Device-detected atrial sensing amplitudes as a marker of increased risk for new onset and progression of atrial high-rate episodes.

BACKGROUND: Atrial high-rate episodes (AHREs) are frequent in patients with cardiac implantable electronic devices. A decrease in device-detected P-wave amplitude may be an indicator of periods of increased risk of AHRE. OBJECTIVE: The objective of this study was to assess the association between P-wave amplitude and AHRE incidence. METHODS: Remote monitoring data from 2579 patients with no history of atrial fibrillation (23% pacemakers and 77% implantable cardioverter-defibrillators, of which 40% provided cardiac resynchronization therapy) were used to calculate the mean P-wave amplitude during 1 month after implantation. The association with AHRE incidence according to 4 strata of daily burden duration (≥15 minutes, ≥6 hours, ≥24 hours, ≥7 days) was investigated by adjusting the hazard ratio with the CHA2DS2-VASc score. RESULTS: The adjusted hazard ratio for 1-mV lower mean P-wave amplitude during the first month increased from 1.10 (95% confidence interval [CI], 1.05-1.15; P < .001) to 1.18 (CI, 1.09-1.28; P < .001) with AHRE duration strata from ≥15 minutes to ≥7 days independent of the CHA2DS2-VASc score. Of 871 patients with AHREs, those with 1-month P-wave amplitude <2.45 mV had an adjusted hazard ratio of 1.51 (CI, 1.19-1.91; P = .001) for progression of AHREs from ≥15 minutes to ≥7 days compared with those with 1-month P-wave amplitude ≥2.45 mV. Device-detected P-wave amplitudes decreased linearly during the 1 year before the first AHRE by 7.3% (CI, 5.1%-9.5%; P < .001 vs patients without AHRE). CONCLUSION: Device-detected P-wave amplitudes <2.45 mV were associated with an increased risk of AHRE onset and progression to persistent forms of AHRE independent of the patient's risk profile.

Ion channel dysfunction and fibrosis in atrial fibrillation: Two sides of the same coin.

BACKGROUND: Atrial fibrillation (AF) is a common heart rhythm disorder that is associated with an increased risk of stroke and heart failure (HF). Initially, an association between AF and ion channel dysfunction was identified, classifying the pathology as a predominantly electrical disease. More recently it has been recognized that fibrosis and structural atrial remodeling play a driving role in the development of this arrhythmia also in these cases. PURPOSE: Understanding the role of fibrosis in genetic determined AF could be important to better comprise the pathophysiology of this arrhythmia and to refine its management also in nongenetic forms. In this review we analyze genetic and epigenetic mechanisms responsible for AF and their link with atrial fibrosis, then we will consider analogies with the pathophysiological mechanism in nongenetic AF, and discuss consequent therapeutic options.

ICD early after myocardial infarction: it is really necessary to wait 40 days before implantation?

ESC Guidelines don't recommend ICD implantation within 40 days after MI, on the basis of old evidence with several limitations. However, a significant number of patients remain at high risk of arrhythmic death also in the early period after ACS, in these patients early ICD implantation or LifeVest may be use with benefit on survival.

Permanent his bundle pacing: Description and comparison of four implantation techniques.

