Direct Oral Anticoagulants for Stroke Prevention in Patients With Device-Detected Atrial Fibrillation: A Study-Level Meta-Analysis of the NOAH-AFNET 6 and ARTESiA Trials.

BACKGROUND: Device-detected atrial fibrillation (also known as subclinical atrial fibrillation or atrial high-rate episodes) is a common finding in patients with an implanted cardiac rhythm device and is associated with an increased risk of ischemic stroke. Whether oral anticoagulation is effective and safe in this patient population is unclear. METHODS: We performed a systematic review of MEDLINE and Embase for randomized trials comparing oral anticoagulation with antiplatelet or no antithrombotic therapy in adults with device-detected atrial fibrillation recorded by a pacemaker, implantable cardioverter defibrillator, cardiac resynchronization therapy device, or implanted cardiac monitor. We used random-effects models for meta-analysis and rated the quality of evidence using the Grading of Recommendations Assessment, Development and Evaluation framework (GRADE). The review was preregistered (PROSPERO CRD42023463212). RESULTS: From 785 citations, we identified 2 randomized trials with relevant clinical outcome data: NOAH-AFNET 6 (Non-Vitamin K Antagonist Oral Anticoagulants in Patients With Atrial High Rate Episodes; 2536 participants) evaluated edoxaban, and ARTESiA (Apixaban for the Reduction of Thrombo-Embolism in Patients With Device-Detected Sub-Clinical Atrial Fibrillation; 4012 participants) evaluated apixaban. Meta-analysis demonstrated that oral anticoagulation with these agents reduced ischemic stroke (relative risk [RR], 0.68 [95% CI, 0.50-0.92]; high-quality evidence). The results from the 2 trials were consistent (I2 statistic for heterogeneity=0%). Oral anticoagulation also reduced a composite of cardiovascular death, all-cause stroke, peripheral arterial embolism, myocardial infarction, or pulmonary embolism (RR, 0.85 [95% CI, 0.73-0.99]; I2=0%; moderate-quality evidence). There was no reduction in cardiovascular death (RR, 0.95 [95% CI, 0.76-1.17]; I2=0%; moderate-quality evidence) or all-cause mortality (RR, 1.08 [95% CI, 0.96-1.21]; I2=0%; moderate-quality evidence). Oral anticoagulation increased major bleeding (RR, 1.62 [95% CI, 1.05-2.50]; I²=61%; high-quality evidence). CONCLUSIONS: The results of the NOAH-AFNET 6 and ARTESiA trials are consistent with each other. Meta-analysis of these 2 large randomized trials provides high-quality evidence that oral anticoagulation with edoxaban or apixaban reduces the risk of stroke in patients with device-detected atrial fibrillation and increases the risk of major bleeding.

Periprocedural Management and Multidisciplinary Care Pathways for Patients With Cardiac Implantable Electronic Devices: A Scientific Statement From the American Heart Association.

The rapid technological advancements in cardiac implantable electronic devices such as pacemakers, implantable cardioverter defibrillators, and loop recorders, coupled with a rise in the number of patients with these devices, necessitate an updated clinical framework for periprocedural management. The introduction of leadless pacemakers, subcutaneous and extravascular defibrillators, and novel device communication protocols underscores the imperative for clinical updates. This scientific statement provides an inclusive framework for the periprocedural management of patients with these devices, encompassing the planning phase, procedure, and subsequent care coordinated with the primary device managing clinic. Expert contributions from anesthesiologists, cardiac electrophysiologists, and cardiac nurses are consolidated to appraise current evidence, offer patient and health system management strategies, and highlight key areas for future research. The statement, pertinent to a wide range of health care professionals, underscores the importance of quality care pathways for patient safety, optimal device function, and minimization of hemodynamic disturbances or arrhythmias during procedures. Our primary objective is to deliver quality care to the expanding patient cohort with cardiac implanted electronic devices, offering direction in the era of evolving technologies and laying a foundation for sustained education and practice enhancement.

Reducing cardiac implantable electronic device-induced artefacts in cardiac magnetic resonance imaging.

