Petr Neuzil

Aims: A novel 122-electrode spherical mapping/pulsed field ablation (PFA) device is known to effectively ablate atrial fibrillation (AF). The aim of this study is threshold optimization of LVA for the unique geometry of the Globe electrodes and the prognostic association, to evaluate if the extent of low voltage areas could predict recurrence. Methods and Results: The PULSAR study was an IDE trial of 183 patients undergoing first-time paroxysmal AF ablation with one-year outcomes of any atrial arrhythmia. During this study, a subset of patients (n=82) had detailed pre-ablation voltage maps performed with the catheter. Pulmonary vein isolation (PVI) was then performed with PFA. Patients were followed with weekly transtelephonic monitoring, ECG, and Holters at 3, 6, and 12 months. Recurrence was defined as any atrial arrhythmia (AA) > 30 seconds. Receiver operator curve (ROC) analysis revealed that a low voltage threshold of 1.0 mV had the highest value (0.735). The percentage LVA surface area resulting from a threshold of 1.0 mV that predicted AA recurrence was 11.6%. Univariate and multivariate analysis revealed the percentage LVA was the strongest predictor of AA recurrence. The 12-month freedom from AA was 84.6% and 52.9% for subjects under and over the low voltage area threshold respectively. Conclusions: A voltage threshold of 1.0 mV is proposed as a threshold for defining LVA using the spherical catheter, but a range of approximately 0.5-1.5 mV yielded similar performance. Increased low voltage area in the pre-ablation atrial map was associated with a higher risk of AA recurrence.

Background and Aims: MODULAR ATP is an ongoing trial assessing the efficacy of a subcutaneous implantable cardioverter defibrillator (S-ICD) in communication with a leadless pacemaker (LP) that can deliver bradycardia pacing and antitachycardia pacing. The objective of this study was to assess safety and pacing performance of the investigational LP. Methods: The study enrolled patients with an ICD indication and at high risk for monomorphic ventricular tachycardia. Pacemaker dependent patients were excluded. Primary safety endpoint 2 was the percentage of patients free from major LP-related complications at 12 months. The secondary effectiveness endpoint assessed the rate response performance of the LP under workload. Parameters related to the pacing performance were also measured. Results: In 297 patients, the mean age was 59±12 years, the mean left ventricular ejection fraction was 35.3±13.1%, and 17.5% were female. LP implant was attempted in 286 patients and was successful in 100%. The major LP-related complication free rate at 12 months was 97.2% (one-sided 97.5% LCL 94.5%), surpassing the performance goal of 81%. There were no LP-related complications following Implant. For the secondary effectiveness endpoint, the slope of the normalized sensor rate versus the normalized workload was 0.96 (95% LCL 0.91, 95% UCL 1.02), within the performance goal range of 0.65-1.35. At 12 months, 96.8% of patients had a pacing capture threshold ≤ 2V @ 0.4ms pulse width. Conclusions: The performance of the modular pacing-defibrillator system at one year demonstrated a low complication rate and reliable pacing functionality.

BACKGROUND: Catheter ablation for atrial fibrillation (AF) is one of the most common cardiovascular procedures being performed worldwide. Despite the large body of evidence of its effectiveness, with a single exception, prior ablation studies were largely unblinded trials. Accordingly, residual concerns remained about placebo effects, both for AF recurrence and, in particular, on subjective outcomes such as quality of life or anxiety. Here, we compared pulsed field ablation (PFA) with a sham procedure to treat patients with symptomatic AF. METHODS: This prospective, sham-controlled, single-blind, randomized clinical trial with blinded end-point assessment enrolled patients with AF that was highly symptomatic (Atrial Fibrillation Effect on Quality-of-Life score 0.99). For the second co–primary end point, Atrial Fibrillation Effect on Quality-of-Life scores showed greater improvement from baseline with PFA than sham (improved by 43.9+18.1 points versus 11.3+27.9 points; posterior median difference, 32.6 [95% bayesian credible interval, 20.2–44.9]; posterior probability of superiority >0.99). AF burden at 6 months was significantly lower in the PFA than the sham group (0 [0–0] versus 0.43 [0.04–3.47]; between group median difference, −0.39 [95% credible interval, −2.5 to −0.1], posterior probability of superiority >0.99). The Hospital Anxiety and Depression Scale score changed by −4 points (−7.8 to −2.0) with PFA and by −0.5 (−4.5 to 1.0) with sham (group median difference, −3.5 [95% credible interval, −6.0 to −1.0]; posterior probability of superiority >0.99). CONCLUSIONS: In patients with AF, PFA was superior to sham in reducing arrhythmia recurrences and burden and improving quality of life and AF-associated psychological distress. REGISTRATION: URL: https://www.clinicaltrials.gov ; Unique identifier: NCT05717725.

