The Diagnostic Value of the 12-Lead ECG in Arrhythmogenic Left Ventricular Cardiomyopathy: Novel ECG Signs

BACKGROUND

Electrocardiographic (ECG) findings in arrhythmogenic left ventricular cardiomyopathy (ALVC) are limited to small case series.

OBJECTIVES

This study aimed to analyze the ECG characteristics of ALVC patients and to correlate ECG with cardiac magnetic resonance and genotype data.

METHODS

We reviewed data of 54 consecutive ALVC patients (32 men, age 39 ± 15 years) and compared them with 84 healthy controls with normal cardiac magnetic resonance.

RESULTS

T-wave inversion was often noted (57.4%), particularly in the inferior and lateral leads. Low QRS voltages in limb leads were observed in 22.2% of patients. The following novel ECG findings were identified: left posterior fascicular block (LPFB) (20.4%), pathological Q waves (33.3%), and a prominent R-wave in V1 with a R/S ratio ≥0.5 (24.1%). The QRS voltages were lower in ALVC compared with controls, particularly in lead I and II. At receiver-operating characteristic analysis, the sum of the R-wave in I to II ≤8 mm (AUC: 0.909; P < 0.0001) and S-wave in V1 plus R-wave in V6 ≤12 mm (AUC: 0.784; P < 0.0001) effectively discriminated ALVC patients from controls. It is noteworthy that 4 of the 8 patients with an apparently normal ECG were recognized by these new signs. Transmural late gadolinium enhancement was associated to LPFB, a R/S ratio ≥0.5 in V1, and inferolateral T-wave inversion, and a ringlike pattern correlated to fragmented QRS, SV1+RV6 ≤12 mm, low QRS voltage, and desmoplakin alterations.

CONCLUSIONS

Pathological Q waves, LPFB, and a prominent R-wave in V1 were common ECG signs in ALVC. An R-wave sum in I to II ≤8 mm and SV1+RV6 ≤12 mm were specific findings for ALVC phenotypes compared with controls.

Asymptomatic Patients With Brugada ECG Pattern: Long-Term Prognosis From a Large Prospective Study

BACKGROUND

Brugada syndrome poses significant challenges in terms of risk stratification and management, particularly for asymptomatic patients who comprise the majority of individuals exhibiting Brugada ECG pattern (BrECG). The aim of this study was to evaluate the long-term prognosis of a large cohort of asymptomatic patients with BrECG.

METHODS

Asymptomatic patients with BrECG (1149) were consecutively collected from 2 Italian centers and followed-up at least annually for 2 to 22 years. For the 539 asymptomatic patients (men, 433 [80%]; mean age, 46±13 years) with spontaneous type 1 documented on baseline ECG (87%) or 12-lead 24-hour Holter monitoring (13%), an electrophysiologic study (EPS) was proposed; for the 610 patients with drug-induced-only type 1 (men, 420 [69%]; mean age, 44±14 years), multiple ECGs and 12-lead Holter were advised in order to detect the occurrence of a spontaneous type-1 BrECG. Arrhythmic events were defined as sudden death or documented ventricular fibrillation or tachycardia.

RESULTS

Median follow-up was 6 (4-9) years. Seventeen (1.5%) arrhythmic events occurred in the overall asymptomatic population (corresponding to an event-rate of 0.2% per year), including 16 of 539 (0.4% per year) in patients with spontaneous type-1 BrECG and 1 of 610 in those with drug-induced type-1 BrECG (0.03% per year; P<0.001). EPS was performed in 339 (63%) patients with spontaneous type-1 BrECG. Patients with spontaneous type-1 BrECG and positive EPS had significantly higher event rates than patients with negative EPS (7 of 103 [0.7% per year] versus 4 of 236 [0.2% per year]; P=0.025). Among 200 patients who declined EPS, 5 events (0.4% per year) occurred. There was 1 device-related death.

CONCLUSIONS

The entire population of asymptomatic patients with BrECG exhibits a relatively low event rate per year, which is important in view of the long life expectancy of these young patients. The presence of spontaneous type-1 BrECG associated with positive EPS identifies a subgroup at higher risk. Asymptomatic patients with drug-induced-only BrECG have a minimal arrhythmic risk, but ongoing follow-up with 12-lead Holter monitoring is recommended to detect the appearance of spontaneous type-1 BrECG pattern.

Artificial Intelligence ECG Analysis in Patients with Short QT Syndrome to Predict Life-Threatening Arrhythmic Events

Short QT syndrome (SQTS) is an inherited cardiac ion-channel disease related to an increased risk of sudden cardiac death (SCD) in young and otherwise healthy individuals. SCD is often the first clinical presentation in patients with SQTS. However, arrhythmia risk stratification is presently unsatisfactory in asymptomatic patients. In this context, artificial intelligence-based electrocardiogram (ECG) analysis has never been applied to refine risk stratification in patients with SQTS. The purpose of this study was to analyze ECGs from SQTS patients with the aid of different AI algorithms to evaluate their ability to discriminate between subjects with and without documented life-threatening arrhythmic events. The study group included 104 SQTS patients, 37 of whom had a documented major arrhythmic event at presentation and/or during follow-up. Thirteen ECG features were measured independently by three expert cardiologists; then, the dataset was randomly divided into three subsets (training, validation, and testing). Five shallow neural networks were trained, validated, and tested to predict subject-specific class (non-event/event) using different subsets of ECG features. Additionally, several deep learning and machine learning algorithms, such as Vision Transformer, Swin Transformer, MobileNetV3, EfficientNetV2, ConvNextTiny, Capsule Networks, and logistic regression were trained, validated, and tested directly on the scanned ECG images, without any manual feature extraction. Furthermore, a shallow neural network, a 1-D transformer classifier, and a 1-D CNN were trained, validated, and tested on ECG signals extracted from the aforementioned scanned images. Classification metrics were evaluated by means of sensitivity, specificity, positive and negative predictive values, accuracy, and area under the curve. Results prove that artificial intelligence can help clinicians in better stratifying risk of arrhythmia in patients with SQTS. In particular, shallow neural networks' processing features showed the best performance in identifying patients that will not suffer from a potentially lethal event. This could pave the way for refined ECG-based risk stratification in this group of patients, potentially helping in saving the lives of young and otherwise healthy individuals.

Risk of cardioembolic ischemic events and relation to atrial fibrillation/flutter in patients with arrhythmogenic cardiomyopathy during a long-term follow-up

BACKGROUND

Arrhythmogenic cardiomyopathy (ACM) is an inherited heart disease characterized by fibro-fatty replacement of myocardium. Limited data is available concerning cardioembolic stroke. This study sought to determine the occurrence of cardioembolic ischemic events (CIEs) in ACM patients and to identify clinical and imaging predictors of CIEs.

METHODS

Every consecutive ACM patient was enrolled. ECG, Holter monitoring or implantable cardiac devices were used to detect atrial arrhythmias (AAs). CIEs were defined according to TOAST classification.

RESULTS

In our cohort of 111 patients, CIEs were observed in eleven (10%) over a 12.9-year median follow-up, with an incidence of 7.9 event/1000 patient-year (HR 4.12 compared to general population). Mean age at the event was 42 ± 9 years. Female sex (p = 0.03), T-wave inversion (p = 0.03), RVOT dilatation (p = 0.006) and lower LVEF (p = 0.006) were associated with CIEs. Among patients with AAs (23/111, 20.7%), 5 (21.7%) experienced CIEs. CHA2DS2-VASc did not prove useful to define patients at higher risk of CIEs (p = 0.098). 60% of stroke suffering patients had a pre-event score between 0 and 1 (if female).

CONCLUSIONS

In ACM patients, CIEs are much more common than in general population and present a high burden at younger age. AAs relate to less than half of these events. In AAs patients, CHA2DS2-VASc is not useful to stratify those requiring oral anticoagulation. As a hypothesis-generating study, our research proposes the role of atrial myopathy, irrespective of AAs, as a pivotal factor in thrombogenesis risk, pointing out a definite unmet need in ACM therapeutic algorithm.

Electrocardiographic characteristics of right-bundle-branch-block premature ventricular complexes predicting absence of left ventricular scar in athletes with apparently structural normal heart

AIMS

Left ventricular scar is an arrhythmic substrate that may be missed by echocardiography and diagnosed only by cardiac magnetic resonance (CMR), which is a time-consuming and expensive imaging modality. Premature ventricular complexes (PVCs) with a right-bundle-branch-block (RBBB) pattern are independent predictors of late gadolinium enhancement (LGE) but their positive predictive value is low. We studied which electrocardiographic features of PVCs with an RBBB pattern are associated with a higher probability of the absence of an underlying LGE.

METHODS

The study included 121 athletes (36 ± 16 years; 48.8% men) with monomorphic PVCs with an RBBB configuration and normal standard clinical investigations who underwent CMR. LGE was identified in 35 patients (29%), predominantly in those with PVCs with a superior/intermediate axis (SA-IntA) compared to inferior axis (IA) (38% vs. 10%, P = 0.002). Among patients with SA-IntA morphology, the contemporary presence of qR pattern in lead aVR and V1 was exclusively found in patients without LGE at CMR (51.0% vs. 0%, P < 0.0001). Among patients with IA, the absence of LGE correlated to a narrow ectopic QRS (145 ± 16 vs. 184 ± 27 msec, P < 0.001).

