detected by echocardiography and delayed contrast-enhanced cardiac MRI.

MA-SOCRATIS: An automatic pipeline for robust segmentation of the left ventricle and scar

Multi-atlas segmentation of cardiac regions and total infarct scar (MA-SOCRATIS) is an unsupervised automatic pipeline to segment left ventricular myocardium and scar from late gadolinium enhanced MR images (LGE-MRI) of the heart.We implement two different pipelines for myocardial and scar segmentation from short axis LGE-MRI. Myocardial segmentation has two steps; initial segmentation and re-estimation. The initial segmentation step makes a first estimate of myocardium boundaries by using multi-atlas segmentation techniques. The re-estimation step refines the myocardial segmentation by a combination of k-means clustering and a geometric median shape variation technique. An active contour technique determines the unhealthy and healthy myocardial wall. The scar segmentation pipeline is a combination of a Rician–Gaussian mixture model and full width at half maximum (FWHM) thresholding, to determine the intensity pixels in scar regions. Following this step a watershed method with an automatic seed-points framework segments the final scar region.MA-SOCRATIS was evaluated using two different datasets. In both datasets ground truths were based on manual segmentation of short axis images from LGE-MRI scans. The first dataset included 40 patients from the MS-CMRSeg 2019 challenge dataset (STACOM at MICCAI 2019). The second is a collection of 20 patients with scar regions that are challenging to segment. MA-SOCRATIS achieved robust and accurate performance in automatic segmentation of myocardium and scar regions without the need of training or tuning in both cohorts, compared with state-of-the-art techniques (intra-observer and inter observer myocardium segmentation: 81.9% and 70% average Dice value, and scar (intra-observer and inter observer segmentation: 70.5% and 70.5% average Dice value).

B-PO02-126 LATE-IODINE ENHANCEMENT COMPUTED TOMOGRAPHY AS A MARKER FOR SCAR LOCALIZATION FOR VENTRICULAR TACHYCARDIA ABLATION IN CARDIAC SARCOIDOSIS

Ventricular tachycardia (VT) portends high morbidity and mortality in cardiac sarcoidosis (CS). Left ventricular scarring in CS is often patchy with a predilection for the basal septum, anterior wall, and perivalvular regions. Reliable pre-procedural imaging modalities as adjuvant tools for VT scar localization are limited. To assess anatomic correlation of late iodine enhancement with procedural scar localization and to determine whether such correlation predicts ablation success. Consecutive VT ablation procedures from January 2017 to December 2020 at the Medical University of South Carolina were retrospectively reviewed. Thirteen patients with CS underwent pre-procedural computed tomography (CT) to identify wall thinning (WT) and late iodine enhancement (LIE). Left ventricular scarring was confirmed with voltage mapping and classified based on anatomical region: LV ostium, anterior, septal, inferior, lateral, and apical. Fisher's exact probability extension for 2 x 2 contingency tables were used to test whether there was significant congruency of two modalities. The cohort included 13 patients with CS (92% male, 60 +/- 11 years, EF 40.9% +/- 12.5). Average procedure time was 279 +/- 89 minutes with > 1 inducible VT per case (8 LBBB, 6 RBBB; average CL 414 ms) in all patients. The presence of WT did not correlate with LIE at the LV ostium (p=0.19) but did with anterior (p=0.007), inferior (p=0.005), and lateral (p=0.005) regions. WT was not associated with scar localization. The presence of LIE demonstrated convergence with scar localization at the LV ostium (p=0.005). Of 6 patients with normal wall thickness and positive LIE at the LV ostium (i.e. discordance), 5 (83%) had noninducible VT substrate post-ablation. Of those 5 patients, 3 (60%) had arrhythmia recurrence and required repeat ablation. In patients with cardiac sarcoidosis, LIE on CT correlates with scar localization at the LV summit. Ablation of LIE-identified LV ostial scars yields a high rate of acute success in patients with CS. Future studies should investigate the association between WT-LIE-scar localization and long-term outcomes.

Cardiovascular Involvement in COVID-19: What Sequelae Should We Expect?

