Leadless Pacing System Research Articles

Never too old for something new: feasibility and long-term outcomes of leadless pacemaker implant in the elderly

Abstract Funding Acknowledgements Type of funding sources: None. Elderly patients may be at great risk of complications and present a higher incidence of comorbidities which make challenging PM implant procedure. The use of leadless pacing systems has imposed itself to overcome peri- and post-procedural complications related to the presence of transvenous leads and the post-operative recovery, being a favorable option in elderly patients. The study aimed to investigate feasibility and long-term outcomes of M-TPS implant in a specific patient population, like the elderly, which represent a challenge for conventional cardiac pacing. Methods Between May 2014 and November 2021, 155 patients (120 males, mean age 78±9 y) underwent M-TPS implantation in our Center, targeting a non-apical site of delivery when feasible. A subgroup of 69 patients (52 males, 75.36%) were older than 80 years. All patients fulfilled standard criteria for PM implantation with specific indication to receive VVI pacing. Study population was divided into two groups according to age (group 1 < 79 years vs group 2≥80 years). The outcome evaluation included electrical performance (capture threshold, pacing impedance, R wave amplitude) before hospital discharge and then followed at 1, 6, and 12 months and then annually. Major complications were defined as life-threatening events, required surgical intervention or any event causing significant hemodynamic instability or resulting in death. Results In 69/155 cases (52 males, 75.36%) M-TPS was implanted in patients older than 80 years. There were no statistically significant differences between groups for demographics characteristics, except for age. The implant procedure was successful in all cases and no device-related events were registered during follow-up. In particular, no device infection and/or malfunction were reported. Patients were followed-up for an average of 24 months (median 18 months). No differences were observed between groups in procedure duration, single device delivery (group 1 vs group 2: 62.79% vs 65.22%, p=0.75), fluoroscopy time (group 1 vs group 2: 11.46 ±6.12 vs 11.37 ± 8.37 minutes, p=0.23), electrical performance at implant (group 1 vs group 2: pacing threshold 0.56 ± 0.37 V/0.24 ms vs 0.58 ± 0.31 V/0.24 ms, p=0.55; impedance 737.86 ± 173.50 Ohm vs 759.56 ± 255.35 Ohm, p=0.87; R wave amplitude 10.5 ± 5.18 mV vs 9.19 ± 4.45 mV, p=0.14) and at 18 [VB2] month F-U (group 1 vs group 2: pacing threshold 0.64 ± 0.55 V/0.24 ms vs 0.51 ± 0.1 V/0.24 ms, p=0.85; impedance 535.34 ± 102.53 Ohm vs 577.34 ± 69 Ohm, p=0.40; R wave amplitude 12.56 ± 4.56 mV vs 12.00 ± 5.8 mV, p=0.77[VB3] ). Conclusions The demand for cardiac pacing is strongly related to ageing, driving the clinical practice to look for the best solution for a considered fragile patient population. MTP-S implant is an effective and safe procedure in elderly patients, with similar electrical performance and outcome compared with younger patients at long-term follow.

Feasibility and long-term outcomes of leadless pacemaker implant after transvenous lead extraction