CONCLUSIONS

Among athletes with apparently idiopathic PVCs with a RBBB configuration, the presence of a concealed LGE at CMR was documented in 29% of cases, mostly in those with a SA-IntA. In our experience, the contemporary presence of qR pattern in lead aVR and V1 in PVCs with RBBB/SA-IntA morphology or, on the other hand, a relatively narrow QRS in PVCs with an IA, predicted absence of LGE.

The Brugada syndrome: pharmacological therapy

Brugada syndrome is an inherited channelopathy with an increased risk of sudden cardiac death (SCD) due to ventricular arrhythmias (VA) and an increased incidence of supraventricular arrhythmias, as compared with the general population. For the prevention of SCD, the guidelines recommend the implantable cardioverter-defibrillator (ICD); however, ICD does not prevent VA. In this article, we provide a brief review of the literature on the Brugada syndrome pharmacological therapy, mainly focusing on quinidine treatment. The efficacy of quinidine therapy in the prevention of VA in Brugada syndrome has been demonstrated by several small studies in patients with ICD and recurrent shocks or in asymptomatic patients with inducible ventricular fibrillation (VF) at electrophysiological study. Quinidine has also been tested for the prophylaxis of supraventricular arrhythmias, especially atrial fibrillation/flutter, and in paediatric patients. In these studies, quinidine proved highly effective in preventing re-induction of VF and spontaneous recurrences of both ventricular and supraventricular arrhythmias. Unfortunately, this therapy is burdened by a high incidence of side effects, which may lead to drug discontinuation.

The Brugada syndrome: risk stratification

Thirty years after its first description, the knowledge regarding Brugada syndrome has greatly increased. Spontaneous type 1 ECG pattern (BrECG) is a well-defined prognostic marker in asymptomatic patients and is associated with a double risk of arrhythmic events during follow-up as compared to drug-induced ECG pattern. Due to the extreme variability of the ECG pattern over time, the spontaneous type 1 BrECG must be carefully sought, not only through periodic ECGs but especially with repeated 12-lead 24-h Holter monitoring, with V1 and V2 electrodes placed also on the second and third intercostal space, in order to explore the right ventricular outflow tract. 12-lead 24-h Holter should also be performed in all the patients with a dubious BrECG pattern even before the drug challenge with sodium channel blockers, which carries a low but definite risk of complications. In addition to spontaneous type 1, other electrocardiographic markers of increased arrhythmic risk have been described, such as first-degree AV block, QRS fragmentation, S wave in lead I and II, and increased QRS duration. The electrophysiological study in asymptomatic patients with a spontaneous ECG Brugada pattern is still under jury and further studies need to clarify its precise role.

Atrial fibrillation fundamentals: from physiopathology to transcatheter ablation

Atrial fibrillation (AF) is a common and harmful arrhythmia. Its complex pathogenesis can be outlined using Coumel's Triangle, that considers at the base of AF three different factors: substrate, trigger, and catalyst factor. The triangle can serve as a guide to understand the mechanism of action of the different possible treatments. Anti-arrhythmic drug therapies have a modest efficacy and no proven benefit on prognosis. Interventional therapy is more effective, especially if employed in the first stages of the disease, and can reduce mortality in selected populations. Ablative schemes must be different depending on the type of AF (paroxysmal, persistent) and the presence or absence of atrial dilation.

Transcatheter ablation in patients with Brugada syndrome

Since the first description of Brugada syndrome (BrS), several studies were carried out aimed at diagnosis, arrhythmic risk stratification, and available strategies for sudden death prevention. In high-risk patients, the use of an implantable cardiac defibrillator was an evident option since the first description of the syndrome. Nevertheless, this strategy, while proven, as expected, to be effective in sudden death prevention, does not prevent arrhythmias and may not be an adequate or accepted solution for all patients. The need of a non-pharmacological therapy as a potential solution based on the electrophysiological mechanisms underlying the syndrome, led to search for substrate as target for catheter ablation. Advances in the tools, technology, and technical approach enabled to launch studies aimed at mapping the epicardium of patients with BrS in order to identify and ablate the substrate. As described in previous work and in our experience, an anatomically identifiable electrical substrate, which correspond to the typical ECG, is the ablation target. Complete substrate is better identified in a larger area with sodium-channel-blockers. Ablation of all abnormal electrical potentials is able to normalize the ECG and prevent arrhythmias induction. Encouraging preliminary data, if confirmed by longer follow-up and by multicentre randomized study, could change the whole therapeutic management in BrS patients.

Right ventricular epicardial arrhythmogenic substrate in long-QT syndrome patients at risk of sudden death

AIMS

The long-QT syndrome (LQTS) represents a leading cause of sudden cardiac death (SCD). The aim of this study was to assess the presence of an underlying electroanatomical arrhythmogenic substrate in high-risk LQTS patients.

METHODS AND RESULTS

The present study enrolled 11 consecutive LQTS patients who had experienced frequent implantable cardioverter-defibrillator (ICD discharges triggered by ventricular fibrillation (VF). We acquired electroanatomical biventricular maps of both endo and epicardial regions for all patients and analyzed electrograms sampled from several myocardial regions. Abnormal electrical activities were targeted and eliminated by the means of radiofrequency catheter ablation. VF episodes caused a median of four ICD discharges in eleven patients (6 male, 54.5%; mean age 44.0 ± 7.8 years, range 22-53) prior to our mapping and ablation procedures. The average QTc interval was 500.0 ± 30.2 ms. Endo-epicardial biventricular maps displayed abnormally fragmented, low-voltage (0.9 ± 0.2 mV) and prolonged electrograms (89.9 ± 24.1 ms) exclusively localized in the right ventricular epicardium. We found electrical abnormalities extending over a mean epicardial area of 15.7 ± 3.1 cm2. Catheter ablation of the abnormal epicardial area completely suppressed malignant arrhythmias over a mean 12 months of follow-up (median VF episodes before vs. after ablation, 4 vs. 0; P = 0.003). After the procedure, the QTc interval measured in a 12-lead ECG analysis shortened to a mean of 461.8 ± 23.6 ms (P = 0.004).

CONCLUSION

This study reveals that, among high-risk LQTS patients, regions localized in the epicardium of the right ventricle harbour structural electrophysiological abnormalities. Elimination of these abnormal electrical activities successfully prevented malignant ventricular arrhythmia recurrences.

AFA-Recur: an ESC EORP AFA-LT registry machine-learning web calculator predicting atrial fibrillation recurrence after ablation

AIMS

Atrial fibrillation (AF) recurrence during the first year after catheter ablation remains common. Patient-specific prediction of arrhythmic recurrence would improve patient selection, and, potentially, avoid futile interventions. Available prediction algorithms, however, achieve unsatisfactory performance. Aim of the present study was to derive from ESC-EHRA Atrial Fibrillation Ablation Long-Term Registry (AFA-LT) a machine-learning scoring system based on pre-procedural, easily accessible clinical variables to predict the probability of 1-year arrhythmic recurrence after catheter ablation.

METHODS AND RESULTS

Patients were randomly split into a training (80%) and a testing cohort (20%). Four different supervised machine-learning models (decision tree, random forest, AdaBoost, and k-nearest neighbour) were developed on the training cohort and hyperparameters were tuned using 10-fold cross validation. The model with the best discriminative performance on the testing cohort (area under the curve-AUC) was selected and underwent further optimization, including re-calibration. A total of 3128 patients were included. The random forest model showed the best performance on the testing cohort; a 19-variable version achieved good discriminative performance [AUC 0.721, 95% confidence interval (CI) 0.680-0.764], outperforming existing scores (e.g. APPLE score: AUC 0.557, 95% CI 0.506-0.607). Platt scaling was used to calibrate the model. The final calibrated model was implemented in a web calculator, freely available at http://afarec.hpc4ai.unito.it/.

CONCLUSION

AFA-Recur, a machine-learning-based probability score predicting 1-year risk of recurrent atrial arrhythmia after AF ablation, achieved good predictive performance, significantly better than currently available tools. The calculator, freely available online, allows patient-specific predictions, favouring tailored therapeutic approaches for the individual patient.

Evidence-based insights on ideal blanking period duration following atrial fibrillation catheter ablation

AIMS

Despite the general adoption of a 3-month blanking period (BP), increasing scientific evidence suggests an association between early recurrences of atrial tachyarrhythmias (ERAT) and failure of atrial fibrillation catheter ablation (AFCA). The aim of the present study was to perform a diagnostic meta-analysis to derive the ideal BP cut-off following AFCA.

METHODS AND RESULTS

PubMed/MEDLINE databases were screened for articles reporting late recurrences of atrial tachyarrhythmias (LRAT) in AFCA patients experiencing an ERAT (with at least one time cut-off). Seventeen studies were finally included in the analysis, encompassing 5837 AF patients experiencing ERAT after AFCA. A random-effect meta-analysis of diagnostic test accuracy studies with multiple cut-offs was performed. The day at which the ERAT occurred was considered the diagnostic 'test', whereas the different time cut-offs reported in the singular studies were treated as cut-offs of interest in the meta-analysis. Overall, a 27.7 day (95% confidence interval: 10.4-45.1 days) cut-off was identified as the optimal BP duration [area under the summary receiver operating characteristic (AUC-SROC) curve: 0.66, 95% CI: 0.56-0.75]. Specificity (95% CI: 63-85%) and positive predictive value were 76%. At subgroup analysis, the optimal BP cut-off was 39.0 days (95% CI: 26.8-51.2 days, AUC-SROC: 0.63) following radiofrequency AFCA and 30.1 days (95% CI: 0-63.4 days, AUC-SROC: 0.76) after cryoballoon ablation.

