BACKGROUND:The impact of various imaging techniques on the safety and outcomes of atrial fibrillation (AF) ablation remains unclear. Intra-procedural three-dimensional rotational angiography (3DRA) is the least used imaging method despite some benefits. The aim is to assess its impact on procedural success, safety, and long-term outcomes of cryoballoon (CB) ablation. METHODS:A single-center, unblinded, randomized controlled trial enrolled 134 patients (64.2% male, 59.0 ± 11.6 years) with paroxysmal (93.3%) or early-persistent AF. Participants were randomized to no imaging or 3DRA. Angiographic images were used to guide the ablation. Follow-up data regarding procedure and AF recurrence were collected during 12 months. RESULTS:66 (49.3%) patients underwent 3DRA. In the control group, 2 (2.9%) pulmonary veins (PVs) could not be isolated, compared with 3 (4.5%) in the 3DRA group (p = 0.636). Procedure was longer in the 3DRA group (86.7 ± 27.8 min vs. 67.2 ± 22.1 min, p < 0.001), with significantly higher radiation dose (447.4 ± 485.0 mGy vs. 133.9 ± 166.2 mGy, p < 0.001) and contrast use (131.8 ± 28.3 mL vs. 40.8 ± 26.5 mL, p < 0.001). At 12 months, 88.2% of patients in the control group and 86.2% in the 3DRA group were free of AF (p = 0.798). CONCLUSION:3DRA did not improve procedural success or long-term outcomes of CB ablation but significantly increased procedure time, radiation dose, and contrast usage.

BackgroundPulmonary vein isolation (PVI) is the cornerstone of atrial fibrillation (AF) ablation, but non-pulmonary vein triggers, particularly the superior vena cava (SVC), may contribute to recurrence. Cryoballoon (CB) ablation has been applied for empirical SVC isolation (SVCI), yet evidence is limited and inconsistent.ObjectiveThe CISPAF trial evaluated the feasibility, safety, and efficacy of adjunctive SVCI using a fourth-generation CB in patients undergoing first-time PVI for paroxysmal AF (PAF).MethodsCISPAF was a prospective, randomized, single-centre trial including 149 patients with PAF assigned to PVI alone (n = 74) or PVI + SVCI (n = 75). Ablations were performed with a fourth-generation 28-mm CB. The primary endpoint was 12-month freedom from AF; safety endpoints included a composite of major procedure-related complications, with particular attention to phrenic nerve injury (PNI) and sinus node impairment.ResultsAcute PVI was achieved in all patients. SVCI succeeded in 62/75 (84.9%), with real-time isolation in 45 (60.0%). Major complications occurred only in the PVI + SVCI group (2.6% vs. 0%), including one sinus node injury requiring pacemaker implantation and one vascular complication requiring surgical repair. Transient or impending PNI and transient bradycardia/junctional rhythm were more frequent with PVI + SVCI (34.7% vs. 10.8% and 17.3% vs. 2.7%; respectively; both p < 0.01), but these events were self-limited and resolved after interruption of energy delivery. At 12 months, AF-free survival did not differ significantly between groups (89.3% vs. 79.7%; log-rank p = 0.096).ConclusionAdjunctive SVCI using a fourth-generation CB did not demonstrate a statistically significant improvement in arrhythmia-free survival at one year and was associated with a higher incidence of procedure-related complications. These findings do not support the routine use of empirical SVCI during initial CB ablation for PAF and should be interpreted as hypothesis-generating.