INTRODUCTION: Permanent His bundle pacing (HBP) is the most physiological pacing modality, and new implantation systems are now available. The aim of the present study was to describe and compare four different techniques to perform HBP. METHODS AND RESULTS: We included all consecutive patients who underwent a HBP attempt in our initial experience between June 2020 and May 2022. The success and characteristics of the procedure were compared among four implantation techniques: the Biotronik Selectra 3D sheath with Solia S60 lead (Selectra 3D), the Boston Scientific Site Selective Pacing Catheter with Ingevity lead (SSPC), the Abbott steerable stylet locator with Tendril lead (Locator), and the use of a standard stylet manually pre-shaped with a conventional pacing lead (Curved stylet). Ninety-eight patients (median age 79 years [interquartile range, 73-83], 83% men) were identified. The Selectra 3D technique was used in 43 procedures, SSPC in 26, Locator in 18 and Curved stylet in 11. The groups had similar clinical characteristics. Overall, procedural success was achieved in 91 patients (93%) with similar proportions among groups (p = .986). Fluoroscopy and procedural times were 6.0 (4.4-8.5) and 60 (45-75) min, respectively, without significant differences (p = .333 and p = .790). The rate of selective capture, the pacing threshold, and the paced QRS duration were also comparable. There was one pre-discharge HBP lead dislodgment (1%) that required implant revision. CONCLUSION: In our experience, four techniques for HBP achieved comparable results in terms of safety and effectiveness. The availability of different systems may lead to widespread use of physiological pacing.

Prognostic significance of remotely monitored nocturnal heart rate in heart failure patients with reduced ejection fraction.

BACKGROUND: Elevated resting heart rate is a risk factor for cardiovascular events. OBJECTIVE: The purpose of this study was to investigate the clinical significance of nocturnal heart rate (nHR) and 24-hour mean heart rate (24h-HR) obtained by continuous remote monitoring (RM) of implantable devices. METHODS: We analyzed daily-sampled trends of nHR, 24h-HR, and physical activity in patients on ß-blocker therapy for chronic heart failure and with implantable cardioverter-defibrillators or cardiac resynchronization therapy defibrillators (CRT-Ds). Patients were grouped by average nHR and 24h-HR quartile during follow-up to estimate the respective incidence of nonarrhythmic death and device-treated ventricular tachycardia/fibrillation (VT/VF). RESULTS: The study cohort included 1330 patients (median age 69 years [interquartile range 61-77 years]; 41% [n = 550] with CRT-D; median follow-up 25 months [interquartile range 13-42 months]). Compared with patients in the lowest nHR quartile (≤57 beats/min) group, patients in the highest quartile group (>65 beats/min) had an increased risk of nonarrhythmic death (adjusted hazard ratio [AHR] 2.25; 95% confidence interval [CI] 1.13-4.50; P = .021) and VT/VF (AHR 1.98; 95% CI 1.40-2.79; P < .001) and were characterized by the lowest level of physical activity (P ≤ .0004 vs every other nHR quartiles). The highest 24h-HR quartile group (>75 beats/min) showed an increased risk of VT/VF (AHR 2.13; 95% CI 1.52-2.99; P < .001) and a weaker though significant association with nonarrhythmic mortality (AHR 1.80; 95% CI 1.00-3.22; P = .05) as compared with the lowest 24h-HR quartile group (≤65 beats/min). CONCLUSION: In remotely monitored patients with implantable cardioverter-defibrillator/CRT-D on ß-blocker therapy for heart failure, elevated heart rates (nHR >65 beats/min and 24h-HR >75 beats/min) were associated with increased mortality and VT/VF risk. nHR showed a stronger association than 24h-HR with worst prognosis and lowest physical activity.

Long-term outcomes following transvenous lead extraction: Data from a tertiary referral center.

BACKGROUND: Transvenous lead extraction (TLE) has shown a safe and efficacy profile in the intraoperative and short-term setting; however, data on long-term outcomes are limited. OBJECTIVE: The purpose of this study was to assess long-term outcomes and prognostic factors in patients who underwent TLE. METHODS: Consecutive patients with cardiac implantable electronic device (CIED) who underwent TLE between 2014 and 2016 were retrospectively studied. The primary outcome was the composite endpoint of death and repeated TLE stratified by infective/non-infective indication. Individual components of the primary outcome were also evaluated. RESULTS: One hundred ninety-one patients were included in the analysis, 50% extracted for CIED-related infection. Complete procedural success was achieved in 189 patients (99%) with no major acute complications. After a median of 6.5 years, infection indication was associated with significantly lower event-free survival (67% vs. 83% non-infection group, adjusted hazard ratio [aHR] 1.97, 95% confidence interval [CI] 1.02-3.81, p = 0.04). All-cause mortality rate was higher in the TLE infection group (30% vs. 10%, p < 0.01). The rate of repeated TLE did not differ between groups (4% vs. 7%, p = 0.62). Among patients who had TLE for infection, the presence of vegetation (aHR 2.56; 95%CI 1.17-5.63, p = 0.02) and positive blood cultures (aHR 2.64; 95%CI 1.04-6.70, p = 0.04) were independently associated with the primary outcome. CONCLUSION: Patients who underwent TLE for CIED-related infection exhibit a high mortality risk during long-term follow-up. Vegetation and positive blood cultures in patients with CIED-related infection are associated with a worse prognosis regardless of successful and uncomplicated TLE.

