Aveir retrievable, 38-mm length, leadless pacemaker implantation in a 23-kg pediatric patient with congenital heart disease

INTRODUCTION

Complications are more prevalent in pediatric patients receiving pacemaker implants.

METHODS

We performed a retrospective review of a retrievable, 38 mm leadless pacemaker implantation in a 23-kg pediatric patient.

CASE/DISCUSSION

An active 9-year-old, 23 kg male patient with tetralogy of Fallot with intermittent pacing need presented with a fractured lead and pacing need. He underwent implant of a retrievable leadless pacemaker (Abbott Aveir) via internal jugular vein access, without complication, and with echocardiographic guidance. His threshold was stable at 1.25 V @0.4 ms, with stable impedance and sensing at 5-month follow-up.

CONCLUSION

Aveir retrievable leadless pacemakers can be implanted safely in a child with tetralogy of Fallot, as small as 23 kilograms.

Emerging Technologies in Cardiac Pacing

Cardiac pacing to treat bradyarrhythmias has evolved in recent decades. Recognition that a substantial proportion of pacemaker-dependent patients can develop heart failure due to electrical and mechanical dyssynchrony from traditional right ventricular apical pacing has led to development of more physiologic pacing methods that better mimic normal cardiac conduction and provide synchronized ventricular contraction. Conventional biventricular pacing has been shown to benefit patients with heart failure and conduction system disease but can be limited by scarring and fibrosis. His bundle pacing and left bundle branch area pacing are novel techniques that can provide more physiologic ventricular activation as an alternative to conventional or biventricular pacing. Leadless pacing has emerged as another alternative pacing technique to overcome limitations in conventional transvenous pacemaker systems. Our objective is to review the evolution of cardiac pacing and explore these new advances in pacing strategies.

Evolution of ventricular and valve function in patients with right ventricular pacing - A randomized controlled trial comparing leadless and conventional pacing

BACKGROUND

Leadless pacemakers (PMs) were recently introduced to overcome lead-related complications. They showed high safety and efficacy profiles. Prospective studies assessing long-term safety on cardiac structures are still missing.

OBJECTIVE

The purpose of this study was to compare the mechanical impact of Micra with conventional PM on heart function.

METHODS

We conducted a non-inferiority trial in patients with an indication for single chamber ventricular pacing. Patients were 1:1 randomized to undergo implantation of either Micra or conventional monochamber ventricular pacemaker (PM). Patients underwent echocardiography at baseline, 6 and 12 months after implantation. Analysis included left ventricular ejection fraction (LVEF), global longitudinal strain (GLS) and valve function. N-terminal-pro hormone B-type natriuretic peptide (NT-pro-BNP) levels were measured at baseline and 12 months.

RESULTS

Fifty-one patients (27 in Micra group and 24 in conventional group) were included. Baseline characteristics were similar for both groups. At 12 months, (1) the left ventricular function as assessed by LVEF and GLS worsened similarly in both groups (∆LVEF -10 ± 7.3% and ∆GLS +5.7 ± 6.4 in Micra group vs. -13.4 ± 9.9% and +5.2 ± 3.2 in conventional group) (p = 0.218 and 0.778, respectively), (2) the severity of tricuspid valve regurgitation was significantly lower with Micra than conventional pacing (p = 0.009) and (3) median NT-pro-BNP was lower in Micra group (970 pg/dL in Micra group versus 1394 pg/dL in conventional group, p = 0.041).

CONCLUSION

Micra is non inferior to conventional PMs concerning the evolution of left ventricular function at 12-month follow-up. Our data suggest that Micra has a comparable mechanical impact on the ventricular systolic function but resulted in less valvular dysfunction.

Atrial mechanical contraction and ambulatory atrioventricular synchrony: Predictors from the OPTIVALL study

INTRODUCTION

The role that preprocedural factors have on atrioventricular synchrony (AVS) provided by leadless pacemakers requires investigation.

METHODS AND RESULTS

We aimed to assess the correlation between mitral inflow echocardiographic parameters and p-wave morphology with the accelerometer A4 signal amplitude. We also sought to identify clinical and echocardiographic predictors of optimal ambulatory AVS (≥85% of cardiac cycles). Forty-three patients undergoing Micra AV implant from June 2020 to March 2023 were prospectively enrolled. Baseline echocardiogram and 12-lead resting ECG were performed. Device follow-up was scheduled at 24 h, 1, 3, and 6 months and yearly after the implant. Ambulatory AVS was studied with a 24 h Holter monitor performed at 3 months follow-up in 35 patients who remained in VDD mode. A4 signal amplitude at 1 month correlated to peak A wave velocity (r = .376; p = .024) at echocardiogram, but no relationship was found with peak A' wave velocity, E/A, or E'/A' ratio. P-wave amplitude in lead I and aVF correlated to A4 signal amplitude at 1- and 3-months follow-up, respectively. Median AVS during 24 h of daily activities was 85.6 ± 7.6% and remained stable up to 100 bpm. Twenty-three out of 35 patients (65.7%) reached optimal ambulatory AVS. There was no association between mitral inflow echocardiographic parameters and optimal AVS. Diabetes (OR: 0.05, 95% CI: 0.01-0.47; p = .009) and chronic obstructive pulmonary disease (COPD) (OR: 0.06, 95% CI: 0.01-0.63; p = .019) strongly predicted ambulatory AVS <85%.