Background/Objectives: The causal role of homocysteine (tHcy) in atrial fibrillation (AF) is unclear. To (re)explore the causal effect of tHcy in non-valvular AF (NVAF). Methods: In a case–control study in overweight/obese adults, cases were patients with NVAF and controls were their peers without AF. They were assessed for clinical, laboratory, and echocardiographic particulars and were genotyped for MTHFR 677C>T (rs1801133), PITX2 C>T (rs2200733), and KCNE1 112A>G (rs1805127) polymorphisms. We employed a conventional case–control, mediation analysis, and one-sample Mendelian randomization (MR) analyses to evaluate forward and reverse tHcy-NVAF associations. Results: We enrolled 180 cases and 179 controls. With an extensive confounder control (i) the MTHFR 677C>T variant allele associated with higher tHcy; (ii) PITX2 C>T variant allele associated with NVAF while KCNE1 112A>G did not; (iii) MTHFR variant associated with NVAF indirectly, through tHcy assuming wild type but not variant genotype (exposure–mediator interaction); (iv) considering all subjects, tHcy associated with NVAF through the effect on renal function and NT-proBNP levels (no exposure–mediator interaction); (v) considering MTHFR wild-type subjects (n = 160), tHcy “directly” strongly associated with NVAF, and considering variant carriers (n = 199), it indirectly associated with NVAF and directly tended to associate with a lower probability of NVAF; (vi) in MR analysis (MTHFR SNP instrument), tHcy associated with NVAF; and vii) mediation and MR analyses [PITX2 SNP (exposure/instrument)—NVAF, (mediator/exposure)—tHcy outcome] excluded the reverse tHcy-NVAF association. Conclusions: Data strongly support the causal role of tHcy in NVAF in overweight/obese patients and suggest that the effect might be modified by the MTHFR 677C>T variant allele.

Background:Implantable cardioverter defibrillators (ICDs) have significantly reduced the incidence of sudden cardiac death in patients with heart failure, particularly those with ischemic heart disease. However, the impact on overall mortality remains controversial, especially in non-ischemic heart failure patients. The Danish Study to Assess the Efficacy of ICDs in Patients with Non-Ischemic Systolic Heart Failure (DANISH) trial and subsequent studies have questioned the efficacy of ICDs in this population, particularly among older patients. The present study aimed to evaluate survival outcomes and predictors in a Croatian cohort of patients with an ICD or cardiac resynchronization therapy defibrillator (CRT-D) device. Methods:This retrospective cohort study analyzed data from 614 patients who received an ICD or CRT-D device at KBC Zagreb between 2009 and 2018. Patient data, including demographic information, device indication, and clinical parameters, were collected at the time of implantation. Follow-up data were systematically recorded to assess device activation and survival outcomes. Statistical analyses included a detailed descriptive analysis, Kaplan-Meier survival estimates, and Cox regression models. Results:The cohort consisted predominantly of males (83.4%), with a mean age of 58.7 years. Most had reduced left ventricular ejection fraction (mean 31.4%) and were classified as New York Heart Association (NYHA) class II or III. Over a median follow-up of 48.4 months, 36.6% of patients died. Device activation occurred in 30.3% of patients, with appropriate activation observed in 88.2% of these cases. Cox regression identified age, non-sustained ventricular tachycardia (NSVT), and decompensation history as significant survival predictors. Conclusions:This study confirmed that appropriate device activation improved survival in patients with an ICD/CRT-D. Age, NSVT, and history of decompensation were key predictors of device activation and survival outcomes. These findings underscore the need for individualized patient assessment when considering inserting ICDs, particularly in non-ischemic heart failure patients. Further research is needed to refine clinical guidelines and optimize patient selection for ICD therapy.

Pulmonary vein isolation (PVI) is the standard treatment for patients with atrial fibrillation (AF). Superior vena cava (SVC) is one of the most important non-pulmonary origins of AF and some studies have reported that empiric superior vena cava isolation (SVCi) could improve outcomes in ablation of paroxysmal atrial fibrillation (PAF). Nevertheless, data from randomized trials are lacking. To evaluate the safety and efficacy of additional SVCi using a fourth-generation cryoballoon to the standard PVI in patients with PAF. We designed an unblinded, prospective, single-center randomized trial, enrolling consecutive patients with PAF who were randomized in a 1:1 fashion to receive either standard cryoballoon PVI or PVI with additional SVCi. Primary efficacy endpoints were acute PVI, acute SVCi, and freedom from AF at a one-year follow-up. The safety endpoint was a composite of overall periprocedural complications. A total of 149 patients (62.4% male; median age 63 years; median CHA2DS2-VASc 2) with paroxysmal AF were randomized (PVI-only: 74; PVI+SVCi: 75). Acute PVI was achieved in all patients in both groups. SVCi was achieved in 62 (84.9%) patients in the PVI+SVCi group, with impending right phrenic nerve palsy (PNP) or loss of sinus rhythm being the most common reasons for SVCi interruption (15.1%; N=13). There was no significant difference in major complications between the groups (0% vs 1.3%; p=0.157). One patient eventually received a permanent AAI pacemaker due to a sinus node injury. The PVI+SVCi group showed a higher rate of overall complications in comparison with the PVI-only group (32% vs 13.5%; p < 0.001), mainly due to the impending or transient right PNP. There were no persistent PNP cases. Bradycardia or junctional rhythm was observed during SVCi in 15 (20%) patients. At the end of the 12-month follow-up, the PVI+SVCi group showed a trend toward higher freedom from AF compared to the PVI-only group, although statistical significance was not reached (89.4% vs 79.8%; log-rank test p = 0.096). Additional SVCi did not significantly improve freedom from AF at a one-year follow-up in comparison with conventional PVI by fourth-generation cryoballoon, and it was associated with a higher risk of periprocedural complications.Freedom from AF in PVI vs. PVI + SVCi

