Sex differences among subcutaneous defibrillator (S-ICD) recipients: a propensity-matched, multicenter, international analysis from the i-SUSI project

BACKGROUND AND AIMS

Women have been historically underrepresented in implantable cardioverter defibrillator (ICD) trials. No data on sex differences regarding subcutaneous-ICDs (S-ICD) carriers have been described. Aim of our study was to investigate sex-related differences among unselected S-ICD recipients.

METHODS

Consecutive patients enrolled in the multicenter, international i-SUSI registry were analyzed. Comparisons between sexes were performed using a 1:1 propensity matching adjusted analysis for age, body mass index (BMI), left ventricular function and substrate. The primary outcome was the rate of appropriate shocks during follow-up. Inappropriate shocks and other device-related complications were deemed secondary outcomes.

RESULTS

A total of 1698 patients were extracted from the iSUSI registry; 399 (23.5%) were females. After propensity matching, two cohorts of 374 patients presenting similar baseline characteristics were analyzed. Despite similar periprocedural characteristics and a matched BMI, women resulted at lower risk of conversion failure as per PRAETORIAN score (73.4% vs 81.3%, p = 0.049). Over a median follow-up time of 26.5 [12.7-42.5] months, appropriate shocks were more common in the male cohort (rate/year 3.4%vs1.7%; log-rank p = 0.049), while no significant differences in device-related complications (rate/year: 6.3% vs 5.8%; log-rank p = 0.595) and inappropriate shocks (rate/year: 4.3%vs3.1%; log-rank p = 0.375) were observed. After controlling for confounders, sex remained significantly associated with the primary outcome (aHR 1.648; CI 0.999-2.655, p = 0.048), while not resulting predictor of inappropriate shocks and device-related complications.

CONCLUSION

In a propensity-matched cohort of S-ICD recipients, women are less likely to experience appropriate ICD therapy, while not showing higher risk of device related-complications.

"Ablate and Pace" with Conduction System Pacing: Concomitant versus Delayed Atrioventricular Junction Ablation

Objectives: Conduction system pacing (CSP) and atrioventricular junction ablation (AVJA) improve the outcomes in patients with symptomatic, refractory atrial fibrillation (AF). In this setting, AVJA can be performed simultaneously with implantation or in a second procedure a few weeks after implantation. Comparison data on these two alternative strategies are lacking. Methods: A prospective, multicentre, observational study enrolled consecutive patients with symptomatic, refractory AF undergoing CSP and AVJA performed in a single procedure or in two separate procedures. Data on the long-term outcomes and healthcare resource utilization were prospectively collected. Results: A total of 147 patients were enrolled: for 105 patients, CSP implantation and AVJA were performed simultaneously (concomitant AVJA); in 42, AVJA was performed in a second procedure, with a mean of 28.8 ± 19.3 days from implantation (delayed AVJA). After a mean follow-up of 12 months, the rate of procedure-related complications was similar in both groups (3.8% vs. 2.4%; p = 0.666). Concomitant AVJA was associated with a lower number of procedure-related hospitalizations per patient (1.0 ± 0.1 vs. 2.0 ± 0.3; p < 0.001) and with a lower number of hospital treatment days per patient (4.7 ± 1.8 vs. 7.4 ± 1.9; p < 0.001). Conclusions: Concomitant AVJA resulted as being as safe as delayed AVJA and was associated with a lower utilization of healthcare resources.

Impact of ventricular tachycardia ablation in subcutaneous implantable cardioverter defibrillator carriers: a multicentre, international analysis from the iSUSI project

AIMS

Catheter ablation (CA) of ventricular tachycardia (VT) has become an important tool to improve clinical outcomes in patients with appropriate transvenous implantable cardioverter defibrillator (ICD) shocks. The aim of our analysis was to test whether VT ablation (VTA) impacts long-term clinical outcomes even in subcutaneous ICD (S-ICD) carriers.

METHODS AND RESULTS

International Subcutaneous Implantable Cardioverter Defibrillator (iSUSI) registry patients who experienced either an ICD shock or a hospitalization for monomorphic VT were included in this analysis. Based on an eventual VTA after the index event, patients were divided into VTA+ vs. VTA- cohorts. Primary outcome of the study was the occurrence of a combination of device-related appropriate shocks, monomorphic VTs, and cardiovascular mortality. Secondary outcomes were addressed individually. Among n = 1661 iSUSI patients, n = 211 were included: n = 177 experiencing ICD shocks and n = 34 hospitalized for VT. No significant differences in baseline characteristics were observed. Both the crude and the yearly event rate of the primary outcome (5/59 and 3.8% yearly event rate VTA+ vs. 41/152 and 16.4% yearly event rate in the VTA-; log-rank: P value = 0.0013) and the cardiovascular mortality (1/59 and 0.7% yearly event rate VTA+ vs. 13/152 and 4.7% yearly event rate VTA-; log-rank P = 0.043) were significantly lower in the VTA + cohort. At multivariate analysis, VTA was the only variable remaining associated with a lower incidence of the primary outcome [adjusted hazard ratio 0.262 (0.100-0.681), P = 0.006].

CONCLUSION

In a real-world registry of S-ICD carriers, the combined study endpoint of arrhythmic events and cardiovascular mortality was lower in the patient cohort undergoing VTA at long-term follow-up.

CLINICALTRIALS.GOV IDENTIFIER

NCT0473876.

Conduction system disease management in patients candidate and/or treated for the aortic valve disease: an Italian Survey promoted by Italian Association of Arrhythmology and Cardiac Pacing (AIAC)

BACKGROUND

Conduction system disorders represent a frequent complication in patients undergoing surgical (surgical aortic valve replacement, SAVR) or percutaneous (transcatheter aortic valve implantation, TAVI) aortic valve replacement. The purpose of this survey was to evaluate experienced operators approach in this clinical condition.

METHODS

This survey was independently conducted by the Italian Association of Arrhythmology and Cardiac Pacing (AIAC) and it consisted of 24 questions regarding the respondents' profile, the characteristics of participating centres, and conduction disease management in different scenarios.

RESULTS

Fifty-five physicians from 55 Italian arrhythmia centres took part in the survey. Prophylactic pacemaker implantation is rare. In case of persistent complete atrioventricular block (AVB), 49% and 73% respondents wait less than one week before implanting a definitive pacemaker after SAVR and TAVI, respectively. In case of second degree AVB, the respondents wait some days more for definitive implantation. Respondents consider bundle branch blocks, in particular pre-existing left bundle branch block (LBBB), the worst prognostic factors for pacemaker implantation after TAVI. The implanted valve type is considered a relevant element to evaluate. In patients with new-onset LBBB and severe/moderate left ventricular systolic dysfunction, respondents would implant a biventricular pacemaker in 100/55% of cases, respectively.

CONCLUSIONS

Waiting time before a definitive pacemaker implantation after aortic valve replacement has reduced compared to the past, and it is anticipated in TAVI vs. SAVR. Bundle branch blocks are considered the worse prognostic factor for pacemaker implantation after TAVI. The type of pacemaker implanted in new-onset LBBB patients without severe left ventricular systolic dysfunction is heterogeneous.

Complications of left bundle branch area pacing compared with biventricular pacing in candidates for resynchronization therapy: Results of a propensity score-matched analysis from a multicenter registry

BACKGROUND

Cardiac resynchronization therapy (CRT) with biventricular pacing (BVP) is a well-established therapy in patients with reduced left ventricular ejection fraction, heart failure, and left bundle branch block. Left bundle branch area pacing (LBBAP) has recently been shown to be a feasible and effective alternative to BVP. Comparative data on the risk of complications between LBBAP and BVP among patients undergoing CRT are lacking.

OBJECTIVE

The aim of this study was to compare the long-term risk of procedure-related complications between LBBAP and BVP in a cohort of patients undergoing CRT.

METHODS

This prospective, multicenter, observational study enrolled 668 consecutive patients (mean age 71.2 ± 10.0 years; 52.2% male; 59.4% with New York Heart Association class III-IV heart failure symptoms) with left ventricular ejection fraction 33.4% ± 4.3% who underwent BVP (n = 561) or LBBAP (n = 107) for a class I or II indication for CRT. Propensity score matching for baseline characteristics yielded 93 matched pairs. The rate and nature of intraprocedural and long-term post-procedural complications occurring during follow-up were prospectively collected and compared between the 2 groups.

RESULTS

During a mean follow-up of 18 months, procedure-related complications were observed in 16 patients: 12 in BVP (12.9%) and 4 in LBBAP (4.3%) (P = .036). Compared with patients who underwent LBBAP, those who underwent BVP showed a lower complication-free survival (P = .032). In multivariate analysis, BVP resulted an independent predictive factor associated with a higher risk of complications (hazard ratio 3.234; P = .042). Complications related to the coronary sinus lead were most frequently observed in patients who underwent BVP (50.0% of all complications).

CONCLUSION

LBBAP was associated with a lower long-term risk of device-related complications compared with BVP in patients with an indication for CRT.

