Redefining the blanking period following pulsed-field ablation in patients with atrial fibrillation.

BACKGROUND: Recurrence during the 3-month blanking period following radiofrequency ablation of atrial fibrillation (AF) is typically not considered as a predictor for late recurrence. OBJECTIVE: We investigated the significance of early recurrence as a risk factor for late recurrence in AF patients receiving pulsed-field ablation (PFA). METHODS: Consecutive patients undergoing PFA were prospectively followed-up for 1 year. All patients received isolation of pulmonary veins. Additional ablations were performed per operator's discretion. Following the procedure all remained on their previously ineffective antiarrhythmic drugs (AAD) during the 2-month blanking period after which the AADs were discontinued. Early recurrence was defined as atrial arrhythmia of > 30 second duration during the 3-mo blanking period and any recurrence beyond 3-mo was considered as late recurrence. RESULTS: A total of 337 patients undergoing PFA for AF were included. Early recurrence was recorded in 53 (15.7%) patients; 10 in the 1st month, 12 in the 2nd month and 31 in the 3rd month. Of the 10 patients having recurrence during the 1st month, 7 (70%) remained in sinus rhythm after cardioversion whereas 3 (30%) underwent redo because of late-recurrence. At 1 year, all patients with recurrence during the 2nd and 3rd month, experienced late-recurrence of which 10/12 and 27/31 underwent redo and the remaining 6 patients were in sinus on-AAD. CONCLUSION: In this consecutive series of AF patients, early-recurrence in the 2nd or 3rd month following the PFA procedure was associated with high risk of late-recurrence. Thus, blanking period could be redefined as 1-month following PFA.

Distance-dependent neuromodulation effect during thermal ablation for atrial fibrillation.

INTRODUCTION: Thermal atrial fibrillation (AF) ablation exerts an additive treatment effect on the cardiac autonomic nervous system (CANS). This effect is mainly reported during ablation of the right superior pulmonary vein (RSPV), modulating the right anterior ganglionated plexus (RAGP), which contains parasympathetic innervation to the sinoatrial node in the epicardial fat pad between RSPV and superior vena cava (SVC). However, a variable response to neuromodulation after ablation is observed, with little to no effect in some patients. Our objective was to assess clinical and anatomic predictors of thermal ablation-induced CANS changes, as assessed via variations in heart rate (HR) postablation. METHODS: Consecutive paroxysmal AF patients undergoing first-time PV isolation by the cryoballoon (CB) or radiofrequency balloon (RFB) within a 12-month time frame and with preprocedural cardiac computed tomography (CT), were evaluated. Preablation and 24-h postablation electrocardiograms in sinus rhythm were collected and analyzed to assess HR. Anatomic evaluation by CT included the measurement of the shortest distance between the SVC and RSPV ostium (RSPV-SVC distance). RESULTS: A total of 97 patients (CB, n = 50 vs. RFB, n = 47) were included, with similar baseline characteristics between both groups. A significant HR increase postablation (ΔHR ≥ 15 bpm) occurred in a total of 37 patients (38.1%), without difference in number of patients between both thermal ablation technologies (CB, 19 [51%]), RFB, 18 [49%]). Independent predictors for increased HR were RSPV-SVC distance (odds ratio [OR]: 0.49, CI: 0.34-0.71, p value < .001), and age (OR: 0.94, CI: 0.89-0.98, p value = .003). CONCLUSIONS: Thermal balloon-based PV isolation influences the CANS through its effect on the RAGP, especially in younger patients and patients with shorter RSPV-SVC distance.

Application Repetition and Electrode-Tissue-Contact Results in Deeper Lesions Using a Pulsed-Field Ablation Circular Variable Loop Catheter.