Several forms of cardiovascular involvement have been described in patients with Coronavirus disease 19 (COVID-19): myocardial injury, acute coronary syndrome, acute heart failure, myocarditis, pericardial diseases, arrhythmias, takotsubo syndrome, and arterial and venous atherothrombotic and thromboembolic events. Data on long-term outcome of these patients are still sparse, and the type and real incidence of cardiovascular sequelae are poorly known. It is plausible that myocardial injury may be the initiator of an inflammatory cascade, edema, and subsequent fibrosis, but also a consequence of systemic inflammation. The extent and distribution of ongoing inflammation may be the basis for ventricular dysfunction and malignant arrhythmias. Indeed, preliminary observational findings seem to emphasize the importance of close monitoring of COVID-19 patients with myocardial injury after discharge. Residual subclinical disease may be effectively investigated by using second-level imaging modalities such as cardiac magnetic resonance, which allows better characterization of the type and extension of myocardial damage, as well as of the ongoing inflammation after the acute phase. In patients with venous thromboembolism, a very common complication of COVID-19, the type and the duration of anticoagulation therapy after the acute phase should be tailored to the patient and based on the estimation of the individual thromboembolic and hemorrhagic risk. Large randomized clinical trials are ongoing to address this clinical question. Whether the severity of cardiovascular involvement, the type of treatments adopted during the acute phase, and the hemodynamic response, may influence the long-term outcome of patients recovered from COVID-19 is unknown. An etiological diagnosis of myocardial injury during the hospitalization is the first step for an appropriate follow-up in these patients. After discharge, the screening for residual left and right ventricular dysfunction, arrhythmias, residual thrombosis, and myocardial scar should be considered on a case-by-case basis, whereas an active clinical surveillance is mandatory in any patient.

A Novel High-Resolution Surface Electrocardiographic Method to Identify and Characterize Myocardial Scar: A Proof-of-Concept Study

BackgroundThe placement of the left ventricular (LV) lead in an area free of myocardial scar is an important determinant of cardiac resynchronization therapy response. We sought to develop and validate a simple, practical, and novel electrocardiographic (ECG)-based approach to intraoperatively identify the presence of LV scar. We hypothesized that there would be a reduction in the measured amplitude of the LV pacing stimulus on the skin surface using a high-resolution (HR) ECG when pacing from LV regions with scar compared with regions without scar. We term this the ECG Amplitude Signal Evaluation (EASE) method. MethodsConsecutive patients with ischemic LV systolic dysfunction and standard criteria for de novo cardiac resynchronization therapy implantation were prospectively enrolled. All underwent a preimplant contrast-enhanced cardiac magnetic resonance study to assess for scar. The average amplitude of the LV pacing impulse was sampled on HR surface ECG intraprocedurally and then compared with the cardiac magnetic resonance results. ResultsA total of 38 LV pacing sites were assessed among 13 recipients. The median voltage measured on the surface HR ECG in regions with scar was reduced by 41% (interquartile range, 17% to 63%), whereas there was no measurable change in voltage (interquartile range, 0 to 0%) in regions without scar compared with the maximal amplitude (Wilcoxon P < 0.0001). ConclusionThe EASE method appears to be of potential value as a novel intraoperative tool to guide LV lead placement to regions free of scar. Future work is required to validate the utility of this method in a larger patient cohort.

Causes of sudden cardiac death in young athletes and nonathletes: systematic review and meta-analysis

Abstract Funding Acknowledgements Type of funding sources: None. Introduction. The etiology of sudden cardiac death (SCD) in young people is still debated. The aim of this meta-analysis was to identify the most frequent causes of SCD in individuals aged ≤35 years, the differences between athletes and nonathletes and among geographic areas. Methods. Studies published between 01/01/1990 and 01/31/2020 and evaluating post-mortem the etiology of SCD in young individuals (≤35 years) were included. Individuals were divided in athletes and nonathletes. Studies that did not report separately data between athletes and nonathletes were excluded. Results. Thirty-four studies met the inclusion criteria and a total population of 5,060 victims of SCD were analysed (2,890 athletes, 2,170 nonathletes). Structurally normal heart, hypertrophic cardiomyopathy (HCM), idiopathic left ventricular hypertrophy, and anomalous origin of coronary arteries (AOCA) were the most frequent causes of SCD in athletes while coronary artery disease (CAD), arrhythmogenic cardiomyopathy (ACM), and channelopathies were frequent causes of SCD in nonathletes. The number of SCDs due to ischemic heart disease (19.6% vs. 9.1%, p = 0.009), ACM (11.5% vs. 4.7%, p = 0.03) and channelopathies (8.4% vs. 1.9%, p = 0.02) was higher in nonathletes comparing with athletes. SCD due to non-ischemic left ventricular scar (5.1% vs. 1.1%, p = 0.01) was more frequent in athletes. HCM (p = 0.01) and AOCA (p = 0.004) were more frequently cause of SCD in US while ACM (p = 0.001), structurally normal heart (p = 0.02), and channelopathies (p = 0.02) in Europe. Conclusions. Structurally normal heart, HCM, AOCA were frequent causes of SCD in athletes while CAD, ACM and channelopathies in nonathletes. The causes of SCD differ between US and Europe.