Abstract Funding Acknowledgements Type of funding sources: None. Background Infections and malfunction are major indications to transvenous lead extraction. Managing extracted patients represents a clinical and interventional challenge, since this population may be at higher risk for mechanical, vascular or infective complications. The use of leadless pacing systems has been described as a potentially useful technology that could tackle the obstacles that affect this peculiar population. The study aimed to investigate feasibility and long-term outcomes of M-TPS implant in a specific patient population, like post transvenous lead extraction patients, which represent a challenge for conventional cardiac pacing. Methods Between May 2014 and November 2021, 155 patients (120 males, 77.42%, mean age 78 ± 9 y) underwent M-TPS implantation in our Center, targeting a non-apical site of delivery when feasible. A subgroup of 48 patients (39 males, 81.25%) had undergone transvenous lead extraction. All patients fulfilled standard criteria for pacemaker implantation with specific indication to receive VVI pacing. The outcome evaluation included electrical performance (capture threshold, pacing impedance, R wave amplitude) before hospital discharge and then followed at 1, 6, and 12 months and then annually. Major complications were defined as life-threatening events, required surgical intervention or any event causing significant hemodynamic instability or resulting in death. High pacing threshold (HPT) was defined as 1.0 V/0.24 ms. Results In 48/155 cases (39 males, 81,25%) M-TPS was implanted after successful transvenous lead extraction. There were no statistically significant differences between groups for demographics characteristics, and PM implant indications. The implant procedure was successful in all cases and no device-related events were registered during follow-up. In particular, no device infection and/or malfunction were reported. Patients were followed-up for an average of 24 months (median 18 months). No differences were observed between groups in procedure duration, single device delivery (group 1 vs group 2: 63.21% vs 73.91%, p=0.20), fluoroscopy time (group 1 vs group 2: 11.79 ± 7.53 vs 10.49 ± 6.19 minutes, p=0.64), electrical performance at implant (group 1 vs group 2: pacing threshold 0.54 ± 0.35 V/0.24 ms vs 0.62 ± 0.32 V/0.24 ms, p=0.09; impedance 758.02 ± 227.89 Ohm vs 724.26 ± 178.14 Ohm, p=0.36; R wave amplitude 10.1 ± 4.73 mV vs 9.59 ± 5.30 mV, p=0.50) and at 18 month F-U (group 1 vs group 2: pacing threshold 0.50 ± 0.10 V/0.24 ms vs 0.85 ± 0.9 V/0.24 ms, p=0.45; impedance 559.58 ± 94.43 Ohm vs 543.34 ± 64.39 Ohm, p=0.69; R wave amplitude 12.00 ± 5.06 mV vs 13.42 ± 5.77 mV, p=0.55). Conclusions Leadless pacemaker implant is a feasible, safe and effective option for patients treated with transvenous lead extraction, with electrical performance and outcomes comparable to a cohort of naïve patients at long-term follow up.

Six year follow-up data on a leadless pacing system real life experience in comparison to data of the prospective trial

Abstract Funding Acknowledgements Type of funding sources: None. Introduction The Micra™ leadless intracardiac pacing system has been introduced and implemented into clinical routine in 2015, with its next generation MICRA AV ™ in 2020. Feasibility, implantation safety, and acute success have been proven in the setting of controlled studies. Even apart from controlled studies, this new technology was beneficial for the individual patient. We aimed to report our single center follow-up (FU) data with a follow-up of up to six years. Methods In 246 patients (134 men; age: 79±8 y), Micra™ implantation was performed. Pacemaker interrogation was performed one to seven days after implantation and during FU (1; 3; 6, then every 6 month) up to 72 months. Data were assessed in a real-life setting and compared with existing data of a controlled prospective trial. Results The implantation was successful in all 246 attempts with only one pericardial effusion as major complication. During follow up there were two patients developing severe heart failure symptoms resulting in an implantation of a CRT-device and switching of the leadless pacemaker system. The average acute thresholds, sensing and impedance after system release were: 0.62±0.45V@0.24ms; 10,55±3,61mV and 697±178Ohm. During follow up of up to 5 years neither, pacemaker failure, nor infections were reported. Measurements were reevaluated for long-term thresholds, sensing and impedance: 0.44 ± 0.07V @ 0.24 ms; 17,25 ±4,65 mV and 572 ± 80 Ohm. During five years, no significant changes from acute to long-term measurements were detectable. In comparison to the controlled trial, our measurements of this real-life cohort were very similar. Conclusion In a real-life setting, the implantation of the leadless Micra™ system demonstrates a high rate of implantation success without major complications. We were also able to show stable long-term system parameters in the clinical setting of up to six years of follow up with a very good battery longevity of about 12 years.