CONCLUSIONS

Diabetes and COPD should be considered when selecting candidates for Micra AV. Measurements of pulsed wave Doppler mitral inflow do not systematically reflect the behavior of the A4 signal amplitude.

Peri-Procedural Management of Direct-Acting Oral Anticoagulants (DOACs) in Transcatheter Miniaturized Leadless Pacemaker Implantation

INTRODUCTION

Data on peri-operative management of direct-acting oral anticoagulants (DOACs) during transcatheter pacing leadless system (TPS) implantations remain limited. This study aimed to evaluate a standardized DOAC management regime consisting of interruption of a single dose prior to implantation and reinitiation within 6-24 h; also, patient clinical characteristics associated with this approach were identified.

METHOD

Consecutive patients undergoing standard TPS implantation procedures from two Swiss tertiary centers were included. DOAC peri-operative management included the standardized approach (Group 1A) or other approaches (Group 1B).

RESULTS

Three hundred and ninety-two pts (mean age 81.4 ± 7.3 years, 66.3% male, left ventricular ejection fraction 55.5 ± 9.6%) underwent TPS implantation. Two hundred and eighty-two pts (71.9%) were under anticoagulation therapy; 192 pts were treated with DOAC; 90 pts were under vitamin-K antagonist. Patients treated with DOAC less often had structural heart disease, diabetes mellitus, and advanced renal failure. The rate of major peri-procedural complications did not differ between groups 1A (n = 115) and 1B (n = 77) (2.6% and 3.8%, p = 0.685). Compared to 1B, 1A patients were implanted with TPS for slow ventricular rate atrial fibrillation (AF) (p = 0.002), in a better overall clinical status, and implanted electively (<0.001).

CONCLUSIONS

Standardized peri-procedural DOAC management was more often implemented for elective TPS procedures and did not seem to increase bleeding or thromboembolic adverse events.

Atrioventricular synchronous leadless pacing: Micra AV

Since the arrival of leadless pacemakers (LPs), they have become a cornerstone in remedial treatment of bradycardia and atrioventricular (AV) conduction disorders, as an alternative to transvenous pacemakers. Even though clinical trials and case reports show indisputable benefits of LP therapy, they also bring some doubts. Together with the positive results of the MARVEL trials, AV synchronization has become widely available in LPs, presenting a significant development in leadless technology. This review presents the Micra AV (MAV), describes major clinical trials, and introduces the basics of AV synchronicity obtained with the MAV and its unique programming options.

A leadless pacemaker in the real-world setting: Patient profile and performance over time

Background

While prior Micra trials demonstrated a high implant success rate and favorable safety and efficacy results, changes in implant populations and safety over time is not well studied. The objective of this analysis was to report the performance of Micra in European and Middle Eastern patients and compare to the Micra Investigational Device Exemption (IDE) and Micra Post Approval Registry (PAR) studies.

Methods

The prospective, single-arm Micra Acute Performance European and Middle Eastern (MAP EMEA) registry was designed to further study the performance of Micra in patients from EMEA. The primary endpoint was to characterize acute (30-day) major complications. Electrical performance was analyzed. The major complication rate through 12 months was compared with the IDE and PAR studies.

Results

The MAP EMEA cohort (n = 928 patients) had an implant success rate of 99.9% and were followed for an average of 9.7 ± 6.5 months. Compared to prior studies, MAP EMEA patients were more likely to have undergone dialysis and have a condition which precluded the use of a transvenous pacemaker (p < .001). Within 30 days of implantation, the MAP EMEA cohort had a major complication rate of 2.59%. Mean pacing thresholds were low and stable through 12 months (0.61 ± 0.40 V at 0.24 ms at implant and 12 months). Through 12 months post-implantation, the major complication rate for MAP EMEA was not significantly different from IDE (p = .56) or PAR (p = .79).

Conclusion

Despite patient differences over time, the Micra leadless pacemaker was implanted with a high success rate and low complication rate, in-line with prior reports.

