Real-world experience with leadless cardiac pacing

Comparative safety of transvenous and leadless pacemakers in patients with cardiovascular diseases: A meta-analysis study

Background

Transvenous pacemakers (TVP) and leadless pacemakers (LP) are two reliable permanent modalities for the treatment of heart rhythm disorders. Several observational studies explored the safety and efficacy of the two devices. The aim of this meta-analysis study is to present a comparative analysis of the safety of leadless versus transvenous pacemakers.

Methods

The study protocol was registered in PROSPERO registry (CRD42024520647). A comprehensive and systematic search was conducted across PubMed, Embase, Cochrane Library, Web of Science and ClinicalTrials.gov, spanning from inception until just before the final analysis. SPSS was used for statistical analysis. Relative risks (RR) and odds ratio (OR) were used to evaluate the outcomes with a 95 % confidence interval (CI).

Results

Nineteen studies met the inclusion criteria and were analyzed, in which the overall effect estimate showed increased risk of major complications in the TVP group (LogOR = -0.27, 95 % CI: [-0.63, 0.10]) compared to the LP group. Among the nineteen studies, seven studies showed that TVP significantly increase the risk of reintervention (LogOR = -0.73, 95 % CI: [-1.15, -0.31]) and thirteen studies showed a higher risk of mortality among patients receiving TVP (Cohen's d = -0.11, 95 % CI: [-0.22, 0.01]) compared to those receiving LP. Conversely, a higher risk of pericardial effusion or tamponade and thromboembolic events was among patients receiving LP with (LogOR = 1.01, 95 % CI: [0.55, 1.46]) and (LogOR = 0.45, 95 % CI: [-0.33, 1.23]) respectively.

Conclusion

This study showed that leadless pacemakers tend to be safer compared to transvenous pacemakers, with reduced risks of major complications, reintervention, generator malfunction, device or lead dislodgement, pneumothorax and hemothorax, infections rates, and mortality. However, higher odds of cardiac perforation and tamponade and thromboembolic events were observed among patients receiving LP. The lack of both randomized clinical trials and long term follow up studies limits our assessment and emphasizes the need for ongoing investigation to understand the extended complications associated with these devices amidst advancing technology.

Impact of leadless pacemaker implantation site on cardiac synchronization and tricuspid regurgitation

BACKGROUND

To investigate the optimization of leadless pacemaker placement and to assess its impact on heart synchronization and tricuspid regurgitation.

RESULTS

A clinical trial was conducted involving 53 patients who underwent leadless pacemaker implantation at the Second Affiliated Hospital of Zhejiang University School of Medicine and Hangzhou First People's Hospital between March 2022 and February 2023. Implantation site localization was determined using the 18-segment method under RAO 30° imaging. Intraoperative and 1-month post-operative echocardiography was performed to assess cardiac electromechanical synchronization and tricuspid regurgitation; parameters of interest included interventricular mechanical delay (IVMD), pre-ejection period of the aorta (L-PEI), and septal-to-posterior wall motion delay (SPWMD). Pacing thresholds, sensing, and impedance exhibited no significant differences between the 8/9 zone and other sites (P > 0.05). In contrast, the 8/9 zone group manifested a significant reduction in L-PEI (128.24 ± 12.27 vs. 146.50 ± 18.17 ms, P < 0.001), IVMD (17.92 ± 8.47 vs. 28.56 ± 15.16 ms, P < 0.001), and SPWMD (72.84 ± 19.57 vs. 156.56 ± 81.54 ms, P < 0.001), compared to the non-8/9 group. Post-pacing QRS duration showed no significant difference between the two groups (139.21 ± 11.36 vs. 143.83 ± 16.35 ms P = 0.310). Notably, for patients with atrial fibrillation, the 8/9 zone placement significantly reduced tricuspid regurgitation. During the 1-month follow-up, neither group reported major complications such as bleeding, cardiac tamponade, pacemaker detachment, or malignant arrhythmias.

CONCLUSION

Implantation of the leadless pacemaker in the right ventricular 8/9 zone provides superior electromechanical synchronization compared to other sites.

Comparison of Postoperative Outcomes between Leadless and Conventional Transvenous Pacemakers Implantation: An Up-to-Date Meta-analysis

Background

Leadless cardiac pacemakers (LCPs) are emerging as viable alternatives to conventional transvenous pacemakers (TVPs). This study aimed to systematically compare the postoperative outcomes of LCPs and TVPs based on available published studies.

