Circulation. Arrhythmia and electrophysiology最新文献

Background: Left bundle branch pacing (LBBP) has emerged as a safe and effective alternative to right ventricular pacing. Traditionally, LBBP is performed with lumenless lead (LLL); however, the use of stylet-driven lead (SDL) is on rise. We aimed to assess acute success and procedural outcomes of SDL versus LLL for LBBP.

Methods: One hundred consecutive patients with bradyarrhythmia, indication of cardiac resynchronization therapy, or ablate and pace strategy were randomized in a 1:1 fashion to the SDL and LLL arms. Tendril STS lead with a CPS Locator 3D catheter and SelectSecure 3830 lead with a C315HIS catheter were used in the SDL and LLL arms, respectively. LBBP was confirmed by standard criteria with measurements done on Labsystem Pro.

Results: Patients in the LLL arm were significantly younger (71.9±11 versus 76.4±8.9 years; P=0.02); all other baseline characteristics were not significantly different. Acute success in LBBP was similar with SDL versus LLL (90% versus 92%; P=0.7). In patients with successful LBBP, screw attempts were not significantly different between the groups (2.3±1.7 in SDL versus 1.9±1.3 in LLL; P=0.2). Implant duration (11±9.6 versus 9.9±7.1 minutes; P=0.4), mean fluoroscopy dose (65.3±82.7 versus 53.5±50.5 mGy; P=0.5), and fluoroscopy time (7.8±4.8 versus 7.4±4 minutes; P=0.7) were also not different in the SDL versus the LLL arm, respectively. Incidence of lead failure (P=0.6), microdislodgement (P=1), and macrodislodgement (P=0.6) were not significantly different. Pacing threshold was comparable at implant and on follow-up at 1, 3, and 6 months.

Conclusions: LBBP was feasible with both lead systems with similar success rate and low capture threshold. No significant difference was observed in procedure duration or fluoroscopy use. No major complications were recorded with either lead.

Registration: URL: https://www.anzctr.org.au; Unique identifier: ACTRN12624000304538.

Background: Recent studies have demonstrated the benefit of early ablation in preventing the progression of atrial fibrillation (AF). Clinical practice has reflected this shift in AF management and no longer requires patients to fail antiarrhythmic drugs (AADs) before receiving ablation. However, there is limited evidence on outcomes with pulsed field ablation (PFA) as a first-line therapy. Examination of real-world data may shed light on clinical practices and the effectiveness of PFA with and without a prior history of AAD usage.

Methods: European Real World Outcomes with Pulsed Field Ablation is an all-comer AF registry enrolling consecutive patients treated with the pentaspline PFA catheter at 7 high-volume centers in Europe. This subanalysis evaluates patients with a history of class I/III AAD use versus those with no documented history of class I/III AAD use (first-line patients). Patients with incomplete AAD history, long-standing persistent AF, and those undergoing a repeat ablation procedure were excluded. Patients were treated and followed based on institutional standard of care. Any episode of atrial tachycardia or AF lasting longer than 30 s was considered an arrhythmia recurrence.

Results: Of 1233 patients enrolled in European real world outcomes with pulsed field ablation, 1091 met the inclusion criteria (mean age, 66 years; 40% females; and persistent AF, 36%). Pulmonary vein isolation-only was used in 90% of the patients, and 10% received extra-PV ablation. Ablation as the first-line approach was chosen in 589 patients, and 502 patients had prior class I/III AAD use. In the first-line PFA group, paroxysmal AF was more frequent (68% versus 59%; P<0.001), and pulmonary vein isolation-only was more frequent (93% versus 86%; P<0.001). At 1-year follow-up, freedom from AF/atrial tachycardia recurrence was similar in the ablation-first versus the ablation after failed AAD group (78% versus 74%, respectively; P=0.076).

Conclusion: In this large real-world PFA registry, freedom from AF/atrial tachycardia recurrence after 1 year was similar in patients undergoing PFA as a first-line treatment and those with prior failed AAD therapy.