Leadless biventricular left bundle and endocardial lateral wall pacing versus left bundle only pacing in left bundle branch block patients

Biventricular endocardial (BIV-endo) pacing and left bundle pacing (LBP) are novel delivery methods for cardiac resynchronization therapy (CRT). Both pacing methods can be delivered through leadless pacing, to avoid risks associated with endocardial or transvenous leads. We used computational modelling to quantify synchrony induced by BIV-endo pacing and LBP through a leadless pacing system, and to investigate how the right-left ventricle (RV-LV) delay, RV lead location and type of left bundle capture affect response. We simulated ventricular activation on twenty-four four-chamber heart meshes inclusive of His-Purkinje networks with left bundle branch block (LBBB). Leadless biventricular (BIV) pacing was simulated by adding an RV apical stimulus and an LV lateral wall stimulus (BIV-endo lateral) or targeting the left bundle (BIV-LBP), with an RV-LV delay set to 5 ms. To test effect of prolonged RV-LV delays and RV pacing location, the RV-LV delay was increased to 35 ms and/or the RV stimulus was moved to the RV septum. BIV-endo lateral pacing was less sensitive to increased RV-LV delays, while RV septal pacing worsened response compared to RV apical pacing, especially for long RV-LV delays. To investigate how left bundle capture affects response, we computed 90% BIV activation times (BIVAT-90) during BIV-LBP with selective and non-selective capture, and left bundle branch area pacing (LBBAP), simulated by pacing 1 cm below the left bundle. Non-selective LBP was comparable to selective LBP. LBBAP was worse than selective LBP (BIVAT-90: 54.2 ± 5.7 ms vs. 62.7 ± 6.5, p < 0.01), but it still significantly reduced activation times from baseline. Finally, we compared leadless LBP with RV pacing against optimal LBP delivery through a standard lead system by simulating BIV-LBP and selective LBP alone with and without optimized atrioventricular delay (AVD). Although LBP alone with optimized AVD was better than BIV-LBP, when AVD optimization was not possible BIV-LBP outperformed LBP alone, because the RV pacing stimulus shortened RV activation (BIVAT-90: 54.2 ± 5.7 ms vs. 66.9 ± 5.1 ms, p < 0.01). BIV-endo lateral pacing or LBP delivered through a leadless system could potentially become an alternative to standard CRT. RV-LV delay, RV lead location and type of left bundle capture affect leadless pacing efficacy and should be considered in future trial designs.

Conduction System Pacing Today and Tomorrow

Conduction system pacing (CSP) encompassing His bundle (HBP) and left bundle branch area pacing (LBBAP) is gaining increasing attention in the electrophysiology community. These relatively novel physiological pacing modalities have the potential to outperform conventional pacing approaches with respect to clinical endpoints, although data are currently still limited. While HBP represents the most physiological form of cardiac stimulation, success rates, bundle branch correction, and electrical lead performance over time remain a concern. LBBAP systems may overcome these limitations. In this review article, we provide a comprehensive overview of the current evidence, implantation technique, device programming, and follow-up considerations concerning CSP systems. Moreover, we discuss ongoing technical developments and future perspectives of CSP.

Removal of an active fixation coronary sinus pacing lead five years post implant: a case report

Active fixation for a lead in the coronary sinus may be essential to select the optimal left ventricular pacing site, maximize the effectiveness of CRT and avoid dislodgement. The Medtronic Attain Stability lead allows fixation through a side helix concentric with the lead body. Although electrical performance of such a lead is well known, evidence of extractability remains poor especially in the long term. We describe the removal of an Attain Stability lead 63 months after implantation which, to the best of our knowledge, is the longest implant duration that has ever been reported, in an 81-year-old male patient. It was successfully achieved using simple traction and rotation maneuvers, demonstrating the long-term removal feasibility of such device. This article is protected by copyright. All rights reserved.

A novel and safe alternative

AIMS

To evaluate safety of leadless pacemaker implantation through the internal jugular vein in a larger cohort with longer follow-up. Moreover, feasibility of non-apical pacing as well as relation between pacing site and QRS duration were assessed.

METHODS

82 consecutive patients, who received a leadless pacemaker though the internal jugular vein were included. Electrical parameters were measured at regular follow-up and any complications were registered. Paced QRS interval was compared for three pacing sites, RVOT, RV mid septum and RV apical septum.

RESULTS

In all patients the leadless pacemaker was implanted successfully. In 69 patients the device was implanted in a non-apical position. In 71% of cases, the device could be deployed at first attempt. The median fluoroscopy time was 4.4minutes (range 0.9-51-) The paced QRS interval was significantly narrower for non-apical pacing compared to apical pacing 156ms. vs 179 ms. P = 0.04 respectively. During mean follow-up of 16 months (range 0-43 months) electrical parameters remained stable. Two complications occurred which could be resolved during the implant procedure. There were no access site related complications.

