Safety and effectiveness of near-zero fluoroscopy paroxysmal AF radiofrequency ablation with a temperature-controlled, contact force-sensing catheter: a Q-FFICIENCY study sub-analysis

Background/Introduction

Q-FFICIENCY evaluated 12-month (M) safety and efficacy of temperature-controlled paroxysmal atrial fibrillation ablation with a novel contact force-sensing, radiofrequency catheter with 3 microelectrodes and 6 thermocouples. Patients underwent pulmonary vein isolation with very high-power short-duration (vHPSD; 90 W/ up to 4 s) mode in combination with conventional-power temperature-controlled (CPTC; 25–50 W) mode.

Purpose

To assess procedural efficiency, safety, and 12M outcomes of participants ablated under near-zero fluoroscopy guidance compared to procedures performed with standard fluoroscopy.

Methods

In this US multi-centre (22 sites), non-randomised investigational study, patients underwent pulmonary vein isolation with vHPSD as primary ablation mode; CPTC was used for PV touch-up or non-PV ablation. Primary safety endpoint was incidence of primary adverse events ≤7 days post-procedure. Primary effectiveness was freedom from documented atrial tachyarrhythmia recurrence and additional pre-defined failure modes (acute failure, repeat ablation, new/higher dose anti-arrhythmic drug). Participants were followed-up through 12M post-ablation (3M blanking & 9M evaluation) to assess safety, effectiveness, and healthcare utilisation.

Results

Of 191 participants enrolled (63.5±10.7 years, CHA2DS2-VASc 2.4±1.5, 60.7% men), 166 were ablated with the investigational catheter, and 165 had fluoroscopy data available for inclusion in this analysis. Forty-four participants received ≤1 minute of fluoroscopy. Compared to the >1-minute of fluoroscopy cohort, the ≤1-minute group showed improved efficiencies in all procedural parameters (Table). Primary adverse event rates were similar among groups (≤1-minute, 4.5%; >1-minute, 3.3%). Kaplan-Meier estimated 12M clinical success rates (i.e., freedom from documented symptomatic recurrence) were similar regardless of fluoroscopy exposure (≤1-minute, 85.4%; >1-minute, 86.0%). Freedom from cardiovascular hospitalisation 12M post-ablation was comparable among groups (90.8% vs 88.0%).

Conclusion

Near-zero fluoroscopy paroxysmal atrial fibrillation ablation with the novel temperature-controlled catheter in vHPSD mode, alone or combined with CPTC, led to enhanced procedural efficiencies with good effectiveness and clinical success without comprising safety.

Funding Acknowledgement

Type of funding sources: Private company. Main funding source(s): Biosense Webster, Inc.

Catheter ablation for atrial fibrillation in adult congenital heart disease: an international registry study

Background

Life expectancies for patients with congenital heart disease (CHD) have dramatically increased in recent years, accompanied by a rise in atrial fibrillation (AF) prevalence. Data on AF ablation strategy and outcomes are limited in CHD.

Purpose

We aimed to investigate the characteristics of CHD patients presenting for AF ablation and their outcomes.

Methods

A multicenter, retrospective analysis was performed of CHD patients undergoing AF ablation between 2004 and 2020 at 13 participating centers. The severity of CHD was classified using the 2014 PACES/HRS guidelines. Clinical data were collected including ablation strategy and follow up. One-year procedural success was defined as freedom from AF in the absence of antiarrhythmic drugs (AADs, complete) or including previously failed AADs (partial).

Results

Of 240 patients, 127 (53.4%) had persistent AF, 62.5% were male, and mean age was 55.2±0.9 years. CHD complexity categories included 147 (61.3%) simple, 69 (28.8%) intermediate and 25 (10.4%) severe. The most common CHD type was atrial septal defect (n=78). More complex CHD conditions included transposition of the great arteries (n=14), anomalous pulmonary veins (n=13), tetralogy of Fallot (n=8), cor triatriatum (n=7), single ventricle physiology (n=2), among others. The majority (71.3%) of patients had AF despite at least one AAD. 46 patients (22.1%) had a reduced systemic ventricular ejection fraction <50%, and the mean left atrial diameter was 44.1±0.7 mm. PV isolation (PVI) was performed in 227 patients (94.6%); additional ablation strategies included left atrial linear ablations (25.4%), CFAE (19.2%), and cavotricuspid isthmus ablation (40.8). One-year complete and partial success rates were 45.0% and 20.5%, respectively, with no significant difference in the rate of complete success between complexity groups. Overall, 38 patients (15.8%) required more than one ablation procedure. There were 3 (1.3%) major and 13 (5.4%) minor procedural complications.

Conclusion

AF ablation in this complex population was safe and resulted in AF control in the majority of patients. Future work should address the most appropriate ablation targets in the challenging population.

Funding Acknowledgement

Type of funding sources: None.

AB1033 RADIOFREQUENCY ECHOGRAPHIC MULTI SPECTROMETRY (REMS) FOR THE ASSESSMENT OF FEMORAL BONE HEALTH IN A MALE POPULATION

Background

Bone mass reaches the peak during the third decade of life. By this age, men reach an increased bone mass that starts declining in their fifties, however less rapidly than women after menopause. However, men and women lose bone mass at the same rate by age 65-70, becoming fragile and more likely to have fracture.

Objectives

This study aimed to evaluate the diagnostic accuracy in osteoporosis diagnosis of Radiofrequency Echographic Multi Spectrometry (REMS) technology applied on the proximal femur in an adult male population in comparison with the Dual-energy X-ray Absorptiometry (DXA).

Methods

A cohort of Caucasian males was enrolled in the study. Inclusion criteria were: age between 30 and 90 years, body mass index (BMI) less than 40 kg/m2, no significant walking impairments and proximal femur DXA medical prescription. All the enrolled patients underwent proximal femur scans with both DXA and REMS. The agreement between REMS and DXA-measured BMD was expressed by Pearson correlation coefficient and Bland-Altman method. The classification into patients “with osteoporosis” or “without osteoporosis” was carried out considering the conventional threshold of T-score (-2.5) for both techniques independently. The accuracy was evaluated by the assessment of sensitivity and specificity considering the DXA outcome as reference [1].

Results

A total of 219 men were included in the analysis, with mean age of 55.5 (± 15.3) years. The Pearson correlation coefficient between REMS- and DXA-measured BMD values was r=0.94. At Bland-Altman analysis, Bias ± 1.96 Standard Deviation were -0.004 ± 0.04 g/cm2. The REMS capability to discriminate osteoporotic patients from non-osteoporotic ones was very high: a sensitivity of 90.0% and specificity of 91.8% was detected.

Conclusion

REMS, applied to the proximal femur site, is a reliable technology for the diagnosis of osteoporosis also in men, thus confirming the diagnostic performance already observed in studies carried out in female populations [1, 2].

