Leadless Technology Research Articles

Cost-effectiveness of Micra™ VR leadless pacemaker in patients with bradycardia and atrial fibrillation in Australia.

Micra™ VR Transcatheter Pacing System (Micra VR) is a single-chamber transcatheter leadless pacemaker. Absence of leads and subcutaneous pocket reduces or completely eliminates the risk of complications associated with the conventional transvenous pacemakers (TVPM). When compared with TVPM, the leadless technology provides a quicker postimplantation recovery and causes less cosmetic concerns/discomfort providing better patient experiences in the long run. We performed a modeled cost-utility analysis of Micra VR versus TVPM for the management of patients with bradycardia. We developed a Markov model comparing Micra VR to TVPM over the device battery life of 17 years. Key data inputs were drawn from the MICRA Coverage with Evidence Development (CED) study. Costs were obtained from Australian sources. The analysis is from the perspective of the Australian healthcare system. The risks of complications, including device-related events, in real-world clinical practice were relatively low for TVPM. The magnitude of cost savings arising from risk reductions provided by Micra VR was however sizable, offsetting roughly a quarter of its additional device cost. Over the 17-year model period, Micra VR was associated with an estimated incremental cost of A$4277 and an incremental quality-adjusted life years (QALYs) of 0.09 when compared with TVPM, yielding an incremental cost-effectiveness ratio of A$47 379 per QALY gain. Micra VR is likely to offer a cost-effective alternative to the conventional TVPM technology for the management of patients with bradycardia.

Emerging Technologies for the Smallest Patients.

Pediatric and congenital heart disease patients may require cardiac implantable electronic device implantation, inclusive of pacemaker, ICD, and implantable cardiac monitor, for a variety of etiologies. While leads, generators, and monitors have decreased in size over the years, they remain less ideal for the smallest patients. The potential for a miniature pacemaker, fetal micropacemaker, improving leadless technology, and rechargeable devices creates hope that the development of pediatric-focused devices will increase. Further, alternative approaches that avoid the need for a transvenous or surgical approach may add more options to the toolbox for the pediatric and congenital electrophysiologist.

Implantation of a leadless pacemaker as a promising solution for patients with arythmia – current state of knowledge

Introduction: In cardiac electrotherapy, new solutions are constantly sought to minimise the invasiveness of methods used so far and reduce the risk of complications. Implantation of traditional cardiac pacemakers carries risks of high probability that may cause both early and late adverse effects which are associated with presence of subcutaneous lodge and intravenous wires. A significant reduction in complications may be achieved by using leadless pacemakers the main representative of which is MicraTM (MicraTM transcatheter pacing system: TPS, Medtronic plc, Mounds View, MN, USA). Micra is 90% smaller than conventional pacemaker. The generator and electrode system is contained in one capsule-like device that is implanted directly into the right ventricle of the heart. The transcatheter pacing system is less invasive because it is placed in the heart with the use of a catheter via a femoral vein. thus no chest incision and scar. Purpose of the work: The aim is to present the subject of leadless cardiac pacing with the use of Micra device based on a review of current scientific publications. Methods and materials: The available medical literature related to cardiac pacing was analysed taking leadless technology into account. The analysed material was obtained from PubMed and Google Scholar. Conclusion: Cardiac electrotherapy with the use of leadless Micra pacemaker is a great example of substantial technological progress. Due to its structure and form, it is a beneficial alternative to a traditional pacemaker. It also offers promising solutions for the future. This is, however, a relatively new method of stimulation requiring further observation and analysis.

The wireless pacemaker is on again; from electro-stimulation to synchronization.

Leadless stimulation of the right ventricle is now a reality, especially in patients with very specific indications and clinical characteristics, even in the absence of randomized studies to support its use. The reduction of device costs and the refinement of atrioventricular synchronization algorithms will sanction its greater diffusion in the future. The possibility of using leadless technology also for resynchronization therapy, on the other hand, is currently a promising option but, pending randomized studies with robust case histories and adequate follow-ups, it should still be considered as a niche therapy, to be limited to centres highly specialized and in patients in whom conventional resynchronization has been impossible or ineffective.

Technological and Clinical Challenges in Lead Placement for Cardiac Rhythm Management Devices.

Cardiac disease is a leading cause of death worldwide. Disturbance in the conduction system of the heart may trigger or aggravate heart dysfunction, affecting the efficiency of the heart, and lead to heart failure or cardiac arrest. Patients may require implantable cardiac rhythm management devices (ICRMDs) to maintain or restore the heart rhythm. ICRMDs have undergone important improvements, yet limitations still exist, presenting important technological challenges. Most ICRMDs consist of a subcutaneous control unit and intracardiac electrodes. The leads, which connect the electrodes to the control unit, are usually placed transvenously through the subclavian veins. Various locations inside the heart are used for placement of electrodes, depending on the specific condition. Some of the limitations to effective pacemaker therapy are associated with placement and location of the leads. Various approaches have been developed to overcome these challenges, such as multi-site pacing and leadless solutions. This paper aims to review the state of the art for the selection of placement sites for pacemakers, implantable cardioverter defibrillator (ICD) and cardiac resynchronization therapy devices (CRT) devices and discuss potential technological advancements to improve the results of ICRMD-therapy including development av leadless technology.