CONCLUSION

The jugular approach for leadless pacemaker implantation is feasibly and may avoid vascular complications. It facilitates non-apical positioning of leadless pacemakers leading to a narrower paced QRS interval. The jugular approach allows for immediate post procedural ambulation. This article is protected by copyright. All rights reserved.

Pediatric Micra leadless pacemaker implantation via internal jugular and femoral veins: experience with 11 patients

In pediatrics, conventional transvenous and epicardial pacemaker systems carry complications, such as lead distortion due to growth and activity, in addition to lead and pocket complications. A retrospective review of pediatric leadless pacing at the University of Minnesota Masonic Children's Hospital (MN, USA) from 2018 through 2021 was performed. Diagnoses, rationale for pacing, demographics, pacing thresholds and longevity of devices were recorded. Twelve leadless pacemaker insertions and one removal were performed successfully in patients weighing 19-90 kg. Six patients had Micra implantation via the internal jugular vein without surgical cut-down. Up to 3 years of follow-up were noted, with median follow-up of 22 months. No late complications occurred. Leadless pacemaker implantation and early retrieval were feasible in pediatric patients.

Leadless Pacemaker Implantation after Lead Extraction for Cardiac Implanted Electronic Device Infection

BACKGROUND

Cardiac implanted electronic device (CIED) pocket and systemic infection remain common complications with traditional CIEDs and are associated with high morbidity and mortality. Leadless pacemakers may be an attractive pacing alternative for many patients following complete hardware removal for a CIED infection by eliminating surgical pocket-related complications as well as lower risk of recurrent complications.

OBJECTIVE

To describe use and outcomes associated with leadless pacemaker implantation following extraction of a prior CIED system due to infection.

METHODS

Patient characteristics and post-procedural outcomes were described in patients who underwent leadless pacemaker implantation at Duke University Hospital between November 11, 2014 and November 18, 2019, following CIED infection and device extraction. Outcomes of interest included procedural complications, pacemaker syndrome, need for system revision, and recurrent infection.

RESULTS

Among 39 patients, the mean age was 71 ±17 years, 31% were women, and the most frequent primary pacing indication was complete heart block (64.1%) with 9 (23.1%) patients being pacemaker dependent at the time of Micra implantation. The primary organism implicated in the CIED infection was Staphylococcus aureus (43.6%). Nine of the 39 patients had a leadless pacemaker implanted before or on the same day as their extraction procedure, and the remaining 30 patients had a leadless pacemaker implanted after their extraction procedure. During the mean follow-up time (mean 24.8 ± 14.7 months) following the leadless pacemaker implantation, there were a total of 3 major complications: 1 groin hematoma, 1 femoral arteriovenous fistula, and 1 case of pacemaker syndrome. No patients had evidence of recurrent CIED infection after leadless pacemaker implantation.

CONCLUSIONS

Despite a prior CIED infection and an elevated risk of recurrent infection, there was no evidence of CIED infection with a mean follow up of over 2 years following leadless pacemaker implantation at or after CIED system removal. Larger studies with longer follow-up are required to determine if there is a long-term advantage to implanting a leadless pacemaker versus a traditional pacemaker following temporary pacing when needed during the peri-extraction period in patients with a prior CIED infection. This article is protected by copyright. All rights reserved.

Leadless pacemaker implant guided by intracardiac echocardiography in a patient after Mustard repair

This case report describes a successful leadless pacemaker implant (Micra VR Medtronic, Inc, Minneapolis, MN) in a 48-year-old patient with a history of Mustard repair. Twenty-one years after dual-chamber pacemaker implant, both conventional leads became dysfunctional. Lead extraction was refused by the patient and the subclavian vein was obstructed. A leadless pacemaker was selected as an alternative. Intracardiac echocardiography allowed the safe introduction of the delivery system into the non-systemic left ventricle. Four months after implant, the pacing parameters are stable and the patient is without new complaints. A leadless pacemaker could be considered in patients with complex grown-up congenital heart disease. This article is protected by copyright. All rights reserved.

Behavior of AV synchrony pacing mode in a leadless pacemaker during variable AV conduction and arrhythmias

Introduction

MARVEL 2 assessed the efficacy of mechanical atrial sensing by a ventricular leadless pacemaker, enabling a VDD pacing mode. The behavior of the enhanced MARVEL 2 algorithm during variable atrio‐ventricular conduction (AVC) and/or arrhythmias has not been characterized and is the focus of this study.