PO-687-06 A CASE OF DIFFICULT LEADLESS PACEMAKER IMPLANTATION DUE TO PACEMAKER DELIVERY SYSTEM FAILURE

The Micra leadless pacing system (Medtronic) is an effective alternative to transvenous pacemaker in selected patients and can be safely implanted in > 99% cases. The tether in the delivery system serves as an important connection between the device and the delivery catheter, allowing multiple recaptures to be performed. Failure of the delivery system resulting in inability to deploy is extremely rare. We describe a case of difficult Micra implantation due to leadless pacemaker delivery system failure. N/A An 88-year-old male with complete heart block post transfemoral aortic valve replacement underwent placement of single chamber leadless pacemaker placement (Micra) using standard techniques. Under local anesthesia, access was obtained in the right femoral vein using ultrasound guidance and a 23 French long sheath was inserted and advanced into the right atrium under fluoroscopy. A Micra leadless pacing system was introduced and placed under fluoroscopic visualization into the right ventricular septum. Gentle manual tension on the tether demonstrated good contact with the myocardium. The tether was cut but significant resistance was felt when attempting to remove it. Despite multiple attempts the tether could not be safely removed, and it was decided to extract the Micra system. Unfortunately, despite multiple attempts by applying significant tension on the tether, the delivery catheter would not align with the pacing capsule for safe extraction. At this time it was decided to remove the delivery system leaving the pacing capsule with the tether in place. A 0 Vicryl suture was placed and using a double knot it was secured on a 035 wire and the suture was pulled through a large curve steerable Agilis sheath. Next, the Vicryl and the tether were knotted together and Agilis sheath was advanced to provide additional support and avoid trauma to any internal structure during extraction. Using Agilis as a rail, the Micra was extracted. Gross visual inspection revealed no clear knot on the tether. After the extraction, a new Micra system was placed using standard techniques. It is important to be aware of failure of the components of the leadless pacemaker delivery system and the techniques to safely extract it.

UK Expert Consensus Statement for the Optimal Use and Clinical Utility of Leadless Pacing Systems on Behalf of the British Heart Rhythm Society.

Pacemakers are a key technology in the treatment of bradyarrhythmias. Leadless pacemakers (LP) were introduced to address limitations of transvenous devices. However, guidelines and other restrictions have led to LPs becoming niche products. The aim of this consensus statement was to determine the strength of opinion of UK implantation experts as to how LPs can be more optimally used. Using a modified Delphi approach, a panel of LP experts developed 36 statements that were used to form a survey that was distributed to LP implanters in the UK. Stopping criteria included a 3-month window for response, a minimum 25% response rate and at least 75% of statements achieving the threshold for consensus (agreed at 66%). In all, 31 of 36 statements reached consensus, and 23 of these achieved ≥90% agreement. Five statements did not achieve consensus. On the basis of these results, seven recommendations were proposed. The implementation of these recommendations may increase the use of LPs, with the aim of improving patient outcomes.

Leadless Pacemaker Implantation in a Patient With Diminutive Subclavian Veins.

Conventional pacemakers have a longstanding history of preventing morbidity and mortality in patients with bradyarrhythmia and conduction disorders. While decades of advancements have improved pacemaker technology and implantation technique, insertion of transvenous leads and formation of a pectoral pocket can lead to complications, including pocket hematoma, pneumothorax, or infection. Leadless pacemakers were introduced in 2012 to address these complications; however, early leadless systems only provided single-chamber ventricular pacing. In 2020, an accelerometer-based atrial sensing feature was developed to allow for atrioventricular (AV) synchrony with these devices. Early evidence suggests that patients with sinus rhythm and AV block can benefit from single-chamber leadless pacing systems with an AV synchrony algorithm. As availability of these devices continues to broaden, identification of appropriate recipients has become increasingly relevant.

Ventricular Fibrillation Cardiopulmonary Arrest Following Micra™ Leadless Pacemaker Implantation

Leadless cardiac pacemakers such as the Micra™ transcatheter leadless pacing system (Medtronic, Minneapolis, MN, USA) are an alternative to traditional transvenous pacemakers. Implantation of leadless pacemakers, albeit safe, may be associated with complications, including cardiac tamponade; high capture thresholds; and, rarely, ventricular arrhythmias. We report a case of ventricular fibrillation arrest following the implantation of a Micra™ leadless pacemaker.

New developments in leadless pacing systems

Leadless pacing systems, especially the Micra™TPS system, deliver an effective and safe alternative to the previous conventional transvenous systems in patients with impossible transvenous access and seem to be compatible with other implantable devices (S-ICD, deep brain stimulators) with no limitations in efficacy or safety. Also, new outlooks on leadless resynchronization therapy seem promising and could prevent future patients from lead- or operation-associated complications. Current limits to the implementation in everyday clinical practice are mostly the unavailability of the devices or cost issues through lack of health insurance reimbursement. However, more promising data through further studies and rising implantation rates are expected based on the positive current clinical data.

