Electroanatomical voltage mapping with contact force sensing for diagnosis of arrhythmogenic right ventricular cardiomyopathy

BACKGROUND

Three-dimensional electroanatomical mapping (EAM) can be helpful to diagnose arrhythmogenic right ventricular cardiomyopathy (ARVC). Yet, previous studies utilizing EAM have not systematically used contact-force sensing catheters (CFSC) to characterize the substrate in ARVC, which is the current gold standard to assure adequate tissue contact.

OBJECTIVE

To investigate reference values for endocardial right ventricular (RV) EAM as well as substrate characterization in patients with ARVC by using CFSC.

METHODS

Endocardial RV EAM during sinus rhythm was performed with CFSC in 12 patients with definite ARVC and 5 matched controls without structural heart disease. A subanalysis for the RV outflow tract (RVOT), septum, free-wall, subtricuspid region, and apex was performed. Endocardial bipolar and unipolar voltage amplitudes (BVA, UVA), signal characteristics and duration as well as the impact of catheter orientation on endocardial signals were also investigated.

RESULTS

ARVC patients showed lower BVA vs. controls (p = 0.018), particularly in the subtricuspid region (1.4, IQR:0.5-3.1 vs. 3.8, IQR:2.5-5 mV, p = 0.037) and RV apex (2.5, IQR:1.5-4 vs. 4.3,IQR:2.9-6.1 mV, p = 0.019). BVA in all RV regions yielded a high sensitivity and specificity for ARVC diagnosis (AUC 59-78%, p < 0.05 for all), with the highest performance for the subtricuspid region (AUC 78%, 95% CI:0.75-0.81, p < 0.001, negative predictive value 100%). A positive correlation between BVA and an orthogonal catheter orientation (46°-90°:r = 0.106, p < 0.001), and a negative correlation between BVA and EGM duration (r = -0.370, p < 0.001) was found.

CONCLUSIONS

EAM using CFSC validates previous bipolar cut-off values for normal endocardial RV voltage amplitudes. RV voltages are generally lower in ARVC as compared to controls, with the subtricuspid area being commonly affected and having the highest discriminatory power to differentiate between ARVC and healthy controls. Therefore, EAM using CFSC constitutes a promising tool for diagnosis of ARVC.

Identifying proteomic profiles as indicators of disease severity in arrhythmogenic cardiomyopathy

Introduction

Arrhythmogenic cardiomyopathy (ACM) is an inherited heart muscle disease characterized by progressive fibrofatty replacement of the myocardium and ventricular arrhythmias. Biventricular (BiV) involvement may lead to heart failure. This study aimed to investigate characteristic proteomic patterns in plasma of ACM patients, and correlated them with clinical outcome as well as physical exercise, to assess if key soluble molecules may serve as specific biomarkers for ACM, and whether mechanical stress induced by physical exercise may alter proteomic patterns in ACM patients.

Methods

In 38 ACM patients clinical parameters and major adverse cardiovascular events (MACE defined as presence of sustained ventricular tachycardia, ventricular fibrillation, appropriate therapy from implantable cardioverter defibrillator, sudden cardiac death, death related to end-stage heart failure or cardiac transplant) were obtained prospectively during a mean follow-up period of 36 months. All patients received genetic testing using next generation DNA sequencing. Plasma protein expression was analysed using the Proximity Extension Assay (PEA) technology, where a pair of oligonucleotide-labelled antibody probe binds to each targeted protein. In a subgroup of 11 patients blood was drawn immediately before and 3 hours after standardised bicycle exercise testing, and plasma protein expression was compared.

Results

12 patients had ACM with BiV involvement, and 26 patients had isolated right ventricular (RV) involvement. During the follow-up period, 34 patients had a MACE (30% with RV and 14% with BiV). Over 360 proteins were assessed in all ACM patients and compared to 24 healthy controls. The proteomic signature of ACM patients differed significantly compared to controls, and 32 proteins were upregulated in ACM (Figure 1). The proteomic profiles of patients with RV involvement also differed from those with BiV involvement. Most importantly, after exercise, over 40 proteins were upregulated specifically in ACM patients compared to controls, including key pro-inflammatory, adipogenic molecules and also markers of cardiac fibrosis.

Conclusion

Our study shows that ACM patients with RV and BiV involvement have different plasma proteomic profiles compared to healthy controls. Furthermore we were able to demonstrate that, specifically in ACM patients, several pro-inflammatory pathways are upregulated after exercise compared to healthy controls, further elucidating the molecular pathways associated with arrhythmogenicity and disease progression and highlighting the key role of physical stress. Our results may enable the identification of potential future biomarkers for diagnosis and risk stratification and may pave the way for personalized patient specific treatments.

Funding Acknowledgement

Type of funding sources: Foundation. Main funding source(s): Baugarten Foundation ZurichSwiss National Foundation

Is less always more? A prospective two-centre study addressing clinical outcomes in leadless versus transvenous single-chamber pacemaker recipients

Background

Transvenous (TV) pacemakers are a well established treatment of bradyarrhythmias yet their complications, namely bleeding, infection and pneumothorax, still pose challenges to modern cardiology. This applies particularly to the older patient subgroup requiring single-chamber pacing due to comorbid atrial fibrillation (AF). Furthermore, conditions such as superior venous access issues, high infectious, or bleeding risk may complicate or preclude transvenous lead implantation. While VVIR leadless (LL) pacemakers aim to tackle these shortcomings, a comparison with contemporary single-chamber TV cohorts is currently lacking thus hindering a clear definition of the scope of LL pacing in clinical practice.

Purpose

To prospectively analyse survival and complication rates in leadless versus transvenous single-chamber pacemaker recipients.

Methods

This is a prospective analysis of 344 consecutive patients who received single-chamber TV or LL pacemakers between June 2015 and May 2021 in two tertiary cardiology centres. Indications for single-chamber pacing were “slow” AF, atrio-ventricular block with comorbid AF (either permanent or accepted as “destination rhythm”) or with sinus rhythm in bedridden cognitively impaired patients. LL indications were ongoing or expected chronic haemodialysis (6.9%), superior venous access issues such as occlusion (11.1%) or need for its preservation (9.7%), active lifestyle with low amount of pacing expected (22.2%), frailty causing high bleeding and infectious risk (23.6%), as well as recent valvular endocarditis (2.8%) or implantable electronic device infection requiring extraction (5.6%).

Results

72 patients (20.9%) received LL and 272 (79.1%) TV single-chamber pacemakers. In keeping with LL indications, diabetes and ongoing haemodialysis were more prevalent in the LL population. No significant difference in overall complication rate was observed between LL and TV patients (5.6% vs. 5.1%, p=0.33) apart from haematomas, which occurred more frequently in the LL population. Only 1 haematoma in the TV group required surgical reintervention. TV recipients survival was lower with greater cardiovascular mortality, likely due to selection of significantly older patients.

Conclusions

Given the limited complication rate observed in this contemporary single-chamber TV cohort and low life expectancy of this particular population, extending LL indications to all VVIR candidates is unlikely to provide a clearcut survival advantage. Considering the higher costs of LL technology, these data prompt a careful selection of those cases where LL approach does indeed provide an advantage. In addition to the setting of vascular access issues and high bleeding or infectious risk, these may include patients with sufficient life expectancy where lead-related risks may indeed adversely affect prognosis. Based on our patient selection criteria, LL might account for approximately 20% of VVIR pacing recipients.

Funding Acknowledgement

Type of funding sources: None.

Early experience with the second generation of leadless pacemakers and correlation with ecg parameters

Funding Acknowledgements

Type of funding sources: None.

Background

Leadless pacing has evolved as a safe and effective treatment option in selected patients. With the updated generation that allows sensing of atrial contraction, atrioventricular synchronized pacing is now possible in a VDD mode. Previous retrospective analyses have demonstrated that echocardiographic parameters may be helpful in selecting patients with a higher chance of good atrioventricular synchronous pacing behaviour.

Purpose

Analysis of the early experience with the second generation of leadless pacemaker and the role of ECG parameters to predict a good atrial contraction signal (so-called A4 amplitude) in patients who underwent leadless pacemaker implantation in four tertiary centres.

Methods and Results

In this retrospective analysis, a total of 136 patients were included. Mean age was 78.0 (64.7 - 84.2 years) years with 48.9 % being male. Coronary artery disease was the leading underlying heart disease with 27.1 % affected patients. 61.7 % of the population suffered from sinus rhythm with complete or intermittent atrioventricular block. The majority of devices were implanted at the mid-septal (61.2 %) or high-septal (25.6 %) right ventricle, respectively. Electrical parameters were optimal at implant (Table 1) and remained stable over time (Table 1). In addition, A4 signal amplitude remained stable too during follow-up compared to the value early after implantation (Table 1). From this entire cohort, patients with an ECG available at implant and those in which the device was working predominantly in the VDD mode were selected for further analyses (62 patients). PR interval measured from the ECG prior to implantation did not correlate with the A4 signal amplitude (Figure 1A; P = NS). Next, P wave amplitudes were measured in all 12 ECG leads. There was a correlation between P wave amplitude from lead V2 with the A4 amplitude (Figure 1B; P = 0.034, R2 = 0.09), whereas the other right-sided ECG leads (V1/aVR), either alone or in combination, did not correlate with the A4 signal amplitude (P = NS).

Conclusions

In our cohort of patients with the second generation of leadless pacemakers, offering VDD pacing, good electrical parameters can be achieved as it has been observed with the first generation. Also the A4 signal amplitude as a marker for atrial contraction remains stable over time. In regard to ECG parameters measured prior to device implantation, only the P wave amplitude in lead V2 correlated with a amplitude of the A4 signal.

Ablation index predicts outcomes of catheter ablation of focal atrial tachycardia: results of a multicenter study

Funding Acknowledgements

Type of funding sources: None.

Background

Ablation index (AI) is a radiofrequency energy lesion quality marker integrating power, contact force, and time, which was recently shown to be linked to successful catheter ablation (CA) of atrial fibrillation, atrial flutter, and premature ventricular complexes. The possible role of AI as a predictor of outcomes after CA of focal atrial tachycardia (AT) has not been explored so far.

Purpose

To evaluate the role of AI as a predictor of arrhythmia-free survival after CA of focal AT.

Methods

We retrospectively enrolled forty-five consecutive patients undergoing CA for focal AT in four referral Italian electrophysiology laboratories. Clinical and procedural information were collected. For each patient, maximum and mean (by averaging maximum AI values for each radiofrequency ablation lesion) values of AI were measured. Focal AT-free survival was the primary outcome, and was assessed with repeated Holter monitors or cardiac implantable electronic devices, when available. The Shapiro-Wilk’s test was used to check continuous variables for normality; non-normal variables were expressed as median (1st-3rd quartile), whereas categorical variables were reported as counts and percentages. The primary outcome was assessed in a time-to-event fashion, with the Kaplan-Meier method, and the role of AI as a predictor of focal AT recurrence was tested with univariable Cox proportional hazard regression. Furthermore, differences in AI values between patients experiencing a primary outcome event and patients not experiencing a primary outcome event were analyzed with the Student t test. Discrimination ability of AI was measured with area under the receiver operating characteristic curve, and the optimal AI cutoff value was identified with Youden’s index. An alpha level &lt;0.05 was considered statistically significant, and the software RStudio (RStudio Inc., Boston, MA) was used for statistical analysis.

