Clinical trials

The aim of the study is to assess sex-related differences in patients who underwent a first ablation procedure for paroxysmal or persistent AF, guided by the personalized ablation strategy of the BY-LAWT protocol. Specifically, to compare anatomical characteristics, procedural parameters, and clinical outcomes between sexes.

Atrial fibrillation is the most common arrhythmia in the population and is often caused by arrhythmogenic foci located in the pulmonary veins. For this reason, the first attempt in atrial fibrillation catheter ablation procedures is to isolate these structures (the procedure is called indeed "pulmonary vein isolation"), which results in abolishment of arrhythmia recurrence in up to 85% of patients at short and mid-term follow-up. However, a subset of patients experience an atrial tachyarrhytmia recurrence and a second catheter ablation procedure has to be performed. If pulmary vein isolation is proven to be durable, other arrhythmogenic foci could be implicated in arrhythmia recurrence. Among extra-pulmonary vein foci, superior vena cava has been described as the most frequently involved in atrial fibrillation initiation. Therefore, its ablation could result in improved freedom from atrial fibrillation episodes during follow-up. In the present study, we sought to evaluate the safety and effectiveness of empirical superior vena cava isolation in terms of arrhythmia-free survival in patients with paroxysmal atrial fibrillation recurrence despite durable pulmonary vein isolation.

Risk stratification for sudden cardiac death (SCD) in patients with non-ischemic cardiomyopathy (NICM) remains suboptimal. Although current guidelines rely on severe left ventricular systolic dysfunction (left ventricular ejection fraction (LVEF) \< 35%) as key predictor of arrhythmic risk and clinical indication of prophylactic implantable cardioverter defibrillator (ICD), this approach seems inadequate, since registries report that only a minority of NICM ICD carriers experience an appropriate ICD shock during follow-up, whereas out-of-hospital cardiac arrests (OHCA) occur in patients with LVEF\>35% in up to 80% of cases. Moreover, pivotal primary prevention trials (DANISH trial, long-term outcome of the SCD-HeFT trial) failed to demonstrate a net mortality benefit of ICD in patients with NICM. As for most structural heart diseases (SHD), scar-related reentry has been addressed as the pathophysiological mechanism of ventricular arrhythmias (VAs) in patients with NICM, with fibrotic tissue being the substrate of this reentry. Late gadolinium enhancement cardiac magnetic resonance (LGE-CMR) is the gold standard for the non-invasive visualization and characterization of the myocardial fibrosis and according to retrospective studies is detected in nearly 30% of patients with NICM. In latest years, several studies and subsequent metanalyses have explored the correlation between CMR-detected LGE and occurrence of VAs, showing that presence, extent, location (septal vs lateral) and patten (focal vs multifocal vs ring-like) of non-ischemic fibrosis help in stratifying arrhythmic risk. Nonetheless, scar heterogeneity (that is, inherent composition of dense scars vs border zone (BZ), presence of strands of viable myocardium within the scar) has been indicated as a potential novel predictor of VAs. In a recent prospective multicenter registry on patients with class I indication for cardiac resynchronization therapy (CRT) (\>60% with NICM), not only scar mass, but even border zone (BZ) mass and presence of BZ channels were identified as independent predictors for VT occurrence in NICM patients. This BZ mass and BZ channels can be automatically identified using a commercially available, post-processing imaging platform named ADAS 3D LV (ADAS3D Medical SL, Barcelona, Spain), with FDA 510(k) Clearance and CE Mark approval. Thus, CMR-derived BZ mass might be used as an automatically reproducible criterium to reclassify those patients with NICM at highest risk for developing VAs/SCD in a relatively short period of at least 2 years. In the present cohort study, the investigators sought to: i) evaluate the usefulness of CMR-derived BZ mass measurement and identification of heterogeneous tissue channels (HTC) (among other scar characteristics derived from image post-processing) to predict the occurrence of VT events in an international, retrospective, multicenter, unselected series of patients with NICM without previous arrhythmia evidence (main study); ii) subsequently validate these predictors of VT occurrence in a prospectively-collected multicenter cohort study (substudy 1); iii) retrospectively evaluate in the subset of patients with \> 1 LGE-CMR performed as part of standard clinical practice if any change in BZ mass and HTC presence occurs over time and if this correlates with occurrence of VAs (substudy 2).

