Sex Differences in Left Bundle Branch Area Pacing Versus Biventricular Pacing for Cardiac Resynchronization Therapy.

BACKGROUND: Women respond more favorably to biventricular pacing (BIVP) than men. Sex differences in atrioventricular and interventricular conduction have been described in BIVP studies. Left bundle branch area pacing (LBBAP) offers advantages due to direct capture of the conduction system. We hypothesized that men could respond better to LBBAP than BIVP. OBJECTIVES: This study aims to describe the sex differences in response to LBBAP vs BIVP as the initial cardiac resynchronization therapy (CRT). METHODS: In this multicenter prospective registry, we included patients with left ventricular ejection fraction ≤35% and left bundle branch block or a left ventricular ejection fraction ≤40% with an expected right ventricular pacing exceeding 40% undergoing initial CRT with LBBAP or BIVP. The composite primary outcome was heart failure-related hospitalization and all-cause mortality. The primary safety outcome included all procedure-related complications. RESULTS: There was no significant difference in the primary outcome when comparing men and women receiving LBBAP (P = 0.46), whereas the primary outcome was less frequent in women in the BIVP group than men treated with BIVP (P = 0.03). The primary outcome occurred less frequently in men undergoing LBBAP (29.9%) compared to those treated with BIVP (46.5%) (P = 0.004). In women, the incidence of the primary endpoint was 24.14% in the LBBAP group and 36.2% in the BIVP group; however, this difference was not statistically significant (P = 0.23). Complication rates remained consistent across all groups. CONCLUSIONS: Men and women undergoing LBBAP for CRT had similar clinical outcomes. Men undergoing LBBAP showed a lower risk of heart failure-related hospitalizations and all-cause mortality compared to men undergoing BIVP, whereas there was no difference between LBBAP and BIVP in women.

Dual Operator Percutaneous Epicardial Access to Minimize Needle Pericardial Dwell-Time: A Modified SAFER Epicardial Approach.

The sustained apnea for epicardial access with right ventriculography technique (SAFER epicardial approach) has been previously shown to be effective and safe (1). However, it requires a brief period of unprotected needle dwell time within the pericardium while the operator switches the contrast syringe for a guidewire. This transition period, though brief, raises concerns regarding the potential risk of inadvertent perforation of the right ventricular (RV) wall given the systolic-diastolic excursion of the heart and/or the possibility of losing epicardial access. In an effort to limit the unprotected needle dwell time in the pericardium, we describe the dual operator modified SAFER epicardial approach.

Feasibility, Efficacy, and Safety of Fluoroless Ablation of VT in Patients With Structural Heart Disease.

BACKGROUND: Catheter ablation of ventricular tachycardia (VT) typically requires radiation exposure with its potential adverse health effects. A completely fluoroless ablation approach is achievable using a combination of electroanatomical mapping and intracardiac echocardiography. Nonetheless, data in patients undergoing VT ablation are limited. OBJECTIVES: This study aimed to determine the feasibility, efficacy, and safety of VT ablation in patients with structural heart disease using a zero-fluoroscopy approach. METHODS: This multicenter study included consecutive patients with ischemic and nonischemic cardiomyopathy undergoing fluoroless VT ablation. Patients requiring epicardial access or coronary angiography were excluded. RESULTS: Between 2017 and 2023 a total of 198 patients (aged 66.4 ± 13.4 years, 76% male, 48% ischemic) were included. Most patients (95.4%) underwent left ventricular (LV) mapping and/or ablation, which was conducted via transseptal route in 54.5% (n = 103), via retrograde aortic route in 43.4% (n = 82), and using a combined approach in 2.1% (n = 4). Two-thirds of patients had a cardiac device, including a biventricular device in 15%; 2 patients had a LV assist device, and 1 patient had a mechanical aortic valve prosthesis. The mean total procedural time was 211 ± 70 minutes, and the total radiofrequency time was 30 ± 22 minutes. During a follow-up period of 22 ± 18 months, the freedom from VT recurrence was 80%, and 7.6% of patients underwent a repeated ablation. Procedural-related complications occurred in 6 patients (3.0%). CONCLUSIONS: Fluoroless ablation of VT in structural heart disease is feasible, effective, and safe when epicardial mapping/ablation is not required.