BACKGROUND: Pulsed field ablation (PFA) is a novel, myocardial-selective, non-thermal ablation modality used to target cardiac arrhythmias. Although prompt EGM signal disappearance is observed immediately after PFA application in the pulmonary veins, whether this finding results in adequate transmural lesions is unknown. STUDY AIM: If application repetition and catheter-tissue contact impact on lesion formation during PFA. METHODS: A circular loop PFA catheter was used to deliver repeated energy applications with various levels of contact-force. A benchtop vegetal potato model and a beating heart ventricular myocardial model were utilized to evaluate the impact of application repetition, contact force, and catheter repositioning on contiguity and lesion depth. Lesion development occurred over 18 hours in the vegetal model and over 6 hours in the porcine model. RESULTS: Lesion formation was found to be dependent on application repetition and contact. In porcine ventricles, single and multiple stacked applications led to a lesion depth of 3.5 ± 0.7 mm and 4.4 ± 1.3 mm, respectively (p =0.002). Furthermore, the greater the catheter-tissue contact, the more contiguous and deeper the lesions in the vegetal model (1.0±0.9 mm with no contact Vs. 5.4±1.4 mm with 30 g of force; p=.0001). CONCLUSION: PFA delivered via a circular catheter showed that both repetition and catheter contact led independently to deeper lesion formation. These findings indicate that endpoints for effective PFA ablation are more related to PFA biophysics than mere EGM attenuation.

The Association of Hematological Markers with Occurrence of Thrombotic and Bleeding Events following Left Atrial Appendage Occlusion.

INTRODUCTION: Patients undergoing left atrial appendage occlusion (LAAO) are at increased risk for bleeding or thromboembolic events. Concurrently, biomarkers are of growing importance in risk stratification for atrial fibrillation patients. We aimed to evaluate the association of hematological markers and clinical characteristics with the occurrence of thromboembolic and bleeding events following LAAO. METHODS: Seven implanting centers retrospectively gathered data on hematological markers (i.e., platelet count [PC], mean platelet volume [MPV], and fibrinogen) prior to LAAO. Prespecified thromboembolic and major bleeding outcomes were collected and the association with pre-procedural hematological markers and clinical characteristics was evaluated using Cox regression analysis. RESULTS: In total, 1,315 patients were included (74 ± 9 years, 36% female, CHA2DS2-VASc 4.3 ± 1.5, HAS-BLED 3.3 ± 1.1). Over a total follow-up duration of 2,682 patient years, 77 thromboembolic events and 107 major bleeding events occurred after LAAO. Baseline PC was the only biomarker showing a signal for a relation to thromboembolic events (HR 1.18, 95% CI: 1.00-1.39) per 50*109 increment, p = 0.056). Thrombotic event rates, including device-related thrombus, increased within higher PC quartiles. Thromboembolism was associated with age (HR 1.05, 95% CI: 1.00-1.10, per year increase) and prior thromboembolism (HR 2.08, 95% CI: 1.07-4.03), but with none of the biomarkers in multivariate analysis. No association of any of the hematological markers with major bleeding was observed. Major bleeding following LAAO was associated with prior major bleeding (HR 5.27, 95% CI: 2.71-10.22), renal disease (HR 1.93, 95% CI: 1.17-3.18), and discharge on dual antiplatelet therapy (DAPT) (HR 1.71, 95% CI: 1.05-2.77). CONCLUSION: Most thrombotic events occurred in the highest PC quartile, but no association of any of the hematological markers with thromboembolism or major bleeding was observed in our analysis. In multivariate analysis, older age and prior thromboembolism were associated with thromboembolism. Prior major bleeding, renal disease and discharge on DAPT were multivariate predictors of major bleeding after LAAO.

Contrast-enhanced excimer laser stepwise approach during PCI for resistant coronary lesions.

BACKGROUND: The treatment of resistant coronary lesions (RCL) is a great challenge for interventional cardiologists. The excimer laser coronary atherectomy (ELCA) is a plaque modification tool based on a main mechanism of photomechanical effect leading to mechanical disruption of the plaque. Contrast dye injection during laser delivery has demonstrated to enhance its power. AIM: To evaluate the effectiveness and safety of the contrast-enhanced ELCA by a stepwise approach in the treatment of RCLs. METHODS: We retrospectively examined consecutive patients undergoing contrast-enhanced ELCA-assisted PCI between 2018 and 2021 at two Italian sites. RCLs were defined as novo or in-stent undilatable/uncrossable with conventional balloons (SC/NC balloon). The primary endpoint was ELCA technical success defined as the laser catheter crossing the entire length of the target lesion established by angiographic evidence of the catheter tip in the artery distal to the stenosis. RESULTS: We enrolled 114 patients who underwent contrast-enhanced ELCA-assisted PCI: 58% of the patients had acute coronary syndrome while the left anterior descending artery was the target vessel in 42.1% of cases. The target lesion was most commonly in-stent (56.2%). The 0.9 mm ELCA catheter tip was employed in 89.5% of cases. The most used frequency/fluency profile was 70/70 (39.5%). The use of contrast-enhanced ELCA was associated with high technical, procedural, and clinical success rates (97.4%, 93.7%, and 90.1%, respectively). CONCLUSIONS: The contrast-enhanced ELCA seems to be a safe and effective treatment option for the management of both de novo and in-stent-resistant coronary lesions.