Upgrade from leadless to transvenous pacemaker with left bundle branch area pacing: A case report

An 80-years-old patient with permanent atrial fibrillation and symptomatic, paroxysmal atrioventricular blocks (AVBs) underwent leadless pacemaker (L-PM) implantation. Seven years after implantation, as a consequence of a progression of the AVB towards a persistent form, resulting in an increased need for pacing, he developed a pacing-induced cardiomyopathy. He then underwent a successful upgrade from L-PM to a transvenous pacemaker (T-PM) with left bundle branch area pacing (LBBAP). The L-PM did not interfere with the T-PM and was turned off and abandoned. One month after the upgrading the patient showed a significant improvement in cardiac function and functional capacity.

Spontaneous Sinus Rhythm Restoration in Patients With Refractory, Permanent Atrial Fibrillation Who Underwent Conduction System Pacing and Atrioventricular Junction Ablation

Ablate and pace (A&P) with conduction system pacing (CSP) improves outcomes in patients with symptomatic permanent atrial fibrillation (AF). Data on spontaneous sinus rhythm restoration (SSRR) in this setting are lacking. This study aimed to assess the incidence and the predictors of SSRR in a population of patients with permanent AF who underwent A&P with CSP. Prospective, observational study, enrolling consecutive patients with symptomatic permanent AF (of documented duration >6 months) and uncontrolled, drug-refractory high ventricular rate, who underwent A&P with CSP. The incidence and predictors of SSRR were prospectively assessed. A total of 107 patients (79.0 ± 9.1 years, 33.6% male, 74.8% with New York Heart Association class ≥III, 56.1% with ejection fraction <40%) were enrolled: 40 received His' bundle pacing, 67 left bundle branch area pacing. During a median follow-up of 12 months SSRR was observed in 14 patients (13.1%), occurring a median of 3 months after A&P (interquartile range 1 to 6; range 0 to 17). Multivariable analysis identified a duration of permanent AF <12 months (hazard ratio 7.7, p = 0.040) and a left atrial volume index <49 ml/m2 (hazard ratio 14.8, p = 0.008) as independent predictors of SSRR. In patients with coexistence of both predictors the incidence of SSRR was of 41.4%. In a population of patients with symptomatic, permanent AF, treated with A&P with CSP, SSRR was observed in 13% of patients during follow-up. A duration of permanent AF <12 months and a left atrial volume index <49 ml/m2 were independent predictors of this phenomenon.

Superior approach from the pocket for atrioventricular junction ablation performed at the time of conduction system pacing implantation

BACKGROUND

Conduction system pacing (CSP) and atrioventricular junction ablation (AVJA) improve outcomes in patients with symptomatic, refractory atrial fibrillation (AF). Superior approach (SA) from the pocket via axillary or subclavian vein has been proposed as an alternative to the conventional femoral venous access (FA) to perform AVJA.

OBJECTIVE

To assess the feasibility and safety of SA for AVJA performed simultaneously with CSP, and to compare this approach with FA.

METHODS

A prospective, observational study, enrolling consecutive patients with symptomatic, refractory AF undergoing simultaneous CSP and AVJA.

RESULTS

A total of 107 patients were enrolled: in 50, AVJA was primarily attempted with SA, in 69 from FA. AVJA with SA was successful in 38 patients (76.0%), while in 12 patients, a subsequent FA was required. AVJA from FA was successful in 68 patients (98.5%), while in one patient, a left-sided approach via femoral artery was required. Compared with FA, SA was associated with a significantly longer duration of ablation (238.0 ± 218.2 vs. 161.9 ± 181.9 s; p = .035), a significantly shorter procedure time (28.1 ± 19.8 vs. 19.8 ± 16.8 min; p = .018), an earlier ambulation (2.7 ± 3.2 vs. 19.8 ± 0.1 h; p < .001), and an earlier discharge from procedure completion (24.0 ± 2.7 vs. 27.1 ± 5.1 h; p < .001). After a median follow-up of 12 months, the rate of complications was similar in the two groups (2.0% in SA, 4.3% in FA; p = .483).

CONCLUSION

Simultaneous CSP and AVJA with SA is feasible, with a safety profile similar to FA. Compared to FA, this approach reduces the procedure times and allows earlier ambulation and discharge.

Catheter ablation in patients with paroxysmal atrial fibrillation and absence of structural heart disease: A meta-analysis of randomized trials

Introduction

Rhythm control strategy in paroxysmal atrial fibrillation (AF) can be performed with antiarrhythmic drugs (AAD) or catheter ablation (CA). Nevertheless, a clear overview of the percentage of freedom from AF over time and complications is lacking. Therefore, we conducted a meta-analysis of randomized controlled trials (RCTs) comparing CA versus AAD.

Methods

We searched databases up to 5 May 2023 for RCTs focusing on CA versus AAD. The study endpoints were atrial tachyarrhythmia (AT) recurrence, progression to persistent AF, overall complications, stroke/TIA, bleedings, heart failure (HF) hospitalization and all-cause mortality.

Results

Twelve RCTs enrolling 2393 patients were included. CA showed a significantly lower AT recurrence rate at one year [27.4 % vs 56.3 %; RR: 0.45; p < 0.00001], at two years [39.9 % vs 62.7 %; RR: 0.56; p = 0.0004] and at three years [45.7 % vs 80.9 %; RR: 0.54; p < 0.0001] compared to AAD. Furthermore, CA significantly reduced the progression to persistent AF [1.6 % vs 12.9 %; RR: 0.14; p < 0.00001] with no differences in overall complications [5.9 % vs 4.5 %; RR: 1.27; p = 0.22], stroke/TIA [0.6 % vs 0.6 %; RR: 1.10; p = 0.86], bleedings [0.4 % vs 0.6 %; RR: 0.90; p = 0.84], HF hospitalization [0,3% vs 0,7%; RR: 0.56; p = 0.37] and all-cause mortality [0,4% vs 0.5 %; RR: 0.78; p = 0.67]. Subgroup analysis between radiofrequency and cryo-ablation or considering RCTs with CA as first-line treatment showed no significant differences.

Conclusion

CA demonstrated lower rates of AT recurrence over the time, as well as a significant reduction in the progression from paroxysmal to persistent AF, with no difference in terms of energy source, complications, and clinical outcomes.

High power short duration versus low power long duration ablation in patients with atrial fibrillation: A meta-analysis of randomized trials

BACKGROUND

High-power-short-duration (HPSD) radiofrequency (RF) ablation is a viable alternative to low-power-long-duration (LPLD) RF for pulmonary vein isolation (PVI). Nevertheless, trials showed conflicting results regarding atrial fibrillation (AF) recurrences and few data concerning complications. Therefore, we conducted a meta-analysis of randomized trials comparing HPSD versus LPLD.

METHODS

We systematically searched the electronic databases for studies published from inception to March 31, 2023 focusing on HPSD versus LPLD. The study endpoints were AF recurrence, procedural times and overall complications.

RESULTS

Five studies enrolling 424 patients met the inclusion criteria (mean age 61.1 years; 54.3% paroxysmal AF; mean LVEF 58.2%). Compared to LPLD, HPSD showed a significantly lower AF recurrence rate [16.3% vs. 30,1%; RR: 0.54 (95% CI: 0.38-0.79); p = 0.001] at a mean 10.9 months follow-up. Moreover, HPSD led to a significant reduction in total procedural time [MD: -26.25 min (95%CI: -42.89 to -9.61); p = 0.002], PVI time [MD: -26.44 min (95%CI: -38.32 to -14.55); p < 0.0001], RF application time [MD: -8.69 min (95%CI: -11.37 to -6.01); p < 0.00001] and RF lesion number [MD: -7.60 (95%CI: -10.15 to -5.05); p < 0.00001]. No difference was found in either right [80.4% vs. 78.2%; RR: 1.04 (95% CI: 0.81-1.32); p = 0.77] or left [92.3% vs. 90.2%; RR: 1.02 (95% CI: 0.94-1.11); p = 0.58] first-pass isolation and overall complications [6% vs. 3.7%; RR: 1.45 (95%CI: 0.53-3.99); p = 0.47] between groups.

CONCLUSION

In our metanalysis of randomized trials, HPSD ablation appeared to be associated to a significantly improved freedom from AF and shorter procedures, without increasing the risk of complications.

Ablate and pace: Comparison of outcomes between conduction system pacing and biventricular pacing

BACKGROUND

Conduction system pacing (CSP), including His-bundle pacing (HBP) and left bundle branch area pacing (LBBAP), have been proposed as alternatives to biventricular pacing (BVP) in patients scheduled for ablate and pace (A&P) strategy. The aim of this study was to compare the clinical outcomes, including the rate and nature of device-related complications, between BVP and CSP in a cohort of patients undergoing A&P.

METHODS

Prospective, multicenter, observational study, enrolling consecutive patients undergoing A&P. The risk of device-related complications and of heart failure (HF) hospitalization was prospectively assessed.