OBJECTIVES: Cardiac implantable electronic device (CIED)-induced metal artefacts possibly significantly diminish the diagnostic value of magnetic resonance imaging (MRI), particularly cardiac MR (CMR). Right-sided generator implantation, wideband late-gadolinium enhancement (LGE) technique and raising the ipsilateral arm to the generator during CMR scanning may reduce the CIED-induced image artefacts. We assessed the impact of generator location and the arm-raised imaging position on the CIED-induced artefacts in CMR. METHODS: We included all clinically indicated CMRs performed on patients with normal cardiac anatomy and a permanent CIED with endocardial pacing leads between November 2011 and October 2019 in our institution (n = 171). We analysed cine and LGE sequences using the American Heart Association 17-segment model for the presence of artefacts. RESULTS: Right-sided generator implantation and arm-raised imaging associated with a significantly increased number of artefact-free segments. In patients with a right-sided pacemaker, the median percentage of artefact-free segments in short-axis balanced steady-state free precession LGE was 93.8% (IQR 9.4%, n = 53) compared with 78.1% (IQR 20.3%, n = 58) for left-sided pacemaker (p < 0.001). In patients with a left-sided implantable cardioverter-defibrillator, the median percentage of artefact-free segments reached 87.5% (IQR 6.3%, n = 9) using arm-raised imaging, which fell to 62.5% (IQR 34.4%, n = 9) using arm-down imaging in spoiled gradient echo short-axis cine (p = 0.02). CONCLUSIONS: Arm-raised imaging represents a straightforward method to reduce CMR artefacts in patients with left-sided generators and can be used alongside other image quality improvement methods. Right-sided generator implantation could be considered in CIED patients requiring subsequent CMR imaging to ensure sufficient image quality. KEY POINTS: • Cardiac implantable electronic device (CIED)-induced metal artefacts may significantly diminish the diagnostic value of an MRI, particularly in cardiac MRIs. • Raising the ipsilateral arm relative to the CIED generator is a cost-free, straightforward method to significantly reduce CIED-induced artefacts on cardiac MRIs in patients with a left-sided generator. • Right-sided generator implantation reduces artefacts compared with left-sided implantation and could be considered in CIED patients requiring subsequent cardiac MRIs to ensure adequate image quality in the future.

Magnetic resonance imaging safety in patients with abandoned or functioning epicardial pacing leads.

OBJECTIVES: The European Society of Cardiology Guidelines on cardiac pacing from 2021 allow magnetic resonance imaging (MRI) in patients with cardiac implantable electronic devices (CIEDs) but do not recommend MRI in patients with epicardial pacing leads. The clinical dilemma remains whether performing an MRI in patients with CIED and epicardial leads is safe. We aimed to evaluate the safety of performing an MRI in patients with CIED and abandoned or functioning epicardial pacing leads. METHODS: We included all adult patients who underwent clinically indicated MRIs with CIED and functioning or abandoned epicardial leads in a single tertiary hospital between November 2011 and October 2019. The data were retrospectively collected. RESULTS: Twenty-six MRIs were performed on 17 patients with functioning or abandoned epicardial pacing leads. Sixty-nine percent of the MRI scans (18/26) were conducted on patients with functioning epicardial pacing leads. A definite adverse event occurred in one MRI scan. This was a transient elevation of the pacing threshold in a patient with a functioning epicardial ventricular pacing lead implanted 29 years previously. An irreversible atrial pacing lead impedance elevation was detected 6 months after the MRI in another patient; the association with the previous MRI remained unclear. No adverse events were detected in MRIs performed on patients with modern (implanted in 2000 or later) functioning epicardial leads. CONCLUSIONS: MRIs in patients with CIED and modern functioning epicardial pacing leads were performed without detectable adverse events. Further large-scale studies are necessary to confirm MRI safety in patients with epicardial pacing leads. KEY POINTS: • Currently, MRI in patients with cardiac implantable electronic devices (CIEDs) and functioning or abandoned epicardial pacing leads is not recommended. • MRIs in patients with CIED and modern functioning epicardial leads (implanted in 2000 or later) were performed without detectable adverse events in our patient cohort. • Allowing MRI in patients with epicardial pacing leads may significantly improve the diagnostic work-up, especially in specific patient groups, such as patients with congenital heart disease.