English

BACKGROUND Echocardiography is considered as a traditional approach to clinically study dilated cardiomyopathy. Because of poor apical visibility, however, volumetric calculations are difficult to ascertain. In calculating left ventricle volumes and ejection fractions, magnetic resonance (MR) imaging has shown to be more accurate than echocardiography. Due to conflicting literature, the present study was conducted to diagnose dilated cardiomyopathy using 2 D - echocardiography and correlate these echocardiographic findings with magnetic resonance imaging (MRI). METHODS This observational cross-sectional study was conducted in the Department of Radio-diagnosis and Imaging, Sri Sathya Sai Institute of Higher Medical sciences, Puttaparthi, Andhra Pradesh, Pin 515134. The study group consisted of consecutive patients who had clinical suspicion of dilated cardiomyopathy. A total of 40 patients underwent both 2 D - echo and cardiac MRI on the same day. All patients underwent 2 - D echo which was performed at the frame rate of 40 - 80 frames per second in the left lateral decubitus position to obtain standard 2, 3, and 4 chambers as well as short axis views (GE Vingmed Vivid 7 Dimensions, Horton, Norway: 2.5 MHz transducer). MRI was performed on a 1.5 T scanner (Mangnetom Aera, Siemens, Erlangen, Germany). For patient monitoring and cardiac synchronization, 3 - lead electrocardiography was used. RESULTS In the present study, in comparison to reference standard (cardiac MRI), 2 D - echocardiography showed significant and systematic underestimation of enddiastolic volume (EDV), end-systolic volume (ESV) and stroke volume (SV). Good correlation between 2 D - echo and cardiac MRI was noted for end-diastolic volume (r = 0.89), stroke volume (r = 0.60) and ejection fraction (r = 0.75). CONCLUSIONS In summary, magnetic resonance imaging is an accurate, non-invasive, safe and advanced modality for evaluation of global left ventricular function and myocardial scarring. 2 D - echocardiography can be used for screening of the patients with clinically suspected dilated cardiac myopathy (DCM) and their follow up. KEYWORDS Echocardiography, MRI, Cardiomyopathy

Hybrid transcatheter left ventricular reconstruction for the treatment of ischemic cardiomyopathy.

Left ventricular (LV) enlargement is a mechanical adaptation to accommodate LV systolic inefficiency following an acute damage or a progressive functional deterioration, which fails to correct the decline of stroke volume in the long term, leading to progressive heart failure (HF). Surgical ventricular reconstruction (SVR) is a treatment for patients with severe ischemic HF aiming to restore LV efficiency by volume reduction and LV re-shaping. Recently, a new minimally-invasive hybrid technique for ventricular reconstruction has been developed by means of the Revivent™ system (BioVentrix Inc., San Ramon, CA, USA). The device for ventricular reconstruction consists of anchor pairs that enable plication of the anterior and free wall LV scar against the right ventricular (RV) septal scar of anteroseptal infarctions to decrease cardiac volume without ventriculotomy in a beating-heart minimally-invasive procedure, consisting of a transjugular and left thoracotomy approach. Patients with severe (Grade 4) functional mitral regurgitation (FMR) or with previous cardiac surgery procedures were excluded. Outcome of the reconstruction procedure: from 2012 until 2019, it has been applied to 203 patients, with 5 (2.5%) in-hospital deaths. LV volume reduction varied according to experience gained along years: LV end-systolic volume index decreased from baseline 43% (post-market registry) vs. 27% (CE-mark study); left ventricular ejection fraction (LVEF) increased from baseline 25% (post-market registry) vs. 16% (CE-mark study). Clinical status (NYHA class, HF questionnaire, 6-minute walking test) improved significantly compared to baseline, and re-hospitalization rate was only 13% at 6-month follow-up (60% of patients in NYHA =3). FMR grade decreased at follow-up in 63%, while it was unchanged in 37% of patients. The hybrid ventricular reconstruction (HVR) seems a promising treatment for HF patients who may benefit from LV volume reduction, with reasonable mortality and good results at follow-up. A baseline less severe clinical profile was not associated to better outcome at follow-up, which makes the procedure feasible in patients with very large ventricles and depressed ejection fraction (EF). LV reshaping has no detrimental effect on FMR, that may, on the contrary, benefit owing to less papillary muscle displacement, partial recovery of torsion dynamics and of myofibers re-orientation. A controlled study on top of optimal medical treatment is warranted to confirm its role in the management of HF patients.