Methods

We conducted a systematic review and meta-analysis of literature comparing outcomes from LCP and TVP implantations. Data analysis was performed using Stata/MP 17.0. The evaluated endpoints included pericardial effusion or perforation, puncture site events, infective endocarditis, lead or device dislodgement, pocket-related complications, tricuspid regurgitation or dysfunction, any infection, increased right ventricle (RV) pacing threshold, embolism, and thrombosis. Aggregated odds ratios (OR) and 95% confidence intervals (CI) were determined. Sensitivity analyses were conducted for heterogeneity if I2 was >50% or p < 0.01, otherwise, the random-effects model was chosen. Publication bias was analyzed if the number studies exceeded ten.

Results

The meta-analysis included 24 observational studies with 78,938 patients, comprising 24,191 with LCP implantation and 54,747 with TVP implantation. The results indicated a significantly lower incidence of lead or device dislodgment (OR = 3.32, 95% CI: 1.91-5.77, p < 0.01), infective endocarditis (OR = 3.62, 95% CI: 3.10-4.24, p < 0.01), and infection (OR = 3.93, 95% CI: 1.67-9.24, p < 0.01) in the LCP group compared to the TVP group. In contrast, incidences of puncture site complications (OR = 0.24, 95% CI: 0.19-0.32, p < 0.01) and pericardial effusion or perforation (OR = 0.33, 95% CI: 0.28-0.39, p < 0.01) were significantly higher in the LCP group.

Conclusions

Compared with TVP, LCP implantation is associated with a lower risk of infective endocarditis, lead or device dislodgment, infections, and pocket-related complications. However, LCP implantation carries a higher risk of puncture site complications and pericardial effusion or perforation. These findings underscore the need for careful consideration of patient-specific factors when choosing between LCP and TVP implantation.

The PROSPERO Registration

https://www.crd.york.ac.uk/prospero/ (CRD42023453145).

Tricuspid Regurgitation Associated with Implantable Cardiac Devices: A Double-Edged Sword

The use of cardiac implantable electronic devices (CIEDs) has increased considerably, becoming a cornerstone of management for patients with brady- or tachyarrhythmia or for the prevention of sudden cardiac death. On the other hand, tricuspid regurgitation (TR) associated with CIEDs is progressively accepted as a serious clinical issue; the prognostic impact of TR is profound, as it is independently associated with increased mortality and a higher risk of heart failure hospitalization. Additionally, the management of established CIED-related TR continues to be challenging, with limited options for intervention once significant TR has developed. The balance between the lifesaving benefits of CIEDs and the risk of TR underlines the necessity for cautious patient selection and innovative approaches to device implantation and management. This review highlights the clinical importance, underlying mechanisms and challenges associated with lead-related tricuspid regurgitation in patients with CIEDs.

The Effectiveness and Safety of Leadless Pacemakers: An Updated Meta-Analysis

BACKGROUND

Leadless pacemakers (LPs) are promising alternatives to traditional transvenous pacemakers (TVPs), but their comparative effectiveness and safety in clinical outcomes remain uncertain.

METHODS

We systematically searched PubMed, Embase, Scopus, Cochrane, and ClinicalTrials.gov for studies comparing LPs and TVPs. A restricted maximum likelihood random-effects model was used for all outcomes. Heterogeneity was assessed using I2 statistics. We performed a subgroup analysis with studies with multivariate-adjusted data.

RESULTS

We included 21 studies involving 47,229 patients, of whom 12,199 (25.8%) underwent LP implantation. Compared with TVPs, LPs were associated with a significantly lower risk of overall complications (OR 0.61; 95% CI 0.45-0.81; p < 0.01), dislodgement (OR 0.34; 95% CI 0.20-0.56; p < 0.01), and pneumothorax (OR 0.27; 95% CI 0.16-0.46; p < 0.01). No significant difference in all-cause mortality was observed in the overall analysis (OR 1.43; 95% CI 0.65-3.15; p = 0.35) and in studies with multivariate-adjusted data (OR 1.34; 95% CI 0.65-2.78; p = 0.43). However, LPs were associated with a higher risk of pericardial effusion (OR 2.47; 95% CI 1.39-4.38; p < 0.01) and cardiac tamponade (OR 3.75; 95% CI 2.41-5.83; p < 0.01). LPs also demonstrated a lower pacing capture threshold (MD -0.19 V; 95% CI [-0.23 V]-[-0.16 V]; p < 0.01), but no significant difference in impedance (MD 32.63 ohms; 95% CI [-22.50 ohms]-[87.76 ohms]; p = 0.25).

CONCLUSIONS

These findings suggest that LPs were associated with lower overall complication rates and similar effectiveness to TVPs. However, randomized controlled trials are warranted to validate these results.