Drug-coated balloon versus drug-eluting stent for treating de novo large vessel coronary artery disease: a systematic review and meta-analysis of 13 studies involving 2888 patients.

INTRODUCTION: Drug-coated balloon (DCB) is an established treatment option for in-stent restenosis and small vessel, de novo, coronary artery disease (CAD). Although the use of this tool is increasing in everyday practice, data regarding performance in the treatment of de novo, large vessel CAD (LV-CAD) is still lacking. A systematic review and meta-analysis were conducted to evaluate the efficacy and safety of DCB versus drug-eluting stent (DES) in this setting. METHODS: A comprehensive literature search was performed including Medline, Embase, and Cochrane electronic databases up to January 24, 2024, for studies which compared the efficacy and safety of DCB versus DES in the treatment of de novo lesions in large vessels (≥ 2.5 mm), reporting at least one clinical outcome of interest (PROSPERO ID: CRD42023470417). The analyzed outcomes were cardiovascular death (CVD), myocardial infarction (MI), target lesion revascularization (TLR), all-cause death (ACD), and late lumen loss (LLL) at follow-up. The effect size was estimated using a random effects model as risk ratio (RR) and mean difference (MD) and relative 95% confidence interval (CI). RESULTS: A total of 13 studies (6 randomized controlled trials and 7 observational studies) involving 2888 patients (DCB n = 1334; DES n = 1533) with de novo LV-CAD were included in this meta-analysis following our inclusion criteria. No differences were observed between DCB and DES in terms of CVD (RR 0.49; 95% CI [0.23-1.03]; p = 0.06), MI (RR 0.48; 95% CI [0.16-1.45]; p = 0.89), TLR (RR 0.73; 95% CI [0.40-1.34]; p = 0.32), ACD (RR 0.78; 95% CI [0.57-1.07]; p = 0.12), and LLL (MD - 0.14; 95% CI [- 0.30 to 0.02]; p = 0.10) at follow-up. DES proved a higher mean acute gain versus DCB [1.94 (1.73, 2.14) vs 1.31 (1.02, 1.60); p = 0.0006]. CONCLUSION: Our meta-analysis showed that DCB PCI might provide a promising option for the management of selected, de novo LV-CAD compared to DES. However, more focused RCTs are needed to further prove the benefits of a "metal-free" strategy in this subset of CAD.

Step-by-step recommendations utilizing four-dimensional intracardiac echocardiography in left atrial appendage procedures.

INTRODUCTION: Four-dimensional (4D) intracardiac echocardiography (ICE) is a novel cardiac imaging modality that has been applied to various workflows, including catheter ablation, tricuspid valve repair, and left atrial appendage occlusion (LAAO). The use of this type of advanced ICE imaging may ultimately allow for the replacement of transesophageal echocardiography (TEE) for LAAO, providing comparable imaging quality while eliminating the need for general anesthesia. METHODS: Based on our initial clinical experience with 4D ICE in LAAO, we have developed an optimized workflow for the use of the NUVISION™ 4D ICE Catheter in conjunction with the GE E95 and S70N Ultrasound Systems in LAAO. In this manuscript, we provide a step-by-step guide to using 4D ICE in conjunction with compatible imaging consoles. We have also evaluated the performance of 4D ICE with the NUVISION Ultrasound Catheter versus TEE in one LAAO case and present those results here. RESULTS: In our comparison of 4D ICE using our optimized workflow with TEE in an LAAO case, ICE LAA measurements were similar to those from TEE. The best image resolution was seen via ICE in 2-dimensional and multislice modes (triplane and biplane). The FlexiSlice multiplanar reconstruction tool, which creates an en-face image derived from a 4D volume set, also provided valuable information but yielded slightly lower image quality, as expected for these volume-derived images. For this case, comparable images were obtained with TEE and ICE but with less need to reposition the ICE catheter. CONCLUSION: The use of optimized 4D ICE catheter workflow recommendations allows for efficient LAAO procedures, with higher resolution imaging, comparable to TEE.