CONCLUSION

The present meta-analysis indicates that a 4-week BP represents the optimal cut-off following AFCA. Altogether, these meta-analytic insights support the need of a revision of the actual 3-month BP duration.

Incidence and Clinical Relevance of COVID-19 in a Population of Young Competitive and Elite Football Players: A Retrospective Observational Study

Background

The COVID-19 pandemic dramatically changed lifestyle worldwide, including sport. A comprehensive evaluation of the prevalence of cardiac involvement in COVID-19 is essential to finalize a safe protocol for resuming elite sport. The aim of this study is to evaluate incidence of cardiac involvement and COVID-19 impact on athletic performance.

Materials and methods

This retrospective observational study analysed the data collected from consecutive competitive athletes who performed medical-sports examinations at the J Medical Center from March 2020 to March 2021. All athletes periodically performed a molecular test using a nasopharyngeal swab to detect COVID-19 infection. Positive athletes performed laboratory (cardiac troponin T—cTnT) and instrumental (echocardiography, stress test, Holter ECG) investigations following recovery to identify any cardiac involvement. Cardiac magnetic resonance imaging (MRI) was performed in case of abnormal findings at first-level evaluation.

Results

Among 238 athletes (median age 20 years), 77 contracted COVID-19, mainly males (79%) with a median age of 16 years. Fifty-one athletes (66%) presented mild symptoms, and none required hospitalization. Evaluation for resuming sport was performed after a median of 30 days from the first positive test. Abnormal findings were obtained in 13 cases (5 athletes [6%] with elevated cTnT values; 13 athletes [17%] with arrhythmias on Holter ECG and/or during stress test; 2 athletes [3%] anomalies at echocardiography). Cardiac MRI discovered abnormalities in 9 cases, but none of these was clearly related to COVID-19 and none fulfilled acute myocarditis criteria. No negative impact on athletic performance was observed, and none of the athletes developed persistent COVID-related symptoms.

Conclusions

Our registry confirms the predominantly self-limiting illness in young athlete population. The incidence of clear COVID-19-related structural myocardial injury was very low, but transient exertional ventricular arrhythmias or pericardial effusion was observed without significant impact on athletic performance. Implemented screening for return to activity is likely reasonable only in moderate-to-severe symptomatic athletes.

Catheter ablation for treatment of bradycardia-tachycardia syndrome: is it time to consider it the therapy of choice? A systematic review and meta-analysis

BACKGROUND

Atrial fibrillation catheter ablation (AFCA) should be considered as a strategy to avoid pacemaker (PM) implantation for patients with bradycardia-tachycardia syndrome (BTS), but lack of evidence is remarkable.

METHODS

Our aim was to conduct a random-effects model meta-analysis on safety and efficacy data from controlled trials and observational studies. We compared atrial fibrillation (AF) recurrence, AF progression, procedural complication, additional procedure, cardiovascular death, cardiovascular hospitalization, heart failure and stroke in patients undergoing AFCA vs. PM implantation.

RESULTS

PubMed/MEDLINE, Cochrane Database and Google Scholar were screened, and four retrospective studies were selected. A total of 776 patients (371 in the AFCA group, 405 in the PM group) were included. After a median follow-up of 67.5 months, lower AF recurrence [odds ratio (OR) 0.06, confidence interval (CI) 0.02-0.18, I2 = 82.42%, P < 0.001], AF progression (OR 0.12, CI 0.06-0.26, I2 = 0%, P < 0.001), heart failure (OR 0.12, CI 0.04-0.34, I2 = 0%, P < 0.001), and stroke (OR 0.30, CI 0.15-0.61, I2 = 0%, P = 0.001) were observed in the AFCA group. No differences were observed in cardiovascular death and hospitalization (OR 0.48, CI 0.10-2.28, I2 = 0%, P = 0.358 and OR 0.43, CI 0.14-1.29, I2 = 87.52%, P = 0.134, respectively). Higher need for additional procedures in the AFCA group was highlighted (OR 3.65, CI 1.51-8.84, I2 = 53.75%, P < 0.001). PM implantation was avoided in 91% of BTS patients undergoing AFCA.

CONCLUSIONS

AFCA in BTS patients seems to be more effective than PM implantation in reducing AF recurrence and PM implantation may be waived in most BTS patients treated by AFCA. Need for additional procedures in AFCA patients is balanced by long-term benefit in clinical end points.

Comparative efficacy and safety of different catheter ablation strategies for persistent atrial fibrillation: a network meta-analysis of randomized clinical trials

AIMS

Whereas pulmonary vein isolation (PVI) is the universally agreed target in catheter ablation of paroxysmal atrial fibrillation (AF), an ideal ablation set in persistent AF remains questioned. Aim of this study is to conduct a network meta-analysis (NMA) of randomized clinical trials (RCTs) comparing different ablation strategies in persistent AF patients.

METHODS AND RESULTS

Network meta-analysis was performed in a frequentist framework with the different ablation strategies constituting the competitive arms of interest. Primary efficacy endpoint was recurrences of atrial tachyarrhythmia (AF, atrial flutter, and/or organized atrial tachycardia). Secondary endpoints included major peri-procedural complications, procedure, and fluoroscopy duration. PubMED/MEDLINE and EMBASE databases were searched through June 2020. 2548 records were screened and 57 full-text articles assessed. Eventually 24 RCTs were included, encompassing 3245 patients (median follow-up 15 months, IQR 12-18). Compared to PVI alone, PVI plus linear lesions in the left atrium and elimination of extra-PV sources was the only strategy associated with a reduced risk of arrhythmia recurrence (RR 0.49, 95%CI 0.27-0.88). Most treatment arms were associated with longer procedural time compared with PVI; however, major peri-procedural complications and fluoroscopy time did not differ.

CONCLUSION

A comprehensive strategy including PVI, linear lesions in the left atrium, and elimination of extra-PV sources (constrained by a heterogeneous definition across studies) was associated with reduced risk of recurrent atrial tachyarrhythmias compared to PVI alone. All investigated treatment arms yielded similar safety profiles. Further research should rely on enhanced substrate-based approach definitions to solve one of the most evident knowledge gaps in interventional electrophysiology.

Long-term efficacy and impact on quality of life of atrial fibrillation catheter ablation in competitive athletes

BACKGROUND

Limited data are available on the efficacy of catheter ablation (CA) for sport-associated atrial fibrillation (AF), in particular at long term follow up. Moreover, the impact of AF CA on quality of life (QoL) in this population remains unknown. We aimed to determine AF CA efficacy in athletes, to assess the impact on athletes' QoL (with SF36 score) and on training capabilities in a long term follow up (FU).

METHODS

A total of 1215 AF patients' candidates to CA between January 2007 and December 2012, were retrospectively screened. Athletes were defined as patients performing ≥ 5h/week of vigorous sports, achieving a total of ≥1500 h lifetime sports activity, for at least one year before AF first symptomatic episode.

RESULTS

Out of 1215 AF patients, 133 were considered competitive athletes and underwent to CA. Overall, 43% of our cohort showed typical or atypical atrial flutter, which required a more extensive ablation procedure. Before AF, athletes used to practice for a mean of 8.5±2.7 h/week, while after the first AF episode the mean practice duration decreased to 2.82.5 h/week. At 10-year follow up, 83% of athletes did not present any recurrent event, and training capabilities increased up to 5.6±3.6 h/week after the procedure. Moreover, intense physical activity before AF CA was related to longterm AF recurrence rates (P = 0.05). QoL scores significantly improved in each single domains (P < 0.05).

CONCLUSIONS

AF CA represents an effective procedure to maintain sinus rhythm in athletes, with a significant improvement in QoL.

787 Ablation of the ventricular ectopic foci: a therapeutic option for dilated cardiomyopathy due to arrhythmic MVP

Aims

A subset of patients with mitral valve prolapse (MVP) are affected by a still not well understood condition characterized by frequent ventricular arrhythmias (mostly originating from papillary muscles) and sudden cardiac death (SCD). It is called MVP malignant syndrome (MVP MS). In these patients, the high arrhythmic burden may lead to left ventricular (LV) dyssynchrony and dysfunction, determining a tachycardia-induced cardiomyopathy (TIC). Reduction in arrhythmic burden determines LV recovery and ejection fraction improvement and interrupts LV progressive dilatation.