Evolution and prognosis of tricuspid and mitral regurgitation following cardiac implantable electronic devices: a systematic review and meta-analysis

AIMS

Significant changes in tricuspid regurgitation (TR) and mitral regurgitation (MR) post-cardiac implantable electronic devices (CIEDs) are increasingly recognized. However, uncertainty remains as to whether the risk of CIED-associated TR and MR differs with right ventricular pacing (RVP) via CIED with trans-tricuspid RV leads, compared with cardiac resynchronization therapy (CRT), conduction system pacing (CSP), and leadless pacing (LP). The study aims to synthesize extant data on risk and prognosis of significant post-CIED TR and MR across pacing strategies.

METHODS AND RESULTS

We searched PubMed, EMBASE, and Cochrane Library databases published until 31 October 2023. Significant post-CIED TR and MR were defined as ≥ moderate. Fifty-seven TR studies (n = 13 723 patients) and 90 MR studies (n = 14 387 patients) were included. For all CIED, the risk of post-CIED TR increased [pooled odds ratio (OR) = 2.46 and 95% CI = 1.88-3.22], while the risk of post-CIED MR reduced (OR = 0.74, 95% CI = 0.58-0.94) after 12 and 6 months of median follow-up, respectively. Right ventricular pacing via CIED with trans-tricuspid RV leads was associated with increased risk of post-CIED TR (OR = 4.54, 95% CI = 3.14-6.57) and post-CIED MR (OR = 2.24, 95% CI = 1.18-4.26). Binarily, CSP did not alter TR risk (OR = 0.37, 95% CI = 0.13-1.02), but significantly reduced MR (OR = 0.15, 95% CI = 0.03-0.62). Cardiac resynchronization therapy did not significantly change TR risk (OR = 1.09, 95% CI = 0.55-2.17), but significantly reduced MR with prevalence pre-CRT of 43%, decreasing post-CRT to 22% (OR = 0.49, 95% CI = 0.40-0.61). There was no significant association of LP with post-CIED TR (OR = 1.15, 95% CI = 0.83-1.59) or MR (OR = 1.31, 95% CI = 0.72-2.39). Cardiac implantable electronic device-associated TR was independently predictive of all-cause mortality [pooled hazard ratio (HR) = 1.64, 95% CI = 1.40-1.90] after median of 53 months. Mitral regurgitation persisting post-CRT independently predicted all-cause mortality (HR = 2.00, 95% CI = 1.57-2.55) after 38 months.

CONCLUSION

Our findings suggest that, when possible, adoption of pacing strategies that avoid isolated trans-tricuspid RV leads may be beneficial in preventing incident or deteriorating atrioventricular valvular regurgitation and might reduce mortality.

Cardiac implantable electronic device-induced tricuspid regurgitation: Implications and management

Tricuspid regurgitation (TR) secondary to cardiac implantable electronic devices (CIEDs) has been well documented and is associated with worse cardiovascular outcomes. A variety of mechanisms have been proposed including lead-induced mechanical disruption of the tricuspid valvular or subvalvular apparatus and pacing-induced electrical dyssynchrony. Patient characteristics such as age, sex, baseline atrial fibrillation, and pre-existing TR have not been consistent predictors of CIED-induced TR. While two-dimensional echocardiography is helpful in assessing the severity of TR, three-dimensional echocardiography has significantly improved accuracy in identifying the etiology of TR and whether lead position contributes to TR. Three-dimensional echocardiography may therefore play a future role in optimizing lead positioning during implant to reduce the risk of CIED-induced TR. Optimal lead management strategies in addition to percutaneous interventions and surgery in alleviating TR are very important.

Incidence, Risk Factors, and Outcomes Associated With Permanent Pacemaker Implantation Following Tricuspid Valve Surgery

BACKGROUND

Data regarding permanent pacemaker (PPM) implantation following tricuspid valve surgery (TVS) are limited. We sought to evaluate its incidence, risk factors, and outcomes.

METHODS AND RESULTS

Medicare beneficiaries who underwent TVS from 2013 to 2020 were identified. Patients who underwent TVS for endocarditis were excluded. The primary exposure of interest was new PPM after TVS. Outcomes included all-cause mortality and readmission with endocarditis or heart failure on follow-up. Among the 13 294 patients who underwent TVS, 2518 (18.9%) required PPM placement. Risk factors included female sex (relative risk [RR], 1.26 [95% CI, 1.17-1.36], P<0.0001), prior sternotomy (RR, 1.12 [95% CI, 1.02-1.23], P=0.02), preoperative second-degree heart block (RR, 2.20 [95% CI, 1.81-2.69], P<0.0001), right bundle-branch block (RR, 1.21 [95% CI, 1.03-1.41], P=0.019), bifascicular block (RR, 1.43 [95% CI, 1.06-1.93], P=0.02), and prior malignancy (RR, 1.23 [95% CI, 1.01-1.49], P=0.04). Tricuspid valve (TV) replacement was associated with a significantly higher risk of PPM implantation when compared with TV repair (RR, 3.20 [95% CI, 2.16-4.75], P<0.0001). After a median follow-up of 3.1 years, mortality was not different in patients who received PPM compared with patients who did not (hazard ratio [HR], 1.02 [95% CI, 0.93-1.12], P=0.7). PPM placement was not associated with a higher risk of endocarditis but was associated with a higher risk of heart failure readmission (HR, 1.28 [95% CI, 1.14-1.43], P<0.001).