Impact of an Organized Treatment Pathway on Management of Atrial Fibrillation: The ER2EP Study.

Background: Atrial fibrillation (AF) is the most common arrhythmia reported worldwide. There is significant heterogeneity in AF care pathways for a patient seen in the emergency room, impacting access to guideline-driven therapies. Objectives: The purpose of this study was to compare the difference in AF outcomes between those treated with an organized treatment pathway vs routine-care approach. Methods: The emergency room to electrophysiology service study (ER2EP) is a multicenter, prospective observational registry (NCT04476524) enrolling patients with AF from sites where a pathway for management of AF was put in place compared to sites where a pathway was not in place within the same health system and the same physicians providing services at all sites. Multivariable regression modeling was performed to identify predictors of clinical outcomes. Beta coefficient or odds ratio was reported as appropriate. Results: A total of 500 patients (ER2EP group, n = 250; control group, n = 250) were included in the study. The mean age was 73.4 ± 12.9 years, and 52.2% were males. There was a statistically significant difference in primary endpoint [time to ablation (56 ± 50.9 days vs 183.3 ± 109.5 days; P < 0.001), time to anticoagulation initiation (2.1 ± 1.6 days vs 19.7 ± 35 days, P < 0.001), antiarrhythmic drug initiation (4.8 ± 7.1 days vs 24.7 ± 44.4 days, P < 0.001) compared to the control group, respectively. As such, this resulted in reduced length of stay in the ER2EP group compared to the control group (2.4 ± 1.4 days vs 3.23 ± 2.5 days, P = 0.002). Conclusions: This study provides evidence that having an organized pathway from the emergency department for AF patients involving electrophysiology services can improve early access to definitive therapies and clinical outcomes.

Percutaneous Coronary Intervention before or after Transcatheter Aortic Valve Replacement: A Systematic Review and Meta-Analysis Involving 1531 Patients.

Background: The optimal timing to perform percutaneous coronary interventions (PCIs) in patients undergoing transcatheter aortic valve replacement (TAVR) is not well established. In this meta-analysis, we aimed to compare the outcomes of patients undergoing PCI before versus after TAVR. Methods: A comprehensive literature search was performed including Medline, Embase, and Cochrane electronic databases up to 5 April 2024 for studies that compared PCI before and after TAVR reporting at least one clinical outcome of interest (PROSPERO ID: CRD42023470417). The analyzed outcomes were mortality, stroke, and myocardial infarction (MI) at follow-up. Results: A total of 3 studies involving 1531 patients (pre-TAVR PCI n = 1240; post-TAVR PCI n = 291) were included in this meta-analysis following our inclusion criteria. Mortality was higher in the pre-TAVR PCI group (OR: 2.48; 95% CI: 1.19-5.20; p = 0.02). No differences were found between PCI before and after TAVR for the risk of stroke (OR: 3.58; 95% CI: 0.70-18.15; p = 0.12) and MI (OR: 0.66; 95% CI: 0.30-1.42; p = 0.29). Conclusions: This meta-analysis showed in patients with stable CAD undergoing TAVR that PCI after TAVR is associated with lower mortality compared with PCI before TAVR.

A cost-consequence analysis comparing three cardiac ablation strategies for the treatment of paroxysmal atrial fibrillation.