Results

CA was acutely effective in every patient; however, 20% (n=9) of the study population had a focal AT recurrence over a median follow-up of 288 (160-560) days. Both maximum and mean AI values were significantly higher among patients without AT recurrences (maximum AI=568±91, mean AI=426±105) than in patients with AT relapses (maximum AI=447±142, mean AI=352±76, p=0.036 and p=0.028, respectively). All other procedural parameters were similar between the two groups. In a time-to-event analysis, only maximum AI was significantly associated with survival free from AT recurrence (p=0.001, Figure), whereas mean AI was not (p=0.08). By receiver operating characteristic (ROC) curve analysis, the optimal maximum AI cutoff for predicting effective CA according to Youden’s index was 461 (sensitivity, 0.89; specificity, 0.56).

Conclusion

We observed a strong association between maximum AI and outcomes, suggesting that maximum AI may be regarded as a quantitative marker of successful CA of focal AT.

The subcutaneous defibrillator in patients with low BMI - insights from a large European multicenter registry

Funding Acknowledgements

Type of funding sources: None.

Background

The subcutaneous implantable cardioverter defibrillator (S-ICD) has become an alternative to transvenous ICDs (tv-ICD), especially in young patients without a need for pacing. One of the current limitations of the S-ICD is the relatively large size of the generator compared to tv-ICDs. There is little evidence whether the size of the current S-ICD generator is associated with an elevated risk of device-related complications in patients with a low body mass index (BMI).

Purpose

To compare the device-related complications and long-term outcomes in a large real world cohort of S-ICD recipients in patients with a BMI &lt;18 kg/m2 compared to patients with a BMI &gt;18 kg/m2.

Methods

The iSuSI registry is a European, multi-center, open-label, independent, and physician-initiated observational registry. A total of twenty-two Public and Private Healthcare Institutions from 4 different countries in Europe were involved in the registry. All consecutive patients meeting current guideline indications for ICD implantation and undergoing implantation of a S-ICD device (Boston Scientific, Marlborough, Massachusetts, USA) at 21 European institutions enrolled in the registry were used for the current analysis. Patients were classified into two cohorts, depending on the BMI at the time of device implantations: BMI &lt; 18 kg/m2 versus &gt; 18 kg/m2.

Results

Out of a total of 1497 pts, 58 pts (3.9%) had a BMI &lt; 18 kg/m2. Patients with BMI &lt;18 kg/m2 were younger (44.6±2.4 vs 50.8±0.4; p=0.004) and more frequently female (58.6% vs 22.3%, p&lt;0.001). No differences in any of the other baseline characteristic were observed. Implantation techniques resulted comparable between the groups (Rates of 2-incision technique: 87.8% vs 91.9%; p=0.256; inter-muscular placement: 89.7% vs 83.3%; p=0.198). Of note, the mean PRAETORIAN score at implantation of patients with BMI &lt;18 kg/m2 was significantly lower (33.8±9.1 vs 54.1±47.3; p=0.035), although the vast majority of pts in both cohorts qualify as at low risk of conversion failure (100% vs 91.4%; p=0.436).

Over a median follow up time of 22.4 [11.6–36.8] months, both overall device-related complications (5.2% vs 7.4%) and rates of inappropriate shocks (12.0% vs 8.8%) resulted comparable between the two groups (p =0.517 and p=0.385, respectively). Figure1 reports Kaplan-Meier curves reporting the combined incidence of device-related complications and inappropriate shocks in the two groups (log-rank p = 0.576).

Conclusion

No difference in device-related complications and long-term outcomes after S-ICD implantation were observed in patients with BMI &lt;18 kg/m2 compared to the remaining recipients from a large, multi-centered S-ICD registry.

Figure 1: Kaplan-Meier-survival curve for the combined endpoint of inappropriate shocks (IAS) and device-related complications (DRC)

S-ICD in heart failure patients: real-world data from a multicenter, european analysis

Funding Acknowledgements

Type of funding sources: None.

Background

Data on patients with heart failure (HF) and subcutaneous implantable cardioverter defibrillator (S-ICD) are very scarce and limited to a single prospective analysis from the UNTOUCHED trial.

Purpose

Aim of this study was to assess clinical outcomes of the S-ICD in HF patients, comparing them with a no-HF population, in a real-world analysis from the largest European retrospective S-ICD registry (ELISIR registry).

Methods

All consecutive patients undergoing S-ICD implantation at 20 European institutions enrolled in the ELISIR registry were used for the current analysis. According to European Guidelines, the registry population was classified into two groups: the HF cohort (further classified as HF with reduced and mid-range ejection fraction – HFrEF and HFmrEF) vs the no-HF group. The primary outcome of the study was the inappropriate shock (IS) rate across the two cohorts. As secondary outcomes, appropriate shocks, cardiovascular mortality and device-related complications during follow-up were assessed.

Results

A total of 1409 patients from the ELISIR registry were included in this analysis; HF patients represented 57.3% of the entire cohort (n=701, 86.9% HFrEF; n=106,13.1% HFmrEF). As expected, the HF cohort showed significantly higher rates of cardiovascular risk factors and comorbidities when compared to the no-HF cohort. Over a median follow-up of approximately 2 years, a total of 133 inappropriate shocks were observed in the entire cohort, without significant differences among the two groups (9.2% vs 9.8%, p=0.689). 133 complex ventricular arrhythmias were adequately recognized and treated in the overall cohort, showing similar rates of appropriate shocks (9.2% vs 9.8%, p=0.689). Inappropriate and effective shocks-free survival has been represented in Figure 1, showing Kaplan-Meier estimates comparing HF vs no-HF patients, also stratified by left ventricular ejection fraction (LVEF). The impact of baseline and procedural characteristics on the primary outcome was tested through univariable and multivariable Cox regression analysis in HF patients; at multivariate analysis, only age (HR=0.974 [0.955–0.992], p=0.005), LVEF (HR=0.954 [0.926-0.984], p=0.003), ARVC (HR=3.364 [1.206-9.384], p=0.020) and smart pass algorithm "on" (HR=0.321 [0.184-0.560], p&lt;0.001) remained associated with inappropriate shocks (Figure 2). A low number of patients (n=76) experienced device-related complications, more frequently in the HF cohort (6.2% vs 3.8%, p=0.031) with no significant differences regarding any specific outcome of interest: lead infection (1.1% vs 0.7%, p=0.381), pocket infection (1.9% vs 0.8%, p=0.107), pocket hematoma (3.2% vs 2.8%, p=0.668).

Conclusion

The rate of inappropriate shocks seems to be comparable in both HF and non-HF patients implanted with S-ICD. However, the rate of device-related complications was slightly more frequent in HF patients.

Age-related differences and associated outcomes of S-ICD: insights from a large, european, multicenter, real-world registry

Funding Acknowledgements

Type of funding sources: None.

Background

Young patients often represent the most suitable candidates for an entirely subcutaenous implantable cardioverter defibrillator (S-ICD) system, since they have to face a lifetime of device therapy and they rarely have a pre-existing or concurrent pacing or cardiac resynchronization therapy (CRT) indication. Moreover, S-ICD offers lower rate and a safer management of lead and major procedure-related complications. To date, a few limited case series and experiences with S-ICD in teenagers and young adults have shown that the S-ICD system is safe and feasible in this population, with a rate of inappropriate shocks (IS) comparable to transvenous (TV) ICD, but focused analysis on a large scale are currently lacking in this setting.

Purpose

The aim of the current study was to compare the age-related differences observed in patient selection, baseline characteristics, and device long-term associated outcomes in a large real world cohort of S-ICD recipients. The primary outcome of the study was defined as the comparisons of the IS rate observed during the entirety of follow up in the teenagers/young adult vs the adult populations. Rate of complications, freedom from sustained ventricular arrhythmic events, overall and cardiovascular mortality were also assessed in the two cohorts and assessed as secondary outcomes.

Methods

All S-ICD recipients in the ELISIR project were enrolled in the current study. Patients were classified into teenagers + young adults (≤ 30 years old) vs adults (&gt; 30 years old), depending from patient age at device implantation (Figure 1). Rates of device-related complications and IS were compared between the cohorts.

Results

A total of 1349 patients were extracted from the ELISIR project. Teenagers and young adults represented 12.4% of the registry (n=56 teenagers; n=112 young adults). Patients were followed-up for a median of 23.1 [12.6–37.9] months. Overall, 117 (8.7%) patients experienced inappropriate S-ICD shocks and 100 (7.4%) device related complications were observed, with no age-related differences. IS resulted more frequent in the teenager and young adult cohort (14.3% vs 7.9%; p=0.006). Figure 2 reports Kaplan Meier curves for the occurrence of IS. At univariate analysis, young age was associated with IS, but after correcting for differences in arrhythmic substrate, this association resulted non-significant (aHR: 1.428 [0.883–2.331]; p=0.146). The use of SMART pass algorithm was instead associated to a strong reduction in IS (aHR 0.367 [0.245–0.548]; p&lt;0.001).

Conclusion

The use of S-ICD in teenagers/young adults resulted safe and effective. Indeed, the rate of complications between teenagers/young adults and adults was not significantly different. Although a higher rate of IS was observed in the teenagers/young adults, when accounting for differences in baseline substrate and comorbidities, young age did not result associated with an increased risk of IS.

C9 SUBCUTANEOUS IMPLANTABLE CARDIOVERTER DEFIBRILLATOR IN PATIENTS WITH LOW BMI: REAL–WORLD DATA FROM A EUROPEAN MULTICENTER ANALYSIS

Background

One of the current limitations of the S–ICD is the relatively large size of the generator compared to the TV (transvenous) ICD. There is little evidence whether the size of the current S–ICD generator is associated with an elevated risk of device–related complications in patients with a low body mass index (BMI).

Purpose

Aim of this study was to compare the device–related complications and long–term outcomes in a large real world cohort of S–ICD recipients in patients with a BMI &lt;18 kg/m2 compared to patients with a BMI &gt;18 kg/m2.

Methods

All consecutive patients meeting current guideline indications for ICD implantation and undergoing implantation of a S–ICD device (Boston Scientific, Marlborough, Massachusetts, USA) at 21 European institutions enrolled in the extended ELISIR registry were used for the current analysis. Patients were classified into two cohorts, depending on the BMI at the time of device implantations: BMI &lt; 18 kg/m2 versus &gt; 18 kg/m2.

Results

Out of a total of 1497 pts, 58 pts (3.9%) had a BMI &lt; 18 kg/m2. Patients with BMI &lt;18 kg/m2 were younger (44.6±2.4 vs 50.8±0.4; p = 0.004) and more frequently female (58.6% vs 22.3%, p &lt; 0.001). No differences in any of the other baseline characteristic were observed. Implantation techniques resulted comparable between the groups (rates of 2–incision technique: 87.8% vs 91.9%; p = 0.256; inter–muscular placement: 89.7% vs 83.3%; p = 0.198). Of note, the mean PRAETORIAN score at implantation of patients with BMI &lt;18 kg/m2 was significantly lower (33.8±9.1 vs 54.1±47.3; p = 0.035), although the vast majority of patients in both cohorts qualified as at low risk of conversion failure (100% vs 91.4%; p = 0.436). Over a median follow up time of 22.4 [11.6–36.8] months, both overall device–related complications (5.2% vs 7.4%) and rates of inappropriate shocks (12.0% vs 8.8%) resulted comparable between the two groups (p = 0.517 and p = 0.385, respectively). Figure 1 reports Kaplan–Meier curves showing the combined incidence of device–related complications and inappropriate shocks in the two groups (log–rank p = 0.576).