Leadless pacemaker implant in the elderly: a safe and feasible solution

Abstract The use of leadless pacing systems could overcome peri-and post-procedural complications related to the presence of transvenous leads and the post-operative recovery, being a favorable option in elderly patients. The study aimed to investigate feasibility and outcomes of M-TPS implant in a specific patient population, like the elderly, which represent a challenge for conventional cardiac pacing. Methods Between May 2014 and March 2021, 138 patients (106 males, 77%, mean age 78) underwent M-TPS implantation in our Centre, targeting a non-apical site of delivery when feasible. A subgroup of 59 patients (43 males, 73%) were older than 80 years. All patients fulfilled standard criteria for pacemaker implantation with specific indication to receive VVI pacing. Study population was divided into two groups according to age (group 1 <80 years vs group 2 ≥80 years). The outcome evaluation included electrical performance (capture threshold, pacing impedance, R wave amplitude) before hospital discharge and then followed at 1, 6, and 12 months and then annually. Major complications were defined as life-threatening events, requiring surgical intervention or any event causing significant hemodynamic instability or resulting in death. High pacing threshold (HPT) was defined as >1.0 V@ 0.24 ms. Results In 59/138 cases (43 males, 73%) M-TPS was implanted in patients older than 80 years. There were no statistically significant differences between groups for demographics characteristics, except for age, and PM implant indications. The implant procedure was successful in all cases and no device-related events were registered during follow-up. In particular, no device infection and/or malfunction were reported. Patients were followed-up for an average of 22,19±20,66 months (median 18 months). No differences were observed between groups in procedure duration (44,97±20,24 min vs 45,80±23,27 min; P=0,83), single device delivery (group 1 vs group 2: 63,16% vs 66,07%; P=0,73), fluoroscopy time (11,64±6,22 min vs 12,13±8,67 min; P=0,72) electrical performance at implant [group 1 vs group 2: pacing threshold 0,56±0,37 vs 0,58±0,32, P=0,78; impedance 727,53±170,36 vs 752,88±256,21, P=0,49; R wave amplitude 10,39±4,86 vs 9,26±4,66, P=0,18] and at median follow-up [group 1 vs group 2: pacing threshold 0,63±0,55 vs 0,51±0,1, P=0,40; impedance 535,34±102,53 vs 577,34±69,02, P=0,20; R wave amplitude 12,56±4,56 vs 12,00±5,80, P=0,77] Conclusions The demand for cardiac pacing is strongly related to ageing, driving the clinical practice to look for the best solution for a considered fragile population. MTP-S implant is an effective and safe procedure in elderly patients, with similar electrical performance and outcome compared with younger patients at mid-term follow-up. Funding Acknowledgement Type of funding sources: None.

Leadless pacing – next generation

In December 2013 leadless pacing system was implanted in humans for the first time. Both in IDE and PAR re­gistries high effectiveness and safety were confirmed. In the mentioned registries risk of severe complication was reduced by 48 and 63% respectively. The reduced risk was mainly shown in a decreased percentage of hospitali­zations and system revisions. MICRA VR system has activity detectors placed in three planes, which allows to detect onset and end of ventricular contraction as well as early, and atrial contraction related ventricular filling. This property allowed to design an algorithm to detect mechanical atrial contraction. This algorithm caused an increase in atrioventricular synchrony to 80,0 and 94,4% in patients with advanced AV block and preserved conduction, respectively. In patients with advanced AV block percentage of those who reached more than 70% of atrioventricular synchrony was 95%. Parameters which increase the likelihood of high percentage of AV synchrony are standard deviation of consecutive P-P intervals < 5/min. and lower E/A in echocardiography. Practical implementation of a new algorithm required redesigning of a circuit to reduce power consumption. New system MICRA AV was developed, which volume, mass and longevity are comparable with MICRA VR.