The ablation of ventricular tachycardia (VT) is becoming the mainstay of therapy in patients with sustained VT. The development of inHEART software as a three-dimensional (3D) cardiac model based on high-resolution cross-section computed tomography (CT) imaging allows preoperative planning for VT ablations and therefore targeted elimination of VT isthmi. To report a single-center experience regarding the use of inHEART imaging software for VT ablations and compare the procedural characteristics and outcomes to legacy procedures. This was a retrospective, single-center analysis of 2 patient cohorts. All patients experienced sustained VT that required DC conversion before the ablation. First cohort consisted of twenty consecutive ablation cases using inHEART imaging software. Second cohort consisted of the last 20 consecutive cases that were performed conventionally. The procedures were performed using Carto3 system with high density substrate mapping in all patients and inHEART model merge in the first cohort. Primary endpoint was non-inducibility of VT. Secondary endpoint was the absence of VT recurrence during a three-month follow up verified by ICD interrogation. A total of 40 patients (mean age 63.3 ± 10.9 years, male 92.5%) were included in the study. Majority of patients suffered from ischemic cardiomyopathy (75.0% vs. 95.0%, p=0.176). There were no significant differences in patients’ characteristics. Furthermore, there was no significant differences in procedural characteristics (Table 1). There were 3 major complications in total, and all consisted of total AV block (2 in inHEART cohort vs. 1 in conventional, p=0.548). Moreover, there was no significant differences both for primary and secondary outcomes (Table 2). The use of CT inHEART 3D cardiac model enables more detailed preoperative planning for VT ablations. There was no significant difference in procedural characteristics, complications and outcomes in two cohorts. Further research and application of this new approach is needed to demonstrate potential clinical benefits.

Pulmonary vein isolation (PVI) is the gold-standard treatment for rhythm control in atrial fibrillation (AF). Cryoballoon (CB) technology is a single-shot technology with established superiority over drug therapy for paroxysmal AF (PAF)¹. By providing two different balloon dimensions (28 and 31 mm), novel resizable CB may improve the effectiveness of pulmonary vein isolation². This study compares a new resizable CB with the fixed-size 28 mm CB. To evaluate the non-inferiority of the resizable POLARx FIT cryoballoon compared to fixed-size Arctic Front Advance Pro cryoballoon. This two-center randomized controlled trial so far enrolled 155 PAF patients with indication for PVI, assigning them in a 1:1 ratio to either the Medtronic 4th generation fixed-size CB (Arctic Front Advance Pro) or the Boston Scientific resizable CB (POLARx FIT). Follow-ups include clinic visits and 24-hour ECG recordings at 3, 6, and 12 months, with additional visits every six months. Among the 155 recruited patients (75 in the Polar group, 80 in the Arctic group), 64 (41.3%) were female, with an average age of 60.4 ± 12.1 years. Groups were similar regarding sex and age. Procedure duration in the Polar group was 67.0 ± 20.2 min compared to 63.5 ± 20.2 min in the Arctic group (p=0.27). Fluoroscopy times and dose area products were comparable as well, with 8.3 ± 7.0 min and 742 ± 753 mcGym² in the Polar group and 7.9 ± 7.1 min and 617 ± 1016 mcGym² in the Arctic group (respectively p = 0.69 and p = 0.39). Complete PVI was achieved in 98.7% of Polar cases and 96.3% of Arctic cases (p=0.36). The Polar group exhibited somewhat higher incidence of impending or transient phrenic nerve palsy (5 cases) compared to the Arctic group (2 cases, p = 0.22). There was one Polar patient who developed effusive pericarditis. Vascular complications were detected in 3 Polar patients (arteriovenous fistula ± pseudoaneurysm) and one Arctic patient (arteriovenous fistula with pseudoaneurysm). No other complications were noted. The differences between the groups were not statistically significant. In our study, the new resizable POLARx FIT cryoballoon was equivalent to the Arctic Front Advance Pro CB regarding procedure duration, fluoroscopy time, radiation dose, and acute PVI success. Only complications related to venous access were reported. Ongoing follow-up is essential to establish non-inferiority in terms of long-term outcomes.