Conclusion

No differences in device–related complications and long–term outcomes after S–ICD implantation were observed in patients with BMI &lt;18 kg/m2 compared to the remaining recipients in a large multicentered real–world analysis.

P21 AGE–RELATED DIFFERENCES AND ASSOCIATED OUTCOMES OF S–ICD: INSIGHTS FROM A LARGE, EUROPEAN, MULTICENTER REGISTRY

Background

The subcutaneous implantable cardioverter defibrillator (S–ICD) has become an alternative to transvenous ICDs (TV–ICD) in patients who do not need pacing. To date, there is little evidence directly comparing the rates of inappropriate shocks (IAS) in young vs old S–ICD recipients.

Purpose

Aim of our study was to assess differences in device–related complications and inappropriate shocks (IS) between teenagers/young adults and adult recipients of a subcutabeous implantable cardioverter defibrillator (S–ICD) device.

Methods

Two propensity–matched cohorts of teenagers + young adults (≤ 30–year–old) and adults (&gt; 30–year–old) were retrieved from the ELISIR registry. The primary outcome was the comparison of the inappropriate shock (IAS) rate; complications, freedom from sustained ventricular arrhythmic events, overall and cardiovascular mortality were deemed secondary outcomes.

Results

A total of 1491 patients were extracted from the ELISIR project. Teenagers + young adults represented 11.0% of the entire cohort. Two propensity–matched groups of 161 patients each were used for the analysis (Figure 1); median follow–up was 23.1 [13.2–40.5] months. 15.2% patients experienced inappropriate S–ICD shocks and 9.3% device related complications were observed with no age–related differences in IAS (16.1% vs 14.3%; p = 0.642) and complication rates (9.9% vs 8.7%; p = 0.701); Figure 2 shows a survival analysis from inappropriate shocks in the teen–ager/young adult cohort (red) and in the adult cohort (blue). At univariate analysis, young age was not associated with increased rates of IAS (HR 1.204 [0.675–2.148]: p = 0.529). At multivariate analysis (Figure 3), the use of SMART pass algorithm was associated to a strong reduction in IAS (aHR 0.292 [0.161–0.525]; p &lt; 0.001), while ARVC was associated with higher rates of IAS (aHR 2.380 [1.205–4.697]; p = 0.012).

Conclusion

In a large multicentered European registry of patients with S–ICD, 11.0% of all recipients were teenagers or young adults. The use of S–ICD in teenagers/young adults resulted safe and effective, and the rates of complications and IAS between teenagers/young adults and adults were not significantly different. The only predictor of increased IAS was a diagnosis of ARVC.

P25 SUBCUTANEOUS–ICD IN PATIENTS WITH HEART FAILURE: RESULTS FROM A MULTICENTER, EUROPEAN ANALYSIS

Background

Data on patients with heart failure (HF) with a subcutaneous implantable cardioverter defibrillator (S–ICD) are scarce.

Objective

Aim of this study was to assess clinical outcomes of the S–ICD in HF patients in a real–world analysis from the largest European retrospective S–ICD registry (ELISIR).

Methods

All consecutive patients undergoing S–ICD implantation at several European institutions were used for the current analysis. The population was classified into two groups: the HF (classified as HF with reduced and mid–range ejection fraction – HFrEF and HFmrEF) vs the no–HF cohort. The primary outcome of the study was the inappropriate shock (IS) rate across the two cohorts. As secondary outcomes, appropriate shocks, cardiovascular mortality and device–related complications during follow–up were assessed

Results

A total of 1409 patients from the ELISIR registry were included; HF patients represented 57.3% of the entire cohort (n = 701, 86.9% HFrEF; n = 106,13.1% HFmrEF). Over a median follow–up of approximately 2 years, a total of 133 inappropriate shocks were observed in the entire cohort, without significant differences among the two groups (9.2% vs 9.8%, p = 0.689). 133 complex ventricular arrhythmias were adequately recognized and treated, with similar rates of appropriate shocks (9.2% vs 9.8%, p = 0.689). Inappropriate and effective shocks–free survival has been represented in Figure 1 (Kaplan–Meier estimates). At multivariate analysis (Figure 2), age (HR = 0.974 [0.955–0.992], p = 0.005), LVEF (HR = 0.954 [0.926–0.984], p = 0.003), arrhythmogenic right ventricular cardiomyopathy – ARVC (HR = 3.364 [1.206–9.384], p = 0.020) and smart pass + (HR = 0.321 [0.184–0.560], p &lt; 0.001) remained associated with inappropriate shocks. Moreover, a low number of patients (n = 76) experienced device–related complications, more frequently in the HF cohort (6.2% vs 3.8%, p = 0.031) with no significant differences regarding any specific outcome of interest: lead infection (1.1% vs 0.7%, p = 0.381), pocket infection (1.9% vs 0.8%, p = 0.107), pocket hematoma (3.2% vs 2.8%, p = 0.668).

Conclusion

The use of S–ICD in HF patients did not result in a higher rate of inappropriate shocks when compared to no–HF patients, even when stratifying for LVEF. Only age, LVEF, ARVC e Smart Pass algorithm were predictors of the primary outcome at multivariate analysis. Despite a lower overall rate of complications in the entire cohort, HF patients experienced device–related complications more frequently.

Prevalence of exercise-induced arrhythmias in young athletes with fragmented QRS pattern in lead V1

Funding Acknowledgements

Type of funding sources: None.

Background

Resting 12-lead electrocardiogram (ECG) in apparently health athletes has specific pattern, typically associate to heart remodelling in response to regular exercise. (1,2) Moreover, these adaptations were correlated to typical ventricular arrhythmias, not associated with underlying cardiac abnormalities.(3) Recently, also fragmented QRS complex in lead V1 (fQRSV1), representing right ventricular (RV) activation, seems related to training-induced RV remodelling in athletes, where its prevalence is greater.(4)

Purpose

Evaluate presence of fQRSV1pattern at resting ECG in a population of young athletes and its relationship with training-associated structural heart adaptations and exercise-induced ventricular arrhythmias.

Methods

This study retrospectively enrolled subjects who consecutively undergo to annual pre-participation screening and also to transthoracic echocardiography assessment, from January 2015 to September 2020. For each participant, medical history, physical examination, resting ECG, maximal standardized exercise test and echocardiographic evaluation were collected. All ECG were reviewed by two independent physicians to evaluate fQRSV1 pattern.

Results

684 young athletes (mean age 14.87±1.96 years, 36% female) were included and the overall prevalence of fQRSV1was 27%. Figure 1 shows an example of fQRSV1 pattern. Principal subject characteristics and evaluations data are shown in Table 1. fQRSV1 subjects presented a significantly wider QRS interval (p=0.004) and lower heart rate at rest (p=0.001). Exercise workload expressed in METs and exercise duration were higher in subjects with fQRSV1 (p=0.002 and p=0.023, respectively). Echocardiographic data showed that subjects with fQRSV1differ in morphological and functional right ventricular (RV) characteristics, especially had a higher indexed RV end diastolic diameter (p=0.019) and higher TAPSE (p=0.013). Patients with fQRSV1did not show an increased occurrence of supraventricular or ventricular arrhythmias, regardless of morphology, neither for isolated nor for repetitive events.

Conclusion

Overall prevalence of fQRSV1 pattern in young athletes is comparable with the one studied in other population of adult athletes in previous studies. Adolescent athletes with fQRSV1 present structural heart characteristic that differ from subjects without this ECG pattern, especially in RV feature. No differences in prevalence of any type of exercise-induced arrhythmias was shown, especially in common ventricular arrhythmias consistent with origin from the right ventricular outflow tract, previously described in healthy athletes.

Anti-desmoglein2 autoantibodies are present in patients with cardiac sarcoidosis and correlate with cardiac inflammation

Funding Acknowledgements

Type of funding sources: Foundation. Main funding source(s): The Zurich ACM Program is supported by generous grants from the Georg and Bertha Schwyzer-Winniker Foundation, the Baugarten Foundation, Swiss National Science Foundation, Swiss Heart Foundation and Wild Foundation. This work is also supported by a Canadian Institutes of Health Research grant (FRN: 162402) and the Labatt Heart Centre and Waugh Family Innovation Funds, Caitlin Elizabeth Morris Memorial Fund, Alex Corrance Memorial Foundation and Meredith Cartwright.

BACKGROUND Arrhythmogenic right ventricular cardiomyopathy (ARVC) has several phenocopies such as cardiac sarcoidosis (CS), idiopathic outflow tract ventricular tachycardia (OT-VT) and myocarditis. Differentiation between these entities can be challenging. Recently, we have identified diagnostic anti-desmoglein-2 autoantibodies (anti-DSG2 Abs) in patients with ARVC.

PURPOSE We sought to examine whether anti-DSG2 Abs are also present in clinical phenocopies of ARVC.

METHODS Anti-DSG2 Abs in sera of 25, 19 and 22 patients with sarcoidosis, OT-VT and myocarditis, respectively, were assessed by western blots and ELISA. Clinical and imaging parameters, as well as conventional biomarkers were correlated to detected anti-DSG2 Ab intensity levels.

RESULTS Anti-DSG2 Abs, at various intensities, were identified in 6/25 (24%) patients with sarcoidosis, all presenting with CS, but were absent in patients with OT-VT and myocarditis. Cardiac 18F- fluorodeoxyglucose positron emission tomography (18F-FDG PET) was positive in all sarcoidosis patients with positive anti-DSG2 Abs, corresponding to a median PET maximum standardized uptake value (SUVmax) of 5.65 [IQR: 5.15 – 10.9]. In sarcoidosis patients without anti-DSG2 Abs, the SUVmax values were significantly lower with a median of 0 [IQR: 0 – 4] (p = 0.011). The Pearson correlation coefficient (R) was 0.188 (p = 0.039) indicating a positive correlation between cardiac 18F-FDG uptake and anti-DSG2 Abs. No significant correlation was detected for any of the other clinical parameters and biomarkers.

CONCLUSIONS In addition to being present in ARVC, anti-DSG2 Abs are also found in CS, a common phenocopy of ARVC; conversely, anti-DSG2 Abs are absent in idiopathic OT-VT and myocarditis. Anti-DSG2 Ab levels positively correlate with myocardial disease activity in CS as indicated by cardiac 18F-FDG PET scanning. Abstract Figure. Central illustration

A novel diagnostic score to differentiate between athlete"s heart and ARVC

Funding Acknowledgements

Type of funding sources: None.

Background

The 2010 Task Force Criteria (TFC), although representing the current gold standard to diagnose arrhythmogenic right ventricular cardiomyopathy (ARVC), have not been tested to differentiate ARVC from the athlete’s heart. Furthermore, not all 6 diagnostic categories are easy to obtain.

Purpose

We hypothesized that atrial dimensions are useful to differentiate between both entities. Therefore, we developed a new diagnostic score based upon readily available clinical parameters including atrial dimensions on TTE to help distinguishing the athlete’s heart from ARVC in daily clinical practice.