References

[1]Di Paola P et al. Osteoporos Int. 2019; 30(2):391-402.

[2]Adami G et al. Bone 2020; 134:115297.

Disclosure of Interests

Fiorella Anna Lombardi: None declared, Paola Pisani: None declared, Alessandra Natale: None declared, Ernesto Casciaro Shareholder of: Ernesto Casciaro owns stocks of Echolight Spa, Marco Di Paola: None declared, Roberto Franchini: None declared, Maurizio Muratore: None declared, Francesco Conversano Shareholder of: Francesco Conversano owns stocks of Echolight Spa, Sergio Casciaro Shareholder of: Sergio Casciaro owns stocks of Echolight Spa

Oxytocin as a peripheral biomarker for Autism Spectrum Disorder: a systematic review and meta-analysis

Introduction

Autism spectrum disorder (ASD) is a group of life-long neurodevelopmental conditions characterized by impairments in social communication and by the presence of restricted interests or repetitive behaviors. Several genetic, biological, and psychosocial mechanisms seem to play a role in the etiopathogenesis of this complex condition. Preclinical models have shown a potential role of oxytocin (OT), a peptide involved in a complex range of behaviors, including those related to social interaction. Therefore, it has been hypothesized that OT levels may be decreased in autistic people.

Objectives

To compare the levels of peripheral OT in autistic people vs neurotypical controls.

Methods

We performed a systematic literature search up to December 2020 according to PRISMA guidelines. Final inclusion was based on the following criteria: (1) Participants: individuals of any age diagnosed with ASD; (2) Controls: neurotypical subjects; (3) Outcome: OT levels, either in saliva, serum, or plasma; (4) Study design: case-control. Meta-analyses are ongoing.

Results

We finally included 21 papers published between 1998 and 2020, of which one recruited adult participants. Fifteen studies measured OT levels in plasma, 4 in saliva, and 2 in serum. Preliminary meta-analyses on 10 studies showed that peripheral OT levels in autistic individuals are reduced compared to neurotypical controls, with sex differences.

Conclusions

Our preliminary findings show that peripheral OT might represent a potential biomarker for ASD. Future well-conducted case-control studies with a detailed phenotypical characterization of samples are needed to understand the role of OT deficits in specific subgroups.

Disclosure

No significant relationships.

AB1373 RADIOFREQUENCY ECHOGRAPHIC MULTI SPECTROMETRY (REMS) AS AN ALTERNATIVE APPROACH TO BIOELECTRICAL IMPEDANCE ANALYSIS (BIA) FOR THE ASSESSMENT OF BODY COMPOSITION

Background

The evaluation of human body composition is crucial for body weight management, especially in pathological conditions. Patients whose body weight greatly exceeds or remain below the reference range, need regular monitoring in order to personalise the nutritional treatment plan. To this end, bioelectrical impedance analysis (BIA) is a widely accepted tool, along with ultrasound techniques.

Among emerging ultrasound-based technologies, Radiofrequency Echographic Multi Spectrometry (REMS) is a powerful approach that can be effectively used for body composition analysis.

Objectives

The present study aims to assess the accuracy of REMS in comparison to BIA for body composition assessment.

Methods

The cohort included 141 males and females aged between 60 and 80 years. All subjects underwent body mass measurement by REMS and BIA and both body fat percentage (BFP) and basal metabolic rate (BMR) parameters were assessed.

Results

The estimation of BFP measured with BIA resulted in 40.4% (interquartile range [IQR]: 35.5% to 45.2%), which value did not differ from 41.1% (IQR: 36.5% to 47.1%) obtained with REMS (p=0.6). The BMR determined by BIA was 1329.0 kcal/day (IQR: 1270.5 to 1423.5 kcal/day), which was in a similar range as the value of 1323.5 kcal/day (IQR: 1266.0 to 1420.0 kcal/day) assessed by REMS (p=0.7).

Conclusion

The present study demonstrated the excellent ability of REMS to accurately determine the body composition, resulting as an alternative approach to conventional BIA.

Disclosure of Interests

Paola Pisani: None declared, Alessandra Natale: None declared, Fiorella Anna Lombardi: None declared, Francesco Conversano Shareholder of: Francesco Conversano owns stocks of Echolight Spa, Ernesto Casciaro Shareholder of: Ernesto Casciaro owns stocks of Echolight Spa, Maurizio Muratore: None declared, Sergio Casciaro Shareholder of: Sergio Casciaro owns stocks of Echolight Spa

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 <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.

P94 LOWER RATE OF MAJOR BLEEDING IN HIGH–RISK PATIENTS UNDERGOING LEFT ATRIAL APPENDAGE OCCLUSION: A PROPENSITY MATCHED COMPARISON WITH DIRECT ORAL ANTICOAGULATION

Background

Stroke prophylaxis in very high risk (CHA2DS2–VASc ≥ 5) patients with atrial fibrillation (AF) is one of the major challenges faced by physicians. Specifically, initiating direct oral anticoagulants (DOACs) in these patients poses a therapeutic conundrum due to the concomitant high risk of bleeding. Left atrial appendage occlusion (LAAO) might be a potential alternative for thromboembolic (TE) prevention; however, there are no studies comparing these two strategies in very high–risk patients.

Objective

To evaluate the efficacy of LAAO versus DOACs in AF patients at very high TE risk.

Methods

Data were extracted from two prospective databases including 1053 Watchman and 1328 DOAC patients. Watchman patients with a CHA2DS2–VASc ≥ 5 accounted for 26.3% (n = 277). In order to attenuate the imbalance in covariates, a 1:1 propensity score matching technique was used (co–variates: age, sex, CHA2DS2–VASc and HAS–BLED scores). This method resulted in 554 matched patients (277 patients per group; mean age: 79±7y; 57.4% F; CHA2DS2–VASc: 5.8±0.9). The primary endpoint was a composite of cardiovascular (CV) death, TE events (Stroke/TIA/peripheral embolism) and clinically significant bleeding. The annual TE and major bleeding risks were estimated based on the CHA2DS2–VASc score and compared with the annualized observed risk.

Results

After a mean follow–up of 26±7 months, total events were 55 (9.4 event rates per 100 patient–years) in LAAO group vs. 78 (14.9 event rates per 100 patient–years) in DOAC group. DOACs had a significantly higher risk of the primary endpoint (hazard ratio [HR]: 1.30; 95% confidence interval [CI]: 1.08 to 1.56; p = 0.03). TE events (HR: 1.15; 95% CI: 0.84 to 1.57; p = 0.63) and CV death (HR: 1.13; 95% CI: 0.84 to 1.54; p = 0.63) did not differ between groups. Major bleeding events were significantly lower in LAAO patients (HR: 0.75; 95% CI: 0.51 to 0.82; p = 0.04). The unadjusted estimated risk of TE events was 12.3% with LAAO and 12.4% with DOACs. The annualized incidence of TE was 3.2% with LAAO and 4.1% with DOACs, which led to a risk reduction of 74% and 67%, respectively.