Methods and reports

We report the case of a 52-year-old woman with MVP and family history of both MVP and SCD who was referred to our department for symptomatic extrasystoles and dyspnoea during exercise. Palpitations begun 11 years before: in that occasion she performed a 3-lead-ECG-Holter monitoring which documented 3457 ventricular extrasystoles. Transthoracic echocardiography (TTE) showed normal LV dimension and function and a myxomatous mitral valve with prolapse of both leaflets. At that time beta-blocker therapy was introduced, but soon suspended because of patient’s clinical intolerance (bradycardia and hypotension). Since then she was lost at follow-up for years, until symptoms worsened. When she came to our attention, TTE showed dilated and hypokinetic LV (ejection fraction was 38%, S2 wave at TDI was 6.4 cm/s and global longitudinal strain value was −13%). CMR was performed and confirmed TTE findings. Mitral-annulus disjunction was described in anterior, lateral, and posterior wall and late gadolinium enhancement analyses showed subendocardial fibrosis in correspondence of the posterior papillary muscle (PM) and in the mid-inferior wall. Holter monitoring enlightened a high arrhythmic burden with 24 065 premature ventricular complexes (PVCs) of two morphologies (right bundle branch block-like and −120° axis and right bundle branch block-like and −75° axis). During stress test, PVCs increased as the heart rate increased, resulting in bigeminism at peak exercise. Considering all these features, we hypothesized a case of MVP MS in which the high ventricular arrhythmic burden resulted in TIC. Any available pharmacological attempt to reduce arrhythmias failed. Transcatheter (TC) ablation of PVCs was then proposed. Electrophysiological study identified the inner part of the posterior papillary muscle implantation region and the antero-lateral basal wall as PVCs sites of origin. Radiofrequency ablation was performed in both sites. After the procedure, despite an incomplete suppression of the posterior PM focus, 12-lead 24-h Holter monitoring and TTE performed during the hospitalization showed a consistent arrhythmic burden reduction and LV function improvement. At 6 months from the procedure, symptoms improved and Holter monitoring showed 7515 PVCs with a 54% arrhythmic burden reduction compared with the presentation. TE showed lower LV end-diastolic volume and an increase in ejection fraction up to 47%; global longitudinal strain was −17% and TDI showed a S2 wave on lateral wall of 11 cm/s, confirming left ventricle improvement after the arrhythmic burden reduction.

Conclusions

Complete suppression of PMs PVCs with TC ablation is difficult to obtain, especially when the focus is in the inner part of the PM and TC ablation of ventricular arrhythmias in MVP patients has not yet demonstrated his efficacy in reducing SCD. Nevertheless, it should be taken into consideration to obtain at least PVCs reduction in patients with high arrhythmic burden leading to TIC.

Prevalence and predictors of left atrial thrombosis in atrial fibrillation patients treated with non-vitamin K antagonist oral anticoagulants

BACKGROUND

Few data are available regarding the prevalence of left atrium (LA) thrombi in atrial fibrillation (AF) patients treated with non-vitamin K antagonist oral anticoagulants (NOACs). Methods: We evaluated the prevalence and predictors of LA/LA appendage (LAA) thrombi in non-valvular AF patients treated with NOACs referring to a single centre for a scheduled electrical cardioversion (ECV) or catheter ablation (CA). Transesophageal echocardiography (TEE) was performed within 12 h prior to the index procedure.

RESULTS

A total of 352 consecutive patients with non-valvular AF treated with NOACs were included in this analysis (ECV group n = 176 and CA group n = 176) between 2013 and 2018. 85 patients (24.2%) were on dabigatran, 150 (42.7%) on rivaroxaban, 104 (29.6%) on apixaban and 13 (3.7%) on edoxaban. A LA/LAA thrombus was detected by TEE in 27 (7.7%) patients, 18 in the ECV group and nine in the ablation group; 18 (5.1%) patients presented dense LA/LAA spontaneous echo contrast (SEC). Predictors of LA/LAA thrombi were a CHA₂DS₂-VASc score > 3 (OR 4.54, 95% CI 1.50 - 13.70, p value = .007) and obesity (OR 6.01, 95% CI 1.95 - 18.50, p value = .001).

CONCLUSIONS

Among real-world patients with non-valvular AF treated with NOACs, we found a high incidence of LA/LAA thrombi compared to previous reports. The main predictors of LA/LAA thrombosis were a CHA₂DS₂-VASc score > 3 and obesity.

Genotype-Phenotype Correlation of SCN5A Genotype in Patients With Brugada Syndrome and Arrhythmic Events: Insights From the SABRUS in 392 Probands

BACKGROUND

Brugada syndrome (BrS) is associated with mutations in the cardiac sodium channel gene, SCN5A. However, genetic studies of patients with BrS with arrhythmic events have been limited. We sought to compare various clinical, ECG, and electrophysiological parameters according to SCN5A genotype in a large cohort of BrS probands with first arrhythmic event.

METHODS

Survey on Arrhythmic Events in Brugada Syndrome is a survey of 10 Western and 4 Asian countries, gathering 678 patients with BrS with first arrhythmic event. Only probands were included, and SCN5A genotype adjudicated. Patients without appropriate genetic data were excluded. Associations of genotype with clinical features were analyzed.

RESULTS

The study group comprised 392 probands: 92 (23.5%) SCN5A+(44 pathogenic/likely pathogenic [P/LP] and 48 variants of unknown significance) and 300 (76.5%) SCN5A-.SCN5A missense variants and the patients hosting them were similar regardless of adjudication. A higher proportion of patients with P/LP were pediatric (<16 years) compared with SCN5A- (11.4% versus 3%, P=0.023). The proportion of females was higher among patients with P/LP compared with SCN5A- (18.2% versus 6.3%, P=0.013). P/LP probands were more likely to have a family history of sudden cardiac death compared with SCN5A- (41.9% versus 16.8%, P<0.001). A higher proportion of patients with P/LP were White compared with SCN5A- (87.5% versus 47%, P<0.001). Ethnicity (odds ratio, 5.41 [2.8-11.19], P<0.001) and family history of sudden cardiac death (odds ratio, 2.73 [1.28-5.82], P=0.009) were independent variables associated with P/LP genotype following logistic regression.

CONCLUSIONS

The genetic basis of BrS has a complex relationship with gender, ethnicity, and age. Probands hosting a P/LP variant tended to experience their first arrhythmic event at a younger age and to have events triggered by fever compared with patients with SCN5A-. In addition, they were more likely to be White and to have family history of sudden cardiac death. Among females, a P/LP variant suggests an increased risk of being symptomatic. This association should be further studied on an ethnically specific basis in large prospectively collected international cohorts.

European position paper on the management of patients with patent foramen ovale. Part II - Decompression sickness, migraine, arterial deoxygenation syndromes and select high-risk clinical conditions

Patent foramen ovale (PFO) is implicated in the pathogenesis of a number of medical conditions but to date only one official position paper related to left circulation thromboembolism has been published. This interdisciplinary paper, prepared with the involvement of eight European scientific societies, reviews the available evidence and proposes a rationale for decision making for other PFO-related clinical conditions. In order to guarantee a strict evidence-based process, we used a modified grading of recommendations, assessment, development, and evaluation (GRADE) methodology. A critical qualitative and quantitative evaluation of diagnostic and therapeutic procedures was performed, including assessment of the risk/benefit ratio. The level of evidence and the strength of the position statements were weighed and graded according to predefined scales. Despite being based on limited and observational or low-certainty randomised data, a number of position statements were made to frame PFO management in different clinical settings, along with suggestions for new research avenues. This interdisciplinary position paper, recognising the low or very low certainty of existing evidence, provides the first approach to several PFO-related clinical scenarios beyond left circulation thromboembolism and strongly stresses the need for fresh high-quality evidence on these topics.

Ticagrelor versus prasugrel in acute coronary syndrome: sex-specific analysis from the RENAMI Registry

BACKGROUND

The use of potent P2Y12 inhibitors (ticagrelor & prasugrel) in acute coronary syndrome (ACS) patients undergoing percutaneous coronary interventions (PCI) is a class I recommendation. We performed a sex-specific analysis comparing the difference in efficacy and safety outcomes between ticagrelor and prasugrel in a real-world ACS population.

METHODS

Data from the multicenter REgistry of New Antiplatelets in patients with Myocardial Infarction (RENAMI) for 4424 ACS patients who underwent PCI and were treated with ticagrelor or prasugrel between 2012 to 2016 were analyzed. Mean follow-up was 17±9 months.

RESULTS

After propensity score matching, there was no significant difference in the occurrence of primary endpoint of net adverse cardiac events between ticagrelor and prasugrel in men (HR: 0.94; 95% CI: 0.69-1.29; P=0.71), or women (HR: 1.17; 95% CI: 0.63-2.20; P=0.62; P interaction [sex] = 0.40). Similarly, no differences were found in the occurrence of any of the secondary endpoints (MACE, all cause death, re-infarction, stent thrombosis, BARC major bleeding and BARC any bleeding) between the two P2Y12 groups between men and women.

CONCLUSIONS

In this real-world ACS population, no relative difference in efficacy or safety outcomes were found between ticagrelor and prasugrel between sexes.

European position paper on the management of patients with patent foramen ovale. Part II - Decompression sickness, migraine, arterial deoxygenation syndromes and select high-risk clinical conditions

Patent foramen ovale (PFO) is implicated in the pathogenesis of a number of medical conditions but to date only one official position paper related to left circulation thromboembolism has been published. This interdisciplinary paper, prepared with the involvement of eight European scientific societies, reviews the available evidence and proposes a rationale for decision making for other PFO-related clinical conditions. In order to guarantee a strict evidence-based process, we used a modified grading of recommendations, assessment, development, and evaluation (GRADE) methodology. A critical qualitative and quantitative evaluation of diagnostic and therapeutic procedures was performed, including assessment of the risk/benefit ratio. The level of evidence and the strength of the position statements were weighed and graded according to predefined scales. Despite being based on limited and observational or low-certainty randomised data, a number of position statements were made to frame PFO management in different clinical settings, along with suggestions for new research avenues. This interdisciplinary position paper, recognising the low or very low certainty of existing evidence, provides the first approach to several PFO-related clinical scenarios beyond left circulation thromboembolism and strongly stresses the need for fresh high-quality evidence on these topics.