RESULTS

A total of 373 patients (75.3 ± 8.7 years, 53.9% male, 68.9% with NYHA class ≥III) were enrolled: 263 with BVP, 68 with HBP, and 42 with LBBAP. Baseline characteristics of the three groups were similar. Compared to BVP and HBP, LBBAP was associated with the shortest mean procedural and fluoroscopy times and with the lowest acute capture thresholds (all p < .05). At 12-month follow-up LBBAP maintained the lowest capture thresholds and showed the longest estimated residual battery longevity (all p < .05). At 12-months follow-up the three study groups showed a similar risk of device-related complications (5.7%, 4.4%, and 2.4% for BVP, HBP, and LBBAP, respectively; p = .650), and of HF hospitalization (2.7%, 1.5%, and 2.4% for BVP, HBP, and LBBAP, respectively; p = .850).

CONCLUSIONS

In the setting of A&P, CSP is a feasible pacing modality, with a midterm safety profile comparable to BVP. LBBAP offers the advantage of reducing procedural times and obtaining lower and stable capture thresholds, with a positive impact on the device longevity.

Possible systolic fascicular potentials in patients with left bundle branch block undergoing left bundle branch area pacing: A case series

INTRODUCTION

In left bundle branch area pacing (LBBAP), several methods allow determination of lead depth during active fixation inside the septum: among these, visualization of a Purkinje potential indicates that the subendocardial area has been reached. In LBB block (LBBB) patients, fascicular potentials are visible as presystolic only in rare conditions.

METHODS AND RESULTS

Since October 2022 until August 2023, LBBAP was attempted in 21 patients with LBBB at our Center: among the 18 consecutive patients (86%) in which it was successful, focusing on the terminal part of the unipolar ventricular electrogram (VEGM) recorded in the LBBA (where fixation beats occurred and conduction system (CS) capture was confirmed), we always observed discrete high-frequency, low-amplitude signals during spontaneous rhythm with LBBB morphology, showing a consistent coupling with the QRS onset, falling in a portion of QRS interval ranging from 58% to 80% of its overall duration, and disappearing during pacing. As found in a recently published case report, these sharp signals could represent the activation of left ventricular CS fibers, occurring passively from the septal working myocardium, and thus appearing lately in the VEGM.

CONCLUSION

The possibility of recognizing discrete high-frequency, low-amplitude signals within the terminal portion of the unipolar VEGM, possibly representing left CS potentials, even in patients with LBBB, may constitute a useful additional means to notice operators about having reached the LBBA, thus helping to avoid perforation in the left ventricle.

Sex differences in leadless pacemaker implantation: A propensity-matched analysis from the i-LEAPER registry

BACKGROUND

The impact of sex in clinical and procedural outcomes in leadless pacemaker (LPM) patients has not yet been investigated.

OBJECTIVE

The purpose of this study was to investigate sex-related differences in patients undergoing LPM implantation.

METHODS

Consecutive patients enrolled in the i-LEAPER registry were analyzed. Comparisons between sexes were performed within the overall cohort using an adjusted analysis with 1:1 propensity matching for age and comorbidities. The primary outcome was the comparison of major complication rates. Sex-related differences regarding electrical performance and all-cause mortality during follow-up were deemed secondary outcomes.

RESULTS

In the overall population (n = 1179 patients; median age 80 years), 64.3% were men. After propensity matching, 738 patients with no significant baseline differences among groups were identified. During median follow-up of 25 [interquartile range 24-39] months, female sex was not associated with LPM-related major complications (hazard ratio [HR] 2.03; 95% confidence interval [CI] 0.70-5.84; P = .190) or all-cause mortality (HR 0.98; 95% CI 0.40-2.42; P = .960). LPM electrical performance results were comparable between groups, except for a higher pacing impedance in women at implant and during follow-up (24 months: 670 [550-800] Ω vs 616 [530-770] Ω; P = .014) that remained within normal limits.

CONCLUSION

In a real-world setting, we found differences in sex-related referral patterns for LPM implantation with an underrepresentation of women, although major complication rate and LPM performance were comparable between sexes. Female patients showed higher impedance values, which had no impact on overall device performance. Electrical parameters remained within normal limits in both groups during the entire follow-up.

Success and complication rates of conduction system pacing: a meta-analytical observational comparison of left bundle branch area pacing and His bundle pacing

BACKGROUND

Left bundle branch area pacing (LBBAP) and His bundle pacing (HBP) are the main strategies to achieve conduction system pacing (CSP), but only observational studies with few patients have compared the two pacing strategies, sometimes with unclear results given the different definitions of the feasibility and safety outcomes. Therefore, we conducted a meta-analysis aiming to compare the success and complications of LBBAP versus HBP.

METHODS

We systematically searched the electronic databases for studies published from inception to March 22, 2023, and focusing on LBBAP versus HBP. The study endpoints were CSP success rate, device-related complications, CSP lead-related complications and non-CSP lead-related complications.

RESULTS

Fifteen observational studies enrolling 2491 patients met the inclusion criteria. LBBAP led to a significant increase in procedural success [91.1% vs 80.9%; RR: 1.15 (95% CI: 1.08-1.22); p < 0.00001] with a significantly lower complication rate [1.8% vs 5.2%; RR: 0.48 (95% CI: 0.29-0.78); p = 0.003], lead-related complications [1.1% vs 4.3%; RR: 0.38 (95% CI: 0.21-0.72); p = 0.003] and lead failure/deactivation [0.2% vs 3.9%; RR: 0.16 (95% CI: 0.07-0.35); p < 0.00001] than HBP. No significant differences were found between CSP lead dislodgement and non-CSP lead-related complications.

CONCLUSION

This meta-analysis of observational studies showed a higher success rate of LBBAP compared to HBP with a lower incidence of complications.

Modern subcutaneous implantable defibrillator therapy in patients with cardiomyopathies and channelopathies: data from a large multicentre registry

AIMS

Patients with cardiomyopathies and channelopathies are usually younger and have a predominantly arrhythmia-related prognosis; they have nearly normal life expectancy thanks to the protection against sudden cardiac death provided by the implantable cardioverter defibrillator (ICD). The subcutaneous ICD (S-ICD) is an effective alternative to the transvenous ICD and has evolved over the years. This study aimed to evaluate the rate of inappropriate shocks (IS), appropriate therapies, and device-related complications in patients with cardiomyopathies and channelopathies who underwent modern S-ICD implantation.

METHODS AND RESULTS

We enrolled consecutive patients with cardiomyopathies and channelopathies who had undergone implantation of a modern S-ICD from January 2016 to December 2020 and who were followed up until December 2022. A total of 1338 S-ICD implantations were performed within the observation period. Of these patients, 628 had cardiomyopathies or channelopathies. The rate of IS at 12 months was 4.6% [95% confidence interval (CI): 2.8-6.9] in patients with cardiomyopathies and 1.1% (95% CI: 0.1-3.8) in patients with channelopathies (P = 0.032). No significant differences were noted over a median follow-up of 43 months [hazard ratio (HR): 0.76; 95% CI: 0.45-1.31; P = 0.351]. The rate of appropriate shocks at 12 months was 2.3% (95% CI: 1.1-4.1) in patients with cardiomyopathies and 2.1% (95% CI: 0.6-5.3) in patients with channelopathies (P = 1.0). The rate of device-related complications was 0.9% (95% CI: 0.3-2.3) and 3.2% (95% CI: 1.2-6.8), respectively (P = 0.074). No significant differences were noted over the entire follow-up. The need for pacing was low, occurring in 0.8% of patients.

CONCLUSION

Modern S-ICDs may be a valuable alternative to transvenous ICDs in patients with cardiomyopathies and channelopathies. Our findings suggest that modern S-ICD therapy carries a low rate of IS.

CLINICAL TRIAL REGISTRATION

URL: http://clinicaltrials.gov/Identifier: NCT02275637.

Endocardial versus epicardial pacing in pacemaker-dependent patients after device extraction: a meta-analysis

INTRODUCTION

Pacemaker-dependent (PM) patients with cardiac implantable electronic device (CIED) infection require implantation of a temporary-pacemaker (TP) and delayed endocardial reimplantation or implantation of an epicardial-pacing-system (EPI) before device extraction. Our aim was to compare the TP and EPI-strategy after CIED extraction through a meta-analysis.

METHODS

We searched electronic databases up to 25 March 2022, for observational studies that reported clinical outcomes of PM-dependent patients implanted with TP or EPI-strategy after device extraction.

RESULTS

3 studies were included enrolling 339 patients (TP: 156 patients; EPI: 183 patients). TP compared to EPI showed reduction in the composite outcome of relevant complications (all-cause death, infections, need for revision or upgrading of the reimplanted CIED) (12.1% vs 28.9%; RR: 0.45; 95%CI: 0.25-0.81; p = 0.008) and a trend in reduction of all-cause death (8.9% vs 14.2%; RR: 0.58; 95%CI: 0.33-1.05; p = 0.07). Furthermore, TP-strategy proved to reduce need of upgrading (0% vs 12%; RR: 0.07; 95%CI: 0.01-0.52; p = 0.009), reintervention on reimplanted CIED (1.9% vs 14.7%; RR: 0.15; 95%CI: 0.05-0.48; p = 0.001) and significant increase in pacing threshold (0% vs 5.4%; RR: 0.17; 95%CI: 0.03-0.92; p = 0.04), with a longer discharge time (MD: 9.60 days; 95%CI: 1.98-17.22; p = 0.01).