Conclusion

In a large cohort of AF patients at very high TE risk (CHA2DS2–VASc ≥ 5), LAAO showed similar stroke prevention but a significantly lower risk of major bleeding than DOACs during a > 2year follow–up.

P95 PERI–PROCEDURAL COMPLICATIONS AND LONG–TERM OUTCOMES IN ATRIAL FIBRILLATION PATIENTS STRATIFIED FOR CHRONIC KIDNEY DISEASE SEVERITY UNDERGOING LEFT ATRIAL APPENDAGE OCCLUSION: RESULTS FROM AN INTERNATIONAL, MULTICENTER REGISTRY

Background

Atrial fibrillation (AF) and chronic kidney disease (CKD) often coexist and share an increased risk of thromboembolic events. CKD concomitantly contributes to several pathophysiological changes predisposing towards a pro–haemorrhagic state.

Objective

To evaluate the impact of kidney function on peri–procedural complications and clinical outcomes in AF patients undergoing left atrial appendage occlusion (LAAO) with a Watchman device.

Methods

2124 consecutive AF patients undergoing Watchman implantation at 8 different centers were categorized into CKD stage 1 + 2 (n = 1089), CKD stage 3 (n = 796), CKD stage 4 (n = 170), CKD stage 5 (n = 69) based on the estimated glomerular filtration rate at baseline. The primary efficacy endpoint included a composite of cardiovascular (CV) mortality, stroke, transient ischemic attack, peripheral thromboembolism (TE), and major bleeding.

Results

A non–significant higher incidence of major peri–procedural adverse events (1.7% vs. 2.3% vs. 4.1% vs. 4.3%) was observed with worsening baseline kidney function (p = 0.14). The mean follow–up period was 13 ± 7 months [2226 patient–years (PY)]. In comparison to CKD stage 1 + 2 as a reference, the incidence of the primary endpoint was significantly higher in CKD stage 3 (log–rank p–value= 0.04), CKD stage 4 (log–rank p–value= 0.01), and CKD stage 5 (log–rank p–value= 0.001) (Fig. 1A). A non–significant increase in event rates for stroke/TIA and clinically relevant bleeding was observed among the four groups. LAAO led to a TE risk reduction of 72%, 66%, 62%, and 41% in each group (Fig. 1B). The relative risk reduction in the incidence of major bleeding was 58%, 44%, 51%, and 52%, respectively (Fig. 1C).

Conclusion

Patients with moderate–to–severe CKD had a higher incidence of the primary composite endpoint. The relative risk reduction in the incidence of TE and major bleeding was consistent across CKD groups, irrespective of the very different risk profiles at baseline.

C32 TRANSCATHETER LEAK OCCLUSION WITH ENDOVASCULAR COILS FOLLOWING LEFT ATRIAL APPENDAGE CLOSURE: PROCEDURAL SUCCESS AND OUTCOMES BEFORE AND AFTER LEAK CLOSURE

Background

Whether residual peri–device leaks after left atrial appendage occlusion (LAAO) portend a higher risk of thromboembolism (TE), it is still a matter of debate.

Objectives

We report the TE risk in patients with incomplete LAA closure before and after leak closure with endovascular coils.

Methods

One hundred twenty–four Watchman patients with a significant (≥3mm) leak (mean age: 74 ± 9 years; 66.9% males; CHA2DS2–VASc: 4.4 ± 1.7; HAS–BLED: 3.1 ± 1) underwent LAA leak coiling. The expected annual TE risk was estimated based on the patients’ CHA2DS2–VASc and compared with the annualized incidence observed before and after coiling (Fig.1B).

Results

The time between LAAO and leak coiling was 8±6 months [83 patients–year (PY)]; before leak closure, 6 (4.8%) patients had a TE event (annualized rate: 7.2%). Coil deployment was successful in all cases [median n. of coils deployed: 5 (IQR: 2–10)]. Procedure time was 79 ± 40 min; the mean volume of iodinated contrast medium used was 80 ± 43mL. The overall complication rate was 2.4% (1 pericardial tamponade, 2 pericardial effusion). Follow–up TEE after 61±14 days revealed complete LAA sealing or a negligible leak in 117 cases (94.4%); the remaining 7 patients had a moderate leak. During 14±6 months post–coiling (145 PY), 1 (0.8%) patient suffered from stroke. The incidence of TE events was significantly lower after leak closure than before coiling (0.8% vs 4.8%; log–rank p = 0.02; Fig.1A). The annualized TE rates were 7.2% before and 0.7% after leak closure (Fig. 1A). According to the expected rate estimated from the patients’ CHA2DS2–VASc (9.8%), LAAO with and without significant leaks yielded to a risk reduction of 26.5% and 92.9% (Fig. 1B).

Conclusions

Transcatheter leak occlusion via endovascular coils was safe. LAA closure led to a significant reduction in TE events.

P4 LEFT ATRIAL APPENDAGE ANATOMICAL CHANGES FOLLOWING RADIOFREQUENCY–BASED OSTIAL ISOLATION

Background

Left atrial appendage (LAA) electrical isolation (ei) may be achieved via radiofrequency (RF) energy applications at the level of the appendage ostium targeting the sites of earliest activation recorded by a mapping catheter. Notably, RF has long been used in vascular, orthopedic, and aesthetic surgery to promote thermal–induced collagen matrix contraction, fibrosis, and tissue retraction. LAA anatomical changes associated to RF–induced tissue retraction have never been reported.

Objective

To quantify the anatomical changes of the LAA ostium following RF–based LAAei.

Methods

Thirty–four consecutive patients requiring AF ablation with LAAei underwent transesophageal echocardiography (TEE) within 7 days before (baseline TEE) and >6 months after (follow–up TEE) ablation. The diameter of LAA orifice and landing zone were measured at 4 different views (0°, 45°, 90°, 135°). Measurements were performed by two independent reviewers blinded to the patient’s identity.

Results

Among 34 AF patients (68±7yrs, 73.5% males), the LAA morphology was classified as chicken wing in 15 (44%) patients, windsock in 10 (29%), cactus in 6 (18%), and cauliflower in 3 (9%). At baseline TEE, the mean maximum and mean minimum ostial diameters were 25±4mm and 22±4mm, respectively. The mean maximum and mean minimum diameters of the landing zone were 26±4mm and 23±3mm, respectively. On average, LAAei was achieved after 16±7 minutes of RF at a power of 45–47W. Follow–up TEE was performed 257±148 days after LAAei. The median LAA contraction velocity was 0.1 m/s (IQR: 0.04–0.18) and was significantly impaired in all patients. At follow–up TEE, the mean maximum and mean minimum ostial diameters were 19±4mm and 17±3mm, respectively. The mean maximum and mean minimum diameters of the landing zone were 20±4mm and 18±4mm, respectively. The mean relative reduction of the ostium and the landing zone were –24.4% and –22.5%, respectively. Box–Whisker plots of the maximum and minimum ostial diameters before and after LAAei are reported in Fig. 1.