Catheter Ablation vs. Anti-Arrhythmic Drugs as First-Line Treatment in Symptomatic Paroxysmal Atrial Fibrillation: A Systematic Review and Meta-Analysis of Randomized Clinical Trials

Background: Catheter ablation has become a well-established indication for long-term rhythm control in atrial fibrillation (AF) patients refractory to anti-arrhythmic drugs (AADs). Efficacy and safety of AF catheter ablation (AFCA) before AADs failure are, instead, questioned. Objective: The aim of the study was to perform a systematic review and meta-analysis of randomized clinical trials (RCTs) comparing first-line AFCA with AADs in symptomatic patients with paroxysmal AF. Methods: We performed a random-effects meta-analysis of binary outcome events comparing AFCA with AADs in rhythm control-naïve patients. The primary outcomes, also stratified by the type of ablation energy (radiofrequency or cryoenergy), were (1) recurrence of atrial tachyarrhythmias and (2) recurrence of symptomatic atrial tachyarrhythmias. The secondary outcomes included adverse events. Results: Six RCTs were included in the analysis. AFCA was associated with lower recurrences of atrial tachyarrhythmias [relative risk (RR) 0.58, 95% confidence interval (CI) 0.46-0.72], consistent across the two types of ablation energy (radiofrequency, RR 0.50, 95% CI 0.28-0.89; cryoenergy, RR 0.60, 95% CI 0.50-0.72; p-value for subgroup differences: 0.55). Similarly, AFCA was related to less symptomatic arrhythmic recurrences (RR 0.46, 95% CI 0.27-0.79). Overall, adverse events did not differ. A trend toward increased periprocedural cardiac tamponade or phrenic nerve palsy was observed in the AFCA group, while more atrial flutter episodes with 1:1 atrioventricular conduction and syncopal events were reported in the AAD group. Conclusions: First-line rhythm control therapy with AFCA, independent from the adopted energy source (radiofrequency or cryoenergy), reduces long-term arrhythmic recurrences in patients with symptomatic paroxysmal AF compared with AADs.

Increased beat-to-beat variability of cerebral microcirculatory perfusion during atrial fibrillation: a near-infrared spectroscopy study

AIMS

Atrial fibrillation (AFib) is associated with cognitive decline/dementia, independently from clinical strokes or transient ischaemic attacks (TIA). Recent in silico data suggested that AFib may induce transient critical haemodynamic events in the cerebral microcirculation. The aim of this study is to use non-invasive spatially resolved cerebral near-infrared spectroscopy (SRS-NIRS) to investigate in vivo beat-to-beat microcirculatory perfusion during AFib and after sinus rhythm (SR) restoration.

METHODS AND RESULTS

Cerebral SRS-NIRS with high-frequency sampling (20 Hz) and non-invasive systemic haemodynamic monitoring were recorded before and after elective electrical cardioversion (ECV) for AFib or atrial flutter (AFL). To assess beat-to-beat effects of the rhythm status, the frequency distribution of inter-beat differences in tissue haemoglobin index (THI), a proxy of microcirculatory cerebral perfusion, was compared before and after SR restoration. Fifty-three AFib/AFL patients (mean age 69 ± 8 years, 79% males) were ultimately enrolled. Cardioversion was successful in restoring SR in 51 (96%) patients. In front of a non-significant decrease in arterial blood pressure extreme events between pre- and post-ECV measurements, a significant decrease of both hypoperfusive and hyperperfusive/hypertensive microcirculatory events was observed after SR restoration (P < 0.001 and P = 0.041, respectively).

CONCLUSION

The present is the first in vivo demonstration that SR restoration by ECV significantly reduces the burden of extreme single-beat haemodynamic events in cerebral microcirculation. Future studies are needed to assess whether SR maintenance might slow long-term AFib-correlated cognitive decline/dementia.

Ante-mortem characterization of sudden deaths as first-manifestation in Italy

PURPOSE

There is a relative paucity of data on ante-mortem clinical characteristics of young (age 1 to 35 years) sudden death (SD) victims. The aim of the study was to characterize ante-mortem characteristics of SD victims, in a selected national cohort identified by a web search.

METHODS

A dataset of all SD (January 2010 and December 2015) was built from national forensic data and medical records, integrated with Google search model. Families were contacted to obtain consent for interviews. Data were obtained on ante-mortem symptoms. ECG characteristics and autopsy data were available.

RESULTS

Out of 301 SD cases collected, medical and family history was available in 132 (43.9%). Twenty-eight (21.1%) had a positive family history for SD. SD occurred during sport/effort in 76 (57.6%). One hundred twelve (85%) SD cases had no prior reported symptoms. Autopsy data were available in 100/132 (75.8%) cases: an extra cardiac cause was identified in 20 (20%). Among the 61 cases with a cardiac diagnosis, 21 (34%) had hypertrophic cardiomyopathy. Among the 19 (19%) victims without structural abnormalities, molecular autopsy identified pathogenic variants for channelopathies in 9 cases. Ten (10%) victims had no identifiable cause.

CONCLUSIONS

Most SD were due to cardiac causes and occurred in previously asymptomatic patients. SD events mainly occurred during strenuous activity. In a minority of cases, no cause was identified. The web-based selection criteria, and incomplete data retrieval, need to be carefully taken into account for data interpretation and reproducibility.

Transcatheter ablation for atrial fibrillation in patients with hypertrophic cardiomyopathy: Long-term results and clinical outcomes

INTRODUCTION

Radiofrequency transcatheter ablation (RFCA) for atrial fibrillation (AF) in patients with hypertrophic cardiomyopathy (HCM) has been proven feasible. However, the long-term results of RFCA and its impact on clinical course of HCM are unknown. The aim of this study was to analyse clinical outcomes and long-term efficacy of RFCA in a multicentre cohort of patients with HCM and concomitant AF.

METHODS

Patients with HCM and AF consecutively undergoing RFCA were included. Ablation failure was defined as recurrence of AF, atrial tachycardia, or flutter lasting more than 3 min and occurring after the blanking period.

RESULTS

Overall, 116 patients with symptomatic AF refractory to antiarrhythmic drugs were included. Over a median follow-up of 6.0 years (interquartile range: 3.0-8.9 years) recurrence rate after a single RFCA was 32.3 per 100 patient/years with 26% of patients free from AF relapses at 6-year follow-up. Among patients experiencing AF recurrence, 51 (66%) underwent at least one redo-procedure. The overall recurrence rate considering redo-procedures was 12.6 per 100 patients/years with 53% of patients free from AF relapses at 6 years. At last follow-up, with an average of 1.6 procedures, 67 (61%) patients were in sinus rhythm (SR). Patients remaining in SR showed better functional status compared with those experiencing arrhythmic recurrences (NYHA Class 1.6 ± 0.1 vs. 2.0 ± 0.1, p = .009).

CONCLUSIONS

RFCA of AF in HCM patients is an effective and safe strategy favoring long-term SR maintenance, reduction of atrial arrhythmic events, and improved functional status. However, most patients need repeat procedures and continuation of antiarrhythmic drugs.

Prevalence and Clinical Significance of Latent Brugada Syndrome in Atrial Fibrillation Patients Below 45 Years of Age

Aim: This study aims to describe prevalence and clinical significance of latent Brugada syndrome (BrS) in a young population with atrial fibrillation (AF).

Methods: Between September 2015 and November 2017, among 111 AF patients below 45 years of age, those without pre-existing pathologies and/or known risk factors were selected for the study. Based on baseline 12-lead−24-h Holter electrocardiogram (ECG), previous class 1C antiarrhythmic drug therapy, or ajmaline testing, patients were stratified as latent type 1 BrS or not.

Results: Within the 78 enrolled patients, 13 (16.7%; group 1) revealed a type 1 BrS ECG pattern, while 65 (83.3%; group 2) did not. Mean age was 37 ± 8 vs. 35 ± 7 (p = 0.42), and males were 7 (54%) vs. 54 (83%) (p = 0.02) in the two groups, respectively. Family history of BrS was significantly more common within group 1 patients (2, 15% vs. 0; p = 0.03), and 4 (31%) patients experienced syncope in group 1 vs. 5 (8%) in group 2 (p = 0.02). After a mean follow-up of 42 ± 18 months from the index AF event, more than 80% of the patients, in both study groups, were in sinus rhythm.

Conclusion: In young patients with AF without pre-existing pathologies and/or known risk factors, latent BrS should be suspected. Syncope and a family history of BrS emerge as easily identifiable factors related to BrS. Long-term sinus rhythm maintenance appears satisfactory, either in the presence or not of BrS.

Ablation of Accessory Pathways with Uncommon Electrophysiologic Properties

In rare cases, atrioventricular reentrant arrhythmias are sustained by accessory pathways with peculiar electrophysiologic features that may be related to their specific anatomy. Most of these bundles show decremental nodelike conduction properties and sustain peculiar forms of arrhythmias that require careful differential diagnosis. On the other hand, some pathways do not actively sustain any reentrant circuit and should nevertheless be promptly recognized to avoid unnecessary ablation attempts. Although rare, these variants of accessory pathway should be known to warrant a safe and effective catheter ablation procedure.

Long-term efficacy and safety of hydroquinidine in patients with Brugada syndrome

Background

Brugada syndrome (BrS) is an inherited channelopathy with an increased risk of supraventricular, ventricular arrhythmias (VAs) and sudden cardiac death (SCD). Implantable cardioverter-defibrillator (ICD) is a cornerstone of SCD prevention, but it does not reduce the incidence of life-threatening VAs and it can carry substantial complications. Hydroquinidine (HQ) is a class IA antiarrhythmic drug used for electrical storms, to reduce ICD's appropriate discharges and as an alternative to ICD in children with BrS or in patients with a contraindication to ICD. Nevertheless, HQ's side effects may undermine treatment compliance.