Leadless pacemaker implantation in dextrocardia with situs viscerum inversus: A case report and literature review.

Leadless pacemaker implantation (LPI) has fewer device complications and reduced chance of infection compared to conventional pacemakers. Dextrocardia with situs viscerum inversus (DC+SVI) is a rare condition, which seldom leads to cardiac complications. However, its presence poses a challenge to operators in cardiac procedures. LPI reports in DC patients are scarce. We report a case of LPI in a DC+SVI patient, followed by a brief but comprehensive literature review.

Lead-related infective endocarditis with vegetations: Prevalence and impact of pulmonary embolism in patients undergoing transvenous lead extraction.

INTRODUCTION: The prevalence and impact of pulmonary embolism (PE) in patients with lead-related infective endocarditis undergoing transvenous lead extraction (TLE) are unknown. METHODS: Twenty-five consecutive patients with vegetations ≥10 mm at transoesophageal echocardiography were prospectively studied. Contrast-enhanced chest computed tomography (CT) was performed before (pre-TLE) and after (post-TLE) the lead extraction procedure. RESULTS: Pre-TLE CT identified 18 patients (72%) with subclinical PE. The size of vegetations in patients with PE did not differ significantly from those without (median 20.0 mm [interquartile range: 13.0-30.0] vs. 14.0 mm [6.0-18.0], p = 0.116). Complete TLE success was achieved in all patients with 3 (2-3) leads extracted per procedure. There were no postprocedure complications related to the presence of PE and no differences in terms of fluoroscopy time and need for advanced tools. In the group of positive pre-TLE CT, post-TLE scan confirmed the presence of silent PE in 14 patients (78%). There were no patients with new PE formation. Large vegetations (≥20 mm) tended to increase the risk of post-TLE subclinical PE (odds ratio 5.99 [95% confidence interval (CI): 0.93-38.6], p = 0.059). During a median 19.4 months follow-up, no re-infection of the implanted system was reported. Survival rates in patients with and without post-TLE PE were similar (hazard ratio: 1.11 [95% CI: 0.18-6.67], p = 0.909). CONCLUSION: Subclinical PE detected by CT was common in patients undergoing TLE with lead-related infective endocarditis and vegetations but was not associated with the complexity of the procedure or adverse outcomes. TLE procedure seems safe and feasible even in patients with large vegetations.

Leadless pacemakers as a new alternative for pacemaker lead-related superior vena cava syndrome: A case report.

Superior vena cava (SVC) syndrome is a rare disease induced by thrombosis and consequent occlusion of SVC, negatively affecting morbidity and mortality. The incidence of SVC syndrome from central venous catheters and pacemaker or defibrillator leads is increasing. Optimal treatment of pacemaker or defibrillator-related SVC syndrome is not well defined. Lead extraction causes mechanical trauma to the vessel wall. In addition, subsequent device implantation on the contralateral side can be an added factor for venous occlusion. The use of leadless pacemakers could be an interesting option to reduce the risk of SVC restenosis after lead extraction. We report a clinical case of PM leads-related SVC syndrome referred to our centers and treated with transvenous lead extraction, leadless pacemaker implantation and subsequent percutaneous angioplasty and stenting of the SVC and left innominate vein.