Improved all-cause mortality with left bundle branch area pacing compared to biventricular pacing in cardiac resynchronization therapy: a meta-analysis.

BACKGROUND: Left bundle branch area pacing (LBBAP) has emerged as a physiological alternative pacing strategy to biventricular pacing (BIVP) in cardiac resynchronization therapy (CRT). We aimed to assess the impact of LBBAP vs. BIVP on all-cause mortality and heart failure (HF)-related hospitalization in patients undergoing CRT. METHODS: Studies comparing LBBAP and BIVP for CRT in patients with HF with reduced left ventricular ejection fraction (LVEF) were included. The coprimary outcomes were all-cause mortality and HF-related hospitalization. Secondary outcomes included procedural and fluoroscopy time, change in QRS duration, and change in LVEF. RESULTS: Thirteen studies (12 observational and 1 RCT, n = 3239; LBBAP = 1338 and BIVP = 1901) with a mean follow-up duration of 25.8 months were included. Compared to BIVP, LBBAP was associated with a significant absolute risk reduction of 3.2% in all-cause mortality (9.3% vs 12.5%, RR 0.7, 95% CI 0.57-0.86, p < 0.001) and an 8.2% reduction in HF-related hospitalization (11.3% vs 19.5%, RR 0.6, 95% CI 0.5-0.71, p < 0.00001). LBBAP also resulted in reductions in procedural time (mean weighted difference- 23.2 min, 95% CI - 42.9 to - 3.6, p = 0.02) and fluoroscopy time (- 8.6 min, 95% CI - 12.5 to - 4.7, p < 0.001) as well as a significant reduction in QRS duration (mean weighted difference:- 25.3 ms, 95% CI - 30.9 to - 19.8, p < 0.00001) and a greater improvement in LVEF of 5.1% (95% CI 4.4-5.8, p < 0.001) compared to BIVP in the studies that reported these outcomes. CONCLUSION: In this meta-analysis, LBBAP was associated with a significant reduction in all-cause mortality as well as HF-related hospitalization when compared to BIVP. Additional data from large RCTs is warranted to corroborate these promising findings.

Intramural needle ablation or repeated standard ablation in patients referred for repeat ablation of scar-related ventricular tachycardia.

INTRODUCTION: When ventricular tachycardia (VT) recurs after standard RF ablation (sRFA) some patients benefit from repeat sRFA, whereas others warrant advanced methods such as intramural needle ablation (INA). Our objectives are to assess the utility of repeat sRFA and to clarify the benefit of INA when repeat sRFA fails in patients with VT due to structural heart disease. METHODS: In consecutive patients who were prospectively enrolled in a study for INA for recurrent sustained monomorphic VT despite sRFA, repeat sRFA was considered first. INA was performed during the same procedure if repeat sRFA failed or no targets for sRFA were identified. RESULTS: Of 85 patients enrolled, acute success with repeat sRFA was achieved in 30 patients (35%), and during the 6-month follow-up, 87% (20/23) were free of VT hospitalization, 78% were free of any VT, and 7 were lost to follow-up. INA was performed in 55 patients (65%) after sRFA failed, or no endocardial targets were found abolished or modified inducible VT in 35/55 patients (64%). During follow-up, 72% (39/54) were free of VT hospitalization, 41% were free of any VT, and 1 was lost to follow-up. Overall, 59 out of 77 (77%) patients were free of hospitalization and 52% were free of any VT. Septal-origin VTs were more likely to need INA, whereas RV and papillary muscle VTs were less likely to require INA. CONCLUSIONS: Repeat sRFA was beneficial in 23% (18/77) of patients with recurrent sustained VT who were referred for INA. The availability of INA increased favorable outcomes to 52%.