Methods

In this observational study, 37 patients with definite ARVC (from the Zurich ARVC Program) were compared to 68 athletes. Base on ROC analysis, the following echocardiographic, laboratory and electrocardiographic parameters were included in the final score: indexed right/left atrial volumes (RAVI/LAVI ratio), NT-proBNP, RVOT measurements (PLAX and PSAX adjusted for BSA) on TTE, tricuspid annular motion velocity (TAM) on TTE, precordial electrocardiographic T-wave inversions and depolarization abnormalities according to the TFC.

Results

ARVC patients had a higher RAVI/LAVI ratio (1.78 ± 1.6vs0.95 ± 0.3,p &lt; 0.001), lower right-ventricular function (fac:28 ± 9.7vs42.1 ± 4.8%,p &lt; 0.001; TAM:17.9 ± 5.6vs23.3 ± 3.7mm,p &lt; 0.001) and higher serum NT-proBNP levels (491 ± 771vs44.8 ± 50.6ng/l,p &lt; 0.001). Our novel score outperformed the performance of the 2010 TFC using those parameters, which are available in routine clinical practice (AUC95%,p &lt; 0.001(95%CI.91-.99)vs.AUC90%,p &lt; 0.001(95%CI.84-.97). A score value of 7/12 points yielded a specificity of 98% and a sensitivity of 61% for a diagnosis of ARVC.

Conclusions

ARVC patients present with significantly larger RA as compared to athletes, resulting in a greater RAVI/LAVI ratio. Our novel diagnostic score includes readily available clinical parameters and has a high diagnostic accuracy to differentiate between ARVC and the athlete´s heart. Abstract Figure. Novel clinical score

Effect of bariatric surgery on blood pressure and workload-indexed pressure during submaximal and maximal exercise

Funding Acknowledgements

Type of funding sources: None.

Background

Obesity is a disease characterized by an increase of resting blood pressure and by an increased risk of developing hypertension and cardiovascular events. Exaggerated blood pressure during exercise increases risk of cardiovascular events independently from the baseline blood pressure levels.

Purpose

to evaluate the blood pressure response and the Workload-indexed blood pressure, during a cardio-pulmonary exercise test (CPET) before and after bariatric surgery (BS).

Methods

257 patients with severe obesity performed maximal incremental CPET one month before and six months after BS under the same experimental protocol. The systolic blood pressure was measured at rest (SBPrest), at the submaximal effort (SBPsubmax) at the same exercise intensity (3 METs), at the exercise peak (SBP max) and lastly in the recovery phase (SBPrec). The submaximal and maximal Workload-indexed Sistolic Blood Pressure (W-SBPsubmax and W-SBPmax, respectively) were calculated with the formula: ΔBP/ΔMETs. Diastolic blood pressure was analysed at rest (DBPrest) and during the recovery phase (DBPrec).

Results

Age was on average 45 ± 10.3 years, BMI before BS was equal to 43.9 ± 6.4 Kg/m2 and 73.5% were females. After BS, there was a significant weight loss (-25.9 ± 6.2%). SBPrest and DBPrest decrease significantly after BS (ΔSBP: -10.2 ± 15.8 and -5.2 ± 11.6 mmHg; p &lt;0.001, respectively), also when considering percentage variation of pre BS values (ΔSBP%: -7.4 ±12.3% and -5.9 ± 15.9%; p&lt; 0.001, respectively). Submaximal and maximal systolic blood pressure showed significant reduction after BS both as ΔSBP (-15.0 ± 19.7 mmHg and -10.3 ± 25.1mmHg; p &lt; 0.001, respectively) and ΔSBP% (-9.6 ± 13.0% and -5.0 ± 14.0%; p &lt; 0.001, respectively). Furthermore, W-SBP decreased significantly during submaximal exercise (-3.0 ± 12.2 mmHg/METs; p 0.001) and at peak of exercise (-2.1 ± 4.8 mmHg/METs; p &lt; 0.001). Lastly, also systolic and diastolic blood pressure during the recovery phase showed a significant reduction (-7.5 ± 7.0 mmHg and -3.3 ± 6.0 mmHg; p &lt; 0.001). A Spearman’s correlation analysis showed a significant but weak correlation between ΔSBP%submax and % of weight loss (rho = 0.138; p = 0.027).

Conclusions

After BS, a marked reduction of all blood pressure values was detectable in all phases of CPET. W-SBPsubmax and W-SBPmax, as expression of load independent pressure response, decreased significantly. The reduction in the submaximal blood pressure was significantly but only weakly correlated with changes in body weight, suggesting its substantial independence from weight loss. These findings also support a potential role of CPET in detecting, high risk patients and adequate treatment effectiveness in patients with severe obesity.

Abstract Figure. Exercise SBP before and after BS

Impact of genetic reclassification on ARVC diagnosis based on the 2010 task force criteria

Introduction

Arrhythmogenic Right Ventricular Cardiomyopathy (ARVC) is an inherited condition, which is associated with potentially life-threatening ventricular arrhythmias in the young. Approximately 60% of patients carry a possibly disease-causing genetic variant.

Purpose

The aim of this study was to investigate the impact of the 2015 American College of Medical Genetics (ACMG) Criteria on ARVC diagnosis based on the 2010 Modified Task Force Criteria (TFC).

Methods

The study included 79 patients from the Swiss ARVC Registry who harbored a genetic variant deemed to be associated with the disease at initial screening, and classified them as definite, borderline or possible ARVC. Every variant found was re-classified on Varsome Genetics, based on the 2015 ACMG Criteria. Clinical information was then assessed at last available follow-up of every patient and ARVC diagnosis was reclassified based on the newest genetic evidence available.

Results

In 42 out of 79 patients (53.2%), genetic variants were reclassified. Out of these, 33 variants (41.8%) were downgraded from pathogenic (P) / likely pathogenic (LP) to either variants of unknown significance (VUS) or benign (B) / likely benign (LB). Three patients (3.8%) were upgraded from VUS / LP to P. Out of the 12 variants initially classified as VUS, 9 (75%) were reclassified as B or LB. Overall, 13 patients (16.5%) were downgraded from their initial diagnosis (11 from definite to borderline and 2 from borderline to possible).

Conclusion

A significant proportion of patients with ARVC diagnosed based on the 2010 TFC were reclassified when the 2015 ACMG Criteria were taken into consideration. These findings may have clinical consequences, particularly for genetic cascade screening of family members of ARVC patients and necessitate reassessment of genetic variants of index patients who were previously diagnosed with ARVC.

Funding Acknowledgement

Type of funding source: Public hospital(s). Main funding source(s): University Hospital Zurich

Role of an extensive diagnostic work-up in the detection of concealed cardiomyopathies in athletes with premature ventricular complexes and implications for sports' eligibility assessment

Background

Premature ventricular complexes (PVCs) are a common clinical problem and a critical issue with regard to sports eligibility in sportsmen. Although PVCs can be considered a benign feature of the athlete's heart adaptive phenotype, they may also be the only clinical manifestation of a concealed cardiomyopathy, potentially heralding sudden cardiac death (SCD) during sports activity. The optimal diagnostic evaluation of athletes with PVCs is currently uncertain.

Purpose

To evaluate the diagnostic contribution and the implications for sports eligibility assessment of a thorough non-invasive and invasive work-up including electroanatomical mapping (EAM) and endomyocardial biopsy (EMB) in athletes with PVCs.

Methods

We conducted a prospective, single-arm, open-label double center study. All consecutive athletes presenting for evaluation at our institution after being disqualified from participating in sports due to PVCs were included in our study. These athletes underwent a baseline non-invasive diagnostic protocol with transthoracic echocardiogram and gadolinium enhanced cardiac magnetic resonance imaging (cMRI). Subsequently, an invasive diagnostic work-up was performed, including EPS with programmed electrical stimulation, EAM and EAM-guided EMB if deemed necessary. When clinically indicated, catheter ablation was performed. Sports eligibility status was re-assessed at six months' follow-up according to Italian sports medicine guidelines.

Results

After diagnostic evaluation, 20 subjects out of 107 (19%) had a diagnosis of heart disease, most commonly myocarditis (n=8), arrhythmogenic right ventricular cardiomyopathy (ARVC, n=7) or dilated cardiomyopathy (DCM, n=2). On multivariate logistic-regression analysis, QRS complex/T wave abnormalities on ECG (OR 23), non left bundle branch block and inferior axis PVC morphology (OR 13), echocardiogram abnormalities (OR 24) and low-voltage areas on EAM (OR 33) were significantly associated with diagnosis of a concealed cardiac disease. Nondiagnostic abnormalities on cMRI were common in this population of athletes, prevalently involving the right ventricle. EAM-guided EMB was performed in 12 subjects (11%) and catheter ablation in 56 (52.3%). After six months, 63 athletes (59%) were judged eligible to participate in competitive sports and 23 subjects (21%) were deemed eligible to participate in non-competitive sports.

Conclusions

Almost one fifth of sportsmen presenting with PVCs have a concealed heart disease, most commonly myocarditis or ARVC. Non-outflow tract PVCs' morphology and abnormalities on ECG, echocardiogram and EAM are predictive of structural heart disease's detection, whereas nondiagnostic findings on cMRI can be misleading in athletes. Invasive diagnostic tests, including EAM and EAM-guided EMB, play a critical role in case of diagnostic uncertainty. More than ¾ of subjects were judged eligible to participate in sports at 6 months' follow-up.

Funding Acknowledgement

Type of funding source: None

Late gadolinium enhancement location and transcatheter ablation efficacy in a large cohort of patients affected by myocarditis with arrhythmic manifestation

Introduction

Myocarditis is a complex inflammatory disease, usually secondary to viral infections or immune system dysregulation, with extremely heterogeneous clinical manifestations. Among them, potentially life-threatening ventricular arrhythmias (VA) may present at any stage of the disease as an expression of myocardial electrical instability.

Purpose

Our aim was to evaluate the efficacy of radiofrequency catheter ablation (RFCA) of VA in our large cohort of myocarditis, trying to understand the predictors of RFCA success.

Methods and results

144 patients (61 men; age 43 [29–54] years) with history of myocarditis with arrhythmic presentation (118 biopsy-proven, 82%) composed our population. At presentation, 26% of patients suffered of ventricular tachycardia (VT) while in 17% cardiac arrest occurred: overall 49 patients (35%) were implanted with an ICD. The median left ventricular ejection fraction (LVEF) was 58% (48–61%). An intensive non-invasive and invasive work-up was performed: 104 patients underwent cardiac magnetic resonance (CMR) that showed late gadolinium enhancement (LGE) in 67 of them (63%). In 37 patients LGE was found in the anteroseptal portion of the left ventricle: this pattern showed association with major arrhythmic relapse (VT and ventricular fibrillation) during follow up (Fig. 1; OR 4.0, CI 95% 1.14–14.1, p=0.03). 95 patients underwent endocardial RFCA, using contact electroanatomic mapping. Interestingly, in patients with anteroseptal LGE RCFA didn't affect significantly the arrhythmic relapse (OR 5, CI 95% 0.9–33, p=0.06). Otherwise RFCA prevent arrhythmic relapse in patients that showed LGE in ventricular portion other than the anteroseptal one (OR 0.027, IC 95% 0.002–0.40, p&lt;0.01). During a median follow-up of 735 days (418–2168) 6 deaths occurred: logistic regression on all-cause death showed LVEF and VT at presentation as the only independent predictors for mortality (p=0.01).