Hybrid transvenous and surgical approach for the extraction of coronary sinus leads: A case series.

BACKGROUND: Transvenous lead extraction is the standard therapy for cardiac device-related infection. In some patients, however, a hybrid surgical and transvenous approach may be necessary. METHODS AND RESULTS: We present three cases who underwent transvenous lead extraction for an infected CRT-D system. In all cases the CS lead could not be retrieved transvenously due to extensive fibrosis. The lead was successfully extracted through left minithoracotomy in two patients and midline sternotomy in one patient. CONCLUSION: In cases where the coronary sinus lead shows severe fibrosis, a transvenous approach can be used to free the proximal part of the lead, while the distal adhesions can be removed surgically through a limited thoracic incision.

The role of preoperative venography in predicting the difficulty of a transvenous lead extraction procedure.

INTRODUCTION: We hypothesized that an accurate assessment of preoperative venography could be useful in predicting transvenous lead extraction (TLE) difficulty. METHODS AND RESULTS: A dedicated preoperative venogram was performed in consecutive patients with cardiac implantable electronic device who underwent TLE. The level of stenosis was classified as without significant stenosis, moderate, severe, and occlusion. The presence of extensive lead-venous wall adherence (≥50 mm) was also assessed. A total of 105 patients (median age: 71 years; 72% male) with a median of 2 (1-2) leads to extract were enrolled. Preoperative venography showed moderate to severe stenosis in 31 (30%), complete occlusion in 15 (14%), and extensive lead-venous wall adherence in 50 (48%) patients. Complete TLE success was achieved in 103 (98%) patients. A total of 55 (52%) were advanced extractions as they required a powered mechanical and/or laser sheath. They were more prevalent in the group with extensive lead-venous wall adherence (72% vs. 34%, p < .001), while no differences were found between patients with and without venous occlusion. In multivariate analysis, the presence of adherence was a predictor of advanced extraction (odds ratio: 2.89 [1.14-7.32], p = .025). The fluoroscopy time was also significantly longer (14.0 [8.2-18.7] vs. 5.1 [2.1-10.0] min, p < .001). The rate of complications did not differ based on the presence of venous lesions. CONCLUSION: Although procedural success and complication rates were similar, patients with extensive lead-venous wall adherence required a longer fluoroscopy time and were three times more likely to need advanced extraction tools. Conversely, the presence of total venous occlusion had no impact on the procedure complexity.

Intraoperative sensing increase predicts long-term pacing threshold in leadless pacemakers.

PURPOSE: High pacing threshold (HPT) and very high pacing threshold (VHPT) are known to have a negative impact on leadless pacemaker battery longevity, representing the most common reason for device repositioning. In this study, we evaluated if intraoperative electrical parameters recorded during Micra™ VR implant would be able to predict device performance during follow-up (FU). METHODS: A total of 93 patients undergoing Micra™ VR implant were retrospectively considered. Patients were enrolled in the study if electrical assessment was performed at least twice at implant, at Micra™ final positioning and after removal of the delivery system. All patients received a FU visit at 1 and 12 month after discharge. R-wave sensing amplitude, pacing threshold (PT), and impedance were recorded at each visit. RESULTS: When compared to the first assessment, R-wave sensing amplitude increased by 19.1% after 13 ± 4 min (+ 1.71 ± 0.2 mV, 95% CI 1.4 to 2.02; p < .001). Conversely, there was a significant PT decrease of 22.1% at 12-month FU (- 0.22 ± 0.03 V, 95% CI - 0.13 to - 0.31; p < .001). Among patients with HPT, acute increase of R-wave sensing of 1.5 mV after 14 ± 4 min predicted a significant reduction of PT below 1 V/0.24, at 12-month post-implant (R = 0.72, 95% CI 0.13 to 0.33, p < .001), with a sensitivity of 87.5% (95% CI 0.61-0.98) and a specificity of 88.8% (95% CI 0.51-0.99). CONCLUSION: A 1.5-mV increase in R-wave amplitude at implant is predictive of PT normalization (< 1.0 V/0.24 ms) at 12-month FU. This finding may have practical implications for device repositioning in case of HPT recording at implant.