Background/Objectives: Pulmonary vein isolation (PVI) is the standard treatment for atrial fibrillation (AF), but medium-term success rates remain suboptimal. Non-pulmonary vein triggers, particularly from the superior vena cava (SVC), contribute to AF recurrence. Empirical SVC isolation (SVCi) in addition to standard PVI may improve outcomes. This study evaluated the acute procedural efficacy and safety of PVI with adjunctive SVCi versus PVI alone in patients with paroxysmal AF (PAF). Methods: In this randomized, controlled, single-center study, 149 patients with PAF were assigned to either standard PVI (n = 74) or PVI with adjunctive empirical SVCi (n = 75) using a fourth-generation CB. Primary endpoints were acute procedural success and the incidence of procedure-related complications, particularly phrenic nerve injury (PNI) and sinus node dysfunction. Results: Acute PVI was achieved in all patients; SVCi was successful in 84.9% of the PVI + SVCi group. Major complication rates were low and comparable between groups (0% vs. 2.6%, p = 0.157). However, the overall complication rate was significantly higher in the PVI + SVCi group (50.6% vs. 6.8%, p < 0.001), driven primarily by transient or impending right PNI (38.6% vs. 6.8%, p < 0.001) and sinus node dysfunction. All PNI events resolved before the end of the procedure. Conclusions: Empirical SVCi using a fourth-generation CB is feasible and generally safe, but carries a higher risk of transient PNI and reversible sinus node dysfunction. Therefore, CB SVCi should be approached with caution. Further studies are needed to evaluate long-term outcomes and assess whether the potential benefits outweigh these procedural risks.

Implantable cardioverter-defibrillators (ICDs) reduce sudden cardiac death (SCD) in heart failure (HF) patients, especially in those with ischemic cardiomyopathy (ICM). However, the overall impact on mortality in non-ischemic cardiomyopathy (NICM) is still debated. The DANISH trial raised questions about ICD efficacy in NICM patients, particularly in older individuals, sparking concerns regarding patient selection and the risk-benefit balance. This study evaluates survival outcomes, device activation, and mortality predictors in ICM and NICM patients with implanted ICD devices. A total of 786 patients who underwent ICD (75%) or CRT-D (25%) implantation between 2009 and 2018 were included in this retrospective cohort study. The mean patient age was 58.2 ± 13.6 years, with 80.7% being male and a reduced left ventricular ejection fraction (LVEF) of 31.9 ± 12.4%. The primary outcome was all-cause mortality, and secondary outcomes included device activation (appropriate or inappropriate) and its correlation with survival. Kaplan-Meier survival estimates and Cox proportional hazard models were used, with comparisons between ischemic and non-ischemic cardiomyopathy patients and primary versus secondary prevention groups. Over follow-up period of +/-47.3 months, 35.2% died. Device activation occurred in 29.1% of patients, with 86% being appropriate. ICM patients had a higher rate of appropriate activations compared to NICM patients (28.0% vs. 23.0%), while inappropriate activations were more frequent in NICM patients (6.1% vs. 1.5%, p=0.003). Device activation was associated with a significant survival advantage (p<0.001). Mortality predictors included older age, non-sustained ventricular tachycardia (NSVT), and a history of decompensation. Cox regression analysis confirmed these as independent mortality predictors, with hazard ratios of age (HR=1.032; p<0.001), NSVT (HR=2.403; p<0.001), and decompensation (HR=1.931; p<0.001). In comparison with the DANISH trial, which reported no significant reduction in all-cause mortality in NICM patients over 70 years old, this study found similar age-dependent survival benefits. Younger patients (<70 years), (especialy with NICM), showed greater survival benefits from ICD implantation. Results emphasize the importance of careful patient selection, especially in older patients, where the benefits of ICDs must be balanced against the risks of inappropriate shocks and device complications. This study found that ICD implantation improved survival. Age, NSVT, and decompensation were key predictors of mortality and device activation, highlighting the need for individualized patient assessments. In line with the DANISH trial, our findings suggest that younger NICM patients benefit more from ICD implantation, while in older populations, the risks and benefits should be carefully weighed.