Conclusion

RF led to a > 20% reduction of the diameters of the ostium and the landing zone. These changes may have important implications for a successful percutaneous occlusion procedure and justify a staged approach of isolation and occlusion.

P26 “FUNCTION FOLLOWS FORM”: THE ROLE OF THE CARDIAC MAGNETIC RESONANCE IN THE ARRHYTHMIC RISK STRATIFICATION IN PATIENTS WITH CARDIAC SARCOIDOSIS

Background

Sarcoidosis is an inflammatory disorder characterized by non–caseating granulomatous infiltration in multiple organs, including the heart. The presence of granulomas within the myocardium can cause heart failure, atrio–ventricular block, ventricular arrhythmias (VA) and sudden cardiac death (SCD). Due to the patchy pattern of sarcoid infiltration, endomyocardial biopsy has a poor sensitivity and cardiac magnetic resonance (CMR) is becoming the gold standard imaging, detecting small area of myocardial fibrosis and scar using late gadolinium enhancement (LGE). The identification of LGE in patients with dilated cardiomyopathy is strongly associated with VA and SCD and similar findings were reported in cardiac sarcoidosis (CS) patients.

Methods

In order to assess the risk of VA and SCD related to LGE in the CS, we performed a meta–analysis including all the studies enrolling patients with suspected or confirmed CS undergoing CMR. We conducted a digital search in PubMed, Embase, Cochrane Database of Systematic Reviews, Web of Science, Scopus, and Google Scholar from inception through October 2021. Clinical outcomes of interest were arrhythmogenic events defined as VA (ventricular tachycardia or ventricular fibrillation), SCD or aborted SCD (appropriate ICD discharge) during follow–up.

Results

Eleven studies with a total of 1.123 CS patients (left ventricular ejection function [LVEF]: 59 ± 23%) with an appropriate follow–up were included in the final analysis. Overall, as depicted in the Figure 1, the identification of LGE at CMR was associated with a 13–fold increase risk in potentially lethal VA (R = 12.76, 95% CI [6.30–25.87]) than patients without LGE.

Conclusions

Our findings suggest that the presence of myocardial scarring as evidenced by the identification of LGE in CMR provides meaningful information about the arrhythmic risk stratification of CS patients.

Atrial fibrillation in unexplained syncope: observations from the Reveal LINQ registry

Background

Implantable loop recorders (ILRs) have come to play an important role in the workup of patients with recurrent syncope of uncertain origin. In addition to detecting bradyarrhythmias related to syncope, which is the main diagnostic focus in these patients, ILRs are also capable of uncovering subclinical atrial fibrillation (AF).

Purpose

We sought to determine the percentage of patients monitored with an ILR for unexplained syncope who have AF detected and to describe clinical actions taken in these patients.

Methods

Patients enrolled in the Reveal LINQ Registry who received an ILR for unexplained syncope and had at least one follow-up form were included. The device automatically detects AF episodes lasting ≥2 minutes. Patients were considered to have AF based on an AF diagnosis made by the treating physician during follow-up or if device-detected AF was adjudicated as true AF by an external reviewer. AF detection rates were calculated using Kaplan-Meier methods.

Results

In total, 498 patients (aged 61.8±20.0 years, 49.6% female, CHA2DS2VASc score 2.2±1.7) were included and followed for 22±12 months. A history of AF was present in 97 (20%) patients, while 401 patients had no history. By 18 months, the incidence of AF was 70.9% (95% CI, 60.8%, 80.3%) in patients with a history of AF and 21.4% (95% CI, 17.4%, 26.1%) in patients without (Figure). AF detection in those with (30.4%) and without (30.1%) syncope during follow-up was similar. By the end of follow-up, and among patients with newly detected AF, 29/86 (33.7%) were on oral anticoagulation, 7 (8.1%) underwent AF ablation, 6 (7.0%) underwent other type of ablation, and 2 (2.3%) received cardioversion. Other actions among the whole cohort included implant of an IPG, ICD, or CRT in 98/498 (19.7%).

Conclusion

Among patients monitored with ILRs to determine the cause of recurrent syncope episodes, approximately 1 in 5 patients had new AF detected. In addition to improving the management of patients with syncope, ILR data served to support AF-related clinical decisions.

Funding Acknowledgement

Type of funding sources: Private company. Main funding source(s): Medtronic Inc Incidence of AF according to baseline AF

Optimal ablation targets during second catheter ablation in patients with persistent AF

Introduction

Pulmonary vein isolation (PVI) is the cornerstone of ablative therapy in atrial fibrillation (AF). However, the one-year success rate after single ablation procedure is known to be up to 60%, necessitating repeat procedures in many.

Purpose

We evaluated the impact of different ablation strategies on procedural success at the second ablation in patients with persistent AF (PerAF).

Methods

Consecutive PerAF patients scheduled to undergo their second ablation were screened and only those that have received PVI plus isolation of left atrial posterior wall (PWI) and superior vena cava (SVC) at the first procedure (n=1390), were included in the analysis. At the second ablation, all reconnected structures were ablated. Additionally, based on operators' decision, non-PV triggers were targeted for ablation.

Patients were classified into two groups based on the ablation strategy: group 1: Re-isolation of reconnected PVs, PW, SVC and group 2: additional ablation of non-PV triggers (from inter-atrial septum, coronary sinus (CS), left atrial appendage (LAA) and crista terminalis). Arrhythmia-monitoring was performed quarterly for 1 year and biannually afterwards. Ablation success was assessed off-antiarrhythmic drugs (AAD).

Results

Of the 1390 patients included in the analysis, 698 were in group 1 and 692 were in group 2.

In group 1, reconnected PV, PW and SVC were re-isolated in 98 (14%), 311 (44.5%) and 173 (24.8%) respectively. In 131 (18.7%) patients, in the absence of any reconnection, CS was empirically isolated.

In group 2, PV, PW and SVC were re-isolated in 83 (12%), 270 (39%) and 113 (16.3%) patients respectively. Additionally, non-PV triggers were ablated in 505 (73%) and empirical isolation of LAA and CS in the absence of detectable triggers and PV reconnection was performed in 187 (27%).

At 2 years of follow-up, 425 (61%) and 602 (87%) from group 1 and 2 were arrhythmia-free off-AAD (p<0.001).

Conclusion

Including non-PV triggers as targets for ablation at the repeat procedure was associated with significantly higher success rate in persistent AF.