Safety and Efficacy of Ultrasound-Guided Sympathetic Blockade by Proximal Intercostal Block in Electrical Storm Patients.

BACKGROUND: Electrical storm (ES) patients who fail standard therapies have a high mortality rate. Previous studies report effective management of ES with bedside, ultrasound-guided percutaneous stellate ganglion block (SGB). We report our experience with sympathetic blockade administered via a novel alternative approach: proximal intercostal block (PICB). Compared with SGB, this technique targets an area typically free of other catheters and support devices, and may pose less strict requirements for anticoagulation interruption, along with lower risk of focal neurological side effects. OBJECTIVES: The authors sought to describe the safety and efficacy of PICB in patients with refractory ES. METHODS: We reviewed our institutional data on ES patients who underwent PICB between January 2018 and February 2023 to analyze procedural safety and short- and long-term outcomes. RESULTS: A total of 15 consecutive patients with ES underwent PICB during this period. Of those, 11 patients (73.3%) were maintained on PICB alone, and 4 patients (26.6%) were maintained on combined block with SGB and PICB. Overall, 72.7% patients who were maintained on PICB alone and 77.8% patients who were maintained on bilateral PICB had excellent arrhythmia suppression. After PICB, implantable cardioverter-defibrillator therapies were significantly reduced (P < 0.05), with 93.3% of patients receiving PICB having no implantable cardioverter-defibrillator shock until discharge or heart transplant. Anticoagulation was continued in all patients and there were no procedure-related complications. Apart from mild transient neurological symptoms seen in 3 patients, no significant neurological or hemodynamic sequelae were observed. CONCLUSIONS: In patients with refractory ES, continuous PICB provided safe and effective sympathetic block (77.8% ventricular arrhythmia suppression), achievable without interruption of anticoagulation, and without significant side effects.

Left Bundle Branch Pacing vs Left Ventricular Septal Pacing vs Biventricular Pacing for Cardiac Resynchronization Therapy.

BACKGROUND: Left bundle branch pacing (LBBP) and left ventricular septal pacing (LVSP) are considered to be acceptable as LBBAP strategies. Differences in clinical outcomes between LBBP and LVSP are yet to be determined. OBJECTIVES: The purpose of this study was to compare the outcomes of LBBP vs LVSP vs BIVP for CRT. METHODS: In this prospective multicenter observational study, LBBP was compared with LVSP and BIVP in patients undergoing CRT. The primary composite outcome was freedom from heart failure (HF)-related hospitalization and all-cause mortality. Secondary outcomes included individual components of the primary outcome, postprocedural NYHA functional class, and electrocardiographic and echocardiographic parameters. RESULTS: A total of 415 patients were included (LBBP: n = 141; LVSP: n = 31; BIVP: n = 243), with a median follow-up of 399 days (Q1-Q3: 249.5-554.8 days). Freedom from the primary composite outcomes was 76.6% in the LBBP group and 48.4% in the LVSP group (HR: 1.37; 95% CI: 1.143-1.649; P = 0.001), driven by a 31.4% absolute increase in freedom from HF-related hospitalizations (83% vs 51.6%; HR: 3.55; 95% CI: 1.856-6.791; P < 0.001) without differences in all-cause mortality. LBBP was also associated with a higher freedom from the primary composite outcome compared with BIVP (HR: 1.43; 95% CI: 1.175-1.730; P < 0.001), with no difference between LVSP and BIVP. CONCLUSIONS: In patients undergoing CRT, LBBP was associated with improved outcomes compared with LVSP and BIVP, while outcomes between BIVP and LVSP are similar.

SARS-CoV-2 Infection Precipitating VT Storm in Patients With Cardiac Sarcoidosis.