CONCLUSIONS

PPM implantation frequently occurs after TVS, notably in female patients and patients undergoing TV replacement. Although mortality is not increased, it is associated with higher rates of heart failure rehospitalization.

Incidence and Prognostic Implications of Cardiac-Implantable Device-Associated Tricuspid Regurgitation: A Meta-Analysis and Meta-Regression Analysis

New-onset or worsening tricuspid regurgitation (TR) is a well-established complication encountered after cardiac implantable electronic devices (CIEDs). However, there are limited and conflicting data on the true incidence and prognostic implications of this complication. This study aimed to bridge this current gap in the literature. Electronic databases MEDLINE, Embase, and Web of Science were systematically searched from inception to March 2023, for studies reporting the incidence and/or prognosis of CIED-associated new or worsening TR. Potentially eligible studies were screened and selected according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. A random effect model meta-analysis and meta-regression analysis were performed, and I-squared statistic was used to assess heterogeneity. A total of 52 eligible studies, with 130,759 patients were included in the final quantitative analysis with a mean follow-up period of 25.5 months. The mean age across included studies was 69.35 years, and women constituted 46.6% of the study population. The mean left ventricular ejection fraction was 50.15%. The incidence of CIED-associated TR was 24% (95% confidence interval [CI] 20% to 28%, p <0.001) with an odds ratio of 2.44 (95% CI 1.58 to 3.77, p <0.001). CIED-associated TR was independently associated with an increased risk of all-cause mortality (adjusted hazard ratio [aHR] 1.52, 95% CI 1.36 to 1.69, p <0.001), heart failure (HF) hospitalizations (aHR 1.82, 95% CI 1.19 to 2.78, p = 0.006), and the composite of mortality and HF hospitalizations (aHR 1.96, 95% CI 1.33 to 2.87, p = 0.001) in the follow-up period. In conclusion, CIED-associated TR occurred in nearly one-fourth of patients after device implantation and was associated with an increased risk of all-cause mortality and HF hospitalizations.

Comparative assessment of safety with leadless pacemakers compared to transvenous pacemakers: a systemic review and meta-analysis

BACKGROUND

Leadless pacemakers (LP) and transvenous pacemakers (TVP) are two stable pacing platforms currently available in clinical practice. Observational data show mixed results with regards to their comparative safety. This meta-analysis was aimed to evaluate the comparative safety of LP over TVP.

METHODS

The study protocol was registered in PROSPERO registry (CRD42022325376). Six databases were searched for published literature from inception to April 12, 2022. RevMan 5.4.1 was used for statistical analysis. Odds ratio (OR) and mean difference were used to estimate the outcome with a 95% confidence interval (CI).

RESULTS

A total of 879 studies were imported from the databases. Among these, 41 papers were screened for full text and 17 meet the inclusion criteria. Among them, pooled results showed 42% lower odds of occurrence of complications in the LP group (OR 0.58, CI 0.42-0.80) compared to TVP group. Notably, 70% lower odds of device dislodgment (OR 0.30, CI 0.21-0.43), 46% lower odds of re-intervention (OR 0.54, CI 0.45-0.64), 87% lower odds of pneumothorax (OR 0.13, CI 0.03-0.57), albeit, 2.65 times higher odds of pericardial effusion (OR 2.65, CI 1.49-4.70) were observed in the LP group.

CONCLUSIONS

This meta-analysis showed LP to be a significantly safer modality compared to TVP, in terms of re-intervention, device dislodgment, pneumothoraxes, and overall complications. However, there were higher rates of pericardial effusion in the LP group. There was a diverse number of patients included, and all studies were observational. Randomized trials are needed to validate our findings.

Worsening tricuspid regurgitation associated with permanent pacemaker and implantable cardioverter-defibrillator implantation: A systematic review and meta-analysis of more than 66,000 subjects

BACKGROUND

Worsening tricuspid regurgitation (TR) after either permanent pacemaker (PPM) or implantable cardioverter-defibrillator (ICD) implantation is an emerging clinical challenge. Early recognition of this entity is essential in guiding treatment.