Registration: URL: https://www.clinicaltrials.gov; Unique identifier: NCT05823818.

Background: Among inherited cardiomyopathies involving the left ventricle, whether dilated or not, certain genotypes carry a well-established arrhythmic risk, notably manifested as sustained monomorphic ventricular tachycardia (SMVT). Nonetheless, the precise localization and electrophysiological profile of this substrate remain undisclosed across different genotypes.

Methods: Patients diagnosed with cardiomyopathy and left ventricle involvement due to high-risk genetic variants and SMVT treated by electrophysiological study were recruited from 18 European/US centers. Electrophysiological study, imaging, and outcomes data after ablation were assessed in relation to genotype.

Results: Seventy-one patients were included (49.6 Q1-Q3 [40-60] years, 76% men). They were divided into 4 groups according to the affected protein: desmosomal (DSP, PKP2, DSG2, and DSC2), nuclear membrane (LMNA and TMEM43), cytoskeleton (FLNC and DES), and sarcoplasmic reticulum (PLN). Desmosomal genes, TMEM43, and PLN were associated with biventricular disease, while variants in LMNA and cytoskeleton genes had predominant left ventricle involvement (P=0.001). The location of the clinical-SMVT substrate was significantly different based on genotype (P=0.005). DSP and cytoskeleton genes presented SMVTs with right bundle branch block morphology, which origin was identified in the inferolateral segments of the left ventricle. The other desmosomal genes (PKP2 and DSG2), along with TMEM43, showed SMVTs with left bundle branch block morphology and predominantly right ventricular substrate. In contrast, LMNA substrate was mainly observed in the interventricular septum. During a median of 26 Q1-Q3 (10.6-65) months, 27% of patients experienced recurrences of clinical SMVT with differences between genotypes (log-rank 0.016). Nuclear membrane genes demonstrated the highest recurrence rate compared with desmosomal genes (hazard ratio, 4.56 [95% CI, 1.5-13.8]).

Conclusions: The anatomic substrate of SMVTs shows a strong correlation with the underlying genotype, electrocardiographic morphology, and recurrence rate. Particularly, patients with nuclear membrane gene variants have a significantly higher recurrence rate compared with those with desmosomal gene variants.

Background: Inappropriate therapy (IAT) is an undesirable side effect of implantable cardiac defibrillator (ICD) therapy. Early studies with the subcutaneous ICD (S-ICD) showed relatively high inappropriate shock (IAS) rates. The PRAETORIAN (Prospective Randomized Comparison of Subcutaneous and Transvenous Implantable Cardioverter Defibrillator Therapy) trial demonstrated that the S-ICD is noninferior to the transvenous ICD (TV-ICD) with regard to the combined end point of IAS and complications. This secondary analyses evaluates all IAT in the PRAETORIAN trial.

Methods: This international, multicenter trial randomized 849 patients with an indication for ICD therapy between S-ICD (n=426) and TV-ICD therapy (n=423). ICD programming was mandated by protocol. All analysis were performed in the modified intention-to-treat population.

Results: In both groups 42 patients experienced IAT (48-month Kaplan-Meier estimated cumulative incidence, 9.9% and 10.1%, respectively; hazard ratio (HR), 0.99 [95% CI, 0.65-1.52]; P=0.97). There was no significant difference in patients experiencing IAS between both groups (P=0.14). In the S-ICD group, 81 IAT episodes with 124 IAS and 1 inappropriate antitachycardia pacing occurred versus 89 IAT episodes with 130 IAS and 124 inappropriate antitachycardia pacing in the TV-ICD group. IAT episodes were most frequently caused by supraventricular tachycardias in the TV-ICD group (n=83/89) versus cardiac oversensing in the S-ICD group (n=40/81). In the TV-ICD group, a baseline heart rate >80 bpm (HR, 1.99 [95% CI, 1.05-3.76]; P=0.03), a history of atrial fibrillation (HR, 2.66 [95% CI, 1.41-5.02]; P=0.003), and smoking (HR, 2.46 [95% CI, 1.31-4.09]; P=0.005) were independent predictors for IAT. A QRS duration >120 ms was an independent predictor for IAT caused by cardiac oversensing in the S-ICD group (HR, 3.13 [95% CI, 1.34-7.31]; P=0.008). Post-IAS interventions significantly reduced IAS recurrence in both groups (P=0.046).