The authors describe 3 patients presenting with cardiac sarcoidosis (CS) flare and ventricular tachycardia (VT) storm following infection with severe acute respiratory syndrome-coronavirus-2 (SARS-CoV-2), the causative agent of COVID-19. COVID-19-related cardiac manifestations can vary and include arrythmias, myocarditis, and exacerbation of underlying cardiovascular disease. The exact mechanism of myocardial involvement is not clear but may include abnormal host immune response and direct myocardial injury, thereby predisposing to enhanced arrhythmic risk. Arrhythmias account for 20% of COVID-19-related complications with ventricular arrythmias occurring in 5.9% of cases. Further studies are needed to better understand mechanisms underlying the intersection between COVID-19 infection and inflammatory cardiomyopathies.

Sustained Apnea for Epicardial Access With Right Ventriculography: The SAFER Epicardial Approach.

BACKGROUND: Epicardial access (EA) has emerged as an increasingly important approach for the treatment of ventricular arrhythmias and to perform other interventional cardiology procedures. EA is frequently underutilized because the current approach is challenging and carries a high risk of life-threatening complications. OBJECTIVE: The purpose of this study was to determine the efficacy and safety of the SAFER (Sustained Apnea for Epicardial Access With Right Ventriculography) epicardial approach. METHODS: Consecutive patients who underwent EA with the SAFER technique were included in this multicenter study. The primary efficacy outcome was the successful achievement of EA. The primary safety outcomes included right ventricular (RV) perforation, major hemorrhagic pericardial effusion (HPE), and bleeding requiring surgical intervention. Secondary outcomes included procedural characteristics and any complications. Our results were compared with those from previous studies describing other EA techniques to assess differences in outcomes. RESULTS: A total of 105 patients undergoing EA with the SAFER approach from June 2021 to February 2023 were included. EA was used for ventricular tachycardia ablation in 98 patients (93.4%), left atrial appendage closure in 6 patients (5.7%), and phrenic nerve displacement in 1 patient (0.9%). EA was successful in all subjects (100%). The median time to EA was 7 minutes (IQR: 5-14 minutes). No cases of RV perforation, HPE, or need of surgical intervention were observed in this cohort. Comparing our results with previous studies about EA, the SAFER epicardial approach resulted in a significant reduction in major pericardial bleeding. CONCLUSIONS: The SAFER epicardial approach is a simple, efficient, effective, and low-cost technique easily reproducible across multiple centers. It is associated with lower complication rates than previously reported techniques for EA.

Worldwide Experience With an Irrigated Needle Catheter for Ablation of Refractory Ventricular Arrhythmias: Final Report.

BACKGROUND: We previously reported feasibility of irrigated needle ablation (INA) with a retractable 27-G end-hole needle catheter to treat nonendocardial ventricular arrhythmia substrate, an important cause of ablation failure. OBJECTIVES: The purpose of this study was to report outcomes and complications in our entire INA-treated population. METHODS: Patients with recurrent sustained monomorphic ventricular tachycardia (VT) or high-density premature ventricular contractions (PVCs) despite radiofrequency ablation were prospectively enrolled at 4 centers. Endpoints included a 70% decrease in VT frequency or PVC burden decrease to <5,000/24 h at 6 months. RESULTS: INA was performed in 111 patients (median: 2 failed prior ablations, 71% nonischemic heart disease, and left ventricular ejection fraction 36% ± 14%). INA acutely abolished targeted PVCs in 33 of 37 patients (89%), and PVCs were reduced to <5,000/day in 29 patients (78%). During 6-month follow-up, freedom from hospitalization was observed in 50 of 72 patients with VT (69%), and improvement or abolition of VT occurred in 47%. All patients received multiple INA applications, with more in the VT group than in the PVC group (median: 12 [IQR: 7-19] vs 7 [5-15]; P < 0.01). After INA, additional endocardial standard radiofrequency ablation was required in 23% of patients. Adverse events included 4 pericardial effusions (3.5%), 3 cases of (anticipated) atrioventricular block (2.6%), and 3 heart failure exacerbations (2.6%). During 6-month follow-up, 5 deaths occurred; none were procedure-related. CONCLUSIONS: INA achieves improved arrhythmia control in 78% of patients with PVCs and avoids hospitalization in 69% of patients with VT refractory to standard ablation at 6-month follow-up. Procedural risks are acceptable. (Intramural Needle Ablation for Ablation of Recurrent Ventricular Tachycardia, NCT01791543; Intramural Needle Ablation for the Treatment of Refractory Ventricular Arrhythmias, NCT03204981).