OBJECTIVE

This meta-analysis was designed to identify the overall incidence and patient-specific predictors of TR post-device implantation.

METHODS

We searched electronic databases from inception to January 2023 for published studies that reported the incidence of TR worsening post-device implantation. The log odds ratio (OR) was used to summarize group differences.

RESULTS

Our analysis included 29 studies with 66,590 participants. Patients who underwent device implantation (n = 1008) were significantly more likely to develop worsening TR than controls who did not undergo device implantation (n = 58,605) (OR 3.18; P < .01). In a total of 7777 patients, the pooled incidence of at least 1-grade worsening of TR post-device implantation was 24%. Worsening TR post-device implantation significantly increases mortality (hazard ratio 1.42; P = .02). Larger right atrial area (OR 1.11; P < .01) is significantly associated with an increased risk of worsening TR post-device implantation, while male patients are less likely to develop this complication than female patients (OR 0.74; P < .01). Importantly, there is no statistically significant difference between the type of implanted device (ICD vs PPM) and post-device implantation TR. Further, right ventricular dysfunction, pulmonary artery pressure, baseline mitral regurgitation, left ventricular ejection fraction, baseline atrial fibrillation, and age have no association with worsening TR post-device implantation.

CONCLUSION

A substantial number of patients undergoing PPM or ICD implantation are at an increased risk of worsening TR. Importantly, in this largest review to date incorporating more than 66,000 subjects, worsening TR significantly increases mortality by greater than 140%, accordingly deserving more recognition and clinical attention in the current era.

Comparison of Safety of Leadless Pacemakers and Transvenous Pacemakers: A Meta-Analysis

Pacemakers have been accessible for six decades, and clearly defined criteria for pacemaker implantation have been established. Within the contemporary clinical practice, two dependable pacing platforms exist leadless pacemakers and transvenous pacemakers. The aim of this meta-analysis is to compare the safety of leadless pacemakers to transvenous pacemakers. This meta-analysis adhered to the guidelines outlined in the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) 2020 framework. A comprehensive and systematic search was conducted across various databases including Scopus, Cochrane Library, and EMBASE, spanning from inception to August 15, 2023. The primary outcomes assessed in this meta-analysis were total complications, all-cause mortality, and device-related complications. Furthermore, secondary outcomes evaluated encompassed the need for reintervention, occurrences of pneumothorax, pericardial effusion, endocarditis, hemothorax, and hematoma. Total 17 studies were included in this meta-analysis. The findings of this study showed that patients with leadless pacemakers had a lower risk of total complications, device-related complications, pneumothorax, and endocarditis. The risk of reintervention was significantly lower in the leadless pacemaker group. However, compared to a transvenous pacemaker, the risk of pericardial effusion was significantly higher in the leadless pacemaker group. It is important to acknowledge the limitations arising from the lack of extensive long-term follow-up data for leadless pacemakers. As technology evolves, continued research will be essential in uncovering the full spectrum of prolonged complications associated with these devices.

The VR leadless pacemaker: Results of an expert panel using the RAND/UCLA method

BACKGROUND

Leadless pacemakers were developed to reduce complications associated with transvenous pacemaker implantation and long-term follow-up. Existing international guidelines lack detailed instructions on patients suitable for leadless pacemaker implantation. Our aim was to develop a consensus document that provides medical guidance for all health professionals involved in the indication and implantation of Transcatheter Pacing System single-chamber device (VR leadless) pacemakers for patients with atrial fibrillation or in sinus rhythm.

METHODS

A panel of experts, including interventional and non-interventional cardiologists, used the Research ANd Development/University of California at Los Angeles (RAND/UCLA) method to rate the appropriateness of leadless pacemaker implantation for 64 scenarios in patients with atrial fibrillation and 192 scenarios in sinus rhythm. The scenarios were rated individually and again during a moderated group session. Median ratings and level of agreement were calculated to classify each scenario as appropriate, inappropriate, or questionable.

RESULTS

This consensus statement, based on available literature and the experts' opinions, summarizes recommendations for standardizing and optimizing leadless pacemaker implantation. The limitation for vascular access via the superior vena cava was the most influential variable when indicating leadless pacemaker implantation in both patients with atrial fibrillation and patients in sinus rhythm.

CONCLUSIONS

Life expectancy, risk of infection, prosthetic valve, left ventricular ejection fraction (LVEF), limitation for vascular access via the superior vena cava, and mobility and exercise capacity determine who is advised to undergo VR leadless pacemaker implantation. More prospective studies are needed to optimize existing recommendations.