Leadless technology: a new paradigm for cardiac pacing?

Leadless pacemaker (LP) technology was recently developed and introduced for clinical purpose as an alternative to traditional systems in order to reduce leads and pocket-related complications. Currently, two self-contained right ventricular pacemakers implanted by using a femoral percutaneous approach have been developed and initial results seem promising. Although the clinical use is still limited to the right ventricular pacing, the LP currently represents a valid and alternative solution in several settings, when the standard pacemaker cannot be used or its use is associated with higher risk of complications. Implementation of particular pacing algorithms in the near future will allow for a VDD pacing mode with only a single ventricular component, whereas the next evolution of technology will lead to develop multicomponent, communicating leadless systems capable to perform a dual-chamber pacing or even a cardiac resynchronization. The management after battery depletion is still controversial and experience on retrievability is anecdotic. Long term data from registry are necessary to reinforce the reliability of these systems in the real life and randomized trials comparing LPs with traditional pacemaker will be essential to better understand if the LP can become a new paradigm in cardiac pacing.

Transcatheter leadless cardiac pacing: The new alternative solution

IntroductionA lack of information about the feasibility and safety of leadless pacemaker (LPMs) exists in a fragile population of patients with limited venous anatomy access or conventional pacemaker (PM) contraindication. Accordingly, the goal of this prospective observational study was to report our experience with this new leadless technology in a subset of patients with contraindication or limited venous access. Methods and resultsBetween May 2015 and July 2016, 14 patients were consecutively included. The indications for initial PM implantation were atrioventricular (AV) block in 10/14 patients (71%), bradyarrhythmia in one (7%), and uncontrolled atrial fibrillation (AFib) requiring AV-node ablation in three (21.5%). AFib was observed in 9 of the 14 patients (64.3%) and 3 were completely dependent with no escape rhythm (21.5%). Normal access pathways via the right or left subclavian veins were occluded due to previous PM implantations and revisions in 4 patients (28.6%) and total vena cava occlusion in 3 (21.4%). End-stage renal disease with hemodialysis was present in 8 (57%) with either local-device infections or presence of long-term implanted dialysis catheters. Evidence of previous bilaterally-infected pectoral tissue was present in 3 patients (21.5%). All procedures were successful (100%) and electrical parameters remained stable over time. No direct pacemaker-related adverse events were reported, including mechanical complications, except for one ventricular fibrillation one day post-implantation under very specific conditions. ConclusionThis series demonstrated very stable performance and reassuring safety results during mid-term follow-up in a very fragile population requiring a PM. The Micra LPM constitutes an excellent alternative to the epicardial surgical approach in this very fragile population.

Feasibility, safety, and short-term outcome of leadless ultrasound-based endocardial left ventricular resynchronization in heart failure patients: results of the Wireless Stimulation Endocardially for CRT (WiSE-CRT) study

Left ventricular (LV) endocardial pacing may address the limitations in the selection of an LV pacing site and provide improvements in cardiac resynchronization therapy (CRT) effectiveness. We report on the feasibility, the safety, and the short-term outcome of a leadless ultrasound-based technology for LV endocardial resynchronization in heart failure (HF) patients enroled into the Wireless Stimulation Endocardially for CRT (WiSE-CRT) study. Seventeen HF patients were enroled and categorized as: (i) patients in whom attempted coronary sinus lead implantation for CRT had failed (n = 7); (ii) patients with a previously implanted CRT device, not responding to CRT (n = 2); and (iii) patients with previously implanted pacemakers or implantable cardioverter-defibrillator and meeting the standard indications for CRT (n = 8). System implantation was achieved in 13 patients (76.5%); mean R-wave amplitude was 5.6 ± 3.2 mV and the mean pacing threshold was 1.6 ± 1.0 V, respectively. In one patient, no sufficient pacing thresholds were found; in three patients pericardial effusion occurred. Biventricular pacing was recorded in 83% and 92% of the patients at 1 month and 6 months, respectively. QRS duration was shorter during biventricular pacing compared with right ventricular pacing at 1 month (-41 ms; P = 0.0002) and 6 months (-42 ms; P = 0.0011), respectively. At the 6-month follow-up, two-thirds of the patients had at least one functional class change. Left ventricular ejection fraction significantly increased (P < 0.01) by 6 points at the 6-month follow-up. The feasibility of providing an endocardial stimulation for CRT with a leadless technology was successfully demonstrated. Despite the promising results for a novel technology, further study is required to definitively conclude the safety and the performance of the system. NCT01294527.

Young Investigator Abstract Session

Young Investigator Abstract Session