CONCLUSION

TP-strategy led to a reduction of the composite outcome of all-cause death and complications, upgrading, reintervention on reimplanted CIED, and risk of increase in pacing threshold compared to EPI-strategy, with longer discharge time.

Procedure, management, and outcome of subcutaneous implantable cardioverter-defibrillator extraction in clinical practice

AIMS

Subcutaneous implantable cardioverter-defibrillator (S-ICD) therapy is expanding rapidly. However, there are few data on the S-ICD extraction procedure and subsequent patient management. The aim of this analysis was to describe the procedure, management, and outcome of S-ICD extractions in clinical practice.

METHODS AND RESULTS

We enrolled consecutive patients who required complete S-ICD extraction at 66 Italian centres. From 2013 to 2022, 2718 patients undergoing de novo implantation of an S-ICD were enrolled. Of these, 71 required complete S-ICD system extraction (17 owing to infection). The S-ICD system was successfully extracted in all patients, and no complications were reported; the median procedure duration was 40 (25th-75th percentile: 20-55) min. Simple manual traction was sufficient to remove the lead in 59 (84%) patients, in whom lead-dwelling time was shorter [20 (9-32) months vs. 30 (22-41) months; P = 0.032]. Hospitalization time was short in the case of both non-infectious [2 (1-2) days] and infectious indications [3 (1-6) days]. In the case of infection, no patients required post-extraction intravenous antibiotics, the median duration of any antibiotic therapy was 10 (10-14) days, and the re-implantation was performed during the same procedure in 29% of cases. No complications arose over a median of 21 months.

CONCLUSION

The S-ICD extraction was safe and easy to perform, with no complications. Simple traction of the lead was successful in most patients, but specific tools could be needed for systems implanted for a longer time. The peri- and post-procedural management of S-ICD extraction was free from complications and not burdensome for patients and healthcare system.

CLINICAL TRIAL REGISTRATION

URL: http://clinicaltrials.gov/Identifier: NCT02275637.

Optimization of the atrioventricular delay in conduction system pacing

INTRODUCTION

In patients receiving conduction system pacing (CSP), it is not well established how to program the sensed atrioventricular delay (sAVD), with respect to the type of capture obtained (selective, nonselective His-bundle [HB] capture or left bundle branch [LBB] capture). The aim of this study was to acutely assess the effectiveness of an electrophysiology (EP)-guided method for sAVD optimization by comparing it with the echocardiogram-guided optimization.

METHODS AND RESULTS

Consecutive patients undergoing HB or LBB pacing were enrolled. The EP-guided sAVD was defined as the sAVD leading to a PR interval of 150 ms on surface electrocardiogram (ECG). In HB pacing patients, EP-guided sAVD was obtained subtracting the time from the onset of the P wave on ECG to the local atrial electrogram (EGM) recorded by the atrial lead (right atrial sensing latency, RASL) and the His-ventricular interval from 150 ms; in LBB pacing patients, subtracting RASL from 150 ms. Transmitral flow assessment by pulsed wave Doppler was used to find the echo-optimized sAVD by a modified iterative method. The discordance between the EP-guided and the echo-optimized sAVD was recorded.

RESULTS

Seventy-one patients were enrolled: 12 with selective, 32 nonselective HB capture, and 27 LBB capture. Overall, the rate of concordance between the EP-guided and the echo-optimized sAVD was 71.8%, with no significant differences between the three groups.

CONCLUSION

In CSP patients, an optimal sAVD can be programmed, in more than 70% of cases, considering only simple EGM intervals to obtain a physiological PR interval on surface ECG.

The PhysioVP-AF study, a randomized controlled trial to assess the clinical benefit of physiological ventricular pacing vs. managed ventricular pacing for persistent atrial fibrillation prevention in patients with prolonged atrioventricular conduction: design and rationale

AIMS

In patients with prolonged atrioventricular (AV) conduction and pacemaker (PM) indication due to sinus node disease (SND) or intermittent AV-block who do not need continuous ventricular pacing (VP), it may be difficult to determine which strategy to adopt. Currently, the standard of care is to minimize unnecessary VP by specific VP avoidance (VPA) algorithms. The superiority of this strategy over standard DDD or DDD rate-responsive (DDD/DDDR) in improving clinical outcomes is controversial, probably owing to the prolongation of the atrialventricular conduction (PR interval) caused by the algorithms. Conduction system pacing (CSP) may offer the most physiological-VP approach, providing appropriate AV conduction and preventing pacing-induced dyssynchrony.

METHODS AND RESULTS

PhysioVP-AF is a prospective, controlled, randomized, single-blind trial designed to determine whether atrial-synchronized conduction system pacing (DDD-CSP) is superior to standard DDD-VPA pacing in terms of 3-year reduction of persistent-AF occurrence. Cardiovascular hospitalization, quality-of-life, and safety will be evaluated. Patients with indication for permanent DDD pacing for SND or intermittent AV-block and prolonged AV conduction (PR interval > 180 ms) will be randomized (1:1 ratio) to DDD-VPA (VPA-algorithms ON, septal/apex position) or to DDD-CSP (His bundle or left bundle branch area pacing, AV-delay setting to control PR interval, VPA-algorithms OFF). Approximately 400 patients will be randomized in 24 months in 13 Italian centres.

CONCLUSION

The PhysioVP-AF study will provide an essential contribution to patient management with prolonged AV conduction and PM indication for sinus nodal disease or paroxysmal 2nd-degree AV-block by determining whether CSP combined with a controlled PR interval is superior to standard management that minimizes unnecessary VP in terms of reducing clinical outcomes.

Reduction in inappropriate therapies through device programming in subcutaneous implantable defibrillator patients: data from clinical practice

AIMS

In subcutaneous implantable cardioverter defibrillator (S-ICD) recipients, the UNTOUCHED study demonstrated a very low inappropriate shock rate on programming a conditional zone between 200 and 250 bpm and a shock zone for arrhythmias >250 bpm. The extent to which this programming approach is adopted in clinical practice is still unknown, as is its impact on the rates of inappropriate and appropriate therapies.

METHODS AND RESULTS

We assessed ICD programming on implantation and during follow-up in a cohort of 1468 consecutive S-ICD recipients in 56 Italian centres. We also measured the occurrence of inappropriate and appropriate shocks during follow-up. On implantation, the median programmed conditional zone cut-off was set to 200 bpm (IQR: 200-220) and the shock zone cut-off was 230 bpm (IQR: 210-250). During follow-up, the conditional zone cut-off rate was not significantly changed, while the shock zone cut-off was changed in 622 (42%) patients and the median value increased to 250 bpm (IQR: 230-250) (P < 0.001). UNTOUCHED-like programming of detection cut-offs was adopted in 426 (29%) patients immediately after device implantation, and in 714 (49%, P < 0.001) at the last follow-up. UNTOUCHED-like programming was independently associated with fewer inappropriate shocks (hazard ratio 0.50, 95%CI 0.25-0.98, P = 0.044), and had no impact on appropriate and ineffective shocks.

CONCLUSIONS

In recent years, S-ICD implanting centres have increasingly programmed high arrhythmia detection cut-off rates, at the time of implantation in the case of new S-ICD recipients, and during follow-up in the case of pre-existing implants. This has contributed significantly to reducing the incidence of inappropriate shocks in clinical practice. Rordorf: Programming of the S-ICD.

CLINICAL TRIAL REGISTRATION

URL: http://clinicaltrials.gov/Identifier: NCT02275637.

Left bundle branch pacing versus biventricular pacing for cardiac resynchronization therapy: A systematic review and meta-analysis

INTRODUCTION

Cardiac resynchronization therapy (CRT) reduces heart failure (HF) hospitalization and all-cause mortality in HF patients with left bundle branch block (LBBB). Biventricular pacing (BVP) is the gold standard for achieving CRT, but about 30%-40% of patients do not respond to BVP-CRT. Recent studies showed that left bundle branch pacing (LBBP) provided remarkable results in CRT. Therefore, we conducted a meta-analysis aiming to compare LBBP-CRT versus BVP-CRT in HF patients.

METHODS

We systematically searched the electronic databases for studies published from inception to December 29, 2022 and focusing on LBBP-CRT versus BVP-CRT in HF patients. The primary endpoint was HF hospitalization. The effect size was estimated using a random-effect model as Risk Ratio (RR) and mean difference (MD).

RESULTS

Ten studies enrolling 1063 patients met the inclusion criteria. Compared to BVP-CRT, LBBP-CRT led to significant reduction in HF hospitalization [7.9% vs.14.5%; RR: 0.60 (95%CI: 0.39-0.93); p = .02], QRSd [MD: 30.26 ms (95%CI: 26.68-33.84); p < .00001] and pacing threshold [MD: -0.60 (95%CI: -0.71 to -0.48); p < .00001] at follow up. Furthermore, LBBP-CRT improved LVEF [MD: 5.78% (95%CI: 4.78-6.77); p < .00001], the rate of responder [88.5% vs.72.5%; RR: 1.19 (95%CI: 1.07-1.32); p = .002] and super-responder [60.8% vs. 36.5%; RR: 1.56 (95%CI: 1.27-1.91); p < .0001] patients and the NYHA class [MD: -0.42 (95%CI: -0.71 to -0.14); p < .00001] compared to BVP-CRT.