Conclusions

In myocarditis patients with VA, LGE pattern predicts arrhythmic relapse during follow-up. RFCA success rate is strictly linked to scar location, being significantly higher in patients with non-anteroseptal LGE.

Figure 1

Funding Acknowledgement

Type of funding source: None

Endomyocardial biopsy: what future in arrhythmogenic right ventricular dysplasia diagnosis?

Background

Arrhythmogenic right ventricular cardiomyopathy (ARVC) is a leading cause of sudden cardiac death, but its diagnosis is challenging and the role of endomyocardial biopsy (EMB) is controversial and has been recently questioned.

Purpose

We aimed to 1) analyse the role of EMB in improving the diagnostic performance of 2010 Task Force Criteria (TFC) in the diagnosis of ARVC; 2) assess EMB safety in our population.

Methods

We retrospectively analysed data from 54 consecutive patients admitted to our Hospital with a clinical suspicion of ARVC undergoing endomyocardial biopsy. During hospitalization a complete assessment was performed for every patient (including electrocardiogram, echocardiogram, cardiac MRI, genetic analysis, and electroanatomic-mapping-guided endomyocardial biopsy). ARVC diagnosis was assessed for every patient using both traditional 2010 TFC and a non-invasive modified TFC (2010 TFC criteria excluding biopsy).

Results

Overall, 9/54 (17%) patients showed a left-dominant variant of ARVC and were therefore excluded from the analysis. Non-invasive modified TFC allowed 16/45 (36%) patients to receive a definite diagnosis; when biopsy results were added the number of definite diagnosis increased to 22/45 (49%), increasing the number of patients with a definite diagnosis by 13%. More specifically: 8/11 patients not reaching a possible diagnosis were reclassified as either possible (4/8) or borderline (4/8); 3/9 patients with a possible diagnosis were reclassified as borderline; 6/9 borderline patients received a definite diagnosis of ARVC. Globally, in 6 out of 29 patients with a non-definite diagnosis, EMB confirmed ARVC diagnosis and 17/45 (38%) patients received an upgrade in their diagnostic status with EMB. Notably, EMB also revealed the coexistence of myocarditis and fibro-fatty replacement in 5/45 (9%) patients. No patient experienced complications related to EMB.

Conclusions

Endomyocardial biopsy is a safe, reliable, and useful tool for ARVC diagnosis, allowing to upgrade the diagnostic status of 38% of our patients with a suspect of ARVC diagnosis. It should be performed in experienced centers and it should be guided by electro-anatomic mapping, to maximize its diagnostic power.

Funding Acknowledgement

Type of funding source: None

Myocarditis and arrhythmogenic right ventricular cardiomyopathy: a diagnostic challenge

Background

Current arrhythmogenic right ventricular cardiomyopathy (ARVC) diagnostic criteria are mostly based on ventricle function and dimension. Previous studies have reported a significant overlap between ARVC and chronic myocarditis, at non-invasive assessment.

Purpose

Tto compare biopsy-proven ARVC and myocarditis patients, in order to identify clinical, imaging and invasive electroanatomic voltage mapping (EVM) differences between the two groups.

Methods

Patients with borderline diagnosis of ARVC or suspected myocarditis underwent compete assessment with cardiac magnetic resonance (CMR). All patients underwent endomyocardial biopsy (EMB) with targeted tissue sampling guided by EVM. All patients with an histological diagnosis of myocarditis or ARVC were included.

Results

83 patients were included, divided into 35 (42.2%) ARVC and 48 (57.8%) myocarditis. Among ARVC patients, 25 (71.4%) had right dominant ARVC, 5 (14.3%) left dominant patter and 5 (14.3%) bi-ventricular involvement. Nine patients (23.1%) with suspected clinic diagnosis of ARVC before EMB, received and histological diagnosis of myocarditis. Two (5.7%) patients with suspected myocarditis were proven to have ARVC. When comparing patients with ARVC and patients with myocarditis, univariate analysis showed that age, sex, family history, arrhythmic disorders at presentation and ECG abnormalities were similar between the two groups (P&gt;0.05 for all the variables). There was also no significant difference with regards to bi-ventricular function and dimension at CMR evaluation. More patients with myocarditis resulted positive at late gadolinium enhancement (LGE) evaluation, although non-significantly (P=0.082). Oedema was more frequently present in patients with myocarditis (P=0.01), while adipose tissue infiltration and segmental wall motion abnormalities were more often observed in patients with ARVC (P=0.002 and P&lt;0.001 respectively). At EVM analysis, a significant greater number of patients had a pathological uni- and bi-polar EVM (P&lt;0.05 in all cases) and the scar-area was greater in patients with ARVC: 18.8 vs 11.0 cmq (P=0.041).

Conclusion(s)

A significant number of patients who received a clinical diagnosis of Myocarditis or ARVC according to current guidelines, were subsequently reclassified after histological analysis. Patients with ARVC and myocarditis were not distinguishable on the basis of clinical features and ventricular function and dimensions. Conversely, tissue analysis with CMR demonstrated how patient with ARVC had less oedema, more adipose tissue infiltration and had more extensive scar at EVM evaluation.

Funding Acknowledgement

Type of funding source: None

Diagnostic yield of Electroanatomic voltage mapping in guiding Endomyocardial biopsies; a comparison with an MRI-guided approach

Background

Electroanatomic voltage mapping (EVM) is a promising modality for guiding Endomyocardial biopsies (EMB). Previous experiences on this techniques have reported safety and feasibility of this approach. These reports however, resulted limited by sample size or imperfect designs, preventing reliable comparisons of the effectiveness of this new methods with a conventional or a cardiac magnetic resonance (CMR) imaging guided approach.

Aim

We now report the largest cohort of patients undergoing EVM-guided EMB in order to show its diagnostic yield and comparing it with a cardiac magnetic resonance (CMR) guided approach.

Methods

One-hundred and sixty-two consecutive patients undergoing EMB at our Institution from 2010 to 2019 were included. Pathological areas identified at EVM and CMR underwent EMB. According to EMB results, CMR and EVM sensitivity and specificity regarding the identification of pathological substrates of myocardium were evaluated.

Results

A gadolinium-enhanced CMR had been performed in 143 (88.9%) of the population and yielded pathological findings in 121 (85.8%) of such cases. Late gadolinium enhancement (LGE) was present in 94 (70%) of the patients, while EVM identified areas of low voltages in 61%. Right (73%), left (19%) or both ventricles (8%) underwent sampling. EVM proved to have similar sensitivity to CMR (74% vs. 77%; P=0.479), with non-significantly higher specificity (70% vs. 47% P=0.738). In 12 patients with EMB-proven cardiomyopathy, EVM identified pathological areas, which had been undetected at CMR evaluation (concordance rate 53.8%; k = 0.26). Sensitivity of pooled EVM and CMR was as high as 95%. Five cases (3,8%) of cardiomyopathies were undetected by both CMR and EVM. Complications rate was low (4,9%), mostly vascular access related, with no patients requiring urgent management.

Conclusion

EVM proved to be a promising tool for targeted-EMB due to its sensitivity and specificity in identifying myocardial pathological substrates. EVM demonstrated to have an accuracy similar to CMR. EVM and CMR together conferred EMB a positive predictive value of 89%.

Funding Acknowledgement

Type of funding source: None

ARVC specific autoantibody identifies cardiac sarcoidosis and correlates with inflammation activity

Introduction

Cardiac sarcoidosis (CS) is an inflammatory granulomatous disease of unknown origin. CS and arrhythmogenic right ventricular cardiomyopathy (ARVC) are overlapping syndromes. With both, patients are at increased risk of ventricular arrhythmias and sudden cardiac death. However, the diagnosis of CS is challenging, especially in patients with no extracardiac involvement, but correct diagnosis has large therapeutic impact. Recently, a novel diagnostic autoantibody (anti-DSG2 Ab) was identified in ARVC. We sought to identify this antibody in CS patients and correlate its levels with inflammation activity using cardiac positron-emission-tomography (18-FDG-PET).

Methods

Recombinant human desmoglein-2 (DSG2) proteins on western blots were exposed to sera as well as purified IgG of 14 patients with sarcoidosis (all confirmed by histology) and 6 controls (1 ARVC patient (positive control) and 5 healthy control subjects (negative control)). Clinical patient characteristics were correlated to detected antibody intensity levels.

Results

The sarcoidosis cohort comprised 43% (6/14) male patients and the average age was 50±12 years. Anti-DSG2 Abs were identified in 43% (6/14) and were detected faintly (below cut off level) in 21% (3/14) of all sarcoidosis patients. Antibody was also present in the ARVC patient (1/1) and was absent in all control subjects (5/5). Myocardial inflammation was present in 18-FDG PET imaging in all CS patients with positive anti-DSG2 Abs, corresponding to an average SUV (standardized uptake value) of 8.1±4.2. In patients with faint or no antibody, the SUV values were significantly lower with 1.2±2.1 and 3.2±4.0, respectively (P=0.044, one-way ANOVA). The Pearson correlation coefficient (R) was 0.6 (P=0.037) for SUV vs. higher antibody levels assessed by pixel count of the western blot bands for purified IgG.

Conclusions

Anti-DSG2 Abs are not only a specific biomarker for ARVC, but are also found in CS, suggesting a similar pathophysiological mechanism in these overlapping syndromes, both involving cardiac inflammation and myocyte cell death. Moreover, antibody levels correlate with disease activity on cardiac PET imaging. Larger cohorts are necessary to confirm these findings.

Funding Acknowledgement

Type of funding source: None

Role of endomyocardial biopsy guided by electroanatomic voltage mapping for the diagnosis of cardiomyopathies in patients with arrhythmic presentation

Background

A myocardial substrate assessment through percutaneous endomyocardial biopsy (EMB) represents an important additional diagnostic test for cardiomyopathies when uncertainties remain after non-invasive evaluation. Yet, extensive application of EMB has been limited by the low sensitivity of biopsies. Electroanatomic voltage mapping (EVM) is a promising modality for guiding Endomyocardial biopsies (EMB).

Aim

The aim of our study is to evaluate the diagnostic yield of EVM-guided EMB and the role of histological analysis in the diagnosis of patients with suspected cardiomyopathies and arrhythmic presentation.