Methods

Of the 75 patients enrolled in the MARVEL 2 study, 73 had a rhythm assessment and were included in the analysis. The enhanced MARVEL 2 algorithm included a mode‐switching algorithm that automatically switches between VDD and ventricular only antibradycardia pacing (VVI)‐40 depending upon AVC status.

Results

Forty‐two patients (58%) had persistent third degree AV block (AVB), 18 (25%) had 1:1 AVC, 5 (7%) had variable AVC status, and 8 (11%) had atrial arrhythmias. Among the 42 patients with persistent third degree AVB, the median ventricular pacing (VP) percentage was 99.9% compared to 0.2% among those with 1:1 AVC. As AVC status changed, the algorithm switched to VDD when the ventricular rate dropped less than 40 bpm. During atrial fibrillation (AF) with ventricular response greater than 40 bpm, VVI‐40 mode was maintained. No pauses longer than 1500 ms were observed. Frequent ventricular premature beats reduced the percentage of AV synchrony. During AF, the atrial signal was of low amplitude and there was infrequent sensing.

Conclusion

The mode switching algorithm reduced VP in patients with 1:1 AVC and appropriately switched to VDD during AV block. No pacing safety issues were observed during arrhythmias.

Micra™ Leadless Intracardiac Pacemaker Implantation: A Safer Option During the Coronavirus Disease 2019 Pandemic

The Micra™ Transcatheter Pacing System (Medtronic, Minneapolis, MN, USA) is a fairly novel leadless intracardiac pacemaker implanted in the right ventricle via a femoral-vein transcatheter approach. Due to the less-invasive nature of the implantation procedure and its smaller size, patients receiving the Micra™ device tend to experience fewer complications, hospitalizations, and revisions when compared with those with transvenous pacemakers. Certain arrhythmias and conduction abnormalities, such as high-degree atrioventricular blocks, require urgent and timely pacemaker insertion—a necessity that has persisted even during the coronavirus disease 2019 (COVID-19) pandemic. Here, we present a case series of 10 patients with various conduction disease abnormalities who required right ventricle pacemaker implantation during the months of March to May 2020, which was the initial peak of the COVID-19 pandemic in New Jersey, including the enhanced precautions taken to avoid viral spread.

Pediatric Micra leadless pacemaker implantation via internal jugular and femoral vein: a single center, US experience

Background: In the pediatric population, conventional transvenous and epicardial pacemaker systems carry complications such as lead distortion due to growth/activity, in addition to other lead/pocket complications. Materials & methods: A retrospective review of pediatric leadless pacing at the University of Minnesota Masonic Children's Hospital from 2018 to 2020 was performed. Rationale for pacing, demographics of patients, thresholds and longevity of devices were recorded. Results: Seven leadless pacemaker insertions and one removal were performed successfully, in patients weighing between 19 kg and 58 kg. Three patients had Micra implantation via internal jugular vein. One pericardial effusion occurred perioperatively in a 19 kg patient with baseline thrombocytopenia, sideroblastic anemia and Pearson Marrow Pancreas syndrome. Conclusion: Leadless pacemaker implantation/early retrieval is feasible in pediatric patients.

VVI pacing with normal QRS duration and ventricular function: MOST trial findings relevant to leadless pacemakers

BACKGROUND

Leadless pacemakers (LPs) provide ventricular pacing without the risks associated with transvenous leads and device pockets. LPs are appealing for patients who need pacing, but do not need defibrillator or cardiac resynchronization therapy. Most implanted LPs provide right ventricular pacing without atrioventricular synchrony (VVIR mode). The Mode Selection Trial in Sinus Node Dysfunction (MOST) showed similar outcomes in patients randomized to dual-chamber (DDDR) versus ventricular pacing (VVIR). We compared outcomes by pacing mode in LP-eligible patients from MOST.

METHODS

Patients enrolled in the MOST study with an left ventricular ejection fraction (LVEF) >35%, QRS duration (QRSd) <120 ms and no history of ventricular arrhythmias or prior implantable cardioverter defibrillators were included (LP-eligible population). Cox proportional hazards models were used to test the association between pacing mode and death, stroke or heart failure (HF) hospitalization and atrial fibrillation (AF).

RESULTS

Of the 2010 patients enrolled in MOST, 1284 patients (64%) met inclusion criteria. Baseline characteristics were well balanced across included patients randomized to DDDR (N = 630) and VVIR (N = 654). Over 4 years of follow-up, there was no association between pacing mode and death, stroke or HF hospitalization (VVIR HR 1.28 [0.92-1.75]). VVIR pacing was associated with higher risk of AF (HR 1.32 [1.08-1.61], P = .007), particularly in patients with no history of AF (HR 2.38 [1.52-3.85], P < .001).