Selección de lo mejor del año 2020 en estimulación cardiaca

This manuscript summarizes the most relevant scientific evidence published during the last year regarding cardiac pacing. Two particular topics are considered of utmost interest: leadless pacing and conduction system pacing. The most recent evidence about safety and efficacy of leadless pacing will be reviewed with a special focus in the possibility of maintenance of AV synchrony using the accelerometer of this single chamber pacemaker. With respect to conduction system pacing, the principal novelties in terms of the potential role of His bundle pacing and left bundle branch pacing as alternatives for conventional cardiac resynchronization therapy will be discussed as well as the recent description of critical anatomical and radiological information about the His bundle area which can help during the implant.

Implantation of leadless pacing systems in patients early after tricuspid valve surgery: A feasible option.

After tricuspid valve (TV) surgery due to tricuspid regurgitation (TR), patients needing a permanent pacemaker often receive an epicardial lead implantation. This may result in delayed recovery from open-chest surgery and increased postoperative risk. Leadless pacemaker (LPM) implantation may represent a valuable option. A total of 14 consecutive patients underwent LPM implantation (Micra Transcatheter Pacing System, Medtronic, Minneapolis, MN) early after TV surgery. The pacing indication in those patients was atrial fibrillation with a slow atrio-ventricular (AV) conduction or atrial fibrillation and a concomitant AV block III. Three patients already had a pacemaker prior to surgery, which was explanted during TV repair. Three patients received a valve replacement with a bioprosthesis, while the remaining eight patients received a TV repair. All procedural data and device measurements during and after LPM implantation were recorded. Transthoracic echocardiography was performed prior and post LPM implantation, showing no changes in TV or bioprosthesis performance. The device measurements were within an adequate range: threshold: 0.83±0.34 V @ 0.24±0ms, impedance: 480 ± 58.88ohm, and R-wave: 10.10±3.60mV. LPM implantation was successful in all patients with a mean procedural time of 32±11.8minutes, fluoroscopy time of 3.71±3.15minutes, and dose-area product of 536.67±811.26 cGy/m2 . Implantation of an LPM early after TV surgery is a feasible option. LPM implantation does not affect TV or bioprosthesis performance in transthoracic echocardiography.

Leadless pacemaker for patients following cardiac valve intervention

Permanent pacing is common after valve intervention. The presence of a conventional pacemaker in this population is recognized as a risk factor for infectious events. Therefore, a leadless pacing system could be the preferred strategy when permanent pacing is required after valve intervention. To report periprocedural outcomes and follow-up of patients undergoing implantation of a leadless pacing system after valve intervention. Patients with previous valve intervention at the time of attempted implantation of a leadless pacemaker (Micra™, Medtronic, Minneapolis, MN, USA) were included, and were compared with a control group (patients also implanted with Micra™ without valve intervention). Among a total of 170 Micra™ implantation procedures, 54 patients (31.8%) had a history of valve intervention: 28 after aortic valve replacement; 10 after mitral valve replacement; one after single tricuspid valvuloplasty; and 15 after multiple valve surgery. Median age of the patients was 82.5 (77.0-86.0) years and 53.7% were male. Patients with previous valve intervention had a higher incidence of arterial hypertension (P=0.014) and ischaemic heart disease (P=0.040). The primary indications for permanent pacing after valve intervention were high-degree atrioventricular block (59.3%) and atrial fibrillation with bradycardia (27.8%). Micra™ was successfully implanted in all patients (n=170) without any procedure-related major complications. During a median follow-up of 12 months, electrical performance was excellent and similar in both groups. Also, a similar reduction in left ventricular ejection fraction was observed at 12 months in both groups, which was correlated with the percentage of right ventricular pacing. A leadless pacemaker is safe and efficient after valve intervention, and therefore represents an effective pacing option in patients after valve intervention.

Tracking the motion of intracardiac structures aids the development of future leadless pacing systems.