Purpose

The aim of this study was to evaluate the efficacy and safety of HQ in reducing VAs (ventricular fibrillation, sustained and non-sustained ventricular tachycardia) inducibility at electrophysiology study (EPS) and atrial fibrillation/flutter (AF/AFL) or VAs recurrence in patients with BrS.

Methods

From the prospective Piedmont Brugada Registry, patients treated with HQ were selected and divided into three groups according to the indication for HQ initiation: index EPS positive for VAs induction (group 1), secondary prevention of AF/AFl (group 2), secondary prevention of VAs (group 3). In group 3 recurrence of VAs was monitored by implantable devices or by periodic 24-hour ECG Holter monitoring. In 5 patients HQ was started for reasons different from the above mentioned, so they were considered only for safety outcomes. Safety was assessed considering the occurrence of HQ side effects and their impact on treatment discontinuation.

Results

A total of 98 patients (79 males, 80,6%) were included. Median follow-up was 61 months (IQR 31–89 months). None of the baseline clinical characteristics was associated with arrhythmic recurrences. Among 46 patients in group 1 HQ was effective in reducing EPS inducibility in 91.9% of patients (p&lt;0.0001); in group 2 (31 patients) HQ reduced palpitations [before HQ 83,8%, with HQ 27,6%, RRR 67.1%, NNT 1.8; p&lt;0.0001] and no AF/AFL recurrence was recorded during follow-up (p&lt;0.0001); in group 3 (17 patients; 70.6% with ICD/LR implanted) VAs recurrences were significantly reduced in patients with HQ (5.9% recurrence rate, p&lt;0.0001). Overall, no cardiac arrest occurred during follow-up. At ECG, HQ determined a significant increase in QTc duration (V5-lead mean QTc duration pre-HQ 406 ms vs with HQ 428 ms; p=0.001).

Overall, 28.6% of patients presented HQ-related side effects, mainly due to gastrointestinal intolerance (18.3%). Treatment discontinuation rate was 25% but only about half of these patients discontinued HQ for adverse events (29.2% for GI intolerance, 16.7% for drug-induced QTc prolongation, 8.3% for elevated liver enzymes; 45.8% self-discontinuation).

Conclusions

In patients with BrS, HQ was effective in reducing VAs inducibility at EPS, AF/AFL and VAs recurrences; moreover, it was effective in reducing symptoms. Overall, HQ proved to be safe and well-tolerated.

Funding Acknowledgement

Type of funding source: None

Short-term anticoagulation after acute cardioversion of early-onset atrial fibrillation

BACKGROUND

Controversy exists regarding anticoagulation management following acute cardioversion in patients with early-onset (<48 hours) atrial fibrillation without class I guideline indication for long-term oral anticoagulation (CHA2DS2-VASc 0-1).

METHODS AND RESULTS

A random-effect meta-analysis of observational studies reporting 30-day incidence of thromboembolic complications after cardioversion without post-procedural oral anticoagulation therapy in patients at low-moderate thromboembolic risk (CHA2DS2-VASc 0-1) was performed. Four studies were included, encompassing 3276 cardioversions. The analysis revealed that the pooled risk of 30-day incidence of thromboembolic complications in this subset of patients is low (0.10%, 95% confidence interval: 0.00%-0.30%).

CONCLUSIONS

Given these data, considering the bleeding risk unavoidably conferred by OAT, which is known to be higher in the first month from treatment onset, short-term anticoagulation limited to 4 weeks post-cardioversion of early-onset (<48 hours) atrial fibrillation in patients with low-moderate risk of stroke (CHA2DS2-VASc 0-1) may be omitted, at least in patients with high-bleeding risk.

Cardiac arrest in takotsubo syndrome: results from the InterTAK Registry

AIMS

We aimed to evaluate the frequency, clinical features, and prognostic implications of cardiac arrest (CA) in takotsubo syndrome (TTS).

METHODS AND RESULTS

We reviewed the records of patients with CA and known heart rhythm from the International Takotsubo Registry. The main outcomes were 60-day and 5-year mortality. In addition, predictors of mortality and predictors of CA during the acute TTS phase were assessed. Of 2098 patients, 103 patients with CA and known heart rhythm during CA were included. Compared with patients without CA, CA patients were more likely to be younger, male, and have apical TTS, atrial fibrillation (AF), neurologic comorbidities, physical triggers, and longer corrected QT-interval and lower left ventricular ejection fraction on admission. In all, 57.1% of patients with CA at admission had ventricular fibrillation/tachycardia, while 73.7% of patients with CA in the acute phase had asystole/pulseless electrical activity. Patients with CA showed higher 60-day (40.3% vs. 4.0%, P < 0.001) and 5-year mortality (68.9% vs. 16.7%, P < 0.001) than patients without CA. T-wave inversion and intracranial haemorrhage were independently associated with higher 60-day mortality after CA, whereas female gender was associated with lower 60-day mortality. In the acute phase, CA occurred less frequently in females and more frequently in patients with AF, ST-segment elevation, and higher C-reactive protein on admission.

CONCLUSIONS

Cardiac arrest is relatively frequent in TTS and is associated with higher short- and long-term mortality. Clinical and electrocardiographic parameters independently predicted mortality after CA.

Incidence, predictors and prognostic impact of intracranial bleeding within the first year after an acute coronary syndrome in patients treated with percutaneous coronary intervention

Background:

The rate of intracranial haemorrhage after an acute coronary syndrome has been studied in detail in the era of thrombolysis; however, in the contemporary era of percutaneous coronary intervention, most of the data have been derived from clinical trials. With this background, we aim to analyse the incidence, timing, predictors and prognostic impact of post-discharge intracranial haemorrhage in patients with acute coronary syndrome undergoing percutaneous coronary intervention.

Methods:

We analysed data from the BleeMACS registry (patients discharged for acute coronary syndrome and undergoing percutaneous coronary intervention from Europe, Asia and America, 2003–2014). Analyses were conducted using a competing risk framework. Uni and multivariate predictors of intracranial haemorrhage were assessed using the Fine–Gray proportional hazards regression analysis. The endpoint was 1-year post-discharge intracranial haemorrhage.

Results:

Of 11,136 patients, 30 presented with intracranial haemorrhage during the first year (0.27%). The median time to intracranial haemorrhage was 150 days (interquartile range 55.7–319.5). The fatality rate of intracranial haemorrhage was very high (30%). After multivariate analysis, only age (subhazard ratio 1.05, 95% confidence interval 1.01–1.07) and prior stroke/transient ischaemic attack (hazard ratio 3.29, 95% confidence interval 1.36–8.00) were independently associated with a higher risk of intracranial haemorrhage. Hypertension showed a trend to associate with higher intracranial haemorrhage rate. The combination of older age (⩾75 years), prior stroke/transient ischaemic attack, and/or hypertension allowed us to identify most of the patients with intracranial haemorrhage (86.7%). The annual rate of intracranial haemorrhage was 0.1% in patients with no risk factors, 0.2% in those with one factor, 0.6% in those with two factors and 1.3% in those with three factors.

Conclusion:

The incidence of intracranial haemorrhage in the first year after an acute coronary syndrome treated with percutaneous coronary intervention is low. Advanced age, previous stroke/transient ischaemic attack, and hypertension are the main predictors of increased intracranial haemorrhage risk.

Is the mid-diastolic isthmus always the best ablation target for re-entrant atrial tachycardias?

AIMS

We evaluated the ability of an ultrahigh mapping system to identify the most convenient Rhythmia ablation target (RAT) in intra-atrial re-entrant tachycardias (IART) in terms of the narrowest area to transect to interrupt the re-entry.

METHODS

A total of 24 consecutive patients were enrolled with a total of 26 IARTs. The Rhythmia mapping system was used to identify the RAT in all IARTs.

RESULTS

In 18 cases the RAT matched the mid-diastolic phase of the re-entry whereas in 8 cases the RAT differed. In these patients, the mid-diastolic tissue in the active circuit never represented the area with the slowest conduction velocity of the re-entry. The mean conduction velocity at the mid-diastolic site was significantly slower in the group of patients in which the RAT matched the mid-diastolic site (P = 0.0173) and that of the remaining circuit was significantly slower in the group in which the RAT did not match (P = 0.0068). The mean conduction velocity at the RAT was comparable between the two groups (P = 0.66).

CONCLUSION

Identifying the RAT in challenging IARTs by means of high-density representation of the wavefront propagation of the tachycardia seems feasible and effective. In one-third of cases this approach identifies an area that differs from the mid-diastolic corridor.

Left atrial appendage morphology at transesophageal echocardiography: how to improve reproducibility?

BACKGROUND

Left atrial appendage (LAA) morphology, investigated by computed tomography and magnetic resonance imaging, has proved to relate to the risk of cerebrovascular events in patients with atrial fibrillation (AF). The aim of the present study was to assess reproducibility of transesophageal echocardiography (TEE) imaging in describing LAA morphology.