Methods

One-hundred and sixty-two consecutive patients undergoing EMB at our Institution from 2010 to 2019 were included. Demographics, clinical data, CMR data and peri-procedural complications were retrospectively retrieved. All procedures were guided by endo-cavitary EVM. According to non-invasive data collected before proceeding with EMB a suspected clinical diagnosis was expressed and compared to histological diagnosis

Results

One-hundred and sixty-two patients were included in the study. Mean age of the cohort resulted 40.9±14.7 years, with 26.5% of the included patients being females. ECG alterations were present in 51.3% of the population, with the most common abnormality being T wave inversion. Sustained or non-sustained ventricular tachycardia was registered in 51 (31.5%) of the patients, while 44 (27.2%) patients were referred for frequent isolated premature ventricular complex (PVC), and 19 (11.7%) after an episode of an arrhythmogenic syncope or resuscitated cardiac arrest. Suspected ARVC (41.6%) together with acute/chronic myocarditis (28.0%) were the main clinical diagnosis leading to an invasive approach. The sampling site was the right ventricle in 116 (72.5%), the left ventricle in 31 (19.4%), and both ventricles in 13 (8.1%) patients. Biopsy samplings were judged appropriate for histological analysis in 141 (87.0%) patients. Among the analyzed samples, a diagnosis was reached in 120 patients (74.1%). In the remaining 21 cases (25.9%), the analysis yielded nonspecific histologic findings, inconclusive results, or sampling error. The biopsy allowed to confirm the clinical diagnosis in 72 (60.0%) patients, while a different diagnosis was reached in 48 (39.0%) cases (Reclassification are showed Figure 1).In particular of 67 (41.6%) patients suspected for ARVC, only 32 (22.7) reached a confirmation. Conversely, the number of patients with acute/chronic myocarditis augmented from 45 (28.0%) to 47 (33.3%).

Conclusion

EMB guided by EVM reached a diagnostic yield as high as 74.1%. EMB proved to be a useful tool in the clinical management of patients, as it allowed to correctly reclassify a significant number of patients who would have been misdiagnosed based only on non-invasive assessment.

Sankey Diagram

Funding Acknowledgement

Type of funding source: None

First-in-world assessment of outcomes of catheter ablation for atrial arrhythmias in arrhythmogenic right ventricular cardiomyopathy

Introduction

Arrhythmogenic right ventricular cardiomyopathy (ARVC) is a genetically inherited disease characterized by fibro-fatty infiltrations (FFI). FFI in ARVC patients usually originates in the ventricles, but recent imaging studies showed FFI at the atrial level as well. Effectiveness of catheter ablation (CA) for atrial arrhythmias (AA) in this subset of patients is currently unknown.

Purpose

Aim of our study is to describe acute and long-term effectiveness of CA for AA in ARVC patients.

Methods

Nine ARVC registries from Europe, US, and China were retrospectively searched for ARVC patients undergoing CA for AA (namely: atrial fibrillation (AF), atrial tachycardia (AT), and cavo-tricuspid dependent atrial flutter (CTI-FL)). Baseline, procedural, and long-term outcome data were collected.

Results

Thirty-five pts (86% male, median CHA2DS2-VASc 1 [1–2], HAS-BLED 1 [0–2], and EHRA scores 2 [2–3]) were enrolled, in which a total of 45 CA procedures for AA were performed (left atrial CA: n=19 AF, n=10 AT; right atrial CA: n=16 CTI). Mean age at AA CA was 48.2±14.8 y.o. At baseline, 63% of pts were on oral anticoagulants (OAC) (n=9 warfarin; n=13 NOAC). Catheter ablation was successful and sinus rhythm obtained at the end of the procedure in all patients, with 2 (6%) AF patients requiring electrical cardioversion. Over a median follow-up of 36 [14–74] months, 12 (27%) pts experienced arrhythmia recurrence (left atrial group: n=6 AF recurrences, n=3 AT recurrences; CTI-FL group: n=1 CTI-FL recurrence; n=1 new AF with previous CTI-dependent flutter ablation), with a 1-year follow-up resulting comparable to what has been reported in the literature for the general population. [Figure 1 and 2]. 61% pts were on OAC at last follow-up.

Conclusion

Age at the time of CA for AA is about 10 years younger in patients with ARVC as compared to the general population. CA for AA in ARVC pts is safe and effective; surprisingly, long-term CA outcomes for AF and left AT result comparable to those reported in the general population, whereas recurrence rates of CTI-dependent flutter seem to be higher.

Funding Acknowledgement

Type of funding source: None

P1110Role of an extensive diagnostic work-up in the detection of concealed cardiomyopathies in athletes with complex ventricular arrhythmias and implications for sports" eligibility assessment

Background

ventricular Arrhythmias (VAs) are a common clinical problem and a critical issue with regards to sports" eligibility in athletes. Although VAs can be considered a benign feature of the athlete’s heart adaptive phenotype, they may also be the only clinical manifestation of a concealed cardiomyopathy, potentially heralding sudden cardiac death (SCD) during sports activity.

Purpose

to evaluate the diagnostic contribution and the implications for sports eligibility assessment of a thorough non-invasive and invasive work-up including electrophysiology study (EPS), electroanatomical mapping (EAM) and endomyocardial biopsy (EMB) in athletes with complex VAs and to derive a multiparametric risk score in order to easily predict structural heart diseases’ diagnosis.

Methods

we conducted a prospective, single-arm, open-label single center, observational study. All consecutive athletes presenting for evaluation at our institution after being disqualified from participating in sports due to complex VAs were enrolled. The athletes underwent a baseline non-invasive diagnostic protocol with transthoracic echocardiogram and gadolinium enhanced cardiac magnetic resonance imaging (cMRI). Subsequently EPS, EAM and EAM-guided EMB were performed if deemed necessary. Sports eligibility status was re-assessed at 6 months’ follow-up. A multivariable logistic regression model was built, considering cMRI as the gold standard exam.

Results

after diagnostic evaluation, 55 subjects (26.4%) had a diagnosis of heart disease, most commonly myocarditis (n = 27) and arrhythmogenic right ventricular cardiomyopathy (ARVC, n = 16). After 6 months, 100 athletes (48.1%) were judged eligible to participate in competitive sports and 46 subjects (22.1%) were deemed eligible to participate in non-competitive sports. On multivariable logistic-regression analysis, abnormalities on ECG (OR 5.3) or on echocardiogram (OR 3.7), sustained VA inducibility on EPS (OR 17.7) and low-voltage areas on EAM (OR 7.7) proved all predictive of concealed structural heart diseases’ diagnosis. We derived two simple risk scores: a 40-points risk score and an 8-points risk score (obtained by weighing each variable according to the regression model’s ORs). Both these risk scores’ performance proved very good (AUC = 0.856 for the 40-points score and AUC = 0.852 for the 8-points score, figure 1).

Conclusions

approximately 1/4 of athletes presenting with complex VAs have a concealed heart disease, most commonly myocarditis or ARVC. ECG, echocardiogram and EAM abnormalities and sustained VAs inducibility on EPS are predictive of structural heart diseases’ detection. Therefore, these diagnostic tests should be routinely included in the evaluation of athletes with complex VAs. A risk score including the results of these tests can greatly help in the prediction of concealed structural heart diseases’ diagnosis. More than 2/3 of subjects were judged eligible to participate in sports at 6 months’ follow-up.

Abstract Figure 1. ROC curves for diagnosis

P1799 The importance of 3D imaging techniques in left atrial appendage closure: landing zone eccentricity influence on peri-device leak incidence and its implication in long-term clinical outcomes

Background

A complex left atrial appendage (LAA) morphology and a non-circular landing zone (LZ) are frequently encountered in patients undergoing percutaneous LAA occlusion (LAAO). Three-dimensional (3D) imaging modalities as 3D transoesophageal echocardiography (3D TOE) and cardiac computed tomography (CCT) should be preferred over two dimensional techniques for better evaluation of LAA diameters, especially for the LZ. In fact, non-circular shape could impair the choice of occluder device size and may be implicated in the occurrence of residual leaks. Incomplete LAA occlusion is recognized to be associated with thromboembolic events.

Purpose

The aim of the study was to evaluate the utility of 3D imaging techniques to predict LAA device size and the landing zone eccentricity index as a potential predictor of residual peri-device leaks and to assess their clinical implications on long-term follow-up.

Methods

It was a retrospective, single-center study including 137 consecutive patients undergoing successful LAAO from January 2010 to July 2018. Pre-procedural 3D TOE and CCT were used to predict device size based upon LZ diameters and quantify LAA orifice eccentricity. Leaks were defined as the presence of peri-device flow at 2D TOE immediately after the device implantation and at 3 months follow-up. Leaks were classified as significant (color jet width ≥4 mm) or minor (&lt;3 mm). A clinical evaluation of thromboembolic events was performed at 48 ± 27 months from the procedure.

Results

LAAO closure was performed implanting either Amulet or Watchman devices (n = 98 and n = 40, respectively). The assessment of LZ measurements with 3D TOE and CCT showed a significant correlation with the device size selected on the basis of 2D techniques (r = 0.82 and r = 0.74, respectively). As concerns the peri-device leaks, the presence of an eccentric LZ (eccentricity index &gt;0.20) was not associated to the development of post-procedural leaks in the overall population; a significant correlation was detected only in the subgroup of patients treated with the Amulet device (p = 0.045). Residual leaks included only 1 significant leak (0.7%) after Amulet device implantation, which was related to a major neurological event (stroke) and 47 (34%) minor leaks (n = 28 in the Amulet group, n = 19 in the Watchman group). In this last population, 2 patients (1.5%) developed minor neurological events (transient ischemic attack).

Conclusions

3D TOE and CCT better predict device size overcoming the limit of 2D imaging techniques undersizing. In eccentric LAA, Watchman device may reduce the incidence of peri-device leaks. The presence of significant residual leaks is uncommon but associated with major clinical events, whilst minor leaks are relatively frequent but do not seem to be related to life-threatining thromboembolic accidents.

P3684Detecting true left dominant arrhythmogenic cardiomyopathy: cardiac magnetic resonance imaging and an invasive diagnostic assessment to go beyond current diagnostic criteria

Background

Left-dominant arrhythmogenic cardiomyopathy (LDACM) represents an underdiagnosed subtype of the classical right-dominant ACM, with a fibro-fatty infiltration of the left ventricle ab disease initio. To date, ACM diagnosing criteria do not include any paradigm for LDACM and no shared consensus or position statement has been issued yet.

Purpose

To analyse the diagnostic work-up needed to reach a definite diagnosis in LDACM patients (pts).

Methods

All pts with a high clinical suspicion of ACM admitted at our institution were evaluated. Disease and familiar history, and both baseline ECG and cardiac ultrasound (US) were retrieved in all pts. Before invasive evaluation, all pts underwent cardiac magnetic resonance imaging (MRI) for morphology assessment and tissue characterization by late gadolinium enhancement (LGE). An invasive evaluation with an electrophysiological study (EPS) and an endo-cavitary electro-anatomical mapping (EAM) was then subsequently performed; EAM-guided endo-myocardial biopsy (EMB) was performed at physician discretion, for direct histological evaluation of myocardial substrate.

Results

30 ACM pts (53±6 y.o.; 66% male) were defined as LDACM; 22 (73%) pts presented unspecific ECG abnormalities, with 8 (27%) pts instead presenting negative t-waves in V4-V6. Cardiac US resulted unremarkable in 27 (90%) pts. Sustained ventricular arrhythmia with right bundle brunch block were experienced in 4 (14%) pts, while frequent premature ventricular beats with the same morphology in 10 (33%).

LDACM diagnosis was mainly suspected upon MRI evaluation: all 30 pts presented a late gadolinium enhancement (LGE) pattern revealing an isolate left ventricle fibro-fatty infiltration, with normal biventricular contractility (LV and RV ejection fraction 57±9% and 53±2%, respectively).