Diagnostic Impact and Prognostic Value of Cardiac Magnetic Resonance in Patients With Ventricular Arrhythmias.

BACKGROUND: Cardiac magnetic resonance (CMR) characterizes myocardial substrate relevant to sudden cardiac death (SCD). However, its clinical value in patients presenting with ventricular arrhythmias is still being defined. OBJECTIVES: The authors sought to examine the diagnostic and prognostic value of multiparametric CMR in a cohort of consecutive patients referred for assessment of ventricular arrhythmias. METHODS: Consecutive patients undergoing CMR for nonsustained ventricular tachycardia (NSVT) (n = 345) or sustained ventricular tachycardia (VT)/aborted SCD (n = 297) were followed over a median of 4.4 years. Major adverse cardiac events included death, recurrent VT/ventricular fibrillation requiring therapy, and hospitalization for congestive heart failure. RESULTS: Of the 642 patients, 256 were women (40%), mean age was 54 ± 15 years, and median left ventricular ejection fraction was 58% (IQR: 49%-63%). A structurally abnormal heart by CMR assessment was detected in 40% of patients with NSVT and 66% in those with VT/SCD (P < 0.001). CMR assessment yielded a diagnostic change in 27% of NSVT patients vs 41% of those with VT/SCD (P < 0.001). During follow-up, 51 patients (15%) with NSVT and 104 patients (35%) with VT/SCD experienced major adverse cardiac events (MACE). An abnormal CMR was associated with a higher annual rate for MACE for both NSVT (0.7% vs 7.7%; P < 0.001) and VT/SCD (3.8% vs 13.3%; P < 0.001) patients. In a multivariate model including left ventricular ejection fraction, an abnormal CMR remained strongly associated with MACE in NSVT (HR: 5.23 [95% CI: 2.28-12.0]; P < 0.001) and VT/SCD (HR: 1.88 [95% CI: 1.07-3.30]; P = 0.03). Adding CMR assessment to the multivariable model for MACE yielded a significant improvement in the integrated discrimination improvement and an improvement in the C-statistic in the NSVT cohort. CONCLUSIONS: In patients presenting with ventricular arrhythmias, multiparametric CMR assessment provides diagnostic clarification and effective risk stratification beyond current standard of care.

2023 HRS expert consensus statement on the management of arrhythmias during pregnancy.

This international multidisciplinary expert consensus statement is intended to provide comprehensive guidance that can be referenced at the point of care to cardiac electrophysiologists, cardiologists, and other health care professionals, on the management of cardiac arrhythmias in pregnant patients and in fetuses. This document covers general concepts related to arrhythmias, including both brady- and tachyarrhythmias, in both the patient and the fetus during pregnancy. Recommendations are provided for optimal approaches to diagnosis and evaluation of arrhythmias; selection of invasive and noninvasive options for treatment of arrhythmias; and disease- and patient-specific considerations when risk stratifying, diagnosing, and treating arrhythmias in pregnant patients and fetuses. Gaps in knowledge and new directions for future research are also identified.

Left Bundle Branch Area Pacing Versus Biventricular Pacing as Initial Strategy for Cardiac Resynchronization.

