Closed Loop Stimulation reduces the incidence of atrial high-rate episodes compared to conventional rate-adaptive pacing in patients with sinus node dysfunctions.

BACKGROUND AND AIMS: Subclinical atrial fibrillation (AF) is associated with increased risk of progression to clinical AF, stroke, and cardiovascular death. We hypothesized that in pacemaker patients requiring dual-chamber rate-adaptive (DDDR) pacing, Closed Loop Stimulation (CLS) integrated into the circulatory control system through intracardiac impedance monitoring would reduce the occurrence of atrial high-rate episodes (AHREs) compared to conventional DDDR pacing. METHODS: Patients with sinus node dysfunctions (SND) and an implanted pacemaker or defibrillator were randomly allocated to dual-chamber CLS (n=612) or accelerometer-based DDDR pacing (n=598) and followed for 3 years. The primary endpoint was time to the composite endpoint of first AHRE lasting ≥6 minutes, stroke, or transient ischemic attack (TIA). All AHREs were independently adjudicated using intracardiac electrograms. RESULTS: The incidence of the primary endpoint was lower in the CLS arm (50.6%) than in the DDDR arm (55.7%), primarily due to the reduction in AHREs lasting between 6 hours and 7 days. Unadjusted site-stratified hazard ratio (HR) for CLS versus DDDR was 0.84 (95%-CI, 0.72-0.99; p=0.035). After adjusting for CHA2DS2-VASc score, the HR remained 0.84 (95%-CI, 0.71-0.99; p=0.033). In subgroup analyses, the incremental benefit of CLS was greatest in patients without atrioventricular block (HR, 0.76; p=0.006) and in patients without AF history (HR, 0.73; p=0.010). The contribution of stroke/TIA to the primary endpoint (1.3%) was low and not statistically different between study arms. CONCLUSIONS: Dual-chamber CLS in patients with SND is associated with a significantly lower AHRE incidence than conventional DDDR pacing.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

The MB score: a new risk stratification index to predict the need for advanced tools in lead extraction procedures.

AIMS: A validated risk stratification schema for transvenous lead extraction (TLE) could improve the management of these procedures. We aimed to derive and validate a scoring system to efficiently predict the need for advanced tools to achieve TLE success. METHODS AND RESULTS: Between November 2013 and March 2018, 1960 leads were extracted in 973 consecutive TLE procedures in two national referral sites using a stepwise approach. A procedure was defined as advanced extraction if required the use of powered sheaths and/or snares. The study population was a posteriori 1:1 randomized in derivation and validation cohorts. In the derivation cohort, presence of more than two targeted leads (odds ratio [OR] 1.76, P = 0.049), 3-year-old (OR 3.04, P = 0.001), 5-year-old (OR 3.48, P < 0.001), 10-year-old (OR 3.58, P = 0.008) oldest lead, implantable cardioverter-defibrillator (OR 3.84, P < 0.001), and passive fixation lead (OR 1.91, P = 0.032) were selected by a stepwise procedure and constituted the MB score showing a C-statistics of 0.82. In the validation group, the MB score was significantly associated with the risk of advanced extraction (OR 2.40, 95% confidence interval 2.02-2.86, P < 0.001) and showed an increase in event rate with increasing score. A low value (threshold = 1) ensured 100% sensibility and 100% negative predictive value, while a high value (threshold = 5) allowed a specificity of 92.8% and a positive predictive value of 91.9%. CONCLUSION: In this study, we developed and tested a simple point-based scoring system able to efficiently identify patients at low and high risk of needing advanced tools during TLE procedures.

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.

Leadless pacing in cardiac transplant recipients: Primary results of a multicenter case experience.

About 4.5-20% of patients after heart transplant require pacemaker (PM) implantation. The high infective risk profile and the low probability of pacing dependency make heart-transplanted patients the ideal candidates for a leadless single-chamber PM. We report the first multicenter experience of leadless PM implantation in a series of heart-transplanted patients with a long-term follow-up. Our data confirm the feasibility and acceptable safety of leadless device in this peculiar kind of patients, despite implantation seems to be slightly more challenging with respect to non-transplanted patients. Although more data are required, a leadless single-chamber surveillance PM seems a valuable option for heart-transplanted patients.

First-in-human retrieval of chronically implanted Micra transcatheter pacing system.

We report the first-in-human retrieval of a chronically implanted Micra transcatheter pacing system (TPS; Medtronic, Minneapolis, MN, USA). A 41-year-old woman suffering from third-degree atrioventricular block was successfully implanted with a TPS in the low septum of the right ventricle. After 29 months, due to an increased electrical threshold and 100% pacing percentage, the device showed low battery voltage. Despite the long implant duration, the attempt of device retrieval using a snare loop inserted in the delivery system of a TPS was successful. In the same procedure, a new leadless pacemaker was implanted in the high right ventricular septum with optimal pacing threshold.

Management of a leadless pacemaker recall via extraction in a patient with a history of multiple previous device implants.

We describe a management strategy of a leadless pacemaker recall (LP) via extraction in a pacemaker-dependent patient with a history of multiple previous device implants. We performed a two-step procedure. First, we implanted a second LP in the right ventricle. Then, 3 days later for concerns about the stability of the newly-implanted device, we retrieved the first LP, 3 years after its original implant. The patient was hemodynamically stable throughout the two procedures and no adverse event occurred in the 3 days of coexistence of the two LPs. Although the limitation of a single case experience, this approach may be taken into consideration when facing similar high-risk cases.