Ventricular arrhythmias (VAs) are frequently associated with structural heart diseases (SHD) such as myocardial infarction, myocarditis, and non-ischemic cardiomyopathies. Myocardial fibrotic tissue plays a central role in the genesis and the maintenance of re-entrant VAs associated with post-myocarditis sequelae and late gadolinium enhancement cardiac magnetic resonance (LGE-CMR) has proven to be a useful tool for the non-invasive characterization of the scarred tissue and the underlying arrhythmogenic substrate. Moreover, a post-processing imaging platform named ADAS 3D LV (ADAS3D Medical SL, Barcelona, Spain) allows to analyze the CMR-derived data and to characterize the scar architecture, differentiating between dense (scar core zone) and more diffuse (border zone \[BZ\]) fibrosis, and identifying the BZ channels (BZCs) that are strands of healthy myocardial tissue within zones of unexcitable tissue and connect areas of normal myocardium. It was described that BZCs could serve as slow-conducting reentrant pathways and are critical to entail VA in ischemic and non-ischemic heart disease. However, the pathophysiological role and the correlation between scar architecture and VAs in post-myocarditis patients is yet to be defined. To date, the standard-of-care evaluation for primary prevention implantable cardioverter-defibrillator (ICD) therapy is LVEF-based, leading to the fact that the contemporary rate of appropriated therapies is very low. Moreover, events may also occur in patients with normal to moderately depressed LVEF, which is particularly relevant, as it constitutes the most prevalent population of patients exposed to an increased risk of VAs. Multiple studies reported that LGE at CMR is a strong and specific predictor of VT occurrence and sudden death in post-myocarditis patients. There were reported cases in which even after the normalization of LVEF, the extension of LGE, the scar architecture, and the presence of BZCs at cMR analysis are determinants of the arrhythmic risk in post-myocarditis patients. The Investigators sought to evaluate the usefulness of CMR-derived scar architecture analysis to predict the occurrence of VT events in an international, multicenter, case-control study on unselected post-myocarditis patients without previous arrhythmia evidence. Aim of the study is also to assess the net reclassification improvement (NRI) for the indication of primary prevention ICD implantation using CMR data and post-processing data as compared to LVEF-based indication

Over recent years, pulmonary vein isolation (PVI) procedures have demonstrated progressively enhanced efficacy and safety, resulting in a substantial increase in the number of atrial fibrillation ablations, not only as a first-line treatment but also for repeat procedures. However, there is still a notable lack of randomized evidence in this area, which limits guidance and decision-making in clinical practice. Recently, the investigators found that employing short-coupled atrial extrastimuli revealed highly fragmented or double atrial evoked electrograms (EGMs) in AF patients, termed as hidden slow conduction (HSC). Identifying HSC sites may provide insight into the early identification of the arrhythmogenic substrate, offering a potential target for ablation This multi-center, prospective, randomized, controlled trial will include two arms: one investigational (PV reconnection + HSC) and one control (PV reconnection). All the subjects will be followed for 12 months after the ablation procedure. The aim of our study is to investigate the impact of ablating HSC sites on arrhythmia recurrence in repeat ablation procedures. The hypothesis is that the additional ablation of HSC zones may improve the freedom from atrial arrhythmia recurrence after repeat ablation procedure.

Outflow tract ventricular arrhythmia (OTVA) is the most common type of ventricular arrhythmia, and catheter ablation (CA) is the primary treatment option for patients experiencing symptoms. Accurately identifying the origin site of OTVA is essential for effective catheter ablation, minimizing procedural risks, and enhancing treatment success. However, most studies that developed algorithms or scoring systems for distinguishing OTVA origins excluded participants with structural heart disease and those with paced rhythms from their study groups. A recent prospective evaluation of a hybrid score (HS) that integrates both clinical and ECG data to predict OTVA-SOO, including patients with cardiac implantable electronic devices and those with structural heart disease in our study. The presented study aimed to assess the effectiveness of the previously described hybrid algorithm in predicting OTVA-SOO in a patient population characterized by a wide basal QRS due to intraventricular conduction defects or paced rhythms. The Hybrid Score The Hybrid Score (HS), involves a sum of points based on clinical and ECG characteristics. Points are assigned as follows: one point each for being over 50 years old, male, and having arterial hypertension. ECG-based points are allocated according to QRS transition: 3 points for a transition in V1, 2 points for V2, 1 point for V3 if the R-wave in V3 is greater than 1 mV; 1 point is subtracted if V3 has an R-wave less than 1 mV, and further deductions or additions apply for transitions up to V6. A score ≤ 1 suggests an RVOT origin, whereas ≥ 2 suggests an LVOT origin. ECGs were recorded with a standard configuration at a 25 mm/s sweep speed. Premature Ventricular Contraction (PVC) Ablation Activation mapping of spontaneous OTVAs was conducted. The procedure aimed to abolish spontaneous OTVAs, with the site of ablation marking the site of origin (SOO). Collected data * Patient Information and Consent (procedure must be done within 60 days of consent) * Demographics (age, gender, etc.) * Vital signs (length, weight, etc.) * Medical history, including cardiovascular risk factors, cardiomyopathy and drugs * ECG data * Echocardiographic data (left ventricular ejection fraction and left ventricular end-diastolic diameter) * Procedure data (number of radiofrequency applications, site of effective ablation, total radiofrequency time, total fluoro time, points mapping, procedure time) * Adverse Events