BACKGROUND: Left bundle branch area pacing (LBBAP) for cardiac resynchronization therapy (CRT) is an alternative to biventricular pacing (BiVp). OBJECTIVES: The purpose of this study was to compare the outcomes between LBBAP and BiVp as an initial implant strategy for CRT. METHODS: In this prospective multicenter, observational, nonrandomized study, first-time CRT implant recipients with LBBAP or BiVp were included. The primary efficacy outcome was a composite of heart failure (HF)-related hospitalization and all-cause mortality. The primary safety outcomes were acute and long-term complications. Secondary outcomes included postprocedural New York Heart Association functional class and electrocardiographic and echocardiographic parameters. RESULTS: A total of 371 patients (median follow-up of 340 days [IQR: 206-477 days]) were included. The primary efficacy outcome occurred in 24.2% in the LBBAP vs 42.4% in the BiVp (HR: 0.621 [95% CI: 0.415-0.93]; P = 0.021) group, driven by a reduction in HF-related hospitalizations (22.6% vs 39.5%; HR: 0.607 [95% CI: 0.397-0.927]; P = 0.021) without significant difference in all-cause mortality (5.5% vs 11.9%; P = 0.19) or differences in long-term complications (LBBAP: 9.4% vs BiVp: 15.2%; P = 0.146). LBBAP resulted in shorter procedural (95 minutes [IQR: 65-120 minutes] vs 129 minutes [IQR: 103-162 minutes]; P < 0.001) and fluoroscopy times (12 minutes [IQR: 7.4-21.1 minutes] vs 21.7 minutes [IQR: 14.3-30 minutes]; P < 0.001), shorter QRS duration (123.7 ± 18 milliseconds vs 149.3 ± 29.1 milliseconds; P < 0.001), and higher postprocedural left ventricular ejection fraction (34.1% ± 12.5% vs 31.4% ± 10.8%; P = 0.041). CONCLUSIONS: LBBAP as an initial CRT strategy resulted in a lower risk of HF-related hospitalizations compared to BiVp. A reduction in procedural and fluoroscopy times, shorter paced QRS duration, and improvements in left ventricular ejection fraction compared with BiVp were observed.

Clinical Outcomes in Patients With Dilated Cardiomyopathy and Ventricular Tachycardia.

BACKGROUND: Recurrent ventricular tachycardia (VT) due to dilated cardiomyopathy (DCM) is difficult to treat, and long-term outcome data are limited. OBJECTIVES: The aim of this study was to identify predictors of mortality or heart transplantation (HTx) and VT recurrence. METHODS: Consecutive patients with DCM accepted for radiofrequency catheter ablation (RFCA) of VT at 9 centers were prospectively enrolled and followed. RESULTS: Of 281 consecutive patients (mean age 60 ± 13 years, 85% men, mean left ventricular ejection fraction [LVEF] 36% ± 12%), 35% had VT storm, 20% had incessant VT, and amiodarone was unsuccessful in 68%. During follow-up of 21 months (IQR: 6-30 months), 67 patients (24%) died or underwent HTx, and 138 (49%) had VT recurrence (45 within 30 days, defined as early); the 4-year rate of VT recurrence or mortality or HTx was 70%. Independent predictors of mortality or HTx were early VT recurrence (HR: 2.92; 95% CI: 1.37-6.21; P < 0.01), amiodarone at discharge (HR: 3.23; 95% CI: 1.43-7.33; P < 0.01), renal dysfunction (HR: 1.92; 95% CI: 1.01-3.64; P = 0.046), and LVEF (HR: 1.36; 95% CI: 1.0-1.84; P = 0.052). LVEF ≤32% identified patients at risk for mortality or HTx (area under the curve: 0.75). Mortality or HTx per 100 person-years was 40.4 events after early, compared with 14.2 events after later VT recurrence and 8.5 events with no VT recurrence after RFCA (P < 0.01 for both). Patients with early recurrence and LVEFs ≤32% had a 1-year rate of mortality or HTx of 55%. VT recurrence was predicted by prior implantable cardioverter-defibrillator shocks, basal anteroseptal VT origin, and procedural failure but not LVEF. CONCLUSIONS: Patients with DCM needing RFCA for VT are a high-risk group. Following RFCA, approximately one-half remain free of VT recurrence. Early VT recurrence with LVEF ≤32% identifies those at very high risk for mortality or HTx, and screening for mechanical support or HTx should be considered. Late VT recurrence after RFCA does not predict worse outcome.