Funding Acknowledgement

Type of funding sources: None.

Acute safety and performance outcomes from the inspIRE trial using a novel pulsed field ablation system for the treatment of paroxysmal atrial fibrillation

Background/Introduction

The inspIRE clinical trial was designed to assess the safety and efficacy of a fully integrated biphasic pulsed field ablation (PFA) system comprised of a multi-channel generator, variable decapolar irrigated loop circular catheter, and mapping system (Figure A) for the treatment of paroxysmal atrial fibrillation (PAF).

Purpose

Using this novel PFA system in a multicentre clinical trial, we present the initial feasibility of electrical pulmonary vein isolation (PVI), procedural performance, and acute safety results.

Methods

inspIRE is a prospective, non-randomized, multi-centre study, planned to enrol up to 550 patients. PVI is performed with the novel, variable loop circular catheter, compatible mapping system and generator. Acute procedural effectiveness (entrance block in all clinically targeted PVs post adenosine/isoproterenol challenge) and the incidence of primary adverse events (PAEs) were assessed. PAEs are defined as the occurrence of cardiac tamponade/perforation, myocardial infarction, stroke/cerebrovascular accident, thromboembolism, transient ischemic attack, permanent phrenic nerve paralysis, pulmonary edema, pericarditis, and any major vascular access complications within 7 days of the ablation procedure. Additionally, any incidence of procedure or device related death, atrio-esophageal fistula, or PV stenosis (related to the ablation procedure or study catheter) within the 12M follow-up period is classified as a PAE.

Results

A total of 35 PAF subjects (age 59.7±10.7 years, 54.3% male) were treated across 5 European sites by 6 operators. Acute procedural success was achieved in 100% of study subjects (Figure B) with zero incidence of PAEs. Mean total procedure time was 82.9±19.9 minutes with 27.0±11.9 minutes of PFA from first to last application. Average fluoroscopy use was 10.6±6.8 minutes and LA dwell time was 45.6±15.3 minutes.

Conclusion

Initial results of the inspIRE trial demonstrate the acute safety and effectiveness of the new integrated IRE circular catheter, mapping system and generator for PVI in PAF patients.

Funding Acknowledgement

Type of funding sources: Other. Main funding source(s): inspIRE is a company-sponsored study funded by Biosense Webster, Inc. Figure 1. (A) PFA System; (B) PVI Voltage Map

Linear increase in the number of non-pulmonary vein triggers from paroxysmal to persistent and long-standing persistent AF in patients undergoing repeat procedure after successful isolation of pulmona

Introduction

This study evaluated the prevalent triggers responsible for recurrence following successful PVI in different types of atrial fibrillation (AF).

Methods

Consecutive AF patients undergoing repeat catheter ablation with permanently isolated PV were included in the analysis. High-dose isoproterenol challenge (20- 30μg/min for 15–20min) was used to confirm PV reconnection and identify non-PV triggers.

Circular mapping catheter (CMC) was used to map the site of origin of significant ectopic activity by comparing the activation sequence of the sinus beat with that of the ectopic beat. For the coronary sinus (CS), ablation catheter was positioned at the level of the mitral valve annulus, parallel to the one positioned in the CS. Left atrial appendage (LAA) firing was detected by placing the CMC in the left superior PV and thus recording far-field potentials from the LAA.

Results

This prospective study included 1850 AF patients undergoing repeat AF ablation (Table 1), of which 573 (31%) had received one and the remaining 1277 patients had received 2 earlier ablations. Permanent PVI was confirmed with isoproterenol challenge.

Table 1 shows the distribution of non-PV triggers. A linear increase in the number of non-PV triggers was observed from PAF to PerAF to LSPAF. Significantly higher number of LSPAF patients had detectable non-PV triggers compared to PerAF and PAF cases.

Conclusion

We observed a linear increase in the number of non-PV triggers in PAF to PerAF and LSPAF patients experiencing recurrence with successful isolation of PVs. As non-PV triggers are often not targeted by operators, this could be the underlying mechanism for more frequent recurrences in non-paroxysmal AF.

Funding Acknowledgement

Type of funding sources: None. Table 1

Recovery of conduction following high power short duration approach in radiofrequency catheter ablation for atrial fibrillation: a single-center experience

Introduction

High-power short-duration (HPSD) ablation is currently being adopted by many as the preferred procedural technique in atrial fibrillation (AF). However, the optimal duration of energy delivery to successfully create a durable lesion is not clear yet.

Purpose

We evaluated the association of electrical reconnection with lesion-duration in HPSD ablation.

Methods

Consecutive AF patients undergoing repeat procedure after a prior HPSD ablation with or without isolation of left atrial appendage (LAA) and coronary sinus (CS) were included in this analysis. HPSD ablation was defined as ablation with maximum temperature setting at 420C and power delivery at 45 W for 10–15 sec (5 seconds in the CS area and posterior wall near the esophagus). In some patients a mechanical esophageal deviation tool was used to deflect the esophagus away from the ablation site.

Results

A total of 2249 AF patients (with LAA and CS isolation: 1451; without LAA and CS isolation: 798) receiving redo ablation after a prior HPSD procedure were included in the analysis. At the prior procedure with the HPSD approach, mean duration of ablation was significantly shorter in the area facing the esophagus compared to elsewhere (5.2±1.5 vs 12.5±1.7 seconds, p<0.001). Application duration was reduced to <10 sec to avoid overheating and steam pops in 1221 (84%) patients receiving LAA and CS isolation.

At the redo, recovery of conduction was noted in the CS (592, 40.8%), LAA (493, 34%), and PV and left atrial posterior wall (LAPW) (310, 13.8%). Of the 310 patients with LAPW reconnection, 91% (n=282) had the conduction recovered in the area facing the esophagus.

In 73 patients, esophageal displacement device was used during the prior HPSD ablation. Average duration of ablation lesions in LAPW among those 73 patients was 9.2±2 seconds. PV-LAPW reconnection was observed in 3/73 (4.1%) patients.

Conclusion

HPSD ablation with lesion duration of <10 sec was associated with conduction recovery in the LAA, CS and the LAPW area facing esophagus.

Funding Acknowledgement

Type of funding sources: None.

Factors predicting adverse cardiovascular outcomes in patients with atrial fibrillation and heart failure with preserved ejection fraction

Funding Acknowledgements

Type of funding sources: Foundation. Main funding source(s): Electrophysiology Research Foundation

Introduction

Atrial fibrillation (AF) is known to impact cardiovascular(CV) mortality in heart failure (HF) patients (pts) with preserved ejection fraction (pEF) but its exact causes are unknown.