Predicting the difficulty of a transvenous lead extraction procedure: Validation of the LED index.

INTRODUCTION: A lead extraction difficulty (LED) score was proposed to predict the difficult transvenous lead extraction (TLE) procedures, defined by means of the fluoroscopy time. The aim of this study was to validate the estimation model based on the LED index above 10 on an independent data set of TLE cases. METHODS: Consecutive patients undergoing TLE between January 2014 and January 2016 were included in this analysis. The fluoroscopy time related to the leads removal was dichotomized as above or below its 90th percentile (PCTL). RESULTS: In total, 446 permanent leads were removed during 233 TLE procedures. Complete procedural success was achieved in 232 (99.1%) patients. The LED index resulted >10 in 83(35.6%) procedures. Among these cases, 20 had fluoroscopy time above the 90th PCTL (23.3 minutes) and were classified as true positive. Over the 150 procedures with LED score <10, 147 were classified as true negative, and only 3 resulted false negative. The sensitivity, the specificity, and the negative predictive value of the LED index in predicting complex cases resulted 86.9 (confidence interval [CI] 66.4-97.2)%, 70.0 (CI 63.3-76.1)%, and 98.0 (CI 94.3-99.6)%, respectively. The multivariate logistic regression analysis confirmed a 12% increased risk of high fluoroscopy for each additional point of the LED score (OR 1.12, CI 1.05-1.21, P = 0.001). CONCLUSION: The validation of the estimation model based on the LED index <10 confirmed its high efficacy in predicting simple TLE procedures.

Hybrid Minimally Invasive Approach for Transvenous Lead Extraction: A Feasible Technique in High-Risk Patients.

INTRODUCTION: Despite the overall safety, transvenous lead extraction (TLE) remains a challenging procedure with inherent risks, where surgery can still be required in elective cases. In this study, we report our experience with a minimally invasive "hybrid" approach, defined as a procedure performed by an electrophysiologist with the support of a cardiac surgeon in the same operative session. METHODS AND RESULTS: We reported 12 cases of planned hybrid lead extraction; minithoracotomy and thoracoscopy were performed on 10 (83%) and 2 (17%) patients, respectively. A total of 25 leads out of 27 (median lead age 19 years) were successfully extracted with laser, mechanical or combined transvenous sheath. In 3 patients, the direct monitoring of vascular and myocardial integrity allowed for prompt treatment of potential vascular injury during the lead extraction maneuvers. Mean in-hospital stay was 4 ± 2 days. There were no major intraoperative complications and no deaths occurred after 30 days' follow-up. CONCLUSION: The hybrid approach, with minithoracotomy or thoracoscopy, is feasible and it might increase the safety in the most challenging TLE procedures: the minimally invasive surgical intervention allows for continuous monitoring of the critical cardiac structures and prompt treatment of potential complications.

The economic impact of battery longevity in implantable cardioverter-defibrillators for cardiac resynchronization therapy: the hospital and healthcare system perspectives.

AIMS: Patients receiving cardiac resynchronization therapy defibrillators (CRT-Ds) are likely to undergo one or more device replacements, mainly for battery depletion. We assessed the economic impact of battery depletion on the overall cost of CRT-D treatment from the perspectives of the healthcare system and the hospital. We also compared devices of different generations and from different manufacturers in terms of therapy cost. METHODS AND RESULTS: We analysed data on 1792 CRT-Ds implanted in 1399 patients in 9 Italian centres. We calculated the replacement probability and the total therapy cost over 6 years, stratified by device generation and manufacturer. Public tariffs from diagnosis-related groups were used together with device prices and hospitalization costs. Generators were from 3 manufacturers: Boston Scientific (667, 37%), Medtronic (973, 54%), and St Jude Medical (152, 9%). The replacement probability at 6 years was 83 and 68% for earlier- and recent-generation devices, respectively. The need for replacement increased total therapy costs by more than 50% over the initial implantation cost for hospitals and by more than 30% for healthcare system. The improved longevity of recent-generation CRT-Ds reduced the therapy cost by ∼6% in both perspectives. Among recent-generation CRT-Ds, the replacement probability of devices from different manufacturers ranged from 12 to 70%. Consequently, the maximum difference in therapy cost between manufacturers was 40% for hospitals and 19% for the healthcare system. CONCLUSIONS: Differences in CRT-D longevity strongly affect the overall therapy cost. While the use of recent-generation devices has reduced the cost, significant differences exist among currently available systems.

The novel active fixation coronary sinus lead: efficacy and safety of transvenous extraction procedure.

AIMS: Benefits of cardiac resynchronization therapy (CRT) are well known for heart failure; however, some patients might experience complications related to the coronary sinus (CS) lead (high pacing threshold, phrenic nerve stimulation, and dislodgment) with unfavourable impact on quality of life, costs, and management. Lead stability is one of the most common unmet needs for CRT procedures. METHODS AND RESULTS: Recently, new model Medtronic 20066 Attain Stability(®) (Maastricht, The Netherlands) active fixation LV lead has been released, to overcome this issue. The lead has a small side helix of 0.20 mm (0.008 in.) that allows for secure placement of the lead within the vein at the desired location. We report our first experience with the extraction of this novel active fixation left ventricular lead. CONCLUSION: In our case, to our knowledge the first reported in humans, the extraction of this new model of active fixation lead was proved to be a safe and effective procedure at 8 months after implantation. Indeed, under angiographic and fluoroscopic check, there was no documented dissection or damage to the CS during and after removal of the lead. The rotation manoeuvre was effective when combined with moderate traction of the lead itself.