METHODS

Two-hundred consecutive patients referred for TEE were enrolled. In the first group of 47 (23.5%) patients LAA morphology was analyzed by conventional TEE and described as ChickenWing, Windsock, Cactus or Cauliflower. In the second group of 153 (76.5%) patients, instead, a 3D-Xplane diagnostic algorithm was performed to stratify LAA morphology as linear (ChickenWing) or complex (Windsock/Cactus and Cauliflower). Interobserver variability within three independent readers was assessed in both groups of patients and stratified by operator's experience and training. In a subgroup of 19 (12.4%) patients, the agreement of LAA morphology description by 3D-Xplane diagnostic algorithm was compared to cardiac magnetic resonance.

RESULTS

By conventional TEE the agreement among operators on LAA morphology classification was poor (ρ<0.13). The 3D-XPlane diagnostic algorithm, significantly increased interobserver agreement up to ρ=0.32 within all readers and up to ρ=0.82 among the experienced and specifically trained operators. LAA morphology description in this latter group provided strong agreement with cardiac magnetic resonance (up to ρ=0.77).

CONCLUSIONS

LAA morphology assessment is challenging by conventional TEE. To improve reproducibility, the use of the 3D-Xplane technique combined with a specific diagnostic algorithm and training of the operators is fundamental.

Late atrial arrhythmias after lung transplantation: a meta-analysis

BACKGROUND

Atrial arrhythmias are common following noncardiac thoracic surgery. In particular, early postoperative atrial arrhythmias after lung transplantation are very frequent, especially atrial fibrillation (AFib). Late atrial arrhythmia occurrence following lung transplantation, instead, has been less commonly reported.

METHODS

The aim of the present systematic review and meta-analysis is to analyse the incidence rate of late atrial arrhythmia and AFib in lung transplantation patients, with a special focus on double lung transplant (DLT), also to assess potential predictors of AFib occurrence. After bibliographic search (PUBMED/Medline and Embase databases), a random-effect model meta-analysis was performed: seven studies were finally included, including 2068 lung transplantation patients.

RESULTS

The pooled incidence rate of late atrial arrhythmia was 4.3%/year [95% confidence interval (CI) 2.8-6.1%/year, I = 69%], whereas late AFib incidence rate was 1.5%/year (95% CI 0.7-2.6%/year, I = 87%). In patients undergoing DLT, the pooled incidence rate of late atrial arrhythmia was 4.1%/year (95% CI 2.5-6.0%/year, I = 67%), while the AFib incidence rate was 0.9%/year (95% CI 0.1-2.4%/year, I = 92%). A longer follow-up duration significantly related to the reduced incidence rate of AFib (P = 0.02). History of AFib (hazard ratio 11.2, 95% CI 5.9-21.3) and early postoperative AFib (hazard ratio 10.3, 95% CI 5.9-18.0) emerged, instead, as relevant predictors of AFib occurrence.

CONCLUSION

Late atrial arrhythmia occurrence is not infrequent in lung transplantation patients; however, late Afib incidence was rare and showed a time-dependent decrease, particularly in DLT patients, suggesting that a transmural pulmonary veins isolation, the mainstay of transcatheter ablation, is effective in decreasing the likelihood of experiencing AFib.

Long versus short dual antiplatelet therapy in acute coronary syndrome patients treated with prasugrel or ticagrelor and coronary revascularization: Insights from the RENAMI registry

Introduction

The benefits of short versus long-term dual antiplatelet therapy (DAPT) based on the third generation P2Y12 antagonists prasugrel or ticagrelor, in patients with acute coronary syndromes treated with percutaneous coronary intervention remain to be clearly defined due to current evidences limited to patients treated with clopidogrel.

Methods

All acute coronary syndrome patients from the REgistry of New Antiplatelets in patients with Myocardial Infarction (RENAMI) undergoing percutaneous coronary intervention and treated with aspirin, prasugrel or ticagrelor were stratified according to DAPT duration, that is, shorter than 12 months (D1 group), 12 months (D2 group) and longer than 12 months (D3 group). The three groups were compared before and after propensity score matching. Net adverse clinical events (NACEs), defined as a combination of major adverse cardiac events (MACEs) and major bleedings (including therefore all cause death, myocardial infarction and Bleeding Academic Research Consortium (BARC) 3–5 bleeding), were the primary end points, MACEs (a composite of all cause death and myocardial infarction) the secondary one. Single components of NACEs were co-secondary end points, along with BARC 2–5 bleeding, cardiovascular death and stent thrombosis.

Results

A total of 4424 patients from the RENAMI registry with available data on DAPT duration were included in the model. After propensity score matching, 628 patients from each group were selected. After 20 months of follow up, DAPT for 12 months and DAPT for longer than 12 months significantly reduced the risk of NACE (D1 11.6% vs. D2 6.7% vs. D3 7.2%, p = 0.003) and MACE (10% vs. 6.2% vs. 2.4%, p < 0.001) compared with DAPT for less than 12 months. These differences were driven by a reduced risk of all cause death (7.8% vs. 1.3% vs. 1.6%, p < 0.001), cardiovascular death (5.1% vs. 1.0% vs. 1.2%, p < 0.0001) and recurrent myocardial infarction (8.3% vs. 5.2% vs. 3.5%, p = 0.002). NACEs were lower with longer DAPT despite a higher risk of BARC 2–5 bleedings (4.6% vs. 5.7% vs. 6.2%, p = 0.04) and a trend towards a higher risk of BARC 3–5 bleedings (2.4% vs. 3.3% vs. 3.9%, p = 0.06). These results were not consistent for female patients and those older than 75 years old, due to an increased risk of bleedings which exceeded the reduction in myocardial infarction.

Conclusion

In unselected real world acute coronary syndrome patients treated with percutaneous coronary intervention, DAPT with prasugrel or ticagrelor prolonged beyond 12 months markedly reduces fatal and non-fatal ischaemic events, offsetting the increased risk deriving from the higher bleeding risk. On the contrary, patients >75 years old and female ones showed a less favourable risk–benefit ratio for longer DAPT due to excess of bleedings.

Subclinical Left Ventricular Dysfunction in Severe Obesity and Reverse Cardiac Remodeling after Bariatric Surgery

Aim:

Obesity is associated with an increased cardiovascular risk. This study aimed to assess the role of echocardiography in the early detection of subclinical cardiac abnormalities in a cohort of obese patients with a preserved ejection fraction (EF) undergoing bariatric surgery.

Methods and Results:

Forty consecutive severely obese patients (body mass index≥35 kg/m2) referring to our center for bariatric surgery were enrolled in this prospective cohort study. Despite a baseline EF of 61% ± 3%, almost half patients (43%) had a systolic dysfunction (SD) defined as global longitudinal strain (GLS)>−18%, and most of them (60%) had left ventricular hypertrophy (LVH) or concentric remodeling (CR). At 10-months after surgery, body weight decreased from 120 ± 15 kg to 83 ± 12 kg, body mass index from 44 ± 5 kg/m² to 31 ± 5 kg/m² (both P < 0.001). Septal and left ventricular posterior wall thickness decreased respectively from 10 ± 1 mm to 9 ± 1 mm (P = 0.004) and from 10 ± 1 mm to 9 ± 1 mm (P = 0.007). All systolic parameters improved: EF from 61% ± 3% to 64% ± 3% (P = 0.002) and GLS from −17% ± 2% to −20% ± 1% (P < 0.001). Epicardial fat thickness reduction (from 4.7 ± 1 mm to 3.5 ± 0.7 mm, P < 0.001) correlated with the reduction of left atrial area (P < 0.001 R = 0.35) and volume (P = 0.02 R = 0.25). Following bariatric surgery, we observed a reduced prevalence of LVH/CR (before 60%, after 22%, P = 0.001) and a complete resolution of preclinical SD (before 43%, after 0%, P < 0.001). Moreover, a postoperative reduction of at least 30 kg correlated with regression of septal hypertrophy (P < 0.001).

Conclusions:

Obese patients candidate to bariatric surgery have an high prevalence of preclinical SD and LVH/CR, early detectable with echocardiography. Bariatric surgery is associated with reverse cardiac remodeling; it might also have a preventive effect on atrial fibrillation occurrence by reducing its substrate.

Impact of atrial fibrillation catheter ablation on mortality, stroke, and heart failure hospitalizations: A meta-analysis

BACKGROUND

The impact of atrial fibrillation catheter ablation (AFCA) on hard clinical endpoints remains controversial.

OBJECTIVE

Our aim was to conduct a random-effect model meta-analysis on efficacy data from high-quality large matched database/registry studies and randomized clinical trials. We compared long-term all-cause mortality, stroke, and hospitalization for heart failure in patients undergoing AFCA vs patients treated with medical therapy alone (rhythm and/or rate control medications) in a general AF population.

METHODS AND RESULTS

PubMed/MEDLINE and Embase databases were screened and a total of nine studies were selected (one randomized clinical trial-CABANA-and eight large matched population studies). A total of 241 372 patients (27 711 in the ablation group, 213 661 in the nonablation group) were included. After a median follow-up of 3.5 years, AFCA decreased the risk of mortality (hazard ratio [HR], 0.62; 95% confidence interval [CI], 0.54-0.72; I² = 54%; number needed to treat [NNT] = 28), stroke (HR, 0.63; 95% CI, 0.56-0.70; I²  = 23%; NNT = 59) and hospitalization for heart failure (HR, 0.64; 95% CI, 0.51-0.80; I²  = 28%; NNT = 33) compared with AF patients treated with medical therapy alone.

CONCLUSION

Based on the currently available efficacy and effectiveness evidence, AFCA significantly reduces the risk of death, stroke, and hospitalization compared with medical therapy alone.