Evidence indicates that pulmonary vein isolation (PVI) is more effective than antiarrhythmic medications in maintaining sinus rhythm in atrial fibrillation (AF) and enhancing quality of life¹. As such, PVI is recommended as a first-line rhythm control treatment for paroxysmal AF patients². Recent research highlights that early rhythm control may be associated with better clinical outcomes³. However, significant barriers in patient education and healthcare logistics hinder the widespread adoption of this approach in clinical practice. To evaluate the effect of streamline cardiology referral for patients presenting with AF to the emergency room (ER). In January 2021 a special clinic was introduced to enable speedy cardiology follow-up for patients presenting to the ER with the first episode of any supraventricular tachycardia (SVT). This analysis included patients with AF who weren’t previously referred for PVI. Patients with known permanent AF, those who previously underwent PVI and those with other SVTs referred to the clinic were excluded from the study. Data was anonymously collected from hospital medical records. Between January 2021 and May 2024, a total of 103 patients with AF were evaluated (63.5 ± 12.7 years-old, 48.5% female). Of these, 73 (70.9%) presented to the ER with the first episode of AF before being referred. The majority were diagnosed with paroxysmal AF (91.3%), followed by persistent (4.9%) and permanent AF (3.9%). The average wait time from the ER to cardiology consultation was 31 ± 30 days. PVI was recommended after the first consultation for 35.0% of patients, following additional assessments in 8.7% or after experiencing AF recurrence in 5.8% of cases. Notably, 25.2% of patients chose not to undergo the PVI. The decision against recommending ablation was primarily influenced by a single episode of AF in 56.6% of cases, perceived low chances of success in 22.6%, presence of permanent AF in 11.3%, ongoing evaluations in 7.5% and the comorbidity concerns in 1.9% of patients. Ultimately, 29 ablations were performed (28.2% of the cohort) with 13 ablations conducted following a single episode of AF. The average time from ER to PVI was 9.0 ± 6.6 months, while the time from the first documented AF episode to PVI was 27.3 ± 53.7 months—significantly shorter than the institutional PVI registry average of 48.7 ± 60.9 months (p=0.02). This initiative led to a notable reduction in the time from the first documented AF episode to PVI compared to historical data. Despite challenges such as patient reluctance and various clinical factors influencing treatment decisions, this can help initiate early rhythm control and potentially improve patients outcomes. Further efforts are needed to address barriers to patient acceptance and optimise the referral process to maximise the benefits of early intervention.