Strategies for Safe Implantation and Effective Performance of Single-Chamber and Dual-Chamber Leadless Pacemakers

Leadless pacemakers (LPMs) have emerged as an alternative to conventional transvenous pacemakers to eliminate the complications associated with leads and subcutaneous pockets. However, LPMs still present with complications, such as cardiac perforation, dislodgment, vascular complications, infection, and tricuspid valve regurgitation. Furthermore, the efficacy of the leadless VDD LPMs is influenced by the unachievable 100% atrioventricular synchrony. In this article, we review the available data on the strategy selection, including appropriate patient selection, procedure techniques, device design, and post-implant programming, to minimize the complication rate and maximize the efficacy, and we summarize the clinical settings in which a choice must be made between VVI LPMs, VDD LPMs, or conventional transvenous pacemakers. In addition, we provide an outlook for the technology for the realization of true dual-chamber leadless and battery-less pacemakers.

Evolution of tricuspid valve regurgitation after implantation of a leadless pacemaker - a single center experience, systematic review and meta-analysis

Introduction

Conventional transvenous pacemaker leads may interfere with the tricuspid valve leaflets, tendinous chords, and papillary muscles, resulting in significant tricuspid valve regurgitation (TR). Leadless pacemakers (LLPMs) theoretically cause less mechanical interference with the tricuspid valve apparatus. However, data on TR after LLPM implantation are sparse and conflicting. Our goal was to investigate the prevalence of significant TR before and after LLPM implantation.

Methods

Patients who received a leadless LLPM (Micra™ TPS, Medtronic) between May 2016 and May 2021 at our center were included in this observational study if they had at least a pre‐ and postinterventional echocardiogram (TTE). The evolution of TR severity was assessed. Following a systematic literature review on TR evolution after implantation of a LLPM, data were pooled in a random‐effects meta‐analysis.

Results

We included 69 patients (median age 78 years [interquartile range (IQR) 72–84 years], 26% women). Follow‐up duration between baseline and follow‐up TTE was 11.4 months (IQR 3.5–20.1 months). At follow‐up, overall TR severity was not different compared to baseline (p = .49). Six patients (9%) had new significant TR during follow‐up after LLPM implantation, whereas TR severity improved in seven patients (10%). In the systematic review, we identified seven additional articles that investigated the prevalence of significant TR after LLPM implantation. The meta‐analysis based on 297 patients failed to show a difference in significant TR before and after LLPM implantation (risk ratio 1.22, 95% confidence interval 0.97–1.53, p = .11).

Conclusion

To date, there is no substantial evidence for a significant change in TR after implantation of a LLPM.

Efficacy and safety of leadless pacemaker: A systematic review, pooled analysis and meta-analysis

Background

Leadless pacemakers have been designed as an alternative to transvenous systems which avoid some of the complications associated with transvenous devices. We aim to perform a systematic review of the literature to report the safety and efficacy findings of leadless pacemakers.

Methods

We searched MEDLINE and EMBASE to identify studies reporting the safety, efficacy and outcomes of patients implanted with a leadless pacemaker. The pooled rate of adverse events was determined and random-effects meta-analysis was performed to compare rates of adverse outcomes for leadless compared to transvenous pacemakers.

Results

A total of 18 studies were included with 2496 patients implanted with a leadless pacemaker and success rates range between 95.5 and 100%. The device or procedure related death rate was 0.3% while any complication and pericardial tamponade occurred in 3.1% and 1.4% of patients, respectively. Other complications such as pericardial effusion, device dislodgement, device revision, device malfunction, access site complications and infection occurred in less than 1% of patients. Meta-analysis of four studies suggests that there was no difference in hematoma (RR 0.67 95%CI 0.21–2.18, 3 studies), pericardial effusion (RR 0.59 95%CI 0.15–2.25, 3 studies), device dislocation (RR 0.33 95%CI 0.06–1.74, 3 studies), any complication (RR 0.44 95%CI 0.17–1.09, 4 studies) and death (RR 0.45 95%CI 0.15–1.35, 2 studies) comparing patients who received leadless and transvenous pacemakers.

Conclusion

Leadless pacemakers are safe and effective for patients who have an indication for single chamber ventricular pacing and the findings appear to be comparable to transvenous pacemakers.