Background: Prolonged invasive mechanical ventilation (IMV) following out-of-hospital cardiac arrest (OHCA) is associated with increased mortality, complications, and long-term functional impairment. Identification of early interventions that may reduce the duration of IMV is therefore clinically relevant. Objective: To evaluate the association between the timing of bronchoscopy and the duration of IMV in patients successfully resuscitated after OHCA. Methods: We performed a retrospective observational study of patients admitted to a cardiac intensive care unit after successful cardiopulmonary resuscitation for OHCA who required IMV for more than 24 h. Patients receiving mechanical circulatory support or those with poor neurological prognosis were excluded. The primary outcome was the total duration of IMV according to the timing of bronchoscopy. Secondary outcomes included associations between IMV duration and return of spontaneous circulation (ROSC) time, initial serum lactate levels, and the impact of bronchoscopy on antibiotic therapy. Results: A total of 38 patients (29 men and 9 women; median age 53 years) were included. Bronchoscopy performed within 24 h of ICU admission was associated with a significantly shorter duration of IMV compared with delayed bronchoscopy (98 ± 15 vs 243 ± 49 h; p < .05). A moderate positive correlation was observed between ROSC duration and IMV duration (Pearson r = .44; p = .006). Initial serum lactate levels were not significantly correlated with IMV duration. Early bronchoscopy led to modification of antibiotic therapy in 56% of patients. Conclusions: Early bronchoscopy after OHCA was associated with a substantial reduction in the duration of IMV. These findings suggest that early bronchoscopic evaluation may represent a readily available ICU intervention to reduce the risk of prolonged mechanical ventilation in selected post–cardiac arrest patients.

BACKGROUND: Remapping studies have evaluated chronic lesion durability of the first-generation pentaspline pulsed field ablation (PFA) catheter that did not have integrated electroanatomical mapping. By invasive remapping, this first-in-human study evaluated the durability of lesions facilitated by the integration of the navigation-enabled pentaspline PFA catheter and mapping system in patients with atrial fibrillation. METHODS: The NAVIGATE-PF Phase 2 trial evaluated the second-generation, mapping-integrated pentaspline PFA catheter. Lesion durability was assessed by invasive remapping 60 days post index procedure. RESULTS: After index ablation in 20 patients with the pentaspline PFA catheter, remaps were performed 60 days later in 17 patients, demonstrating a high rate of lesion durability in the pulmonary veins (95%) and posterior wall (86%). CONCLUSIONS: By facilitating real-time visualization of catheter positioning and acute lesion estimation through tags, the second-generation map-and-ablate pentaspline PFA catheter and integrated mapping system may enhance procedural success. REGISTRATION: URL: https://www.clinicaltrials.gov ; Unique identifier: NCT06175234.

Aims: Congestion signals heart failure (HF) progression and drives decompensation. Reliable management strategies remain poorly developed. We evaluated 12 months of congestion-guided clinical management following implantation of an inferior vena cava (IVC) sensor. Methods and Results: Data were combined from two prospective studies (FUTURE-HF and FUTURE-HFII) (N =65, mean age 65.7 ± 9.5 years; 75.4% NYHA III; 90.8% heart failure with reduced ejection fraction. Patients recorded daily IVC parameters. Adjudicated safety outcomes, sensor-derived IVC area measurement versus CT imaging, medication adjustments, and clinical outcomes at 12 months were analysed. No adjudicated device or procedure-related serious adverse events occurred. Excellent correlation was observed between sensor-derived and CT-derived IVC area (n = 44; R2 = 0.97; mean relative error <5%). Patient adherence was 93%, and a sustained, significant reduction in IVC area was observed (8.1%, P < .005), correlated with clinical improvements (P < .001), despite no significant change in body weight. Improvements were observed in the New York Heart Association (NYHA) functional class (Class III: 74.5% improved to 40.0%; P < .01) and N-terminal pro-B-type natriuretic peptide (median 1697 reduced to 998 ng/L; P < .001). HF events (HFEs) were lower post-implant (0.31/year, 1.67/year pre-implant; 84.5% relative reduction; rate ratio: 0.18; 95% CI: 0.08–0.29). Medication adjustments (n = 415) included diuretic titration (57%) and increased use of guideline directed medical therapy from baseline to 12-months (28%). Conclusions: Congestion management through ambulatory IVC monitoring demonstrated excellent safety, sustained accuracy, and high levels of patient adherence at 12-months after sensor implantation. This was associated with improved HF congestion status and a lower observed rate of HFEs, supporting investigation of congestion-guided management using IVC monitoring in a pivotal randomized clinical trial.