Sub-pocket small-hole drainage for pocket hematoma after cardiac device implantation.

AIMS: Pocket hematoma is a common complication associated with cardiac device implantation, but there are limited strategies to deal with this problem. We aimed to evaluate the effectiveness of sub-pocket small-hole drainage (SSD) as a new way to manage severe pocket hematoma. METHODS: A total of 11 patients with severe pocket hematoma were selected for this case series study. The SSD procedure was performed and wound healing was monitored. RESULTS: The SSD procedure was successfully performed on all 11 patients. The time window for SSD was 10-14 days (mean 12.0 ± 1.3 days) after cardiac device implantation. On average, 18.3 ± 2.3 ml of hematoma was drained , with a mean procedural time of 21.3 ± 2.6 min. The patients were followed up for 4-12 months and all pockets healed well, without any complications such as pocket infection, bleeding, device exposure, and electrode fracture. CONCLUSION: Sub-pocket small-hole drainage is an alternative approach for dealing with severe pocket hematoma after cardiac device implantation.

Stroke Risk as a Function of Atrial Fibrillation Duration and CHA2DS2-VASc Score.

BACKGROUND: Studies of patients with cardiovascular implantable electronic devices show a relationship between atrial fibrillation (AF) duration and stroke risk, although the interaction with CHA2DS2-VASc score is poorly defined. The objective of this study is to evaluate rates of stroke and systemic embolism (SSE) in patients with cardiovascular implantable electronic devices as a function of both CHA2DS2-VASc score and AF duration. METHODS: Data from the Optum electronic health record deidentified database (2007-2017) were linked to the Medtronic CareLink database of cardiovascular implantable electronic devices capable of continuous AF monitoring. An index date was assigned as the later of either 6 months after device implantation or 1 year after electronic health record data availability. CHA2DS2-VASc score was assessed using electronic health record data before the index date. Maximum daily AF burden (no AF, 6 minutes-23.5 hours, and >23.5 hours) was assessed over the 6 months before the index date. SSE rates were computed after the index date. RESULTS: Among 21 768 nonanticoagulated patients with cardiovascular implantable electronic devices (age, 68.6±12.7 years; 63% male), both increasing AF duration (P<0.001) and increasing CHA2DS2-VASc score (P<0.001) were significantly associated with annualized risk of SSE. SSE rates were low in patients with a CHA2DS2-VASc score of 0 to 1 regardless of device-detected AF duration. However, stroke risk crossed an actionable threshold defined as >1%/y in patients with a CHA2DS2-VASc score of 2 with >23.5 hours of AF, those with a CHA2DS2-VASc score of 3 to 4 with >6 minutes of AF, and patients with a CHA2DS2-VASc score ≥5 even with no AF. CONCLUSIONS: There is an interaction between AF duration and CHA2DS2-VASc score that can further risk-stratify patients with AF for SSE and may be useful in guiding anticoagulation therapy.

Making MRI available for patients with cardiac implantable electronic devices: growing need and barriers to change.

More than half of us will need a magnetic resonance imaging (MRI) scan in our lifetimes. MRI is an unmatched diagnostic test for an expanding range of indications including neurological and musculoskeletal disorders, cancer diagnosis, and treatment planning. Unfortunately, patients with cardiac pacemakers or defibrillators have historically been prevented from having MRI because of safety concerns. This results in delayed diagnoses, more invasive investigations, and increased cost. Major developments have addressed this-newer devices are designed to be safe in MRI machines under specific conditions, and older legacy devices can be scanned provided strict protocols are followed. This service however remains difficult to deliver sustainably worldwide: MRI provision remains grossly inadequate because patients are less likely to be referred, and face difficulties accessing services even when referred. Barriers still exist but are no longer technical. These include logistical hurdles (poor cardiology and radiology interaction at physician and technician levels), financial incentives (re-imbursement is either absent or fails to acknowledge the complexity), and education (physicians self-censor MRI requests). This article therefore highlights the recent changes in the clinical, logistical, and regulatory landscape. The aim of the article is to enable and encourage healthcare providers and local champions to build MRI services urgently for cardiac device patients, so that they may benefit from the same access to MRI as everyone else. KEY POINTS: • There is now considerable evidence that MRI can be provided safely to patients with cardiac implantable electronic devices (CIEDs). However, the volume of MRI scans delivered to patients with CIEDs is fifty times lower than that of the estimated need, and patients are approximately fifty times less likely to be referred. • Because scans for this patient group are frequently for cancer diagnosis and treatment planning, MRI services need to develop rapidly, but the barriers are no longer technical. • New services face logistical, educational, and financial hurdles which can be addressed effectively to establish a sustainable service at scale.