Reproductive outcomes and Y chromosome instability in radiation-exposed male workers in cardiac catheterization laboratory

Occupational radiation exposure may impact the reproductive outcome of male workers in the cardiac catheterization laboratory (cath Lab) who receive a dose of ~1-10 mSv/year. An increased copy number variation (CNV) in azoospermia factor region c (AZFc) of the Y chromosome is a marker of spermatogenic failure, previously associated with radiation exposure. This study sought to investigate the association between paternal exposure in the Cath Lab and adverse reproductive outcomes as well as to assess the induction of CNV in the AZFc region. In a case-control study, we enrolled 193 catheterization lab workers (Group I) and 164 age-matched unexposed controls (Group II). Reproductive outcomes were assessed through a structured questionnaire. Two sequence-tagged sites (SY1197 and SY579) in AZFc region were evaluated by qRT-PCR in 83 exposed and 47 unexposed subjects. Exposed workers had a higher prevalence of low birth weight in offspring (Group I = 13% vs. II = 5.3%, P = 0.02; OR_adjusted = 2.7; 95% CI: 1.1-6.3; P = 0.02). The mean of CNV (microdeletion and microduplication) for SY1197 was significantly higher in the exposed workers (Group I = 1.53 ± 0.85 vs. Group II = 1.02 ± 0.41; P = 0.0005). Despite the study design limitations, our findings show that chronic occupational radiation exposure of male workers is correlated with higher prevalence of low birth weight in offspring and instability in the Y chromosome AZFc region. Environ. Mol. Mutagen. 61:361-368, 2020. © 2019 Wiley Periodicals, Inc.

Ventricular conduction delay as marker of risk in Brugada Syndrome. Results from the analysis of clinical and electrocardiographic features of a large cohort of patients

BACKGROUND

Brugada Syndrome is a genetic arrhythmogenic disease with a variable clinical spectrum. The role of clinical and ECG parameters in the risk stratification is still uncertain.

AIMS

In a large cohort of Brugada patients we analysed clinical and ECG features to determine the variables with prognostic value for the occurrence of a first documented arrhythmic event and for recurrences.

METHODS

We enrolled 614 patients, subdivided into 3 groups according to their clinical presentation: 531 (88%) asymptomatic, 69 (10%) with previous unexplained syncope and 14 (2%) with aborted sudden death. We also compared the ECG characteristics of patients with a single documented arrhythmic event (either at presentation or at follow-up, 17 patients), with those of patients with arrhythmic recurrences (13 patients).

RESULTS

The event rate was 1.3% in the asymptomatic patients and 15% among patients with unexplained syncope (median follow-up 6 years), p < 0.0001. In both groups a QRS duration ≥110 ms in lead II and/or V6 and/or S wave duration ≥40 ms in lead I and/or II were significant risk factors for the occurrence and timing of events at follow-up. The same ECG risk factors were also significantly associated with arrhythmic recurrences.

CONCLUSIONS

The arrhythmic risk of Brugada patients is related not only to the symptoms at presentation, but also to the presence of a ventricular conduction delay (QRS duration ≥ 110 ms and/or S wave duration ≥ 40 ms). The ECG conduction parameters also affect the timing of events and recurrences.

P4355Echocardiographic estimation of right ventricle wall tension: hemodynamic comparison and long term follow up

Introduction

Prognosis in pulmonary hypertension (PH) is strictly linked to right ventricle (RV) failure, which results from uncoupling between RV and the superimposed pressure load; in first phases, coupling between these two actors still be preserved, at the price of augmented right ventricle wall tension (RVWT).

Purpose

We sought to describe how to estimate RVWT with echocardiography, how it correlates with RV hemodynamics and if it may predict prognosis.

Methods

A total of 190 patients without overt RV failure, with suspected pulmonary hypertension (PH) to a previous echocardiography, underwent to right heart catheterization (RHC) and nearly-simultaneous echocardiography. We estimated RVWT according to Laplace law (RV length × tricuspid regurgitation peak gradient [TRPG]), in order to predict initial RV stress, and was correlated with RV hemodynamic profile; its potential prognostic impact was tested along with canonical RV function parameters.

Results

In patients enrolled in our study, RVWT correlated significantly with invasive estimation of right ventricle end diastolic pressure (R 0.343, p<0.001); a significant relationship between RVWT and several hemodynamic variables was observed (mean pulmonary artery pressure, pulmonary artery compliance, transpulmonary gradient, pulmonary vascular resistance, RV telediastolic pressure, right atrial pressure, RV stroke work index; all p<0.001). At a mean follow up of five years and three months, only RVWT predicted all-cause mortality (p 0.036), while TAPSE, TAPSE/TRPG, RV fractional area change and RV S' wave did not.

Correlation: RWVT and RV hemodynamic Hemodynamic variable R R2 p value Mean pulmonary artery pressure 0.742 0.550 <0.001 RV differential pressure 0.794 0.630 <0.001 Pulmonary artery pulsatory pressure 0.740 0.547 <0.001 Mean right atrium pressure 0.326 0.106 <0.001 Cardiac index/right atrial pressure 0.209 0.044 0.012 RV stroke work index 0.588 0.346 <0.001 Pulmonary artery compliance 0.449 0.202 <0.001 Pulmonary vascular resistance 0.531 0.282 <0.001

Prognosis: different RV variables

Discussion

We identified a novel bedside echocardiographic predictor of altered RV hemodynamic, which results precociously altered in patients without overt RV failure, and able to predict all cause mortality at a long term follow up. Further studies are needed to confirm its role in PH patients.

P6580Prevalence and clinical significance of latent Brugada syndrome in juvenile lone atrial fibrillation

Introduction

Brugada syndrome (BrS) cause about 20% of sudden cardiac death (SCD) in young healthy adults. Nearly 20% of Brugada patients develop supraventricular arrhythmias, mostly atrial fibrillation (AF). But whether lone AF may be the first clinical manifestation in young patients with latent BrS remains unclear.

Purpose

To estimate the prevalence and clinical significance of latent Brugada ECG pattern in young population (age ≤45 years) with lone AF.

Methods

A total of 78 patients with lone atrial fibrillation (mean age 35±7) were selected from 111 young patients with juvenile atrial fibrillation (age ≤45 years) between January 2015 and November 2017. All patients were clinically evaluated. Moreover 12 lead-24H Holter ECG and pharmacological class 1C antiarrhythmic drug (AAD) test were done for high suspicious cases of Brugada ECG. The diagnosis of Brugada ECG pattern was established according to the second consensus report criteria 2005 and since 2013, according to HRS/EHRA/APHRS expert consensus statement.

Results

According to the study protocol, we considered two groups of patients, group 1: 13 patients (16.7%; mean age 37±8) were diagnosed with type 1 Brugada ECG pattern (3 during class 1C AADs therapy and 10 induced by class 1C AAD test), group 2: 65 patients (83%; mean age 35±7) diagnosed as lone AF without type 1 Brugada ECG. The clinical characteristics of the two groups are described in table 1. Regarding to group 1, two patients had positive electrophysiological study with subsequent ICD implantation and genetic test for SCN5A mutation was positive in 3 patients.

Table 1. G1, G2 clinical characteristics Patients characteristics Group 1 (n=13) Group 2 (n=65) P value Mean age (years) 37±8 35±7 0.42 Gender (Male %) 7 (54%) 54 (83%) 0.02 Family history of BrS 2 (15%) 0 (0%) 0.03 Family history of SCD 1 (8%) 1 (1.5%) 0.20 Syncope 4 (31%) 5 (8%) 0.02 Sick Sinus Syndrome 1 (8%) 7 (11%) 0.70 Paroxysmal AF 12 (92%) 54 (83%) 0.40 Suspected basal ECG for BrS 13 (100%) 28 (43%) <0.01 Statistical test is considered significant when p value <0.05.

Conclusions

Up to our knowledge this study is the first one that estimate the prevalence of latent BrS in juvenile lone AF patients. Young patients with lone AF had a high prevalence of latent BrS. Syncope, family history of SCD and family history of BrS are significant indicators of the presence of latent BrS in young patients with lone atrial fibrillation.

Thermodynamic properties of atrial fibrillation cryoablation: a model-based approach to improve knowledge on energy delivery

The objective of this study is to describe a suitable model of atrial fibrillation cryoablation thermodynamic properties. Three different thermal loads were applied to a cylindrical copper element simulating the cryoprobe, thermally coupled with a Peltier stack producing the freezing effect, and in contact with a bovine liver sample. Thermal events occurring inside the samples were measured using mirror image technique. Heat subtracted flux during ice formation and minimum temperature measured at probe-tissue interface were, respectively, 1.33 W cm^-2 and -27.8°C for Sample#0, 1.88 W cm^-2 and -35.6°C for Sample#1 and 1.82 W cm^-2 and 1.44 W cm^-2 before and after the ice trigger, respectively, and -29.3°C for Sample#2. Ice trigger temperature was around -8.5°C for Sample#0 and Sample#2, and -10.4°C for Sample#1. In all the investigated samples, ice front penetration was proportional to the square root of time and its velocity depended on the heat flux subtracted. The fraction of the useful energy spent for ice formation was less than 60% for Sample#0, and about 80% for Sample#1 and for Sample#2, before the reduction of the removed heat flux. Freezing time exceeding a cut-off, according to the heat subtracted flux, does not improve the procedure effectiveness and is detrimental to the surrounding tissues.