Right ventricular, left ventricular and biventricular endo-cavitary EAM was performed in 10 (33%), 11 (37%) and 9 (30%) pts respectively, revealing pathologically low unipolar voltages in 7 (23%) and both unipolar and bipolar low voltages in 15 (50%) pts. In 18 (60%) pts an EMB was performed, revealing in 15 (83%) a fibro-fatty infiltrate and a fibro-fatty infiltrated with a superimposed viral myocarditis in a single pt. Genetic testing was performed in 16 (53%) pts, of which 10 (33%) showed causative mutation of desmosomal genes.

If strictly adhering to the existing criteria, only 7 (23%) LDACM definite diagnosis would have been reached, even when using EMB and genetic testing.

LDACM EAM with late potentials

Conclusion

LDACM is an underestimated ACM subtype that require MRI evaluation and an invasive work-up for definite diagnosis. Although EMB and genetic testing being the most effective diagnostic tools currently at disposal adhering to existing criteria, a definite diagnosis could be reached only in a fraction of patient population. Existing diagnostic criteria should be revised, mainly to take in consideration EAM specific role and to properly define the LDACM entity.

P3682Myocardial structural abnormalities in nonischemic patients presenting with ventricular arrhythmias

Background

The diagnosis of concealed cardiomyopathies in patients with ventricular arrhythmias (VAs) is one of the major challenging issues faced by physicians.

Purpose

We aimed at reporting the cardiomyopathic substrate in patients with recurrent arrhythmias of ventricular origin.

Methods

Consecutive patients with unexplained VAs underwent a complete diagnostic work-out, including endomyocardial biopsy (EMB).

Results

Ninety-seven patients were enrolled (76.3% male, age 39.7±13.3 yrs). The presenting arrhythmic manifestation was aborted cardiac arrest in 30 (30.9%) patients, sustained ventricular tachycardia (VT) in 9 (9.3%), nonsustained VT in 15 (15.5%) and frequent premature ventricular complexes in 43 (44.3%). Overall, 350 biopsies were collected (3.6/patient). The incidence of procedure-related complications was 5.1% (n=5): 4 major complications (1 rupture of a tricuspid chorda tendinea w/o hemodynamic impairment, 1 dissection of right external iliac artery treated with stent, 1 thrombotic occlusion of left superficial femoral artery which required surgical treatment, 1 TIA) and 1 minor complication (groin hematoma) occurred. The final diagnosis was arrhythmogenic right ventricular dysplasia/cardiomyopathy (ARVD/C) (n=41; 42.3%), followed by myocarditis (n=20; 20.6%), dilated cardiomyopathy (n=6; 6.2%), cardiac sarcoidosis (n=6; 6.2%), and myocarditis in ARVD/C (n=5; 5.1%). Among the 25 patients whose final diagnosis was consistent with myocarditis, an acute stage of the disease was documented in 7 (7.2%), while a chronic myocarditis in 18 (18.5%). Additionally, according to medical history and diagnostic workout, in 2 of the 6 patients the dilated cardiomyopathy had a likely post-inflammatory etiology. Absence of myocardial abnormalities was documented in 15 (15.5%) patients: this group included 1 case of methadone-induced torsade de pointes. The remaining 4 (4.1%) patients were diagnosed with a cardiac hypertrophy (n=2, 2.1%, secondary to exercise or Fabry disease), a dilated mitochondrial cardiomyopathy (n=1, 1.0%), a dilated cardiomyopathy in Emery-Dreifuss muscular dystrophy (n=1; 1.0%).

Conclusion

In our series, approximately 45% of patients with unexplained VAs had a final diagnosis of ARVD/C.

P4761Impact of focal ablation versus isolation of the coronary sinus in patients undergoing repeat radiofrequency catheter ablation of persistent atrial fibrillation

Introduction

Non-pulmonary vein (PV) triggers originating from the coronary sinus (CS) are a common finding in atrial fibrillation (AF) patients. To date, no studies have investigated the clinical impact of focal ablation versus isolation of the CS in patients presenting triggers from this area.

Purpose

This study analyzed the effectiveness of two different approaches for CS ablation (total isolation vs focal ablation) in persistent AF patients undergoing repeat AF ablation.

Methods

Consecutive persistent AF patients undergoing repeat ablation were enrolled in this prospective analysis. All patients had triggers from the CS documented during high-dose isoproterenol. Pulmonary vein antrum isolation (PVAI) extended to the posterior wall (PW) plus superior vena cava (SVC) isolation was performed in all patients at first procedure. At repeat procedure, PV, PW, and SVC were re-isolated, if needed. Focal ablation or isolation of the CS was performed based on operator's choice either at first and/or repeat procedure, along with ablation of other non-PV triggers. Patients with triggers from left atrial appendage were excluded from the study.

Results

Overall, 628 consecutive patients (73.4% male, age 66.9±9.0 years) were enrolled. On the basis of the CS ablation strategy, patients were categorized into two groups: Group I received CS isolation (n=389) and Group II received CS focal ablation (n=239). Major clinical characteristics were not different between groups. PV reconnection was documented in 55 (14.1%) patients of Group I and 33 (13.8%) of Group II. The incidence of procedure-related complications was similar between the two groups (10 [2.6%] in Group I vs 6 [2.5%] in Group II; p=0.9). After a follow-up of 18±8 months, 276 (71%) patients in Group I and 115 (48%) in Group II remained arrhythmia-free (p<0.001, figure.1). After adjusting for age, gender and clinically relevant variables, CS isolation was associated with a significantly higher arrhythmia-free survival rate (HR: 0.47; 95% CI: 0.37–0.61, p-value<0.001).

Conclusions

In patients with documented triggers from the CS undergoing repeat ablation of persistent AF, isolation rather than focal ablation of the CS significantly increased freedom from atrial tachyarrhythmias in the long term.

P3687Abnormal voltage recordings in patients with ventricular arrhythmias: comparison between right and left cardiomyopathy

Background

Arrhythmogenic Cardio-Myopathy (ACM) is characterized by epi-endocardial fibro-fatty replacement. Depending on the most affected ventricle, right dominant (RDACM) or left dominant (LDACM) phenotypes can be defined. RDACM voltage mapping characteristics have already been described, with late potentials strongly correlating with arrhythmia recurrence risk; LDACM voltage features have not been described yet.

Purpose

To analyze voltage map characteristics in LDACM patients (pts) and compare them with RDACM; to assess if there is any correlation between late potentials and recurrence rate in LDACM as well.

Methods

We retrospectively enrolled all consecutive ACM patients treated c/o our center and diagnosed according to the 2010 Task Force Criteria. Procedural and follow up data were collected. Patient were sorted by ventricular involvement lateralization. Recurrence rates were evaluated and linearly regressed for the presence of late potentials.

Results

89 ACM patients were enrolled (67 RDACM, 22 LDACM; 76% males, 69±4 y.o.) in our study. All patients underwent endocardial voltage mapping; procedurally, 43 (48%) pts underwent catheter ablation, while 46 (52%) were managed conservatively with anti-arrhythmic drugs.

Bipolar pathological potentials were found in 43 (64%) and 13 (59%), unipolar pathological potentials in 45 (67%) and 14 (63%), while late potentials in 19 (31%) and 8 (36%) in the RDACM and LDACM group respectively [p = 0.66, p=0.63, and p=0.33].

The average follow-up was 18 months [14–48]; 15 (22%) in the RDACM and 9 (40%) in LDACM arrhythmic recurrences were respectively encountered; recurrences in both groups were regressed for the presence of late potentials. Results were as follows: the presence of late potentials correlated with recurrences with an 4,3 [1.15–16.1; p=0.03] OR and with an 11 [0.4–85; p=0.022] OR in the RDACM and LDACM group respectively.

Conclusion

Pathologically low unipolar, bipolar and late potentials can be found in comparable % both in RDACM and LDACM; like in RDACM, late potentials represent an important risk factor for arrhythmic recurrence in LDACM as well.

P4652Magnetic resonance and electroanatomical guided endomyocardial biopsy as a diagnostic tool in the clinician's box: a 5 year experience

Background

Percutaneous endo-myocardial biopsy (EMB) is an invasive diagnostic test used to reach or confirm a diagnosis when structural or substrate anomalies are suspected, such as in cardiomyopathies or myocarditis evaluation. In recent years, cardiac magnetic resonance imaging (MRI) and endo-cavitary electro-anatomical mapping (EAM) have been used to localize the most significant myocardial area to sample, therefore increasing EMB overall effectiveness and reliability.

Purpose

To describe and characterize safety, feasibility and anatomical findings of a large cohort of patients (pts) undergoing diagnostic EMB and to assess its impact on the treatment decision making algorithm.

Methods

A cohort of all pts undergoing a percutaneous EMB at our Institution from January 2014 to January 2019 was analyzed. All EMB procedures were guided by a pre-procedural cardiac MRI radiological alteration analysis and an endo-cavitary EAM. Intra-cardiac echography (ICE) was used in all procedures, to directly visualize the sample area and to evaluate in real time post-EBM complications. Demographics, clinical data, MRI data, pathological EMB features, and peri-procedural data were systematically retrieved.

Results

One-hundred and eleven pts were enrolled (78% male, 47±4 y.o., 33% athletes). EMB indication was abnormal MRI findings in 94 (85%), pathological EMB voltages in 10 (9%) and clinical suspect and patient history in 7 (6%) pts.

EMB sample area was determined by both MRI and EAM pathological area analysis in 92 (83%) pts, while by EAM alone in 19 (17%) pts (n=6 pathological unipolar EAM; n=13 bipolar and unipolar pathological EAM). The sample site was the right ventricle in 89 (80%), the left ventricle in 20 (18%), and both in 3 (2%) pts.

In 103 (93%) pts a concomitant electrophysiological induction study was performed (40% positive for sustained ventricular arrhythmias) and 35 (32%) pts underwent a trans-catheter ablation (TCA) (n=8 epicardial TCA; n=2 endo-epicardial TCA; n=25 endocardial ATC). Only 2 (2%) peri-procedural adverse events were witnessed, specifically femoral pseudo-aneurysms, requiring surgical repair. EMB analysis allowed to confirm 58 (52%) pre-procedural diagnosis and to reach 32 (29%) new diagnosis, while resulting inconclusive or non-specific in the diagnostic process only in 21 (19%) cases [Figure1]. A total of 33 (30%) intra-cardiac devices (ICDs) were implanted contextually in the cohort, of which 9 (8%) solely upon EMB indication; in 4 (4%) other patients, biopsy represented a strong decisional factor in the multi-modality decision process for abstaining from ICD implant.

Dashed lines: diagnosis changed upon EMB

Conclusion

MRI and EAM guided EMBs allowed to finely define a large cohort of patients by representing a disease defining parameter in over 80% of the enrolled pts while and a decision shifting parameter in ICD implant algorithm in a high % of pts.

P5560Assessing etiology in a cohort of patients with myocarditis presenting with complex ventricular arrhythmias: can the percutaneous endomyocardial biopsy help?

Background

Myocarditis represents a common but often under-diagnosed disease, with a wide range of clinical presentations; diagnosis is often presumptive and a clear etiology leading to a specific therapeutic approach is usually not identified.

Purpose

To describe and assess disease etiology in a cohort of myocarditis patients (pts) with arrhythmic presentation undergoing an invasive diagnostic work-up.