CONCLUSION

In patients without reduced LVEF or prolonged QRSd who would be eligible for LP, DDDR, and VVIR pacing demonstrated similar rates of death, stroke or HF hospitalization; however, VVIR pacing significantly increased the risk of AF development.

Comparison of Leadless Pacing and Temporary Externalized Pacing Following Cardiac Implanted Device Extraction

Pacemaker-dependent (PD) patients undergoing implantable cardiac electronic device extraction often must be subjected to temporary pacing interventions. We sought to determine the safety and utility of a leadless pacing system (Micra™; Medtronic, Minneapolis, MN, USA) in patients undergoing system extraction as compared with externalized temporary transvenous right ventricular lead (temp-perm) placement. We performed a retrospective cohort analysis of all patients receiving either permanent Micra™ or temp-perm systems following system extraction from October 2013 to September 2017 at Vanderbilt University Hospital. The Micra™ and temp-perm cohorts included nine and 27 patients meeting the inclusion criteria, respectively. System infection was the most common indication for extraction (67% Micra™, 84% temp-perm), but no patients had active bacteremia at the time of permanent system reimplantation. There was no difference in system type (p = 0.09) or mean lead dwell time extracted (109 versus 81 months; p = 0.93). Procedure times were comparable between the two groups (180 versus 194 minutes; p = 0.74). Patients receiving Micra™ systems had shorter hospital stays after extraction (two versus eight days; p < 0.005), with no difference in major complications (11% versus 15%; p = 0.78) or 30-day (11% versus 7%; p = 0.77) or 90-day (11% versus 11%; p = 0.45) mortality. No reinfections were observed in either group at 90 days. Implantation of the Micra™ pacing system in select PD patients after system extraction is feasible and appears to reduce the hospital length of stay as compared with the use of temp-perm systems.

Pacemaker complications and costs: a nationwide economic study

Aims: Novel leadless pacemakers (LPMs) may reduce complications and associated costs related to conventional pacemaker systems. This study sought to estimate the incidence and associated costs of traditional pacemaker complications, in those patients who were eligible for LPM implantation. Methods: A retrospective analysis was conducted on the French National Hospital Database (PMSI), including all patients implanted with a pacemaker in France in 2012, who could have alternatively received an LPM. Complication rates and their associated costs 3 years post-implantation were estimated from the perspective of the French social security system. Results: From a total of 65,553 patients, 11,770 (18%) met the inclusion criteria. Overall, 618 patients (5.3%) had a record of pacemaker complications during follow-up, of which 89% were related to the lead and pocket. Most common were pocket bleeding, lead- or generator-related mechanical complications, and pneumothorax. Overall, the mean cost of pacemaker complications per patient was €6,674 ± 3,867 at 3 years. Specifically, €7,143 ± 2,685 for pocket bleeding, €5,123 ± 2,676 for pneumothorax, and €6,020 ± 3,272 for mechanical complications. Conclusions: Major complications associated with the lead and pocket of conventional pacemaker systems are still common, and these represent a significant burden to healthcare systems as they generate substantial costs.

Improving Cardiac Resynchronisation Therapy

CRT is a cornerstone of therapy for patients with heart failure and reduced ejection fraction. By restoring left ventricular (LV) electrical and mechanical synchrony, CRT can reduce mortality, improve LV function and reduce heart failure symptoms. Since its introduction, many advances have been made that have improved the delivery of and enhanced the response to CRT. Improving CRT outcomes begins with proper patient selection so CRT is delivered to all populations that could benefit from it, and limiting the implantation of CRT in those with a small chance of response. In addition, advancements in LV leads and delivery technologies coupled with multimodality imaging and electrical mapping have enabled operators to place coronary sinus leads in locations that will optimise electrical and mechanical synchrony. Finally, new pacing strategies using LV endocardial pacing or His bundle pacing have allowed for CRT delivery and improved response in patients with poor coronary sinus anatomy or lack of response to traditional CRT.

Leadless pacing with Micra TPS: A comparison between right ventricular outflow tract, mid-septal, and apical implant sites

BACKGROUND

With its steerable transcatheter delivery system, the Micra can be deployed in nonapical positions within the right ventricle, potentially allowing reduction of the paced QRS width. We sought to evaluate the safety and long-term performance of the right ventricular outflow tract (RVOT) pacing using the Micra transcatheter pacing system (TPS). We also compared the paced QRS between RVOT, mid-septal, and apical implant positions.

METHODS

All patients who underwent a Micra TPS implantation at the University Hospitals of Leuven were enrolled in this observational study. Right ventricular (RV) position of the device was assessed on per-procedural ventriculography. Paced QRS was analyzed and follow-up completed at 1 month and then every 6 months.