Combining home monitoring temporal trends from implanted defibrillators and baseline patient risk profile to predict heart failure hospitalizations: results from the SELENE HF study.

AIMS: We developed and validated an algorithm for prediction of heart failure (HF) hospitalizations using remote monitoring (RM) data transmitted by implanted defibrillators. METHODS AND RESULTS: The SELENE HF study enrolled 918 patients (median age 69 years, 81% men, median ejection fraction 30%) with cardiac resynchronization therapy (44%), dual-chamber (38%), or single-chamber defibrillators with atrial diagnostics (18%). To develop a predictive algorithm, temporal trends of diurnal and nocturnal heart rates, ventricular extrasystoles, atrial tachyarrhythmia burden, heart rate variability, physical activity, and thoracic impedance obtained by daily automatic RM were combined with a baseline risk-stratifier (Seattle HF Model) into one index. The primary endpoint was the first post-implant adjudicated HF hospitalization. After a median follow-up of 22.5 months since enrolment, patients were randomly allocated to the algorithm derivation group (n = 457; 31 endpoints) or algorithm validation group (n = 461; 29 endpoints). In the derivation group, the index showed a C-statistics of 0.89 [95% confidence interval (CI): 0.83-0.95] with 2.73 odds ratio (CI 1.98-3.78) for first HF hospitalization per unitary increase of index value (P < 0.001). In the validation group, sensitivity of predicting primary endpoint was 65.5% (CI 45.7-82.1%), median alerting time 42 days (interquartile range 21-89), and false (or unexplained) alert rate 0.69 (CI 0.64-0.74) [or 0.63 (CI 0.58-0.68)] per patient-year. Without the baseline risk-stratifier, the sensitivity remained 65.5% and the false/unexplained alert rates increased by ≈10% to 0.76/0.71 per patient-year. CONCLUSION: With the developed algorithm, two-thirds of first post-implant HF hospitalizations could be predicted timely with only 0.7 false alerts per patient-year.

Transvenous lead extraction in patients with persistent left superior vena cava.

PURPOSE: Predictors of difficulty and complications of transvenous lead extraction (TLE) have been investigated in several studies; however, little is known about the venous anatomical characteristics that can have an impact on procedural outcomes. Among them, the persistent left superior vena cava (PLSVC) is a common anomaly often discovered incidentally during cardiac device implantation and could raise concerns if TLE is indicated. We report technical considerations and outcomes of TLE for two patients with leads implanted via PLSVC. METHODS AND RESULTS: Two cardiac implantable electronic device recipients with isolated PLSVC required TLE due to infective endocarditis in one case and lead failure in the other. In the first case, TLE procedure was performed in a hybrid operating room with minimally invasive video-assisted thoracoscopic monitoring due to the high procedural risk. Two active fixation 20-year-old pacing leads were removed with a relatively short fluoroscopy time. In the second case, we successfully extracted a single-coil active fixation lead without the need of a locking stylet or advanced extraction tools. There were no procedural complications or adverse events at 1-year follow-up. CONCLUSION: TLE procedures for two patients with isolated PLSVC were successfully completed with less difficulty and tools than expected based on the characteristics of the targeted leads. If indicated, TLE in the presence of a PLSVC should be considered in experienced centers.

Use of a novel implantable cardioverter-defibrillator multisensor algorithm for heart failure monitoring in a COVID-19 patient: A case report.

We report the case of a patient implanted with an implantable defibrillator endowed with a multisensor algorithm for heart failure monitoring. Automatic measurement of multiple clinical variables allowed to detect impending heart failure decompensation and showed its ability to facilitate differential diagnosis in the context of the current COVID-19 pandemic.