Prognostic Value of Nonischemic Ringlike Left Ventricular Scar in Patients With Apparently Idiopathic Nonsustained Ventricular Arrhythmias.

Left ventricular (LV) scar on late gadolinium enhancement (LGE) cardiac magnetic resonance has been correlated with life-threatening arrhythmic events in patients with apparently idiopathic ventricular arrhythmias (VAs). We investigated the prognostic significance of a specific LV-LGE phenotype characterized by a ringlike pattern of fibrosis. A total of 686 patients with apparently idiopathic nonsustained VA underwent contrast-enhanced cardiac magnetic resonance. A ringlike pattern of LV scar was defined as LV subepicardial/midmyocardial LGE involving at least 3 contiguous segments in the same short-axis slice. The end point of the study was time to the composite outcome of all-cause death, resuscitated cardiac arrest because of ventricular fibrillation or hemodynamically unstable ventricular tachycardia and appropriate implantable cardioverter defibrillator therapy. A total of 28 patients (4%) had a ringlike pattern of scar (group A), 78 (11%) had a non-ringlike pattern (group B), and 580 (85%) had normal cardiac magnetic resonance with no LGE (group C). Group A patients were younger compared with groups B and C (median age, 40 vs 52 vs 45 years; P<0.01), more frequently men (96% vs 82% vs 55%; P<0.01), with a higher prevalence of family history of sudden cardiac death or cardiomyopathy (39% vs 14% vs 6%; P<0.01) and more frequent history of unexplained syncope (18% vs 9% vs 3%; P<0.01). All patients in group A showed VA with a right bundle-branch block morphology versus 69% in group B and 21% in group C (P<0.01). Multifocal VAs were observed in 46% of group A patients compared with 26% of group B and 4% of group C (P<0.01). After a median follow-up of 61 months (range, 34-84 months), the composite outcome occurred in 14 patients (50.0%) in group A versus 15 (19.0%) in group B and 2 (0.3%) in group C (P<0.01). After multivariable adjustment, the presence of LGE with ringlike pattern remained independently associated with increased risk of the composite end point (hazard ratio, 68.98 [95% CI, 14.67-324.39], P<0.01). In patients with apparently idiopathic nonsustained VA, nonischemic LV scar with a ringlike pattern is associated with malignant arrhythmic events.

Ventricular Arrhythmias in Athletes: Role of a Comprehensive Diagnostic Workup

BACKGROUND: Ventricular arrhythmias (VAs) represent a critical issue in regard to sports eligibility assessment in athletes. The ideal diagnostic evaluation of competitive and leisure-time athletes with complex VAs has not been clearly defined. OBJECTIVE: To assess the clinical implications of invasive electrophysiological assessments and endomyocardial biopsy among athletes with VAs. METHODS: We evaluated 227 consecutive athletes who presented to our institutions after being disqualified from participating in sports because of VAs. After noninvasive tests, electrophysiology study (EPS), electroanatomical mapping (EAM), and EAM- or cMRI-guided endomyocardial biopsy (EMB) were performed, following a prespecified protocol. Sports eligibility status was redefined at 6-month follow-up. RESULTS: From our sample, 188 (82.8%) athletes underwent EAM and EPS, while 42 (15.2%) underwent EMB. In this latter subset, the invasive diagnostic workup allowed diagnostic reclassification of half of athletes (n=21, 50%). Reclassification was particularly common among subjects without definitive findings after noninvasive evaluation (n=23; 87% reclassified), especially in the presence of cMRI-proven left ventricular (LV) nonischemic scar (n=13; 92% reclassified). History of syncope, abnormal echocardiogram, presence of late gadolinium enhancement, and abnormal EAM were linked to sports ineligibility at six-month follow-up, whereas performance of catheter ablation was associated with sports eligibility. CONCLUSIONS: A comprehensive invasive workup provided important additional diagnostic elements and could improve the sports eligibility assessment of athletes presenting with VAs. The presented extensive invasive evaluation could be routinely performed when noninvasive tests show unclear findings and/or LV nonischemic scar in order to inform athletes' management.