Aims: The aim of this analysis was to evaluate the upgradeability of a single-chamber leadless pacemaker (LP) to a dual-chamber system in patients indicated for a dual-chamber pacemaker. Methods and results: A prospective, multicentre study evaluated the safety and performance of a dual-chamber LP. The study included patients with a prior ventricular LP to evaluate its upgradeability. Patients had an attempted atrial LP implant, and if successfully implanted, the LPs were paired to a dual-chamber pacing mode to evaluate upgrade success. Patients were followed for 12 months from the attempted atrial LP implantation. Among 35 patients with an attempted upgrade (62.9% male, average age 70 years), the most common primary indication was sinus node dysfunction (57.1%). Out of 35 patients, 91.4% had successful upgrades. The mean atrial device electrical measurements stabilized within 1 month from the procedure and remained stable through 12 months (capture threshold at 0.4 ms 0.8 ± 0.6 V, sense amplitude 4.5 ± 2.7 mV at 12 months). A total of five (14.3%) patients experienced seven complications, all of which were procedure-related. There were no device or procedure-related deaths. The total estimated battery longevity (accounting for time since implant) evaluated at 12 months was 11.3 ± 4.2 and 5.7 ± 2.6 years for the ventricular and atrial LPs, respectively. One patient required an atrial LP revision 10 months after implantation. The LP was retrieved and replaced. Conclusion: These data confirm the feasibility, safety, and long-term effectiveness of adding an atrial LP in patients with a pre-existing ventricular LP to achieve dual-chamber leadless pacing.

Aims: A dual-chamber leadless pacemaker (LP) system relies on a beat-to-beat, wireless, implant-to-implant (i2i™) communication between implanted devices in the right atrium and right ventricle (A-to-V and V-to-A). Atrioventricular (AV) synchrony was evaluated during an ambulatory 24 h period of daily living to determine if its effectiveness can be maintained under real-world conditions. Methods and results: A prospective, single-arm, multicentre clinical study (ClinicalTrials.gov identifier NCT05252702) evaluated the overall safety and performance of the dual-chamber LPs in patients with standard indications for dual-chamber pacing. Following the 3-month visit, eligible patients wore 12-lead Holter monitors for 24 h while resuming the activities of daily living while under clinically driven programmed settings. Leadless pacemaker diagnostic data were interrogated when patients returned to the clinic. An independent Holter core laboratory adjudicated the proportion of synchronous beats (PR intervals within paced and sensed AV delay bounds). Relationships between AV synchrony and i2i communication success rate, implant indication, heart rate, and AV event type were evaluated. Among 47 analysable patients, mean AV synchrony was achieved in 96.7% of beats, exceeding mean A-to-V and V-to-A transmission success rates of 93.4% and 92.1%, respectively. There were no significant differences in AV synchrony between sinus node and AV block patients. Across all AV paced/sensed cycle combinations and heart rate ranges (including >100 b.p.m.), AV synchrony was sustained >90% in an ambulatory real-world setting. Conclusion: A dual-chamber leadless pacing system demonstrated >96% overall AV synchrony for a 24 h period of daily living while programmed to clinically appropriate settings, thus showing that true dual-chamber DDD(R) pacing can be maintained in a real-world environment.

BACKGROUND: MODULAR antitachycardia pacing (ATP), a multicenter, international trial, assesses a modular cardiac rhythm management system: a subcutaneous implantable cardioverter defibrillator in wireless communication with a leadless pacemaker (LP) capable of pace-terminating ventricular tachycardia. METHODS: Enrolees had one or more clinical risk factors for ventricular tachycardia and did not require chronic pacing. Complications included prespecified major LP system- and procedure-related complications, and any complication related to the LP, subcutaneous implantable cardioverter defibrillator, implantation, or study protocol. Survival analysis was performed to identify complication-free rates, therapy delivery, and all-cause mortality. RESULTS: The 297 patients enrolled had an ejection fraction of 35±13%, 43% secondary prevention indications, and 59% with prior ventricular arrhythmias. Of 286 patients undergoing LP implantation (100% success), 251 patients completed 12-month follow-up. Mortality rate was 6%, with none related to the implant procedure. Median follow-up duration was 23.4 months (interquartile range, 17.9–28.1). The LP major complication-free rate was 97.2%, exceeding the performance goal. The overall LP+ subcutaneous implantable cardioverter defibrillator system-related complication-free rate was 88.5%. Appropriate tachyarrhythmia-therapy (ATP+shock) rates were 14.4%, and appropriate shock rates were 8.5%. Inappropriate total tachyarrhythmia therapy was 9.5% of which 8.5% were shocks. ATP was 67.3% successful in terminating ventricular arrhythmia episodes and accelerated ventricular arrhythmias in 10.1% of episodes. Overall therapy burden (ATP+shock) was 96/100 patient-years, of which 44/100 patient-years was for shock delivery. CONCLUSIONS: One-year outcomes of the first modular pacing-defibrillator system reveal low system and LP complication rates and good ATP efficacy rates, suggesting that the modular cardiac rhythm management is a viable alternative to single-chamber implantable cardioverter defibrillators using low-energy pacing capability without the need for transvenous leads. CLINICAL TRIAL REGISTRATION: URL: https://clinicaltrials.gov/ ; Unique identifier: NCT04798768.