CONCLUSION

In HF patients, LBBP-CRT was superior to BVP-CRT in reducing HF hospitalization. Further significant benefits occurred within the LBBP-CRT group in terms of QRSd, LVEF, pacing thresholds, NYHA class and the rate of responder and super-responder patients.

Predicting all-cause mortality by means of a multisensor implantable defibrillator algorithm for heart failure monitoring

BACKGROUND

The HeartLogic algorithm (Boston Scientific) has proved to be a sensitive and timely predictor of impending heart failure (HF) decompensation.

OBJECTIVE

The purpose of this study was to determine whether remotely monitored data from this algorithm could be used to identify patients at high risk for mortality.

METHODS

The algorithm combines implantable cardioverter-defibrillator (ICD)-measured accelerometer-based heart sounds, intrathoracic impedance, respiration rate, ratio of respiration rate to tidal volume, night heart rate, and patient activity into a single index. An alert is issued when the index crosses a programmable threshold. The feature was activated in 568 ICD patients from 26 centers.

RESULTS

During median follow-up of 26 months [25th-75th percentile 16-37], 1200 alerts were recorded in 370 patients (65%). Overall, the time IN-alert state was 13% of the total observation period (151/1159 years) and 20% of the follow-up period of the 370 patients with alerts. During follow-up, 55 patients died (46 in the group with alerts). The rate of death was 0.25 per patient-year (95% confidence interval [CI] 0.17-0.34) IN-alert state and 0.02 per patient-year (95% CI 0.01-0.03) OUT of the alert state, with an incidence rate ratio of 13.72 (95% CI 7.62-25.60; P <.001). After multivariate correction for baseline confounders (age, ischemic cardiomyopathy, kidney disease, atrial fibrillation), the IN-alert state remained significantly associated with the occurrence of death (hazard ratio 9.18; 95% CI 5.27-15.99; P <.001).

CONCLUSION

The HeartLogic algorithm provides an index that can be used to identify patients at higher risk for all-cause mortality. The index state identifies periods of significantly increased risk of death.

Combination of an implantable defibrillator multi-sensor heart failure index and an apnea index for the prediction of atrial high-rate events

AIMS

Patients with atrial fibrillation frequently experience sleep disorder breathing, and both conditions are highly prevalent in presence of heart failure (HF). We explored the association between the combination of an HF and a sleep apnoea (SA) index and the incidence of atrial high-rate events (AHRE) in patients with implantable defibrillators (ICDs).

METHODS AND RESULTS

Data were prospectively collected from 411 consecutive HF patients with ICD. The IN-alert HF state was measured by the multi-sensor HeartLogic Index (>16), and the ICD-measured Respiratory Disturbance Index (RDI) was computed to identify severe SA. The endpoints were as follows: daily AHRE burden of ≥5 min, ≥6 h, and ≥23 h. During a median follow-up of 26 months, the time IN-alert HF state was 13% of the total observation period. The RDI value was ≥30 episodes/h (severe SA) during 58% of the observation period. An AHRE burden of ≥5 min/day was documented in 139 (34%) patients, ≥6 h/day in 89 (22%) patients, and ≥23 h/day in 68 (17%) patients. The IN-alert HF state was independently associated with AHRE regardless of the daily burden threshold: hazard ratios from 2.17 for ≥5 min/day to 3.43 for ≥23 h/day (P < 0.01). An RDI ≥ 30 episodes/h was associated only with AHRE burden ≥5 min/day [hazard ratio 1.55 (95% confidence interval: 1.11-2.16), P = 0.001]. The combination of IN-alert HF state and RDI ≥ 30 episodes/h accounted for only 6% of the follow-up period and was associated with high rates of AHRE occurrence (from 28 events/100 patient-years for AHRE burden ≥5 min/day to 22 events/100 patient-years for AHRE burden ≥23 h/day).

CONCLUSIONS

In HF patients, the occurrence of AHRE is independently associated with the ICD-measured IN-alert HF state and RDI ≥ 30 episodes/h. The coexistence of these two conditions occurs rarely but is associated with a very high rate of AHRE occurrence.

CLINICAL TRIAL REGISTRATION

URL: http://clinicaltrials.gov/Identifier: NCT02275637.

Outcomes of leadless pacemaker implantation following transvenous lead extraction in high-volume referral centers: Real-world data from a large international registry

BACKGROUND

Limited data on the real-world safety and efficacy of leadless pacemakers (LPMs) post-transvenous lead extraction (TLE) are available.

OBJECTIVE

The purpose of this study was to assess the long-term safety and effectiveness of LPMs following TLE in comparison with LPMs de novo implantation.

METHODS

Consecutive patients who underwent LPM implantation in 12 European centers joining the International LEAdless PacemakEr Registry were enrolled. The primary end point was the comparison of LPM-related complication rate at implantation and during follow-up (FU) between groups. Differences in electrical performance were deemed secondary outcomes.

RESULTS

Of the 1179 patients enrolled, 15.6% underwent a previous TLE. During a median FU of 33 (interquartile range 24-47) months, LPM-related major complications and all-cause mortality did not differ between groups (TLE group: 1.6% and 5.4% vs de novo group: 2.2% and 7.8%; P = .785 and P = .288, respectively). Pacing threshold (PT) was higher in the TLE group at implantation and during FU, with very high PT (>2 V@0.24 ms) patients being more represented than in the de novo implantation group (5.4% vs 1.6 %; P = .004). When the LPM was deployed at a different right ventricular (RV) location than the one where the previous transvenous RV lead was extracted, a lower proportion of high PT (>1-2 V@0.24 ms) patients at implantation, 1-month FU, and 12-month FU (5.9% vs 18.2%, P = .012; 3.4% vs 12.9%, P = .026; and 4.3% vs 14.5%, P = .037, respectively) was found.

CONCLUSION

LPMs showed a satisfactory safety and efficacy profile after TLE. Better electrical parameters were obtained when LPMs were implanted at a different RV location than the one where the previous transvenous RV lead was extracted.

Rate and nature of complications with leadless transcatheter pacemakers compared with transvenous pacemakers: results from an Italian multicentre large population analysis

AIMS

The safety and efficacy of leadless intracardiac-permanent pacemaker (L-PM) have been demonstrated in multiple clinical trials, but data on comparisons with conventional transvenous-permanent pacemaker (T-PM) collected in a consecutive, prospective fashion are limited. The aim of this analysis was to compare the rate and the nature of device-related complications between patients undergoing L-PM vs. T-PM implantation.

METHODS AND RESULTS

Prospective, multicentre, observational project enrolling consecutive patients who underwent L-PM or T-PM implantation. The rate and nature of device-related complications were analysed and compared between the two groups. Individual 1:1 propensity matching of baseline characteristics was performed. A total of 2669 (n = 665 L-PM) patients were included and followed for a median of 39 months, L-PM patients were on average older and had more co-morbidities. The risk of device-related complications at 12 months was significantly lower in the L-PM group (0.5% vs. 1.9%, P = 0.009). Propensity matching yielded 442 matched pairs. In the matched cohort, L-PM patients trended toward having a lower risk of overall device-related complications (P = 0.129), had a similar risk of early complications (≤30 days) (P = 1.000), and had a significantly lower risk of late complications (>30 days) (P = 0.031). All complications observed in L-PM group were early. Most (75.0%) of complications observed in T-PM group were lead- or pocket-related.

CONCLUSION

In this analysis, the risk of device-related complications associated with L-PM implantation tended to be lower than that of T-PM. Specifically, the risk of early complications was similar in two types of PMs, while the risk of late complications was significantly lower for L-PM than T-PM.

Peri-procedural and mid-term follow-up age-related differences in leadless pacemaker implantation: Insights from a multicenter European registry

BACKGROUND

Age-related differences on leadless pacemaker (LP) are poorly described. Aim of this study was to compare clinical indications, periprocedural and mid-term device-associated outcomes in a large real-world cohort of LP patients, stratified by age at implantation.

METHODS

Two cohorts of younger and older patients (≤50 and > 50 years old) were retrieved from the iLEAPER registry. The primary outcome was to compare the underlying indication why a LP was preferred over a transvenous PM across the two cohorts. Rates of peri-procedural and mid-term follow-up major complications as well as LP electrical performance were deemed secondary outcomes.

RESULTS

1154 patients were enrolled, with younger patients representing 6.2% of the entire cohort. Infective and vascular concerns were the most frequent characteristics that led to a LP implantation in the older cohort (45.8% vs 67.7%, p < 0.001; 4.2% vs 16.4%, p = 0.006), while patient preference was the leading cause to choose a LP in the younger (47.2% vs 5.6%, p < 0.001). Median overall procedural (52 [40-70] vs 50 [40-65] mins) and fluoroscopy time were similar in both groups. 4.3% of patients experienced periprocedural complications, without differences among groups. Threshold values were higher in the younger, both at discharge and at last follow-up (0.63 [0.5-0.9] vs 0.5 [0.38-0-7] V, p = 0.004).