Does Left Ventricular Dyssynchrony by Positron Emission Tomography Predict Ventricular Tachyarrhythmia?

While left ventricular (LV) dyssynchrony and myocardial scar have been associated with ventricular tachyarrhythmia, the utility of these parameters measured by positron emission tomography (PET) is lacking. We investigated the relationship between LV dyssynchrony and myocardial scar burden assessed by PET and ventricular tachyarrhythmia.

Predictors of Left Ventricular Scar Using Cardiac Magnetic Resonance in Athletes With Apparently Idiopathic Ventricular Arrhythmias.

BackgroundIn athletes with ventricular arrhythmias (VA) and otherwise unremarkable clinical findings, cardiac magnetic resonance (CMR) may reveal concealed pathological substrates. The aim of this multicenter study was to evaluate which VA characteristics predicted CMR abnormalities.Methods and ResultsWe enrolled 251 consecutive competitive athletes (74% males, median age 25 [17‐39] years) who underwent CMR for evaluation of VA. We included athletes with >100 premature ventricular beats/24 h or ≥1 repetitive VA (couplets, triplets, or nonsustained ventricular tachycardia) on 12‐lead 24‐hour ambulatory ECG monitoring and negative family history, ECG, and echocardiogram. Features of VA that were evaluated included number, morphology, repetitivity, and response to exercise testing. Left‐ventricular late gadolinium‐enhancement was documented by CMR in 28 (11%) athletes, mostly (n=25) with a subepicardial/midmyocardial stria pattern. On 24‐hour ECG monitoring, premature ventricular beats with multiple morphologies or with right‐bundle‐branch‐block and intermediate/superior axis configuration were documented in 25 (89%) athletes with versus 58 (26%) without late gadolinium‐enhancement (P<0.001). More than 3300 premature ventricular beats were recorded in 4 (14%) athletes with versus 117 (53%) without positive CMR (P<0.001). At exercise testing, nonsustained ventricular tachycardia occurred at peak of exercise in 8 (29%) athletes with late gadolinium‐enhancement (polymorphic in 6/8, 75%) versus 17 athletes (8%) without late gadolinium‐enhancement (P=0.002), (P<0.0001). At multivariable analysis, all 3 parameters independently correlated with CMR abnormalities.ConclusionsIn athletes with apparently idiopathic VA, simple characteristics such as number and morphology of premature ventricular beats on 12‐lead 24‐hour ambulatory ECG monitoring and response to exercise testing predicted the presence of concealed myocardial abnormalities on CMR. These findings may help cost‐effective CMR prescription.

Impact of Myocardial Scar on Prognostic Implication of Secondary Mitral Regurgitation in Heart Failure

ObjectivesThe objective of the present study was to use cardiovascular magnetic resonance (CMR) to examine the natural history of secondary MR severity and the implication of left ventricular (LV) scar on its prognostic significance. BackgroundThere is a need for further understanding of the prognostic implication of secondary mitral regurgitation (MR) given the heterogeneous findings of the 2 recent randomized trials on percutaneous mitral intervention in patients with secondary MR. MethodsPatients with heart failure were enrolled into a prospective observational registry between 2008 and 2019. Outcomes were a composite of all-cause death, heart transplantation, or LV assist device implantation at follow-up. CMR was used to quantify the mitral regurgitation volume and mitral regurgitation fraction (MRF) along with scar burden utilizing late gadolinium enhancement. Patients were categorized into 4 subgroups based on presence and tertiles of scar extent: no scar, limited scar (scar burden 1% to 4%), intermediate scar (scar burden 5% to 20%), and extensive scar (scar burden >20%). ResultsAmong patients (n = 441) included in the study (age 59 ± 14 years, 43% with ischemic etiology), 85 (19%) experienced an adverse event. MRF ≥30% was associated with increased risk of events among the study group (hazard ratio: 1.74; 95% confidence interval: 1.10 to 2.76; p = 0.02). When stratified by presence or absence of scar, MRF ≥30% was associated with events only among patients with scar (hazard ratio: 1.67; 95% confidence interval: 1.02 to 2.76; p = 0.04) but not among patients without scar. On further classification of patients with scar, the prognostic significance of secondary MR was observed primarily among patients with intermediate scar burden. ConclusionsThe natural history of secondary MR is complex, and outcomes are affected by severity of MR and vary depending upon the extent of scar. (DeBakey Cardiovascular Magnetic Resonance Study [DEBAKEY-CMR]; NCT04281823)