Background Challenges or opportunities remain for improvement of pulsed field ablation (PFA) for atrial fibrillation (AF). Objective BURST-AF evaluated safety and lesion durability of a novel PFA system, Coherent Sine Burst Electroporation (CSE). Methods Patients with AF who failed ≥ 1 antiarrhythmic drug and undergoing de novo ablation were included. The CSE system includes a PFA generator and stylet-configurable catheter (circular, linear, focal). Pulmonary veins (PVs) were isolated with overlapping circular PFA applications. Ablation of additional lesions (posterior wall [PW]/cavotricuspid isthmus [CTI]) was performed at investigator discretion. Acute end point was isolation of PVs after a 20-minute waiting period. Chronic end point was isolation of PVs, bidirectional block (CTI), and/or absence of PW electrical activity at remap. Freedom from > 30 seconds of atrial arrhythmias was evaluated till 6 months. Results A total of 90 patients were enrolled (54% men, 62 years old, 60% paroxysmal AF). Targeted PVs (344) were isolated with 6.5 ± 1.7 PFA lesions/PV. PFA lesions for CTI and PW were 8.3 ± 4.7 and 14.4 ± 3.9, respectively. Procedure, catheter dwell, and fluoroscopy times were 93 ± 28 minutes, 54 ± 28 minutes, and 13.3 ± 5.5 minutes, respectively. Per PV isolation was 94.1% (317/337), and per patient isolation was 78.4% (69/88). Additional lesion set durability was 94.4% (102/108). At 6-month follow-up, 92.6% (63/68 patients) were free from atrial arrhythmias. One primary safety event of renal insufficiency was reported. Conclusion CSE PFA system durably isolated PVs, PW, and CTI with a low rate of complications in this first-in-human study. (CSE System Pilot Study in Patients with Atrial Fibrillation - BURST-AF, NCT05572047).

Background: Catheter ablation is an established first-line treatment for supraventricular tachycardia (SVT). Traditionally, these procedures have been performed under fluoroscopic guidance. The objective of this study was to demonstrate the feasibility and safety of a completely fluoroless approach, as well as to evaluate clinical outcomes. Methods: This retrospective, single-center analysis included two patient cohorts, comprising a total of 400 patients: 200 in the main (fluoroless) group and 200 in the control (fluoroscopy) group. In the main group, ablation was performed using a 3D mapping system and intracardiac echocardiography (ICE) without the use of fluoroscopy and lead aprons. In the control group, procedures were conducted under fluoroscopic guidance. The primary outcomes were feasibility and safety. Secondary outcomes included acute procedural success, defined as non-inducibility of tachycardia, and chronic success, measured as arrhythmia recurrence-free survival during a 6-month follow-up period. Results: Completely fluoroless ablation was successfully performed in all patients in the main group (100%). Procedures were shorter in the fluoroless group (59.0 ± 25.8 min vs. 72.7 ± 34.0 min, p < 0.001), with no difference in acute success rates (100% vs. 100%). No serious complications occurred in the main group, compared to one event in the control group (0 vs. 1.0, p = 0.313). Arrhythmia recurrence rates during follow-up were similar between groups (HR: 0.877, 95% CI: 0.367–2.097, p = 0.769). Conclusions: A completely fluoroless, “apron-less” approach to SVT ablation is feasible, with complication and success rates comparable to the traditional fluoroscopy-guided approach.

We aimed to investigate the feasibility and safety of zero-fluoro approach for the repeat atrial fibrillation (AF) procedures after initial cryoballoon (CB) ablation. We have performed a retrospective study on patients that have undergone repeat pulmonary vein isolation (PVI) procedures in our institution since zero-fluoro program was initiated in 2020. All patients received CB ablation for the initial procedure. Repeat procedures were performed under conscious sedation and with intracardiac echo (ICE) and 3D mapping system - without the use of fluoroscopy and lead aprons. We have analysed in total 50 patients (76% male, 57.9 ± 10.2 years old), 50% of which suffered from paroxysmal AF. All procedures were successfully performed without the use of fluoroscopy. The mean procedure time was 93.9 ± 27.1 min and the mean RF time was 825 ± 468 s. The mean of 0.98 ± 0.91 veins was reconnected per patient and 36% of patients did not have PV reconnections. In all patients successful PV isolation was performed, confirmed by entry and exit block. No major periprocedural complications were observed. After the mean follow up of 12.5 ± 3.4 months: 68% of mixed AF population patients were free from AF after one year. In our cohort of patients, zero-fluoro, apron-less approach for repeat PVI procedures after index cryoballoon ablation proved to be feasible and safe. Index CB ablation resulted with low rates of PV reconnections and mid-term results after repeat procedures are favourable.