Methods

 We analyzed demographic, clinical, ECG and AF presentation as predictors of CV mortality, sudden death( SCD) and pump failure death(PFD) in HFpEF pts in the TOPCAT AMERICAS trial. We analyzed two AF presentations 1. Pts in sinus rhythm (SR, n = 1319) compared to AF  on ECG (n = 446) at entry or 2. Pts with no AF event by history or ECG ( n = 1007 ) to those with any AF event (n = 760 ).

Results (Table): 5 year (yr) CV mortality was higher in pts with AF on ECG (30%) than SR (18%, p = 0.014) but 5 yr SCD was (10% in AF on ECG & 7% in any AF) & comparable to SR (7% & 9% respectively, p = ns). 5 yr PFD was higher in AF on ECG  (13%) than SR (5%, p = 0.007) 

Conclusions

: 1. CV death risk in HFpEF pts increased with AF on ECG.. 2. SCD was not more frequent with both AF presentations 3. PFD in HFpEF increased with age, ECG recorded AF & elevated heart rate. 4. The recording of AF on ECG was more strongly associated with CV death & PFD, possibly due to greater AF burden . Predictors of adverse outcomes in HFpEF AF on ECG* Any AF* Endpoint Covariate HR (95% CI) p-value HR (95% CI) p-value Time to cardiovascular death Atrial Fibrillation* 1.44 (1.08, 1.92) 0.014 1.15 (0.87, 1.51) 0.338 Age (years) 1.03 (1.02, 1.05) <.001 1.03 (1.02, 1.05) <.001 Black/AA (vs. White) 0.97 (0.65, 1.46) 0.002 0.96 (0.64, 1.44) 0.004 Other race (vs. White) 2.41 (1.46, 3.99) 2.32 (1.41, 3.83) Smoking 2.62 (1.63, 4.20) <.001 2.60 (1.62, 4.17) <.001 Diabetes 1.47 (1.12, 1.94) 0.006 1.45 (1.10, 1.91) 0.009 Systolic BP (mmHg) 0.99 (0.98, 1.00) 0.022 0.99 (0.98, 1.00) 0.014 Heart rate (bpm) 1.02 (1.00, 1.03) 0.012 1.02 (1.01, 1.03) 0.006 Time to Any sudden cardiac death Atrial Fibrillation* 1.17 (0.69, 1.96) 0.563 0.85 (0.53, 1.35) 0.484 Female (vs. Male) 0.46 (0.28, 0.75) 0.002 0.46 (0.28, 0.74) 0.002 Black/AA (vs. White) 1.57 (0.87, 2.82) 0.194 1.49 (0.83, 2.69) <.001 Other race (vs. White) 1.76 (0.70, 4.41) 1.70 (0.68, 4.25) Diabetes 1.70 (1.07, 2.70) 0.024 1.65 (1.04, 2.62) 0.033 Time to pump failure death Atrial Fibrillation* 2.04 (1.22, 3.42) 0.007 1.62 (0.96, 2.75) 0.074 Age (years) 1.06 (1.03, 1.10) <.001 1.06 (1.03, 1.10) <.001 Heart rate (bpm) 1.03 (1.00, 1.05) 0.034 1.03 (1.01, 1.05) 0.015 Cox model of covariates associated with outcomes adjusted for baseline imbalances

Characterization of atrial lesion safety and efficacy utilizing a circular catheter and the IRE generator with an in vivo porcine model

Funding Acknowledgements

Type of funding sources: Other. Main funding source(s): Biosense Webster, Inc.

Introduction/Objectives:

Pulsed field ablation (PFA) is a non-thermal ablative method that delivers high voltage, very-short duration pulses that cause pore formation in the cytoplasmic membrane and cell death. The tissue selectivity of PFA is expected to reduce the risk of collateral tissue injury compared to radiofrequency catheter ablation (RFCA), while maintaining effectiveness.  The objective of this study was to perform pulmonary vein (PV) isolation in a porcine model to characterize the safety and performance of a novel, fully-integrated biphasic PFA system. The system is comprised of a multi-channel generator, a variable loop circular catheter, and an integrated irreversible electroporation (IRE) mapping software module.

Methods

The study evaluated safety and efficacy of IRE in 8 healthy swine. First, to evaluate safety, multiple ablations were performed at various cardiac structures, including within the lumen of the right pulmonary vein (RIPV), at the right superior pulmonary vein (RSPV) ostium, and adjacent to the esophagus. Second, to evaluate efficacy, animals were recovered and followed for 30 (±3) days, then re-mapped. Gross pathological and histopathological examinations were performed to assess for procedural injury, chronic thrombosis, tissue ablation, depth of penetration, healing, and level of inflammatory response.

Results

All 8 swine survived for the 30 (±3) day follow up (FU) period. There were no acute (day of procedure) incidents of pulmonary vein narrowing of >70%, nor at 30 d follow-up (FU), even when ablation was purposefully performed directly deep to the ostium of the vein. No injury was seen grossly or histologically in the adjacent esophagus. All PVs were durably isolated as confirmed by bidirectional block at the 30 (±3) day re-map procedure, and histological examination showed complete, transmural necrosis around the entire circumference of the ablated section of the right PVs [Figure].

Conclusion(s): This pre-clinical evaluation of a fully integrated PFA system demonstrated effective and durable ablation of cardiac tissue and PV isolation with no collateral damage to adjacent structures. Notably, histological staining confirmed complete transmural cell necrosis around the circumference of the ostial PV at 30 days. Abstract Figure. PVI maps (A) histology (B) and safety(C)

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

Risk factors for progression of paroxysmal to persistent atrial fibrillation following successful PV isolation

Background

Progression from paroxysmal (PAF) to persistent atrial fibrillation (PerAF) following effective PV isolation (PVI) has important clinical implications, as it is relevant for subsequent management of the arrhythmia.

Objective

We evaluated risk factors responsible for progression of PAF to PerAF following successful PVI.

Methods

Consecutive AF patients that received their first catheter ablation as well as the first redo at our center were identified (n=1352). Patients were included in group 1 if the diagnosis was PAF at both first and redo procedure (PAF to PAF) and group 2 if PAF at index progressed to PerAF at redo. All patients received PVI plus isolation of LA posterior wall and SVC at the first procedure.

Results

A total of 822 patients remained as PAF at redo, whereas 530 (39%) progressed from PAF to PerAF. Clinical characteristics of the study population are presented in table 1. In multivariate analysis, BMI (OR 1.02, 1.01–1.04, p=0.04), hypertension (1.4, 1.08–1.8, p=0.01), heart failure (1.67, 1.03–2.69, p=0.03), LA size (2.75, 2.29–3.31, p<0.001) were independent predictors of progression of PAF to PerAF. Data on serum-transthyretin level was available for 37 and 48 patients in group 1 and 2 respectively. It was <18 mg/dL (normal) in 33 (68.7%) patients in group 2 vs 6 (16.2%) in group 1 (p<0.001).