Leadless pacemakers preclude the need for permanent leads to pace endocardium. However, it is yet to be determined whether a leadless pacemaker of a similar design to those manufactured for the right ventricle (RV) fits within the left ventricle (LV), without interfering with intracardiac structures. Cardiac computed tomography scans were obtained from 30 patients indicated for cardiac resynchronisation therapy upgrade. The mitral valve annulus, chordae tendineae, papillary musclesand LV endocardial wall were marked in the end-diastolic frame. Intracardiac structures motions were tracked through the cardiac cycle. Two pacemaker designs similar to commercially manufactured leadless systems (Abbott's Nanostim LCP and Medtronic's Micra TPS) as well as theoretical designs with calculated optimal dimensions were evaluated. Pacemakers were virtually placed across the LV endocardial surface and collisions between them and intracardiac structures were detected throughout the cycle. Probability maps of LV intracardiac structures collisions on a 16-segment AHA model indicated possible placement for the Nanostim LCP, Micra TPS, and theoretical designs. Thresholding these maps at a 20% chance of collision revealed only about 36% of the endocardial surface remained collision-free with the deployment of Micra TPS design. The same threshold left no collision-free surface in the case of the Nanostim LCP. To reach at least half of the LV endocardium, the volume of Micra TPS, which is the smaller design, needed to be decreased by 41%. Due to the presence of intracardiac structures, placement of leadless pacemakers with dimensions similar to commercially manufactured RV systems would be limited to apical regions.

P1468Four years follow-up of leadless pacing system single center real life experience compared to data of the prospective trial

Abstract Funding Acknowledgements none OnBehalf Cologne Registry Introduction The Micra™ leadless intracardiac pacing system has been introduced and implemented into clinical routine more than three years ago. Feasibility, implantation safety and acute success have been proven in the setting of controlled studies. Additionally few real- life and post-implantation data exist. We aimed to report our single center follow-up (FU) data in comparison with the results of the prospective controlled Micra™- studie. Methods In 112 patients (69 men; age: 79 ± 10 y) successful Micra™ implantation was performed.Pacemaker interrogation was performed one to seven days after implantation and during FU (1; 3; 6, than every 6 month) up to 48 month. Data were assessed in a real-life setting and compared with existing data of the controlled prospectiv trial. Results The implantation was successful in all 112 attempts without procedure or device-related major complications. During Follow up there was one patient developing severe heart failure symptoms resulting in an implantation of a CRT-device and switching of the leadless pacemaker system. The average acute thresholds, sensing and impedance after system release were: 0.63 ± 0.42V@0.24ms; 9,94 ± 3,61mV and 705 ± 166 Ohm. During follow up of up to 4 years neither, pacemaker failure, nor infections were reported. Measurements were reevaluated for long-term thresholds, sensing and impedance: 0.54 ± 0.16V @ 0.24 ms; 16,15 ±4,22 mV and 579 ± 133 Ohm. In the first three years no significant changes from acute to long-term measurements were detectable. In comparison to the data of the controlled trial the measurements of our real-life cohort was very similar. Conclusion In a real life setting the implantation of the leadless Micra™ system demonstrates high rate of implant success without major complications. Also shown were stable long-term system parameters in the clinical setting of up to two years of follow up. These data of every day clinical practice support the findings of the prospectiv trials.

Leadless cardiac pacing in resource limited settings: A Groote Schuur hospital experience with the Micra leadless pacemaker

Background: Cardiac pacemakers improve survival and quality of life in patients with atrioventricular (AV) block. However, conventional pacemakers carry a small risk of both acute and chronic lead and pacemaker generator complications. Leadless pacemakers negate these risks by not having a pacing lead and a subcutaneous generator. We report our Groote Schuur Hospital experience with the Medtronic Micra transcatheter pacing system (TPS). Methods: We report a consecutive case series of patients that received the Micra leadless pacemaker. The Micra transcatheter pacemaker, a single chamber ventricular pacemaker, is inserted using a TPS via the femoral vein into the right ventricle. Implantation data were obtained, and medical records were reviewed for the 6 weeks and 1-year follow-up visits. Results: A total of 5 patients were implanted with a Micra leadless pacemaker from 11 March 2015 - 2 November 2016. Four patients were male and 1 female, with an average age of 64 years. Four patients received the pacemaker for a second- or third-degree AV block and 1 patient received the pacemaker for unexplained syncope and right bundle branch block. The Micra leadless pacemaker was successfully implanted in all patients with no acute implantationrelated complications. One-year follow-up was available for 4 patients with good pacing thresholds, sensitivity and impedance. One patient demised after 9 months post Micra implantation due to unrelated causes (acute myeloid leukaemia). Conclusion: The Micra leadless pacing system is safe and effective and shows good short-term results in a real-world, resource-limited setting. This form of pacing offers a viable option for patients who require pacing for AV block, especially in patients with vascular access problems or who are at high risk of lead or pacemaker generator complications.