Safety and Efficacy of Leadless Pacemakers: A Systematic Review and Meta-Analysis

Background Leadless pacemaker is a novel technology, and evidence supporting its use is uncertain. We performed a systematic review and meta-analysis to examine the safety and efficacy of leadless pacemakers implanted in the right ventricle. Methods and Results We searched PubMed and Embase for studies published before June 6, 2020. The primary safety outcome was major complications, whereas the primary efficacy end point was acceptable pacing capture threshold (≤2 V). Pooled estimates were calculated using the Freedman-Tukey double arcsine transformation. Of 1281 records screened, we identified 36 observational studies of Nanostim and Micra leadless pacemakers, with most (69.4%) reporting outcomes for the Micra. For Micra, the pooled incidence of complications at 90 days (n=1608) was 0.46% (95% CI, 0.08%-1.05%) and at 1 year (n=3194) was 1.77% (95% CI, 0.76%-3.07%). In 5 studies with up to 1-year follow-up, Micra was associated with 51% lower odds of complications compared with transvenous pacemakers (3.30% versus 7.43%; odds ratio [OR], 0.49; 95% CI, 0.34-0.70). At 1 year, 98.96% (95% CI, 97.26%-99.94%) of 1376 patients implanted with Micra had good pacing capture thresholds. For Nanostim, the reported complication incidence ranged from 6.06% to 23.54% at 90 days and 5.33% to 6.67% at 1 year, with 90% to 100% having good pacing capture thresholds at 1 year (pooled result not estimated because of the low number of studies). Conclusions Most studies report outcomes for the Micra, which is associated with a low risk of complications and good electrical performance up to 1-year after implantation. Further data from randomized controlled trials are needed to support the widespread adoption of these devices in clinical practice.

Incidence, Risk Factors, and Prognosis of Tricuspid Regurgitation After Cardiac Implantable Electronic Device Implantation: A Systematic Review and Meta-analysis

This study aimed to determine the pooled incidence, risk factors, and clinical prognosis of tricuspid regurgitation (TR) deterioration after implantation of a cardiac implantable electronic device (CIED). The study was designed as a meta-analysis of randomized controlled trials and observational studies. Patients with indications for CIEDs were selected as participants and CIED implantation was the intervention. PubMed, EMBASE, the Cochrane Library, China National Knowledge Infrastructure, Wanfang Data, and China Science and Technology Journal Database were searched systematically to identify studies. Thirty-seven studies with 8,144 patients were included. The pooled incidence of TR deterioration of at least one grade was 25.1% (95% confidence interval [CI], 20.9-29.3; Z = 11.60; p < 0.01; I² = 94.8%, p < 0.01). Compared with TR incidence after permanent pacemaker implantation, that after implantable cardioverter-defibrillator implantation did not significantly increase (22.68% v 29.18%; odds ratio [OR], 0.615; 95% CI, 0.271-1.339; Z =1.16; p = 0.246). The pooled incidence of TR deterioration of at least two grades was 9.4% (95% CI, 6.6-12.1; Z = 6.72; p < 0.01; I² = 86.0%, p < 0.01). Lead interference (OR, 8.704; 95% CI,4.450-17.028; Z= 6.32; p < 0.001) and pacemaker implantation time (OR, 1.153; 95% CI, 1.082-1.229; Z = 4.37; p < 0.001) were risk factors for worsening TR. Baseline atrial fibrillation, age, baseline mild TR, and left ventricular ejection fraction were not associated with TR. All-cause mortality (>one year after pacemaker implantation) was higher in patients with TR deterioration (hazard ratio, 1.598; 95% CI, 1.275-2.002; Z = 4.07; p < 0.01; I² = 0%). TR is a common complication after CIED implantation. Lead interference and pacemaker implantation time were risk factors for TR worsening. Compared with patients without TR deterioration after pacemaker implantation, patients with TR deterioration had a poorer prognosis.

A Meta-analysis of Major Complications between Traditional Pacemakers and Leadless Pacemakers

Objectives: We aim to compare the major complications between leadless pacemakers and traditional pacemakers.Background: Leadless pacemakers, which are increasingly used in clinical practice, have several advantages compared with traditional pacemakers in avoiding pocket- and lead-related complications. However, the clinical effect of leadless pacemakers remains controversial.Methods: PubMed, Embase, the Cochrane Central Register of Controlled Trials (CENTRAL), the CNKI database, and the Wanfang database were searched from July 2013 to December 2019. Studies comparing leadless pacemakers and traditional pacemakers were included. The primary end point was major complications. The secondary end points were cardiac perforation/pericardial effusion, device revision or extraction, loss of device function, and death.Results: Six studies fulfilled the inclusion criteria. Only four of the six studies reported data on major complications. Leadless pacemakers were associated with a lower incidence of major complications (risk ratio 0.33, 95% confidence interval 0.25‐0.44, P<0.00001, I2=49%). We extracted data on cardiac perforation/pericardial effusion, device revision or extraction, loss of device function, and death from six studies. Our meta-analysis showed that leadless pacemakers have a higher risk of cardiac perforation or pericardial effusion (risk ratio 4.28, 95% confidence interval 1.66‐11.08, P=0.003, I2=0%). No statistically significant differences were found for mortality, device revision or extraction, and loss of device function.Conclusion: Compared with traditional pacemakers, leadless pacemakers have a significantly decreased risk of major complications, but have a higher risk of cardiac perforation or pericardial effusion.