CONCLUSION

When considering LP indications, patient preference was more common in younger, while infective and vascular concerns were more frequent in the older cohort. Rates of device-related complications did not differ significantly. Younger patients tended to have a slightly higher pacing threshold at mid-term follow-up.

Five waves of COVID-19 pandemic in Italy: results of a national survey evaluating the impact on activities related to arrhythmias, pacing, and electrophysiology promoted by AIAC (Italian Association of Arrhythmology and Cardiac Pacing)

BACKGROUND

The subsequent waves of the COVID-19 pandemic in Italy had a major impact on cardiac care.

METHODS

A survey to evaluate the dynamic changes in arrhythmia care during the first five waves of COVID-19 in Italy (first: March-May 2020; second: October 2020-January 2021; third: February-May 2021; fourth: June-October 2021; fifth: November 2021-February 2022) was launched.

RESULTS

A total of 127 physicians from arrhythmia centers (34% of Italian centers) took part in the survey. As compared to 2019, a reduction in 40% of elective pacemaker (PM), defibrillators (ICD), and cardiac resynchronization devices (CRT) implantations, with a 70% reduction for ablations, was reported during the first wave, with a progressive and gradual return to pre-pandemic volumes, generally during the third-fourth waves, slower for ablations. For emergency procedures (PM, ICD, CRT, and ablations), recovery from the initial 10% decline occurred in most cases during the second wave, with some variability. However, acute care for atrial fibrillation, electrical cardioversions, and evaluations for syncope showed a prolonged reduction of activity. The number of patients with devices which started remote monitoring increased by 40% during the first wave, but then the adoption of remote monitoring declined.

CONCLUSIONS

The dramatic and profound derangement in arrhythmia management that characterized the first wave of the COVID-19 pandemic was followed by a progressive return to the volume of activities of the pre-pandemic periods, even if with different temporal dynamics and some heterogeneity. Remote monitoring was largely implemented during the first wave, but full implementation is needed.

Effectiveness and safety of implantable loop recorder and clinical utility of remote monitoring in patients with unexplained, recurrent, traumatic syncope

BACKGROUND

Implantable loop recorder (ILR) is still underutilized in clinical practice, especially in the setting of elderly patients with recurrent, traumatic, unexplained syncope. Data on the actual risk of traumatic syncopal recurrence during ILR monitoring in this specific patient setting are lacking.

RESEARCH DESIGN AND METHODS

Prospective, multicentre registry enrolling consecutive patients undergoing ILR insertion for unexplained, recurrent, traumatic syncope. In a proportion of enrolled patients, remote monitoring (RM) was used for device follow-up. The risk of traumatic and non-traumatic syncopal recurrences during ILR observation were prospectively assessed.

RESULTS

A total of 483 consecutive patients (68±14 years, 59% male) were enrolled. During a median follow-up of 18 months, a final diagnosis was reached in 270 patients (55.9%). The risk of syncopal and traumatic syncopal recurrence was of 26.5 and 9.3%, respectively. RM significantly reduced the time to diagnosis (19.7±10.3 vs. 22.1±10.8 months; p=0.015) and was associated with a significant reduction in the risk of syncope recurrence of 48% (p<0.001), and of traumatic syncope recurrence of 49% (p=0.018).

CONCLUSIONS

ILR monitoring is effective and safe in patients with unexplained, recurrent, traumatic syncope. RM reduces the time to diagnosis and significantly reduces the risk of traumatic and non-traumatic syncopal relapses.

929 LEADLESS PACEMAKER IMPLANTATION FOLLOWING TRANSVENOUS LEAD EXTRACTION: DATA FROM HIGH-VOLUME REFERRAL CENTERS

Background

limited data on real-world safety and efficacy of leadless pacemakers (LPMs) in patients who underwent transvenous lead extraction (TLE) are currently available. The present study aims to assess long-term safety and efficacy of LPMs implantation following TLE, compared with LPM de novo implant patients.

Methods

consecutive patients who underwent LPM implantation in 12 centers joining the International LEAdless PacemakEr (i-LEAPER) registry were enrolled end retrospectively considered. Patients receiving LPM following TLE (n=184) were compared with patients with de novo implant (n=995). The primary endpoint was LPM-related complications rate at implant and during follow-up (FU). Additionally, differences in electrical performance were assessed between the two groups.

Results

1179 patients were enrolled in this study and followed for a median of 33 months. LPM related major complications and all-cause mortality did not differ among the two groups (1.6% TLE group vs. 2.2% de novo group, p=0.785, and 5.4% TLE group vs. 7.8% de novo group, p=0.288, respectively). Pacing threshold (PT) resulted higher in the TLE group throughout the whole follow-up (FU) (Figure 1). Higher PTs were recorded in LPMs implanted at same location from where the previous transvenous lead was removed, as far as 24-months postimplant (Figure 2), with a higher proportion of patients with high PT (&gt;1 to 2V @0.24ms) in the first group at implant, 1-month, and 12-month FU (Figure 3).

Conclusion

In this real-world registry, LPMs showed a satisfactory safety and efficacy profile after TLE. In the post-TLE cohort, better electrical parameters were obtained when LPMs were implanted at a different location from where the previous transvenous lead was extracted.

The need for a subsequent transvenous system in patients implanted with subcutaneous implantable cardioverter-defibrillator

BACKGROUND

The absence of pacing capabilities may reduce the appeal of subcutaneous implantable cardioverter-defibrillator (S-ICD) devices for patients at risk for conduction disorders or with antitachycardia pacing (ATP)/cardiac resynchronization (CRT) requirements. Reports of rates of S-ICD to transvenous implantable cardioverter-defibrillator (TV-ICD) system switch in real-world scenarios are limited.

OBJECTIVE

The purpose of this study was to investigate the need for a subsequent transvenous (TV) device in patients implanted with an S-ICD and its predictors.

METHODS

All patients implanted with an S-ICD were enrolled from the multicenter, real-world iSUSI (International SUbcutaneouS Implantable cardioverter defibrillator) Registry. The need for a TV device and its clinical reason, and appropriate and inappropriate device therapies were assessed. Logistic regression with Firth penalization was used to assess the association between baseline and procedural characteristics and the overall need for a subsequent TV device.

RESULTS

A total of 1509 patients were enrolled (age 50.8 ± 15.8 years; 76.9% male; 32.0% ischemic; left ventricular ejection fraction 38% [30%-60%]). Over 26.5 [13.4-42.9] months, 155 (10.3%) and 144 (9.3%) patients experienced appropriate and inappropriate device therapies, respectively. Forty-one patients (2.7%) required a TV device (13 bradycardia; 10 need for CRT; 10 inappropriate shocks). Body mass index (BMI) >30 kg/m2 and chronic kidney disease (CKD) were associated with need for a TV device (odds ratio [OR] 2.57 [1.37-4.81], P = .003; and OR 2.67 [1.29-5.54], P = .008, respectively).

CONCLUSION

A low rate (2.7%) of conversion from S-ICD to a TV device was observed at follow-up, with need for antibradycardia pacing, ATP, or CRT being the main reasons. BMI >30 kg/m2 and CKD predicted all-cause need for a TV device.

Impact of atrioventricular junction ablation and CRT-D on long-term mortality in patients with left ventricular dysfunction, permanent, refractory atrial fibrillation and narrow QRS: results of a propensity matched analysis

INTRODUCTION

In patients with symptomatic permanent atrial fibrillation (PEAF) and narrow QRS, atrio-ventricular junction ablation (AVJA) plus cardiac resynchronization therapy (CRT) is superior to medical therapy in reducing heart failure (HF) hospitalization and all-cause mortality. To compare the mortality of a population of patients with HF, reduced EF (rEF) and PEAF treated with AVJA plus CRT with that of a contemporary cohort of patients in sinus rhythm (SR) with similar baseline characteristics.

METHODS AND RESULTS

In this prospective, multicentre, observational study, all-cause mortality in a group of consecutive patients undergoing AVJA and implantable cardioverter-defibrillator (ICD) combined with CRT implantation for HFrEF, narrow QRS, and PEAF with uncontrolled ventricular rate was compared with that of a contemporary cohort of patients in SR undergoing ICD implantation (not combined with CRT) for HFrEF and narrow QRS. Individual 1:1 propensity matching of baseline characteristics was performed. A total of 824 patients were enrolled. Propensity matching yielded 107 matched pairs. After a median follow-up of 52 months, all-cause mortality was similar in patients treated with AVJA plus CRT and in the control group (p=0.434). In AVJA plus CRT patients, mortality was significantly lower than in control group patients with a history of paroxysmal/persistent AF (n=45, p=0.020), and similar to that of patients without a history of AF (n=62, p=0.459).

CONCLUSIONS

After adjustment for patient characteristics, the long-term prognosis of patients with HFrEF, narrow QRS and PEAF who underwent AVJA plus CRT was similar to that of a population of patients in SR with similar characteristics. This article is protected by copyright. All rights reserved.