Individual programming of current multiprogrammable pacemakers : Still unsatisfactory?

BACKGROUND: Pacemaker (PM) technology has developed tremendously in recent decades. We evaluated the extent of individual programming in current PMs. METHODS: Over a 7-month period in 2016, all deceased persons taken to the Rostock crematorium were prospectively screened for cardiac implantable electronic devices (CIEDs) and these were interrogated in situ. Programming of patient data, leads, and study parameters including mode, lower rate, upper tracking or sensor rate (UTSR), ventricular refractory time, sleeping function, hysteresis, and PM-mediated tachycardia intervention were analyzed and compared with delivery settings. Alterations in atrial/ventricular capture management and atrial/ventricular sensing assurance as well as changes in sensitivity and lead output were evaluated. RESULTS: We examined 2297 subjects, of whom 154 (6.7%) had CIEDs, with 125 (81.2%) being PMs. Finally, 72 (57.6%) PMs were eligible for analysis with an operation time of 31.0 ± 27.0 months. We excluded 28 (18.2%) implantable cardioverter defibrillators (ICDs), 51 (41%) PMs presenting elective replacement indicator (ERI), two (1.6%) PMs with programming to insufficient function prior to death, and the left ventricle parameter of one (1.4%) cardiac resynchronization therapy pacemaker (CRT-P); further one CIED (0.6%) was not contactable. PMs offered in mean 75.2% of study parameters thereof 88.0% were to adjust manually, whereof 49.3% stayed unchanged to delivery mode. Lead output, UTSR, lower rate, and mode were the most frequently changed parameters (>85.7%, 65.3%, 54.2%, and 52.8%, respectively) compared with unmodified ventricular refractory time and hysteresis (91.7% and. 85.4%, respectively); 2.8% of PMs had out-of-the-box settings. The most frequent personalized data were last (88.9%) and first name (73.6%), while atrial and ventricular serial lead numbers were rarely entered (18.2% and 23.4%, respectively). CONCLUSION: The programming possibilities of PMs have advanced greatly. Nonetheless, improvements in individual PM programming are still needed as demonstrated by the findings in this study, e.g., PMs with manufacturer settings and lack of individual data.

Deactivation of cardiovascular implantable electronic devices in patients nearing end of life : Reality or only recommendation?

BACKGROUND: Current guidelines recommend considering deactivation of cardiac implantable electronic devices (CIEDs) in patients nearing death. We evaluated the implementation of this recommendation in unselected deceased individuals with CIEDs. METHODS: Over a 7-month period in 2016, all deceased persons taken to the Rostock crematorium were prospectively screened for CIEDs and these were interrogated in situ. Pacing rate, pacing mode, and lead output were documented as well as patient data including location and time of death. In implantable cardioverter-defibrillators (ICDs), tachycardia therapy adjustment and occurrence of shocks 24 h prior to death were also recorded. RESULTS: We examined 2297 subjects, of whom 154 (6.7%) had CIEDs. Of these subjects, 125 (100%) pacemakers (PMs) and 27 (96.4%) ICDs were eligible for analysis. Death in persons with ICDs occurred most frequently in hospital (55.6%), while this was less frequently the case for individuals with PMs (43.2%). Furthermore, 33.3% of subjects with ICDs and 18.5% with PMs died in palliative care units (PCU). Shock therapies were switched off in three (60%) individuals with ICDs who died in the PCU, whereas antibradycardia therapy was not withdrawn in any PM patient in the PCU. Therapy withdrawal occurred in two patients with PMs (1.3%) who died in hospital. Patients with PMs had high ventricular pacing rates at the last interrogation (69 ± 36.0%) and often suffered atrioventricular block (39.2%). Six (25%) of the 24 active ICDs presented shocks near the time of death. CONCLUSION: Many CIED patients died in hospital; nonetheless, in practice, CIED deactivation near death is rarely performed and might be less feasible in subjects with PMs. However, there is still a need to consider deactivation, especially in individuals with ICDs, as one fourth of them received at least one shock within 24 h prior to death.