Conclusions: There was no significant difference in IAT and IAS rates between the S-ICD and TV-ICD in a conventional ICD population, but causes and predictors for IAT differed between the devices. After the first IAS, an intervention significantly reduced the recurrence rate of IAS.

Registration: URL: https://www.clinicaltrials.gov; Unique identifier: NCT01296022.

Background: Atrial fibrillation (AF) is associated with an increased risk of stroke, yet the limitations of conventional monitoring have restricted our understanding of AF burden risk thresholds. Predictive algorithms incorporating continuous AF burden measures may be useful for predicting stroke. This study evaluated the performance of temporal AF burden trends as predictors of stroke from a large cohort with insertable cardiac monitors.

Methods: Using deidentified data from Optum Clinformatics Data Mart (2007-2019) linked with the Medtronic CareLink insertable cardiac monitor database, we identified patients with an insertable cardiac monitor for AF management (n=1197), suspected AF (n=1611), and cryptogenic stroke (n=2205). Daily AF burden was transformed into simple moving averages, and temporal AF burden trends were defined as the comparison of unique simple moving average pairs. Classification trees were used to predict ischemic stroke, and AF burden significance was quantified using bootstrapped mean variable importance.

Results: Of 5013 patients (age, 69.2±11.7 years; 50% male; CHA₂DS₂-VASc, 3.7±1.9) who met inclusion criteria, 869 had an ischemic stroke over 2 409 437 days total follow-up. Prior stroke or transient ischemic attack (variable importance, 13.13) was the number 1 predictor of future stroke followed by no prior diagnosis of AF (7.35) and AF burden trends in follow-up (2.59). Temporal proximity of AF and risk of stroke differed by device indication (simple moving averages: AF management, <8 days and suspected AF and cryptogenic stroke, 8-21 days). Together, baseline characteristics and AF burden trends performed optimally for the area under the receiver operating characteristic curve (0.73), specificity (0.70), and relative risk (5.00).

Conclusions: AF burden trends may provide incremental prognostic value as leading indicators of stroke risk compared with conventional schemes.

Background: Macroreentry stands as the predominant mechanism of typical and atypical flutter. Despite advances in mapping, many aspects of macroreentrant atrial tachycardia remain unsolved. In this translational study, we applied principles of topology to understand the activation patterns, entrainment characteristics, and ablation responses in a large clinical macroreentrant atrial tachycardia database.

Methods: Because the atrium can be topologically seen as a closed sphere with holes, we used a computational fixed spherical mesh model with a finite number of holes to induce and analyze macroreentrant atrial tachycardia. The ensuing insights were used to interpret high-density activation maps, postpacing interval-tachycardia cycle length values (difference between postpacing interval and tachycardia cycle length), and ablation response in 131 cases of typical and atypical flutter (n=106 left atrium, n=25 right atrium).

Results: Modeling of macroreentrant atrial tachycardia revealed that reentry on closed surfaces consistently manifests itself as paired rotation and that an odd number of critical boundaries is mathematically impossible. Together with mathematical confirmation by the index theorem, this led to a unifying construct that could explain the number of loops, difference between postpacing interval and tachycardia cycle length values, and ablation outcomes (termination, no change, or prolongation in tachycardia cycle length) in all 131 cases.

Conclusions: Combining topology with the index theorem offers a novel and cohesive framework for understanding and managing typical and atypical flutter.