Technical considerations for CRT-D implantation in different varieties of persistent left superior vena cava.

PURPOSE: The persistent left superior vena cava (PLSVC) is usually asymptomatic and creates a challenge when detected incidentally during cardiac resynchronization therapy defibrillator (CRT-D) implantation. The purpose of our cases is to show different anatomical variables of PLSVC and different strategies used for CRT-D implantation. METHODS: Four cases of PLSVC were presented. Pre-procedural bilateral venography was done to define anatomical variant of PLSVC. The side of approach and vein of approach were chosen according to the anatomical variant. Major challenges, electrical parameters, procedural times, long-term follow up, and complications were addressed. RESULTS: Two cases were de novo CRT-D implantation. One case was an extraction/re-implantation of the coil lead, and one case was an upgrading. In one case, CRT-D implantation was followed by AVN ablation. All cases had successful devices implantation. Two cases had isolated PLSVC: one of them had right approach and the other had left approach. One case had double SVC with no connecting brachiocephalic veins and underwent a left-sided approach. One case had double SVC with a small connecting brachiocephalic vein and had a left approach for implantation with using the small brachiocephalic vein for the RV lead. Electrical parameters were acceptable for all leads implanted. Long-term follow-up was done for 6 months to 5 years. One complication occurred (acute atrial lead dislodgement). CONCLUSIONS: In our case series, the presence of PLSVC did not preclude successful placement of pacemaker/defibrillator leads using standard tools. Bilateral venography helped to decide the side and vein of lead insertion.

Clinical impact of defibrillation testing in a real-world S-ICD population: Data from the ELISIR registry.

BACKGROUND: Current guidelines recommend defibrillation testing (DT) performance in patients with a subcutaneous implantable cardioverter defibrillator (S-ICD), theoretically to reduce the amount of ineffective shocks. DT, however, has been proven unnecessary in transvenous ICD and real-world data show a growing trend in avoidance of DT after S-ICD implantation. METHODS: All patients undergoing S-ICD implant at nine associated Italian centers joining in the ELISIR registry (ClinicalTrials.gov Identifier: NCT04373876) were enrolled and classified upon DT performance. Long-term follow-up events were recorded and compared to report the long-term efficacy and safety of S-ICD implantations without DT in a real-world setting. RESULTS: A total of 420 patients (54.0 ± 15.5 years, 80.0% male) were enrolled in the study. A DT was performed in 254 (60.5%) patients (DT+ group), while in 166 (39.5%) was avoided (DT- group). Over a median follow-up of 19 (11-31) months, a very low rate (0.7%) of ineffective shocks was observed, and no significant differences in the primary combined arrhythmic outcome were observed between the two groups (p = .656). At regression analysis, the only clinical predictor associated with the primary combined outcome was S-ICD placement for primary prevention (odds ratio: 0.42; p = .013); DT performance instead was not associated with a reduction in primary outcome (p = .375). CONCLUSION: Implanting an S-ICD without DT does not appear to impact the safety of defibrillation therapy and overall patients' survival.

Leadless pacemaker: State of the art and incoming developments to broaden indications.

Theleadless pacemaker (LLPM) therapy has been developed in recent years to overcome the transvenous lead and device pocket-related complications. The LLPMs now available are self-contained right ventricular pacemakers and are limited to single-chamber ventricular pacing modality. This literature review deals with the current status of LLPM technology and current areas of clinical applicability. The safety and efficacy outcomes published from randomized clinical trials and real world registries are analyzed and compared with historical conventional transvenous pacemaker data. Furthermore, new pacing modalities and future perspectives to broaden the clinical use and cover most of pacing indications are discussed. Due to the overall safe and effective profile in the short term and intermediate term, also in fragile patients, the LLPM use is constantly growing in daily clinical practice. Actually, it can be considered a landmark innovation, through which a new era of cardiac pacing has begun.