Leadless transcatheter pacemaker: Indications, implantation technique and peri-procedural patient management in the Italian clinical practice

BACKGROUND

Safety and efficacy of leadless pacemakers (L-PM) have been demonstrated in multiple clinical trials, but real-world data on patient selection, implantation technique, and peri-procedural patient management in a clinical practice setting are lacking.

METHODS

Consecutive patients undergoing L-PM implantation in 14 Italian centers were followed in a prospective, multicentre, observational project. Data on baseline patient characteristics, clinical indications, implantation procedure, and peri-procedural patient management were collected. The rate and nature of device-related complications were also recorded.

RESULTS

A total of 782 L-PM patients (68.4% male, 75.6 ± 12.4 years) were included in the analysis. The main patients-related reason leading to the choice of implanting a L-PM rather than a conventional PM was the high-risk of device infection (29.5% of cases). The implantation success rate was 99.2%. The median duration of the procedure was 46 min. In 90% of patients the device was implanted in the septum. Of patients on oral anticoagulant therapy (OAT) (n = 498) the implantation procedure was performed without interrupting (17.5%) or transiently interrupting OAT without heparin bridging (60.6%). During a median follow-up of 20 months major device-related complications occurred in 7 patients (0.9%): vascular access-site complications in 3 patients, device malfunction in 2 patients, pericardial effusion/cardiac tamponade in one patient, device migration in one patient.

CONCLUSIONS

In the real world setting of Italian clinical practice L-PM is often reserved for patients at high-risk of infection. The implantation success rate was very high and the risk of major complications was low. Peri-procedural management of OAT was consistent with available scientific evidence.

The subcutaneous defibrillator in patients with low BMI - insights from a large European multicenter registry

Funding Acknowledgements

Type of funding sources: None.

Background

The subcutaneous implantable cardioverter defibrillator (S-ICD) has become an alternative to transvenous ICDs (tv-ICD), especially in young patients without a need for pacing. One of the current limitations of the S-ICD is the relatively large size of the generator compared to tv-ICDs. There is little evidence whether the size of the current S-ICD generator is associated with an elevated risk of device-related complications in patients with a low body mass index (BMI).

Purpose

To compare the device-related complications and long-term outcomes in a large real world cohort of S-ICD recipients in patients with a BMI &lt;18 kg/m2 compared to patients with a BMI &gt;18 kg/m2.

Methods

The iSuSI registry is a European, multi-center, open-label, independent, and physician-initiated observational registry. A total of twenty-two Public and Private Healthcare Institutions from 4 different countries in Europe were involved in the registry. All consecutive patients meeting current guideline indications for ICD implantation and undergoing implantation of a S-ICD device (Boston Scientific, Marlborough, Massachusetts, USA) at 21 European institutions enrolled in the registry were used for the current analysis. Patients were classified into two cohorts, depending on the BMI at the time of device implantations: BMI &lt; 18 kg/m2 versus &gt; 18 kg/m2.

Results

Out of a total of 1497 pts, 58 pts (3.9%) had a BMI &lt; 18 kg/m2. Patients with BMI &lt;18 kg/m2 were younger (44.6±2.4 vs 50.8±0.4; p=0.004) and more frequently female (58.6% vs 22.3%, p&lt;0.001). No differences in any of the other baseline characteristic were observed. Implantation techniques resulted comparable between the groups (Rates of 2-incision technique: 87.8% vs 91.9%; p=0.256; inter-muscular placement: 89.7% vs 83.3%; p=0.198). Of note, the mean PRAETORIAN score at implantation of patients with BMI &lt;18 kg/m2 was significantly lower (33.8±9.1 vs 54.1±47.3; p=0.035), although the vast majority of pts in both cohorts qualify as at low risk of conversion failure (100% vs 91.4%; p=0.436).

Over a median follow up time of 22.4 [11.6–36.8] months, both overall device-related complications (5.2% vs 7.4%) and rates of inappropriate shocks (12.0% vs 8.8%) resulted comparable between the two groups (p =0.517 and p=0.385, respectively). Figure1 reports Kaplan-Meier curves reporting the combined incidence of device-related complications and inappropriate shocks in the two groups (log-rank p = 0.576).

Conclusion

No difference in device-related complications and long-term outcomes after S-ICD implantation were observed in patients with BMI &lt;18 kg/m2 compared to the remaining recipients from a large, multi-centered S-ICD registry.

Figure 1: Kaplan-Meier-survival curve for the combined endpoint of inappropriate shocks (IAS) and device-related complications (DRC)

Long-term incidence of cardiac device complications with intrathoracic versus extrathoracic venous access: results from the PLACE (Planning Lead Access for Cardiac Electrostimulation) study

Funding Acknowledgements

Type of funding sources: None.

Introduction

Optimal venous access is crucial in successful cardiac device implantation. Most commonly used accesses are subclavian or axillary vein puncture and cephalic vein cutdown. The extrathoracic access has the advantage of reducing the risk of pneumothorax and lead disfunction; thus, this approach is recommended as the first choice approach.

Purpose

The aim of our retrospective registry was to evaluate the incidence of long-term device complications (pneumothorax, lead rupture or displacement, hematoma, infection or bleeding) with different venous approaches in four high-volume centers in Italy.

Methods

We collected data from implantation and device complications during follow up using available electronic records from each center.

Results

We included 4443 patients, mean age 73±11 years. Median follow up was 118 months (IC range 59-198 months). The incidence of any complication was 7.7 %, without difference between intrathoracic and extrathoracic access (7.8% vs 7.7% respectively, p=0.70). However, lead rupture was more frequent in the intrathoracic group (5.3% vs 1.4%, p=0.04).

Conclusion

In experienced, high-volume centers, the use of intrathoracic vein puncture in the case of unsuitable extrathoracic access may represent a safe alternative of venous access in patients undergoing cardiac device implantation, although associated with a higher occurrence of lead rupture.

C9 SUBCUTANEOUS IMPLANTABLE CARDIOVERTER DEFIBRILLATOR IN PATIENTS WITH LOW BMI: REAL–WORLD DATA FROM A EUROPEAN MULTICENTER ANALYSIS

Background

One of the current limitations of the S–ICD is the relatively large size of the generator compared to the TV (transvenous) ICD. There is little evidence whether the size of the current S–ICD generator is associated with an elevated risk of device–related complications in patients with a low body mass index (BMI).

Purpose

Aim of this study was to compare the device–related complications and long–term outcomes in a large real world cohort of S–ICD recipients in patients with a BMI &lt;18 kg/m2 compared to patients with a BMI &gt;18 kg/m2.

Methods

All consecutive patients meeting current guideline indications for ICD implantation and undergoing implantation of a S–ICD device (Boston Scientific, Marlborough, Massachusetts, USA) at 21 European institutions enrolled in the extended ELISIR registry were used for the current analysis. Patients were classified into two cohorts, depending on the BMI at the time of device implantations: BMI &lt; 18 kg/m2 versus &gt; 18 kg/m2.

Results

Out of a total of 1497 pts, 58 pts (3.9%) had a BMI &lt; 18 kg/m2. Patients with BMI &lt;18 kg/m2 were younger (44.6±2.4 vs 50.8±0.4; p = 0.004) and more frequently female (58.6% vs 22.3%, p &lt; 0.001). No differences in any of the other baseline characteristic were observed. Implantation techniques resulted comparable between the groups (rates of 2–incision technique: 87.8% vs 91.9%; p = 0.256; inter–muscular placement: 89.7% vs 83.3%; p = 0.198). Of note, the mean PRAETORIAN score at implantation of patients with BMI &lt;18 kg/m2 was significantly lower (33.8±9.1 vs 54.1±47.3; p = 0.035), although the vast majority of patients in both cohorts qualified as at low risk of conversion failure (100% vs 91.4%; p = 0.436). Over a median follow up time of 22.4 [11.6–36.8] months, both overall device–related complications (5.2% vs 7.4%) and rates of inappropriate shocks (12.0% vs 8.8%) resulted comparable between the two groups (p = 0.517 and p = 0.385, respectively). Figure 1 reports Kaplan–Meier curves showing the combined incidence of device–related complications and inappropriate shocks in the two groups (log–rank p = 0.576).

Conclusion

No differences in device–related complications and long–term outcomes after S–ICD implantation were observed in patients with BMI &lt;18 kg/m2 compared to the remaining recipients in a large multicentered real–world analysis.

P21 AGE–RELATED DIFFERENCES AND ASSOCIATED OUTCOMES OF S–ICD: INSIGHTS FROM A LARGE, EUROPEAN, MULTICENTER REGISTRY

Background

The subcutaneous implantable cardioverter defibrillator (S–ICD) has become an alternative to transvenous ICDs (TV–ICD) in patients who do not need pacing. To date, there is little evidence directly comparing the rates of inappropriate shocks (IAS) in young vs old S–ICD recipients.

Purpose

Aim of our study was to assess differences in device–related complications and inappropriate shocks (IS) between teenagers/young adults and adult recipients of a subcutabeous implantable cardioverter defibrillator (S–ICD) device.