RESULTS

Among the 133 patients included (mean follow-up: 13 ± 11 months), 45 were implanted in the RVOT, 58 midseptally, and 30 at the apex. All implant procedures were successful and no pericardial effusion was encountered within the 30 days post-implant. Two major complications were reported with devices implanted at the apex. Pacing impedance was significantly higher in the RVOT compared to the mid-septal and apical position (P < .001). Pacing threshold and R-wave amplitude did not differ over time in either position. The median narrowest paced QRS duration was observed in the RVOT (142 ms) compared to mid-septal (159 ms; P < .001), and apical position (181 ms; P < .001).

CONCLUSION

Implantation of the Micra TPS in the RVOT is safe and feasible. Electrical performance over time was comparable to mid-septal and apical positions. The narrowest paced QRS complexes is achieved with RVOT pacing.

Leadless pacing: Going for the jugular

Background

Leadless pacing is generally performed from a femoral approach. However, the femoral route is not always available. Until now, data regarding implantation using a jugular approach other than a single‐case report were lacking.

Methods

The case records of all patients who underwent internal jugular venous (IJV) leadless pacemaker implantation (Micra, Medtronic, Dublin, Ireland) at our center were analyzed retrospectively.

Results

Nineteen patients underwent IJV leadless pacemaker implantation, nine females, mean age of 77.5 ±9.6  years; permanent atrial fibrillation in all patients with normal left ventricular ejection fraction. Implant indication was atrioventricular conduction disturbance in 10, pre‐AV node ablation in seven, and replacement of a conventional VVI pacemaker in two (infection in one and lead malfunction in the other). The device was positioned at the superior septum in seven patients, apicoseptal in seven patients, and midseptal in five patients. In 12 patients, a sufficient device position was obtained at the first attempt, in three at the second, in one at the third, in one at the fourth, and in two at the sixth attempt.

The mean pacing threshold was 0.56 ± 0.39V at 0.24‐ms pulse width, sensed amplitude was 9.1 ± 3.2 mV, mean fluoroscopy duration was 3.1 ± 1.6 min. There were no vascular or other complications. At follow‐up, electrical parameters remained stable in 18 of 19 patients.

Conclusion

Although experience is minimal, we suggest that the IJV approach is safe and may be considered in patients where the femoral approach is contraindicated.

Health-related quality of life impact of a transcatheter pacing system

BACKGROUND

Transcatheter pacing systems (TPS) provide a novel, minimally invasive approach in which a miniaturized, leadless pacemaker (PM) is transfemorally implanted in the right ventricle. We evaluated the health-related quality of life (HRQoL) impact, patient satisfaction, and activity restrictions following TPS in a large prospective multicenter clinical trial.

METHODS AND RESULTS

Patients who underwent a Micra TPS implantation between December 2013 and May 2015 were included. HRQoL impact was evaluated using the Short-Form-36 (SF-36) questionnaire at baseline, 3, and 12 months. Patient satisfaction was assessed using a three-item questionnaire determining recovery, activity level, and esthetic appearance at 3 months. Implanting physicians compared the patient activity restrictions for TPS to traditional PM therapy. A total of 720 patients were implanted with a TPS (76 ± 11 years; 59% male). Of these patients, 702 (98%), 681 (95%), and 635 (88%) completed the SF-36 at baseline, 3 and 12 months, respectively. Improvements were observed at 3 and 12 months in all SF-36 domains and all attained statistical significance. Of 693 patients who completed the patient satisfaction questionnaire, 96%, 91%, 74% were (very) satisfied with their esthetic appearance, recovery, and level of activity, respectively. TPS discharge instructions were rated less restrictive in 49%, equally restrictive in 47%, and more restrictive in 4% of cases compared with traditional PM systems.

CONCLUSIONS

TPS resulted in postimplant HRQoL improvements at 3 and 12 months, and high levels of patient satisfaction at 3 months. Further, TPS was associated with less activity restrictions compared with traditional PM systems.

Leadless Cardiac Pacemakers: The Next Evolution in Pacemaker Technology

Implantable pacemakers stand as a mainstay in our therapeutic arsenal, affording those suffering from advanced cardiac conduction system disease both an improved quality of life and reduced mortality. Annually, over 225,000 new pacemakers are implanted in the United States for bradyarrhythmias and heart block. The first implantable transvenous pacemakers appeared in 1965; they were bulky devices, hobbled by a short battery life, and a single pacing mode. Modern transvenous pacemakers have evolved considerably with significant improvements in battery life, pacing options, and lead technology but are still subject to a spectrum of complications stemming from either the subcutaneous pocket or the leads, including: hematoma, infection, wound dehiscence, pneumothorax, cardiac tamponade, lead dislodgment, upper extremity deep vein thrombosis, lead failure, venous obstruction, tricuspid valve insufficiency, and endocarditis. Single-chamber right ventricular (RV) leadless cardiac pacemakers, a concept from the past, has been revitalized to address these complications. Improvements in battery life, device miniaturization, catheter-based delivery tools, and advanced programming have made leadless cardiac pacemakers a viable option. In this review, we will discuss single-component leadless cardiac pacemaker technology, provide an overview of the two approved devices, and discuss their benefits as well as their limitations. [Full article available at http://rimed.org/rimedicaljournal-2017-11.asp].