First transcatheter leadless pacemaker implantation in apediatric patient with agenetic disease.

Apediatric patient suffering from Marden-Walker syndrome, arare genetic disease, was referred to the authors' hospital for syncope due to bradycardia. Since this disease is associated with severe joint contractures, atranscatheter leadless pacing system (TPS) was chosen. Despite the small body size and complex anatomy, TPS implantation was feasible, demonstrating that it is asafe alternative in difficult venous access compared to aconventional pacemaker with increased risk of lead complications in these patients.

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.

Rendimiento del marcapasos cardiaco Micra en nonagenarios

Introduction and objectivesThe Micra transcatheter pacing system has shown high effectiveness and a lower complication rate than conventional transvenous pacemakers. However, the benefit of the device is unknown in the very old population (≥ 90 years). The aim of this study was to evaluate the safety and effectiveness of Micra in patients ≥ 90 years. MethodsWe present a prospective observational study with consecutive patients aged >70 years who underwent implantation of a Micra pacemaker system. Patients were divided into 2 groups: ≥ 90 and<90 years. ResultsThe Micra system was implanted in 129 patients, of whom 41 were aged ≥ 90 years and 88<90 years. The device was successfully implanted in 40 (97.6%) patients ≥ 90 years and in 87 (98.9%) patients<90 years (P=.58). An adequate position was achieved with need for ≤ 2 repositions in 97.5% and 91.9% of patients, respectively (P=.32). Procedure time (26.1 ±11.6 vs 30.3 ±14.2minutes; P=.11) and fluoroscopy time (6.4 ±4.7 vs 7.2 ±4.9minutes; P=0.41) were similar in the 2 groups. There were 3 major complications (2.3%), all in the group aged<90 years: 1 cardiac perforation, 1 femoral hematoma, and 1 femoral pseudoaneurysm. Thirteen patients aged ≥ 90 years (31.7%) and 16 patients aged <90 years (18.2%) died during a mean follow-up of 230±233 days and 394±285 days, respectively. There were no device-related deaths. No infection, dislocation or migration of Micra were observed. The electrical performance was optimal at follow-up. ConclusionsThe Micra leadless pacing system seems to be safe and effective in patients older than 90 years. It may be considered a reasonable alternative to conventional transvenous pacing in this population.Full English text available from: www.revespcardiol.org/en

Performance of the Micra cardiac pacemaker in nonagenarians

The Micra transcatheter pacing system has shown high effectiveness and a lower complication rate than conventional transvenous pacemakers. However, the benefit of the device is unknown in the very old population (≥ 90 years). The aim of this study was to evaluate the safety and effectiveness of Micra in patients ≥ 90 years. We present a prospective observational study with consecutive patients aged >70 years who underwent implantation of a Micra pacemaker system. Patients were divided into 2 groups: ≥ 90 and<90 years. The Micra system was implanted in 129 patients, of whom 41 were aged ≥ 90 years and 88<90 years. The device was successfully implanted in 40 (97.6%) patients ≥ 90 years and in 87 (98.9%) patients<90 years (P=.58). An adequate position was achieved with need for ≤ 2 repositions in 97.5% and 91.9% of patients, respectively (P=.32). Procedure time (26.1 ±11.6 vs 30.3 ±14.2minutes; P=.11) and fluoroscopy time (6.4 ±4.7 vs 7.2 ±4.9minutes; P=0.41) were similar in the 2 groups. There were 3 major complications (2.3%), all in the group aged<90 years: 1 cardiac perforation, 1 femoral hematoma, and 1 femoral pseudoaneurysm. Thirteen patients aged ≥ 90 years (31.7%) and 16 patients aged <90 years (18.2%) died during a mean follow-up of 230±233 days and 394±285 days, respectively. There were no device-related deaths. No infection, dislocation or migration of Micra were observed. The electrical performance was optimal at follow-up. The Micra leadless pacing system seems to be safe and effective in patients older than 90 years. It may be considered a reasonable alternative to conventional transvenous pacing in this population.