Methods

All pts with myocarditis presenting with ventricular arrhythmias undergoing an electro-anatomical mapping (EAM) guided endo-myocardial biopsy (EMB) at our institution were enrolled. All enrolled pts also underwent cardiac magnetic resonance imaging (MRI) and an electrophysiological study (EPS). Demographics, arrhythmic presentation, MRI data, arrhythmic inducibility at EPS, EAM and EMB biopsy data were retrieved and analyzed. Molecular biology testing for cardio-tropic virus genome as well as leukocyte immunohistochemical typization were routinely performed on all EMB samples.

Results

Twenty-six pts were enrolled (85% male, 39±6 y.o.). Clinical presentation was an organized ventricular arrhythmia in 16 (62%) pts (n=3 non-sustained ventricular arrhythmia; n=9 sustained ventricular arrhythmia; n=4 ventricular fibrillation) while frequent (>10.000) premature ventricular complexes (PVCs) in the remaining 10 (38%) pts.

MRI showed a late gadolinium enhancement (LGE) pattern consistent with myocarditis in all pts (35% left LGE; 65% right LGE). At the EPS, 10 (38%) pts showed inducibility for SVTs and underwent an intra-cardiac defibrillator (ICD) implant, while 4 (16%) more were implanted for secondary arrhythmic prevention.

EAM was performed in 18 (70%), 6 (22%) and 2 (8%) pts in the right, left and in both ventricle respectively; in all cases, abnormal myocardial voltages were retrieved in the area showing LGE at MRI. Extensive myocardial scarring was detected in 7 (27%) pts.

All EMB were performed without peri-procedural complications; inflammatory infiltrate and substrate alteration consistent with myocarditis were retrieved in 100% of the bioptic samples. Viral genome was identified in 13 (50%) samples (n=5 Human Herpes Virus 6; n=2 Parvovirus B 19; n=3 Adenovirus; n=1 Ebstein Barr Virus; n=1 Cytomegalovirus; n=1 Rhinovirus) and specific human immunoglobulin treatment was undergone by a single pt; eosinophilic infiltration was found in 2 (8%) patients; lymphocite invasion and auto-antibodies consistent with auto-immune myocarditis were detected in 2 (8%) patients and appropriate immunosuppressive therapy was started, while a myocardial band contraction pattern typical of toxic myocarditis was found in a single (4%) patient [Figure 1].

Different Myocarditis Etiology Rates

Conclusion

In our myocarditis cohort, EMB confirmed viruses to represented the first myocarditis etiological agent. Despite an invasive work-out, 31% of the cohort etiology still remains unclear.

P993Diagnostic accuracy of cardiac magnetic resonance and endomyocardial biopsy for arrhythmogenic right ventricular dysplasia/cardiomyopathy and myocarditis

Introduction

Patients with myocarditis may fulfill the cardiac magnetic resonance (CMR) criteria set forth by the 2010 Task Force for arrhythmogenic right ventricular dysplasia/cardiomyopathy (ARVD/C), thereby increasing the risk of misdiagnosis.

Purpose

We sought to evaluate the role of CMR and endomyocardial biopsy (EMB) in the differential diagnosis between myocarditis and ARVD/C.

Methods

Consecutive patients presenting with ventricular arrhythmias, underwent a complete diagnostic work-out, which included CMR and EMB. The final diagnosis served as the gold standard to assess the diagnostic accuracy of CMR and EMB.

Results

Overall, 74 consecutive patients presenting with VAs underwent a complete diagnostic workout at our institution. The cohort was 70.3% male, with a mean age of 38.9±12.1 years. A final diagnosis of ARVD/C was made in 30 (40.5%) patients, whereas 19 (25.7%) had a diagnosis of myocarditis.

The McNemar's test showed significant differences in the diagnostic performance of EMB and cardiac MRI (p=0.003 for ARVD/C, p=0.04 for myocarditis).

At receiver operating characteristic (ROC) analyses, the area under the curve (AUC) to discriminate between controls and ARVD/C patients was 0.711 (95% CI: 0.59–0.83) for MRI and 0.944 (95% CI: 0.88–1.00) for biopsy (p<0.001). The AUC to discriminate between controls and patients with myocarditis was 0.656 (95% CI: 0.51–0.80) for MRI and 0.893 (95% CI: 0.80–0.99) for biopsy (p=0.006).

Diagnostic performance of CMR and EMB

Conclusion

Even though CMR has good diagnostic performances as single technique, a complete diagnostic work-out including EMB may frequently reduce the risk of misdiagnoses.

P307Magnetic resonance, electroanatomical mapping, and endomyocardial biopsy to solve the diagnostic and sport eligibility dilemma in a cohort of competitive athletes with ventricular arrhythmias

Background

Ventricular arrhythmias (VAs) are a frequent finding in agonist athletes (athl) at routine sport medicine visits. VAs impact on sport eligibility, their management, and the sudden arrhythmic death risk evaluation in athletes currently represents one of the greatest challenges across both the cardiology and sport medicine field.

Purpose

To describe how an advanced multi-methodical evaluation allowed diagnosis, risk stratification, targeted therapy and sport eligibility reassessment in a competitive athl cohort with ventricular arrhythmias and pathological findings at magnetic resonance (MR).

Methods

All consecutive competitive athl with denied sport eligibility due to ventricular arrhythmias that underwent an advanced invasive evaluation at our institute were enrolled.

A baseline and stress ECG, and late gadolinium enhanced evaluation (LGE) at MR were performed prior to invasive evaluation in all athl.

Invasive evaluation performed in all athl comprised of an electrophysiological study (EPS) to assess arrhythmic inducibility, an endo-cavitary electro-anatomical mapping (EAM), and a EAM and MR guided endo-myocardial biopsy (EMB). A defined diagnosis was postulated in all cases, specific therapeutic interventions were started and sport eligibility status reassessed after 6 months from discharge.

Results

Thirty-two competitive athl were enrolled in our study (32±6 y.o.; 77% male; 4±1 1h-training session/week); 26 (81%) athl practiced a mixed aerobic-anaerobic, 5 (16%) a pure-aerobic, while only 1 (3%) a pure anaerobic sport.

Arrhythmic presentation leading to sport eligibility revoke was: in 13 (40%) athl frequent (>2000/day) premature ventricular contractions (PVCs) at rest, in 2 (6%) PVCs during stress ECG, in 6 (18%) non-sustained ventricular tachycardia (VT), in 8 (25%) sustained VT, and in 3 (11%) ventricular fibrillation/cardiac arrest during sport practice.

MR alterations were described in all cases, and LGE at MR was found in 31 (87%) athl; a definite radiological diagnosis was obtained in 13 (40%) athl.

A normal myocardium at EMB was found only in 3 (8%) pts; in 15 (45%) a leukocyte infiltrate pattern compatible with myocarditis, in 11 (39%) fibro-fatty replacement, in 2 (5%) a mitochondrial disease and in 1 (3%) a sarcoidosis were proven, and diagnosis were consequently postulated.

EPS showed complex VAs inducibility in 8 (25%) cases, while a trans catheter ablation was performed in 10 (31%) athl. A total of 9 (28%) implantable cardioverter devices (ICDs) were implanted, for primary or secondary prevention.

According to invasive diagnostic findings and sport medicine guidelines, 8 (25%) athl had their sport eligibility statuts re-instated.

Conclusion

An invasive multi-methodical assessment allowed in all cases to reach a diagnosis and to start a targeted therapy in a cohort of competitive athl with VA and a pathological MR, granting in a significant (25%) percentage sport eligibility status re-instatement.

P5556Impact of viral genome detection in endo-myocardial biopsy of arrhythmogenic cardiomyopathy substrate

Background

Arrhythmogenic cardiomyopathy (ACM) is a genetically inherited cardiomyopathy characterized by myocardial fibro-fatty replacement. A pathogenetic role of viral myocardial infections in ACM natural history has been proposed over the years, although no definitive conclusion has been reached yet.

Purpose

To describe viral genome presence into a cohort of ACM biopsy proven patients (pts) and its impact on clinical features and outcome.

Methods

A cohort of all ACM pts undergoing an invasive third level evaluation at our institution was enrolled. All pts underwent a cardiac magnetic resonance (MR), an invasive electrophysiological study (EPS) with endo-cavitary electro-anatomical mapping (EAM), and a EAM guided endo-myocardial biopsy (EMB). Viral genome research through molecular biology techniques was performed on all biopsied samples.

According to arrhythmic risk evaluation, a trans-catheter ablation (TCA) and/or an internal cardioverter device (ICD) implant was performed. Clinical arrhythmic presentation, MR data, arrhythmia inducibility at EPS, EAM and EMB characteristic, and arrhythmic events at a 12-month follow up visit were retrieved in all pts and compared between the viral genome positive (v+ACM) and negative group (v-ACM).

Results

Forty-five pts were enrolled in our study (48±13 years; 66% male); the EMB samples of 7 (15%) pts presented a lymphocytic infiltrate and tested positive for viral genome (n=3 B19 Parvovirus; n=2 for Citomegalovirus; n=2 for Ebstein-Bar Virus) [Figure1].

At arrhythmic presentation, complex ventricular arrhythmias (NSVT, SVT and FV) were more frequent in the v+ACM group (86% vs 50%; p=0.039). Both left and right ventricular ejection fraction at MR resulted more depressed in the v+ACM group (44±7 vs 52±2 and 47±2 vs 52±2; p=0.047 and p=0.041). Complex ventricular arrhythmia inducibility at EPS was more frequent in v+ACM (72% vs 34%; p=0.032), while no differences in pathological potentials rate and extension at unipolar and bipolar EAM were found. TCA was performed in 55% and 57% and an ICD was implanted in 29% and 42% in the v+ACM and v-ACM group respectively. No differences in 12-months arrhythmic event rates (39% vs 42%) between the two groups were described.

EBM at different magnifications/stains

Conclusion

In our cohort a viral infection super-imposed to the fibrofatty infiltration was found in 15% of the patients. ACM pts testing positive for viral genome at the EMB had a more severe arrhythmic disease presentation, a more impaired heart function, and a higher rate of complex ventricular arrhythmias at disease presentation, but seemed to respond as well as viral genome negative ACM to ablative and pharmacological treatment

A new method of measure of bubble gas volume shows that interleukin-6 injected into rats has no effect on gas embolism

The pleiotropic cytokine interleukin-6 increases in the plasma of rats after an air dive. Interleukin-6 shares both of inflammatory and anti-inflammatory properties and may condition the vascular system and gas embolism after an air dive. Up to now it is not known whether interleukin-6 has an effect on gas embolism. Aim of this work is to study the effect of interleukin-6 on gas embolism after a standard decompression protocol in a rat model. The volume of gas bubbles was measured in the heart cavities with a new method based on the buoyancy of the heart at different pressures which is physically sound, accurate and precise down to 10(-4) cm3. No effect was found after injecting physiological doses of interleukin-6 at different times before the air dive. The mortality of the rats in the first half hour after the decompression was associated with a substantial gas volume measured in the heart. Multi-variate logistic regression analysis showed that the female rats had a higher risk compared to male rats of developing a substantial bubble volume and of not surviving; the spring-summer season was a risk factor for the survival. Further studies are needed to see whether interleukin-6 in association with other cytokines has an effect on gas embolism.