BACKGROUND AND AIMS: Cardiac ablation is a well-established method for treating atrial fibrillation (AF). Pulsed field ablation (PFA) is a non-thermal therapeutic alternative to radiofrequency ablation (RFA) and cryoballoon ablation (CRYO). PFA uses high-voltage electric pulses to target cells. The present analysis aims to quantify the costs, outcomes, and resources associated with these three ablation strategies for paroxysmal AF. METHODS: Real-world clinical data were prospectively collected during index hospitalization by three European medical centers (Belgium, Germany, the Netherlands) specialized in cardiac ablation. These data included procedure times (pre-procedural, skin-to-skin and post-procedural), resource use, and staff burden. Data regarding complications associated with each of the three treatment options and redo procedures were extracted from the literature. Costs were collected from hospital economic formularies and published cost databases. A cost-consequence model from the hospital perspective was built to estimate the impact of the three treatment options in terms of effectiveness and costs. RESULTS: Across the three centers, N = 91 patients were included over a period of 12 months. A significant difference was seen in pre-procedural time (mean ± SD, PFA: 13.6 ± 3.7 min, CRYO: 18.8 ± 6.6 min, RFA: 20.4 ± 6.4 min; p < .001). Procedural time (skin-to-skin) was also different across alternatives (PFA: 50.9 ± 22.4 min, CRYO: 74.5 ± 24.5 min, RFA: 140.2 ± 82.4 min; p < .0001). The model reported an overall cost of €216,535 per 100 patients treated with PFA, €301,510 per 100 patients treated with CRYO and €346,594 per 100 patients treated with RFA. Overall, the cumulative savings associated with PFA (excluding kit costs) were €850 and €1,301 per patient compared to CRYO and RFA, respectively. CONCLUSION: PFA demonstrated shorter procedure time compared to CRYO and RFA. Model estimates indicate that these time savings result in cost savings for hospitals and reduce outlay on redo procedures. Clinical practice in individual hospitals varies and may impact the ability to transfer the results of this analysis to other settings.

Fascicular Substrate Modification to Treat Human Ventricular Fibrillation.

BACKGROUND: Purkinje fibers play an important role in initiation and maintenance of ventricular fibrillation (VF) and polymorphic ventricular tachycardia (PMVT). Fascicular substrate modification (FSM) approaches have been suggested to treat recurrent VF in case reports and small case series. OBJECTIVES: The aim of this study was to investigate outcomes of catheter-based FSM to treat VF and PMVT. METHODS: Of 2,212 consecutive patients with ventricular arrhythmia undergoing catheter ablation, 18 (0.81%) underwent FSM of the Purkinje fibers as identified with high-density mapping during sinus rhythm. Fascicular substrate and VF initiation were mapped using a multipolar catheter. The endpoint of the ablation was noninducibility of VF and PMVT. In select patients, remapping revealed elimination of the targeted Purkinje potentials. Demographic, clinical, and follow-up characteristics were prospectively collected in our institutional database. RESULTS: A total of 18 patients (mean age 56 ± 3.8 years, 22% women) were included in the study. Of those, 11 (61.1%) had idiopathic VF, 3 (16.7%) had nonischemic cardiomyopathy, and 4 (22.2%) had mixed cardiomyopathy. The average left ventricular ejection fraction was 42.5%. At least 2 antiarrhythmic drugs had failed preablation. At baseline, all patients had inducible VF or PMVT. At the end of the procedure, no patient demonstrated new evidence of fascicular block or bundle branch block. There were no procedure-related complications. After a median follow-up period of 24 months, 16 patients (88.9%) were arrhythmia free on or off drugs: 11 of 11 patients (100%) with idiopathic VF vs 5 of 7 patients (71.4%) with underlying cardiomyopathy (P = 0.06). CONCLUSIONS: Catheter ablation of human VF and PMVT with FSM is feasible and safe and appears highly effective, with high rates of acute VF noninducibility and long-term freedom from recurrent VF.

Functional substrate analysis in patients with persistent atrial fibrillation.

OBJECTIVES: The aim of this study was to describe the correlation between atrial electrogram duration map (AEDUM), spatiotemporal electrogram dispersion (STED) and low voltage areas (LVA) in patients with persistent atrial fibrillation (PsAF). BACKGROUND: The degree of left atrial (LA) tissue remodelling and augmented anisotropic conduction is one of the major issues related to PsAF ablation outcome. METHODS: This study enrolled consecutive patients with PsAF undergoing pulmonary vein isolation. In all patients, voltage, AEDUM and STED maps were created, and the correlation was reported between these three mapping methods. RESULTS: A total of 40 patients with PsAF were enrolled. The mean age was 62.2 ± 7.4 years, and males were 72.5% (n = 29). The overall bipolar voltage of the LA was 3.06 ± 1.87 mV. All patients had at least one AEDUM area (overall AEDUM area: 21.8 ± 8.2 cm2); the mean longest electrogram (EGMs) duration was 90 ± 19 ms. STED areas with < 120 ms was 46.3 ± 20.2 cm2 which covered 45 ± 22% of the LA surface. AEDUM and STED areas were most frequently reported on the roof, the anterior wall and the septum. The extension of the AEDUM areas was significantly smaller than STED areas with CL < 120 ms (21.8 ± 8.2 vs 46.3 ± 20.2; p-value < 0.0001). In 24 patients (60%), AEDUM areas was entirely included in the STED areas with CL < 120 ms. In the three (7.5%) patients with LVA, no correspondence with STED and AEDUM was noted. CONCLUSION: AEDUM and STED maps allow to identify areas of conductive dysfunction as a possible atrial substrate even if a normal voltage is detected.