QOL-41. CARDIAC DYSFUNCTION IN MEDULLOBLASTOMA SURVIVORS TREATED WITH PHOTON IRRADIATION

BACKGROUNDMedulloblastoma is an aggressive central nervous system (CNS) tumor that occurs mostly in the pediatric population. Treatment includes surgical resection, craniospinal radiation (CSI) and chemotherapy. Children who receive standard photon radiation (RT) are at risk for cardiac toxicities. Potential late effects include coronary artery disease, left ventricular scarring and dysfunction, valvular damage and atherosclerosis. Current survivorship guidelines recommend routine ECHO surveillance for these patients but this comes at significant health care costs over a lifetime. We describe the experience of cardiac dysfunction in medulloblastoma survivors in a multi-institution study.METHODSA retrospective chart review of medulloblastoma patients treated between 1980 and 2010 with radiation at Lurie Children’s Hospital and Dana-Farber/ Boston Children’s Hospital who had an echocardiogram done following completion of therapy.RESULTS168 patients were treated for medulloblastoma during the study time. Of whom, 80 patients had echocardiogram follow up and 76 received photon irradiation. The latter were included in the study. The mean age at CSI was 8.6 years (range 2.9- 20), and mean number of years post RT at echocardiogram 7.4 years (range 2–16). Mean ejection fraction (EF) was 60.03% and shortening fraction (SF) 33.8%. Four patients (5%) had abnormal results, all of which had EF<50%.CONCLUSIONPatients who received craniospinal irradiation for medulloblastoma therapy have relatively normal echocardiograms post treatment. Although RT may result in cardiac risks, echocardiograms may not be the most cost effective or efficacious mode to evaluate the risk in these survivors long term.

Abstract 16755: Personalized Virtual Cardiac Resynchronization Therapy Simulation Based on a 12-Lead ECG and CMR Predicts Electrical Activation Changes After Cardiac Resynchronization Therapy

Introduction: Simulating electrical remodeling after cardiac resynchronization therapy (CRT) based on individual patient characteristics could enhance the effectiveness of the procedure, help select optimal CRT candidates, and yield important prognostic data. Hypothesis: A Virtual CRT (V-CRT) simulation based on the 12-lead ECG and cardiac magnetic resonance (CMR) for evaluation of biventricular structure and extent of scar with late gadolinium enhancement (LGE) would predict changes in electrical activation after CRT. Methods: V-CRT uses cardiac geometry and scar (LGE) from CMR, a torso avatar from CMR scouts, and an electrophysiology model derived from the baseline ECG, the left ventricular (LV) pacing site, and programmed CRT pacing parameters. Ventricular activation times and the resulting QRS duration (QRSd) after CRT were estimated. The predicted QRS durations were then compared with the actual QRS durations after CRT pacing. Results: 20 CRT patients (age 67.3 ± 10.2 years, 30% female, 50% with LV scar) had a mean pre-CRT QRSd of 151 ± 12.8 ms. This predicted post-CRT QRSd depended significantly on the LV pacing site with a median maximum-minimum difference per patient over all possible pacing sites of 39.8 ms (IQR 32.5-44.2 ms). The post-CRT QRSd predicted by V-CRT based on the actual LV pacing site correlated well with the observed post-CRT QRS duration (r=0.51, p=0.02) (Figure). Predicted changes in the QRS duration were strongly associated with changes in LV activation times (r=0.74, p=0.0002), but not RV activation times (no correlation). Greater predicted reductions in LV activation times were more common in patients with greater LV end-diastolic volume indices (LVEDVIs) by CMR (r=-0.58, p=0.01). Conclusions: V-CRT effectively predicts changes in electrical activation after CRT. These findings have important implications for patient selection for CRT, prognosis after CRT, and CRT implementation strategies.