Cardiac Stimulation in the Third Millennium: Where Do We Head from Here?

Over the years, pacemakers have evolved from a life-saving tool to prevent asystole to a device to treat heart rhythm disorders and heart failure, aiming at improving both cardiac function and clinical outcomes. Cardiac stimulation nowadays aims to correct the electrophysiologic roots of mechanical inefficiency in different structural heart diseases. This has led to awareness of the concealed risks of customary cardiac pacing that can inadvertently cause atrioventricular and inter-/intra-ventricular dyssynchrony, and has promoted the development of new pacing modalities and the use of stimulation sites different from the right atrial appendage and the right ventricular apex. The perspective of truly physiologic pacing is the leading concept of the continued research in the past 30 years, which has made cardiac stimulation procedure more sophisticated and challenging. In this article, we analyze the emerging evidence in favor of the available strategies to achieve an individualized physiologic setting in bradycardia pacing.

Pacing devices to treat bradycardia: current status and future perspectives

Introduction: Cardiac stimulation evolved from life-saving devices to prevent asystole to the treatment of heart rhythm disorders and heart failure, capable of remote patient and disease-progression monitoring. Cardiac stimulation nowadays aims to correct the electrophysiologic roots of mechanical inefficiency in different structural heart diseases.Areas covered: Clinical experience, as per available literature, has led to awareness of the concealed risks of customary cardiac pacing, that can inadvertently cause atrio-ventricular and inter/intra-ventricular dyssynchrony. New pacing modalities have emerged, leading to a new concept of what truly represents 'physiologic pacing' beyond maintenance of atrio-ventricular coupling. In this article we will analyze the emerging evidence in favor of the available strategies to achieve an individualized physiologic setting in bradycardia pacing, and the hints of future developments.Expert opinion: 'physiologic stimulation' technologies should evolve to enable an effective and widespread adoption. In one way new guiding catheters and the adoption of electrophysiologic guidance and non-fluoroscopic lead implantation are needed to make His-Purkinje pacing successful and effective at long term in a shorter procedure time; in the other way leadless stimulation needs to upgrade to a superior physiologic setting to mimic customary DDD pacing and possibly His-Purkinje pacing.

Single-chamber leadless pacemaker for atrial synchronous or ventricular pacing

Leadless pacing is a major breakthrough in the management of bradyarrhythmia. Results of initial clinical trials that have demonstrated a significant reduction in acute and long-term pacing-related complications have been confirmed by real-world experience in a broader spectrum of patients. Nonetheless current use of a leadless pacemaker is hampered by its limited atrial sensing and pacing capability, as well as battery life-span and retrievability. We review the current clinical outcome data, indications and contraindications, implantation and retrieval techniques, synchronous ventricular pacing, and other clinical considerations. We also provide an overview of the latest advancements in leadless pacing technology including device-to-device communication and energy harvesting technology.

Clinical outcomes of leadless pacemaker: a systematic review

INTRODUCTION

Transvenous pacemakers are associated with a significant amount of complications. Leadless pacemakers (LP) are emerging as an alternative to conventional devices. This article provides a systematic review of patient eligibility, safety and clinical outcomes of the LP devices.

EVIDENCE ACQUISITION

A systematic search for articles describing the use of LP was conducted. Out of two databases, 24 articles were included in the qualitative analysis. These articles comprised a total of 4739 patients, with follow-up times of 1-38 months. Further information was obtained from 10 more studies.

EVIDENCE SYNTHESIS

From a population of 4739 patients included in the qualitative analysis, 4670 LP were implanted with success (98.5%). A total of 248 complications were described (5.23%) during the follow-up. The most common were pacing issues such as elevated thresholds, dislodgements or battery failure (68 patients), events at the femoral access site such as hemorrhage, hematoma or pseudoaneurysms (64 patients) and procedure related cardiac injuries such as cardiac perforation, tamponade or pericardial effusion (47 patients). There were 360 deaths during the follow-up and 11 were described as procedure or device related. Four studies presented the strategy of using a combined approach of atrioventricular node ablation (AVNA) and LP implantation.

CONCLUSIONS

Leadless pacemakers seem to have a relatively low complication rate. These devices may be a good option in patients with an indication for single-chamber pacing, in patients with conditions precluding conventional transvenous pacemaker implantations. Studies directly comparing LP and transvenous pacemakers and data on longer follow-up periods are needed.