Sequential Unipolar Biventricular Pulsed Field Ablation for Refractory Intramural Septal Ventricular Tachycardia.

Catheter ablation of septal ventricular tachycardia (VT) is challenging. Pulsed field ablation is a promising technology, potentially reaching deep substrates. We report the first sequential unipolar biventricular pulsed field ablation targeting refractory septal VT. Besides, we illustrate the importance of searching underlying cardiomyopathy in patients with recurrent multiple morphology VTs and normal magnetic resonance imaging.

Catheter ablation as an adjunctive therapy to ICD implantation in Brugada syndrome.

BACKGROUND: Brugada Syndrome (BrS) is a life-threatening cardiac arrhythmia disorder associated with an increased risk ventricular arrhythmias (VAs) and sudden cardiac death (SCD). Current management primarily relies on implantable cardioverter-defibrillators (ICDs), but patients may experience ICD shocks. Catheter ablation (CA) has emerged as a potential intervention to target the arrhythmogenic substrate. This systematic review aims to evaluate the safety and efficacy of catheter ablation in BrS patients. METHODS AND RESULTS: Studies with BrS patients undergoing catheter ablation for VAs were included. 14 studies that involved a total population of 709 BrS patients, with catheter ablation performed in 528 of them, were included. Catheter ablation resulted in non-inducibility of VAs in 91% (95% CI: 83-99, I2 = 76%) and resolution of Type 1 ECG Brugada pattern in 88% (95% CI: 81-96.2, I2 = 91%) of the patients. After a mean follow-up of 30.7 months, 87% (95% CI: 80-94, I2 = 82%) of patients remained free from VAs. The incidence of VAs during follow-up was significantly lower in the ablation cohort in comparison to the group receiving only ICD therapy (OR = 0.03, 95% CI: 0.01-0.12, I2 = 0%). CONCLUSION: Catheter ablation shows potential as a therapeutic approach to reduce VAs and improve outcomes in BrS patients. While further research with long follow-up period is required to confirm these findings, it represents a valuable tool as an add-on intervention to ICD implantation in BrS patients with high burden of VAs.Protocol registration: CRD42024506439.

Italian Registry in the Setting of Atrial Fibrillation Ablation with Rivaroxaban - IRIS.

BACKGROUND: Catheter ablation (CA) of atrial fibrillation is routinely used to obtain rhythm control. Evidence suggest that catheter ablation should be done during uninterrupted oral anticoagulation. METHODS: Italian Registry in the setting of atrial fibrillation ablation with rivaroxaban (IRIS) is an Italian multicenter, non-interventional, prospective study which enrolled 250 consecutive atrial fibrillation patients eligible for catheter ablation on rivaroxaban. The decision for rivaroxaban management was left to the physician: uninterrupted or shortly interrupted prior to Catheter ablation. Patients received a follow-up visit at 1 month and 12 months after the procedure. RESULTS: The primary outcome, represented by all-cause death and systemic embolism at 1 month and 12 months was characterized by one transient ischemic attack and one myocardial infarction in the first 30 days. Both events happened in patients with shortly interrupted strategy (P=0.147), and both in patients who underwent radiofrequency ablation (P=0.737). In the primary safety outcome represented by major bleeding we did not register any event in the 12-month follow-up. The secondary outcome constituted by minor bleeding registered 1 event, after the first 30 days since CA. CONCLUSIONS: IRIS is the biggest real-life data registry regarding CA ablation on rivaroxaban in Italian setting, proving the safety and efficacy of rivaroxaban.