Advances and Future Directions in Cardiac Pacemakers: Part 2 of a 2-Part Series

In the second part of this 2-part series on pacemakers, we present recent advances in pacemakers and preview future developments. Cardiac resynchronization therapy (CRT) is a potent treatment for heart failure in the setting of ventricular dyssynchrony. Successful CRT using coronary venous pacing depends on appropriate patient selection, lead implantation, and device programming. Despite optimization of these factors, nonresponse to CRT may occur in one-third of patients, which has led to a search for alternative techniques such as multisite pacing, His bundle pacing, and endocardial left ventricular pacing. A paradigm shift in pacemaker technology has been the development of leadless pacemaker devices, and on the horizon is the development of batteryless devices. Remote monitoring has ushered in an era of greater safety and the ability to respond to device malfunction in a timely fashion, improving outcomes.

Subcutaneous Double "Purse String Suture"-A Safe Method for Femoral Vein Access Site Closure after Leadless Pacemaker Implantation

BACKGROUND

Leadless cardiac pacemaker (LCP) requires large-caliber venous sheaths for device placement. Sheath sizes for these procedures vary from 18- to 23-French (F). The most common complications are hematomas, pseudoaneurysms, and arteriovenous fistulas. Complete and secure closure of the venous access is an important step at the end of such a procedure.

METHODS

We performed a retrospective analysis of all patients who had undergone LCP implantation at our institution. Patients and procedural characteristics as well as groin complications at 30 days and 3 months were evaluated. After sheath removal venous access sites were closed performing a so-called "purse-string" suture (PSS).

RESULTS

Seventy-seven patients received an LCP at our institution. In 27 (35%) of these patients a heparin bolus was given at the beginning of the procedure. Anticoagulation therapy with phenprocoumon was present in 32 (40%) of patients. In 76 (98.7%) patients, the LCP was implanted without complications. In one (1.3%) patient a perforation occurred during implantation, which required surgical intervention. Access site complications occurred in three (3.9%) patients, two (2.6%) groin hematomas, and one (1.3%) arteriovenous fistula. The hematomas disappeared completely after 3 weeks, and the fistula was not detectable by ultrasound anymore after 4 weeks.

CONCLUSION

Use of subcutaneous absorbable double PSS closure after removal of large-caliber venous sheaths is a safe technique to achieve immediate postprocedural hemostasis. Especially for sheath sizes with an inner diameter of 23F, this technique creates a very secure and also cosmetically appealing closure.

Chronic performance of a leadless cardiac pacemaker: 1-year follow-up of the LEADLESS trial

BACKGROUND

A leadless cardiac pacemaker (LCP) system was recently introduced to overcome lead-related complications of conventional pacing systems. To date, long-term results of an LCP system are unknown.

OBJECTIVES

The aim of this study was to assess the complication incidence, electrical performance, and rate response characteristics within the first year of follow-up of patients implanted with an LCP.

METHODS

We retrospectively assessed intermediate-term follow-up data for 31 of 33 patients from the LEADLESS trial cohort who had an indication for single-chamber pacing and received an LCP between December 2012 and April 2013.

RESULTS

The mean age of the cohort was 76 ± 8 years, and 65% were male. Between 3 and 12 months of follow-up, there were no pacemaker-related adverse events reported. The pacing performance results at 6- and 12-month follow-up were, respectively, as follows: mean pacing threshold (at a 0.4-ms pulse width), 0.40 ± 0.26 V and 0.43 ± 0.30 V; R-wave amplitude 10.6 ± 2.6 mV and 10.3 ± 2.2 mV; and impedance 625 ± 205 Ω and 627 ± 209 Ω. At the 12-month follow-up in 61% of the patients (n = 19 of 31), the rate response sensor was activated, and an adequate rate response was observed in all patients.

CONCLUSIONS

The LCP demonstrates very stable performance and reassuring safety results during intermediate-term follow-up. These results support the use of the LCP as a promising alternative to conventional pacemaker systems. Continued evaluation is warranted to further characterize this system. (Evaluation of a New Cardiac Pacemaker; NCT01700244).