Conclusion

In our patients, after successful PVI, progression of PAF to PerAF was mediated by independent risk factors such as high BMI, heart failure, hypertension, larger LA size and lower LVEF.

Funding Acknowledgement

Type of funding source: None

Positive clinical benefit on patient care, quality of life and symptoms after radiofrequency ablation with contact force in persistent atrial fibrillation: analyses from PRECEPT

Background

The management of persistent (PsAF) aims to prevent AF recurrence and associated disabilities while reducing side effects from treatment. Contact force (CF)-guided RF catheters have proven efficacious and safe for pulmonary vein isolation (PVI) to treat paroxysmal AF; however, there is limited evidence on clinical benefits with ablation of PsAF.

Purpose

To assess long-term clinical effects on patients care, symptoms and QOL after CF-guided RF ablation in PsAF.

Methods

PRECEPT was a multicenter study evaluating the safety and efficacy of CF RF catheters in the treatment of symptomatic PsAF (NCT02817776). PVI was performed with or without substrate modification. Patients were followed at 6, 9, 12 and 15 mos to collect the following data: Atrial Fibrillation Effect on Quality-of-Life (AFEQT) score, Canadian Cardiovascular Society Severity of Atrial Fibrillation (CCS-SAF) score, Class I/III AAD use, and incidence of cardioversion and cardiovascular hospitalization.

Results

A total of 333 enrolled patients (65.4±8.8 yrs, 71.2% male, CHA2DS2-VASC score 2.3±1.5) underwent PVI. Compared to baseline, 1) improvements in the AFEQT composite and subscores were seen from 6–15 mos, exceeding Clinical Important Difference (±5 points) in majority of subjects (Figure), 2) proportion of CCS-SAF Class 0 patients (asymptomatic with respect to AF) rose from 0.7% to 81.0%, 3) class I/III AAD use was reduced from 97.0% to 24.7%, and 4) incidence of cardioversion decreased from 62.0% to 10.7%. Moreover, the 1-yr Kaplan-Meier estimate of freedom from hospitalization was 84.2% [95% CI: 80.2%, 88.2%].

Conclusion

CF-guided RF ablation in PsAF patients led to a clinically meaningful improvement in QOL, as well as a reduction in AAD use, cardioversion, and hospitalization.

Figure 1. Mean AFEQT composite and subscore

Funding Acknowledgement

Type of funding source: Private company. Main funding source(s): This study was funded by Biosense Webster, Inc.

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<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

Extended Pulmonary Vein Isolation: is it sufficient to achieve long-term sinus rhythm in octogenarian women with atrial fibrillation?

Background

Atrial fibrillation (AF) is a disease of the elderly and women typically present with AF at an older age than men do. Moreover, they tend to experience more symptoms and post-ablation recurrences, have worse quality of life and increased risk of stroke and mortality.

Objective

We evaluated long-term efficacy of our standard ablation approach of extended pulmonary vein isolation (PVI) in octogenarian women undergoing their first AF ablation.

Methods

Consecutive female AF patients aged ≥80 years receiving their first catheter ablation at our center were included in the analysis. Our standard ablation approach at the first procedure includes PVI + empirical isolation of left atrial posterior wall (LAPW) and superior vena cava (SVC). Complete abolition of all potentials rather than decrease in amplitudes was the procedural end point. Patients were prospectively monitored at regular intervals for 3 years after the index procedure with event recorders, 12-lead ECG, cardiology evaluation at office visits and 7-day Holter monitoring.

Results

A total of 194 patients with mean age of 84.2±1.4 years were included in the analysis. Of the 194, 120 (61.8%) had non-paroxysmal AF. All received PVI+ isolation of LAPW and SVC. Acute procedural success was achieved in 100% of cases.

At 3 years of follow-up, 24 (12.4%) patients remained in sinus rhythm; 22 on- and 2 off-antiarrhythmic drugs (AAD). All of the 23 patients had paroxysmal AF as their initial diagnosis.

Of the 170 patients experiencing recurrence, 147 underwent repeat ablation. PV/PW/SVC reconnection was noted in only 6 (4.1%) patients at redo. Triggers originating from non-PV sites were targeted for ablation in all. At 1.5 years after the repeat procedure, 136 (92.5%) patients were in sinus rhythm; 131 off-AAD and 5 patients on-AAD.

Conclusion

Extended PVI including isolation of posterior wall and SVC was not sufficient to maintain long-term sinus rhythm in majority of octogenarian women, regardless of AF type. Moreover, non-PV triggers rather than PV reconnection was the major cause of recurrence in this subset of AF population.

Funding Acknowledgement

Type of funding source: None

A novel cardiac signal processing system for electrophysiology procedures: early insights from the pure ep 2.0 study

Background

Intracardiac electrogram data remain one of the primary diagnostic inputs guiding complex ablation procedures. However, the technology to collect, process, and display intracardiac signals has remained relatively unchanged for the past two decades.

Purpose

We test a new platform, the PURE EP™ 2.0 system (PEP; BioSig Technologies) for signal processing and display.

Methods

Identical electrocardiographic and intracardiac signal data were recorded during 15 AF ablation procedures from the PEP system, the signal recording system, and the 3D mapping system (Figure). The collected signals underwent blinded, controlled evaluation by three independent electrophysiologist reviewers to determine whether the PEP signals are a viable alternative to conventional sources and if it provides additional or clearer diagnostic information. Reviewers were asked to record the quality of each signal sample on a scale of 1–10 and select a rationale for their rating in a dropdown menu. Each paired signal rating was collected and unblinded for the analysis. If the reviewer rated the samples in the set within 1 point of each other, the PEP sample was deemed equivalent to the control. Using a 2+1 statistical method, the ratings from the three reviewers were then compared looking for at least two positive reviews for each PEP sample.

Results

Based on the ratings for each pair of signals, a cumulative total of 29 PEP signals out of 34 (85.3%) were rated as statistically equivalent or better for this dataset. In 35.5% of samples, the reviewers selected PEP because “more signal components were visible”.

Conclusion

The PURE EP 2.0 system is able to produce reliable and high-quality signals when compared to available standard of care systems. Further studies with larger dataset across multiple sites are needed to validate these results.

Funding Acknowledgement

Type of funding source: Private company. Main funding source(s): BioSig Technologies

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>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<0.001 respectively). At EVM analysis, a significant greater number of patients had a pathological uni- and bi-polar EVM (P<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

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

Risk factors and effective ablation strategy in patients presenting with left atrial flutter with no previous ablation for atrial fibrillation

Background

A typical left atrial flutter (LAFL) may occur as a proarrhythmic complication of ablation for atrial fibrillation (AF).

Objective

We evaluated the risk factors and the best ablation strategy for LAFL in patients with no prior AF ablation.