Predictors of left ventricular scar at cardiac magnetic resonance in athletes with apparently idiopathic ventricular arrhythmias

Abstract Introduction In athletes with ventricular arrhythmias (VA) and otherwise unremarkable clinical findings, cardiac magnetic resonance (CMR) may reveal concealed pathological substrates. The aim of this multicentre study was to evaluate which VA characteristics were associated with CMR abnormalities. Methods We enrolled a consecutive series of 251 competitive athletes (74% males, mean age 28.5±14.5 years) who underwent CMR for evaluation of VA. We included athletes with &amp;gt;100 premature ventricular beats (PVBs)/24-hour or ≥1 repetitive VA (couplets, triplets or non-sustained ventricular tachycardia) on 12-lead 24-hour ambulatory ECG monitoring and negative family history, electrocardiogram and echocardiogram. Features of VA that were evaluated included number, morphology, repetitivity and response to exercise testing. Results Left-ventricular late gadolinium-enhancement (LGE) was documented in 28 (11%) athletes, mostly (N=25) with a subepicardial/midmyocardial (non-ischemic) distribution. On 24-hour ECG monitoring, PVBs with a right-bundle-branch-block and intermediate/superior axis configuration or multiple morphologies were documented in 24/28 (86%) athletes with versus 55/223 (25%) without LGE (p&amp;lt;0.001). More than 2000 PVBs were recorded in 6 (21%) athletes with versus 127 (57%) without positive CMR (p&amp;lt;0.001). At exercise testing, repetitive VA occurred at high work-load in 12 (43%) athletes with versus 26 (12%) without LGE (p&amp;lt;0.001). At multivariable analysis, all three VA features independently correlated with CMR abnormalities. Conclusions In athletes with apparently idiopathic VA, simple characteristics such as number and morphology of PVBs on 12-lead 24-hour ambulatory ECG monitoring and response to exercise testing predicted the presence of concealed myocardial abnormalities on CMR. These findings may help cost-effective CMR prescription. Flow chart Funding Acknowledgement Type of funding source: None

Cardiac magnetic resonance features of acute myocarditis presenting as acute coronary syndrome

Abstract Background Clinical presentation of myocarditis varies, one specific form of myocarditis appears with the clinical signs of acute coronary syndrome (ACS). Cardiac magnetic resonance (CMR) is an important method for assessing ventricular function and morphology, additionally provides accurate tissue specific and functional information of the heart. Aims Our aim was to investigate the characteristics, and prognosis of myocarditis presenting with ACS symptoms. Methods 113 patients with the clinical signs of ACS but nonobstructed coronary arteries in whom the CMR revealed acute myocarditis were included in our study. CMR was performed in acute phase and at 3–6-month follow-up. Left ventricular (LV) volumes, mass and strain parameters expressing myocardial deformity were determined. Additional images were taken to represent tissue specific information. Relationships between laboratory and CMR parameters were investigated. Parameters predicting changes in LV ejection fraction (LVEF) were analyzed by logistic regression. Results A total of 113 patients with myocarditis (98 males, 31±11 years) underwent acute and follow-up CMR. Sixty two patients reported fever or infection before the beginning of their complaints, most commonly gastroenteritis (33%) and pharyngitis (32%). The creatinine kinase MB value measured in the acute phase showed positive correlation with the extent of necrosis, and the global longitudinal- and circumferential strain. The extent of the LV necrosis showed negative correlation with LVEF and positive correlation with global circumferential strain (GCS) (p&amp;lt;0.05). On the control CMR examination LVEF and all global strain values improved, fibrosis persisted in 82% of cases but shrank (15±11 vs 5±4 g) and LV mass decreased (p&amp;lt;0.01) compared to the acute phase. Compared to the acute phase, 21% of the patients had lower LVEF on the follow-up CMR. Lower initial LVEF, worse acute GCS, and greater LV necrosis were independent predictors of LVEF reduction in the logistic regression model. During a median follow-up of 6-years of patients treated at our clinic (n=39) no patient suffered cardiac death, heart failure, or documented ventricular arrhythmia but 21% of them had recurrent myocarditis. Conclusion Myocarditis mimicking ACS affects predominantly young men and shows functional improvement and good prognosis on follow-up, but it may reoccur in some cases. The reduction of LV function on control CMR may be predicted by worse initial LVEF, GCS, and a larger LV scar. Strain, LGE in acute phase and follow-up Funding Acknowledgement Type of funding source: Public grant(s) – National budget only. Main funding source(s): Project no. NVKP_16-1-2016-0017 has been implemented with the support provided from the National Research, Development and Innovation Fund of Hungary, financed under the NVKP_16 funding scheme. This project was supported by a grant from the National Research, Development and Innovation Office (NKFIH) of Hungary (K 120277).