Methods

Two propensity–matched cohorts of teenagers + young adults (≤ 30–year–old) and adults (&gt; 30–year–old) were retrieved from the ELISIR registry. The primary outcome was the comparison of the inappropriate shock (IAS) rate; complications, freedom from sustained ventricular arrhythmic events, overall and cardiovascular mortality were deemed secondary outcomes.

Results

A total of 1491 patients were extracted from the ELISIR project. Teenagers + young adults represented 11.0% of the entire cohort. Two propensity–matched groups of 161 patients each were used for the analysis (Figure 1); median follow–up was 23.1 [13.2–40.5] months. 15.2% patients experienced inappropriate S–ICD shocks and 9.3% device related complications were observed with no age–related differences in IAS (16.1% vs 14.3%; p = 0.642) and complication rates (9.9% vs 8.7%; p = 0.701); Figure 2 shows a survival analysis from inappropriate shocks in the teen–ager/young adult cohort (red) and in the adult cohort (blue). At univariate analysis, young age was not associated with increased rates of IAS (HR 1.204 [0.675–2.148]: p = 0.529). At multivariate analysis (Figure 3), the use of SMART pass algorithm was associated to a strong reduction in IAS (aHR 0.292 [0.161–0.525]; p &lt; 0.001), while ARVC was associated with higher rates of IAS (aHR 2.380 [1.205–4.697]; p = 0.012).

Conclusion

In a large multicentered European registry of patients with S–ICD, 11.0% of all recipients were teenagers or young adults. The use of S–ICD in teenagers/young adults resulted safe and effective, and the rates of complications and IAS between teenagers/young adults and adults were not significantly different. The only predictor of increased IAS was a diagnosis of ARVC.

P25 SUBCUTANEOUS–ICD IN PATIENTS WITH HEART FAILURE: RESULTS FROM A MULTICENTER, EUROPEAN ANALYSIS

Background

Data on patients with heart failure (HF) with a subcutaneous implantable cardioverter defibrillator (S–ICD) are scarce.

Objective

Aim of this study was to assess clinical outcomes of the S–ICD in HF patients in a real–world analysis from the largest European retrospective S–ICD registry (ELISIR).

Methods

All consecutive patients undergoing S–ICD implantation at several European institutions were used for the current analysis. The population was classified into two groups: the HF (classified as HF with reduced and mid–range ejection fraction – HFrEF and HFmrEF) vs the no–HF cohort. The primary outcome of the study was the inappropriate shock (IS) rate across the two cohorts. As secondary outcomes, appropriate shocks, cardiovascular mortality and device–related complications during follow–up were assessed

Results

A total of 1409 patients from the ELISIR registry were included; HF patients represented 57.3% of the entire cohort (n = 701, 86.9% HFrEF; n = 106,13.1% HFmrEF). Over a median follow–up of approximately 2 years, a total of 133 inappropriate shocks were observed in the entire cohort, without significant differences among the two groups (9.2% vs 9.8%, p = 0.689). 133 complex ventricular arrhythmias were adequately recognized and treated, with similar rates of appropriate shocks (9.2% vs 9.8%, p = 0.689). Inappropriate and effective shocks–free survival has been represented in Figure 1 (Kaplan–Meier estimates). At multivariate analysis (Figure 2), age (HR = 0.974 [0.955–0.992], p = 0.005), LVEF (HR = 0.954 [0.926–0.984], p = 0.003), arrhythmogenic right ventricular cardiomyopathy – ARVC (HR = 3.364 [1.206–9.384], p = 0.020) and smart pass + (HR = 0.321 [0.184–0.560], p &lt; 0.001) remained associated with inappropriate shocks. Moreover, a low number of patients (n = 76) experienced device–related complications, more frequently in the HF cohort (6.2% vs 3.8%, p = 0.031) with no significant differences regarding any specific outcome of interest: lead infection (1.1% vs 0.7%, p = 0.381), pocket infection (1.9% vs 0.8%, p = 0.107), pocket hematoma (3.2% vs 2.8%, p = 0.668).

Conclusion

The use of S–ICD in HF patients did not result in a higher rate of inappropriate shocks when compared to no–HF patients, even when stratifying for LVEF. Only age, LVEF, ARVC e Smart Pass algorithm were predictors of the primary outcome at multivariate analysis. Despite a lower overall rate of complications in the entire cohort, HF patients experienced device–related complications more frequently.

Performance of transcatheter pacing system use in relation to patients' age

PURPOSE

Real-world safety data on the use of transcatheter pacing systems particularly in very elderly patients is still limited. The aim of this analysis was to investigate the effect of age on the safety and efficacy of leadless pacemaker implant.

METHODS

From May 2016 through July 2019, 577 patients were implanted with a leadless single-chamber pacemaker according to current pacing indication in 15 Italian cardiologic centers. The population was divided into age quartiles for evaluation, including (1) < 70 years, (2) 70-77 years, (3) 78-83 years, and (4) ≥ 83 years. Procedural data, complications, and electrical parameters were collected at baseline and during the follow-up.

RESULTS

Procedural-related complication occurrence was very low (< 1.0%) and similar in the four subgroups according to age even if the older patients were more frail. No cardiac tamponade was reported. Among the groups, no difference was observed in procedural time, fluoroscopy time duration, and electrical parameters (mean pacing impedance: 750 ± 192 and 599 ± 156, mean pacing threshold: 0.7 ± 0.5 and 0.7 ± 0.6, and mean right ventricular sensing 10.7 ± 6.1 and 11.5 ± 4.8 at implant and last follow-up, respectively).

CONCLUSIONS

The reported data demonstrated a high degree of safety during leadless implant across all patient ages. Procedural complications and device electrical measurements were similar among the different ages.

Incidence and Predictors of Infections and All-Cause Death in Patients with Cardiac Implantable Electronic Devices: The Italian Nationwide RI-AIAC Registry

Background: The incidence of infections associated with cardiac implantable electronic devices (CIEDs) and patient outcomes are not fully known. Aim: To provide a contemporary assessment of the risk of CIEDs infection and associated clinical outcomes. Methods: In Italy, 18 centres enrolled all consecutive patients undergoing a CIED procedure and entered a 12-months follow-up. CIED infections, as well as a composite clinical event of infection or all-cause death were recorded. Results: A total of 2675 patients (64.3% male, age 78 (70–84)) were enrolled. During follow up 28 (1.1%) CIED infections and 132 (5%) deaths, with 152 (5.7%) composite clinical events were observed. At a multivariate analysis, the type of procedure (revision/upgrading/reimplantation) (OR: 4.08, 95% CI: 1.38–12.08) and diabetes (OR: 2.22, 95% CI: 1.02–4.84) were found as main clinical factors associated to CIED infection. Both the PADIT score and the RI-AIAC Infection score were significantly associated with CIED infections, with the RI-AIAC infection score showing the strongest association (OR: 2.38, 95% CI: 1.60–3.55 for each point), with a c-index = 0.64 (0.52–0.75), p = 0.015. Regarding the occurrence of composite clinical events, the Kolek score, the Shariff score and the RI-AIAC Event score all predicted the outcome, with an AUC for the RI-AIAC Event score equal to 0.67 (0.63−0.71) p < 0.001. Conclusions: In this Italian nationwide cohort of patients, while the incidence of CIED infections was substantially low, the rate of the composite clinical outcome of infection or all-cause death was quite high and associated with several clinical factors depicting a more impaired clinical status.

Usefulness of the MAGGIC Score in Predicting the Competing Risk of Non-Sudden Death in Heart Failure Patients Receiving an Implantable Cardioverter-Defibrillator: A Sub-Analysis of the OBSERVO-ICD Registry

The role of prognostic risk scores in predicting the competing risk of non-sudden death in heart failure patients with reduced ejection fraction (HFrEF) receiving an implantable cardioverter-defibrillator (ICD) is unclear. To this goal, we evaluated the accuracy and usefulness of the Meta-Analysis Global Group in Chronic Heart Failure (MAGGIC) score. The present analysis included 1089 HFrEF ICD recipients enrolled in the OBSERVO-ICD registry (NCT02735811). During a median follow-up of 36 months (1st-3rd IQR 25-48 months), 193 patients (17.7%) experienced at least one appropriate ICD therapy, and 133 patients died (12.2%) without experiencing any ICD therapy. The frequency of patients receiving ICD therapies was stable around 17-19% across increasing tertiles of 3-year MAGGIC probability of death, whereas non-sudden mortality increased (6.4% to 9.8% to 20.8%, p < 0.0001). Accuracy of MAGGIC score was 0.60 (95% CI, 0.56-0.64) for the overall outcome, 0.53 (95% CI, 0.49-0.57) for ICD therapies and 0.65 (95% CI, 0.60-0.70) for non-sudden death. In patients with higher 3-year MAGGIC probability of death, the increase in the competing risk of non-sudden death during follow-up was greater than that of receiving an appropriate ICD therapy. Results were unaffected when analysis was limited to ICD shocks only. The MAGGIC risk score proved accurate and useful in predicting the competing risk of non-sudden death in HFrEF ICD recipients. Estimation of mortality risk should be taken into greater consideration at the time of ICD implantation.