Background: This study was conducted to evaluate compliance with guideline-directed optimal medical therapy (OMT) and its association with early implantable cardioverter-defibrillator (ICD) activation in patients with heart failure and reduced ejection fraction (HFrEF). Methods: Retrospective data from 307 patients who underwent ICD implantation for primary prevention from 2011 to 2017 were collected and analyzed. Results: Among the study participants, only 23.8% received the maximum tolerated dose of OMT prior to ICD implantation, with 59.0% receiving all three OMT medication groups. No significant difference in OMT compliance was found between patients with ischemic cardiomyopathy (ICM) and those with non-ischemic dilated cardiomyopathy (DCM). However, DCM patients received ICDs more frequently at the time of diagnosis than ICM patients (13.8% vs. 0.7%). Early ICD activation (within 3 months) occurred in only one patient who had not received appropriate OMT, representing 0.7% of all ICM patients. Furthermore, early activation was also infrequent in patients who received OMT (2.9% of ICM patients and 2.6% of DCM patients). Echocardiography follow-up data revealed that 20.4% of ICM patients and 29.8% of DCM patients who did not receive OMT before ICD implantation showed improvement in the left ventricular ejection fraction (EF) to 35% or more. Conclusions: This study found suboptimal compliance with OMT prior to ICD implantation in HFrEF patients. The results showed that early ICD activation was rare in all patient groups, especially those who did not receive the prescribed 3 months of OMT. More research is needed to investigate longer waiting periods for the evaluation of potential EF improvement, and to better evaluate the eligibility of HFrEF patients for ICD. The current findings have potential implications for clinical practice and patient outcomes.

Abstract Introduction There are a variety of approaches for pre-procedural imaging to facilitate atrial fibrillation (AF) ablation. Intra-procedural three-dimensional rotational angiography (3DRA) is the least employed method and it can be advantageous regarding efficiency and procedural logistics (1). There is an open question whether LA imaging could improve safety and outcomes of cryoballoon (CB) ablation. Purpose The aim of this study is to evaluate possible benefits of 3DRA for procedural success, safety and long-term outcomes of CB ablation. Methods We designed a single-centre unblinded randomised clinical trial and recruited 134 patients (64.2% male, 59.0±11.6 years) with paroxysmal (93.3%) and early-persistent AF. Patients were randomised to no imaging or 3DRA which was performed intra-procedurally after trans-septal puncture. Angiographic images were segmented and overlaid to the fluoroscopy screen to guide the ablation procedure. Patients were scheduled for follow-up visits and twenty-four hour ECG recordings at 3, 6 and 12 months, and every 6 months thereafter. Results Of all the patients recruited, 66 (49.3%) were randomised to 3DRA and angiography was successfully performed in all but one patient (1.5%). Procedure time was significantly longer when 3DRA was performed (86.7±27.8 min compared to 67.2±22.1 in non-3DRA group, p<0.001). Total radiation dose (447.4±485.0 vs. 133.9±166.2 mGy, p<0.001) and contrast administration (131.8±28.3 vs. 40.8±26.5 ml, p<0.001) were significantly higher in the 3DRA group (Table 1). In patients who received no imaging one pulmonary vein (PV) couldn’t be isolated in 2 patients while this occurred in 3 patients in the 3DRA group (OR 1.57, 95% CI 0.25-9.72). Only minor complications were reported in both groups. Five patients developed large haematoma (4 in the 3DRA group vs. 1 in the control group). In each group there were 3 incidents of impending or transient phrenic nerve palsy. During 12 months of follow-up, 88.2% of patients in the control group and 81.8% in the 3DRA group were free of atrial fibrillation (OR 1.67, 95% CI 0.63-4.38). Two patients from the control group developed atrial flutter and were treated by ablation. In total, 10 patients underwent redo procedures (7 in the control and 3 in the 3DRA group respectively) and PV reconnections were detected in 9 cases. Conclusion 3DRA is a safe and efficient intra-procedural imaging method to guide CB ablation of AF. However, it significantly increases procedure duration, total radiation dose and contrast expenditure. In our trial it did not have any impact on the acute success rate of PV isolation or freedom from atrial fibrillation during 12-month follow-up.