Methods

Consecutive patients undergoing first catheter ablation for AFL with no prior procedure for AF were included in this prospective analysis. Based on the ablation strategy, patients were divided into, Group 1: PVI+ Flutter ablation (ablation of re-entry circuits) and Group 2: PVI+ Non-PV trigger ablation (targeting areas of focal activity as triggers). 3-D mapping of the LA was performed during tachycardia to identify the reentrant circuit.

PV isolation was performed in all patients. In group 1, ablation line was chosen to transect the area critical for the circuit (roof and mitral line). In group 2, ectopic beats arising from extra-PV foci detected by isoproterenol challenge were ablated. Off-drug success rate was assessed in all.

Results

A total of 92 and 90 patients were included in group 1 and 2 respectively. Baseline characteristics are provided in table 1. Pre-existent LA scar was detected in 91.3% and 90% of patients in group 1 and 2 respectively.

At 2 years of follow-up, 11/92 (12%) from group 1 and 60/90 (66.7%) from group 2 remained arrhythmia-free off-drugs (p<0.001). In the multivariate analysis, PVI +flutter ablation was detected to be associated with significantly high risk of recurrence [HR: 3.92 (95% CI: 2.52–6.1, p<0.001)]

Conclusion

In this series of patients presenting with LAFL with no earlier AF ablations, pre-existent left atrial scar was detected in majority of cases and PVI+ non-PV trigger ablation provided significantly better success rate than PVI+ flutter ablation.

Funding Acknowledgement

Type of funding source: None

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.

P2844Novel temperature guided irrigated ablation catheter: reproducibility of procedural efficiencies and acute success to isolate the pulmonary veins from two multicenter, feasibility studies

Background/Introduction

The novel catheter with 6 thermocouples for real-time temperature monitoring during irrigated radiofrequency ablation was designed to potentially enhance safety and effectiveness of the Smart Touch Surround Flow (STSF) catheter by incorporating real-time temperature sensing. A supplementary, novel algorithm was developed to modulate power to maintain target temperature during high power/short duration ablation (90W, 4s).

Purpose

This sub-analysis was performed to examine consistency and reproducibility of the procedural efficiencies and acute success of the novel catheter with optimized temperature control and microelectrodes in treating paroxysmal atrial fibrillation (PAF) across multiple sites from two initial feasibility studies, in standard (QMODE) and high power/short duration (QMODE+) temperature-control ablation modes.

Methods

The QDOT-MICRO (QMODE, NCT02944968; N=42) and QDOT-FAST (QMODE+, NCT03459196; N=52) studies were both prospective, non-randomized multi-center, clinical investigations completed across 6 and 7 centers, respectively, in Europe. Procedural efficiencies and acute success (PVI via entrance block) was examined across sites within the study.

Results

In the QDOT-MICRO study, median procedure time (105–155 min), RF ablation time (27.7–39.5 min), and fluoroscopy times (2.2–8 min) during QMODE ablation were similar across the 6 sites. In QMODE+ ablation, median procedure time, RF ablation time, and fluoroscopy times all fall within (84–134 min), (4.8–9.7 min) and (1.1–9.6 min), respectively, across the 7 sites. Fluid delivery by the study catheter was low in both studies: QDOT-MICRO 547±278mL (mean ± SD); QDOT-FAST 382±299. mL (mean ± SD); which is 39.1 and 57.4% lower, respectively, than reported in the SMART SF trial. Esophageal temperature probe was used in the majority of patients (30/42 for QDOT MICRO and 51/52 for QDOT-FAST). Acute PVI was successful in 100% of patients in both studies with no deaths or unanticipated AEs.

Conclusion(s)

In both feasibility studies, procedural efficiencies were reproducible across study sites in both QMODE and QMODE+, with 100% acute success and good safety outcomes. Efficiencies are likely to improve with further experience. These results need to be confirmed in larger trials.

Acknowledgement/Funding

Both Studies are Company Sponsored Studies funded by Biosense Webster, Inc.

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

Identification of a zoonotic genotype 3 hepatitis E subtype in wildlife in north-eastern Italy

Hepatitis E virus (HEV) is an emerging zoonosis caused by a positive RNA single stranded virus of the Hepeviridae family. In developed countries, pigs and wild boars are the main reservoir for zoonotic genotypes 3 and 4. In spring 2017, for the first time HEV was detected in wild boars captured in the Regional Park of the Euganean Hills, in north-eastern Italy. Phylogenetic analysis of two complete viral genomes and seven partial ORF1 and ORF2 sequences of HEV viruses, selected from twelve positive animals, showed that the viruses grouped together within genotype 3 but clustered separately from previously identified subtypes, thus suggesting the identification of a novel genotype 3 subtype. The phylogenetic analysis of nine partial ORF2 sequences showed the closest similarity with wild boar/human viruses identified in central-northern Italy in 2012. The circulation of HEVs in this area, characterized by a vast man-made environment, an overpopulation of wild boars and >150 swine farms, should be considered in a public health perspective. Further investigations at the wild/domestic species and human interface are therefore necessary to gain a deeper understanding of HEV dynamics.

Individual- and community-level risk factors for ESBL Enterobacteriaceae colonization identified by universal admission screening in London

OBJECTIVES

We evaluated risk factors for gastrointestinal carriage of Enterobacteriaceae which produce extended-spectrum β-lactamases (ESBL-E), including individual-level variables such as antibiotic use and foreign travel, and community-level variables such as housing and deprivation.

METHODS

In an observational study in 2015, all patients admitted to a London hospital group were approached to be screened for ESBL-E carriage using rectal swabs for 4 months. Patients completed a risk factor questionnaire. Those with a residential postcode in the local catchment area were linked to a database containing community-level risk factor data. Risk factors for ESBL-E carriage were determined by binary logistic regression.

RESULTS

Of 4006 patients, 360 (9.0%) carried ESBL-E. Escherichia coli was the most common organism (77.8%), and CTX-M-type ESBLs were the most common genes (57.9% CTX-M-15 and 20.7% CTX-M-9). In multivariable analysis, risk factors for phenotypic ESBL-E among the 1633 patients with a residential postcode within the local catchment area were: travel to Asia (OR 4.4, CI 2.5-7.6) or Africa (OR 2.4, CI 1.2-4.8) in the 12 months prior to admission, two or more courses of antibiotics in the 6 months prior to admission (OR 2.0, CI 1.3-3.0), and residence in a district with a higher-than-average prevalence of overcrowded households (OR 1.5, CI 1.05-2.2). .

CONCLUSIONS

Both individual and community variables were associated with ESBL-E carriage at hospital admission. The novel observation that household overcrowding is associated with ESBL-E carriage requires confirmation, but raises the possibility that targeted interventions in the community could help prevent transmission of antibiotic-resistant Gram-negative bacteria.