[Feasibility and safety of new simplified left bundle branch area pacing via nine-partition method].

Objective: To investigate the efficacy and safety of left bundle branch area pacing (LBBaP) with the new simplified approach (nine-partition method). Methods: A total of 118 patients with clinical indications and received pacemaker implantation from December 1, 2018 to December 31, 2019 in Beijing Anzhen Hospital were enrolled. LBBaP was performed with the nine-partition method (in the right anterior oblique 30° position, the ventriculogram was divided into nine partitions and the initial implant sites were located in the lower base 1/3 partitions). In X-ray image, the 3830 lead is located in the left bundle branch area, the unipolar pacing QRS wave is in the form of right bundle branch block, and the peak time from stimulation to left ventricular activation<90 ms is defined as successful operation. The clinical characters, such as the methods of venipuncture, electrode parameters, operation duration, fluoroscopy duration, the peak time from stimulation to left ventricular, pacemaker types, surgical success rate, complications, and immediate postoperative ECG parameters were collected. The patients were followed up after the operation, and the electrode parameters and postoperative complications were recorded. Results: This study is a retrospective study. There were 62 (52.5%) male patients in this cohort, the average age was (65.9±13.4) years old,and there were 49(41.5%) sick sinus syndrome, 6(5.1%) abnormal sinus node and atrioventricular node simultaneously, 63(53.4%) atrioventricular block, 26(22.0%) atrial fibrillation, 20(16.9%) cardiomyopathy; the baseline duration of QRS was (109.21±39.03) ms. Successful LBBaP was achieved in 109 patients with"nine-partition method"and the success rate was 92.4%; 104 patients (95.5%) were axillary vein puncture, 5 (4.6%) were subclavian vein puncture; the operation duration was (80.3±23.0) min, the fluoroscopy duration was (12.29±5.13) min; the QRS duration after LBBaP was (116.36±18.11) ms. The threshold of the left bundle branch (LBB) lead was (0.92±0.63) V, the R wave amplitude was (10.60±5.04) mV and the impedance was (798.71±194.90) Ω. In 1 V pacing, the peak time from stimulation to left ventricular activation was (67.91±12.15) ms, and in 5 V pacing was (67.52±12.45) ms; 1 case (0.9%) with a single-chamber pacemaker implanted, 106 cases (97.3%) with dual-chamber pacemaker and 2 cases (1.8%) with three-chamber pacemakers. There were no hematomas, pneumothorax, hemothorax, electrode dislocation, infection, and capsular hemorrhage and other serious surgery-related complications during the operation. A total of 97 patients (89.0%) were followed up for (6.21±2.90) months. The electrode parameters of all patients were stable and no complications observed. Conclusions: The LBBaP with nine-partition method is a simple, safe and effective physiological pacing approach. However, its long-term effect still needs to be further verified.

MANAGEMENT OF PATIENTS WITH CARDIAC IMPLANTABLE ELECTRONIC DEVICES UNDERGOING MAGNETIC RESONANCE IMAGING - PROPOSAL FOR UNIFIED HOSPITAL PROTOCOL: CROATIAN WORKING GROUP ON ARRHYTHMIAS AND CARDIAC PACING.

For many years, magnetic resonance imaging (MRI) was contraindicated in patients with cardiac implantable electronic devices (CIED). Today, there is a growing amount of evidence that MRI can be performed safely in the majority of patients with CIEDs. Firstly, there are devices considered MRI conditional by manufacturers that are available on the market and secondly, there is clear evidence that even patients with MRI non-conditional devices can also undergo MRI safely. Protocols have been developed and recommendations from different cardiac and radiologic societies have been published in recent years. However, the majority of physicians are still reluctant to refer these patients to MRI. Therefore, this document is published as a joint statement of the Croatian Working Group on Arrhythmias and Cardiac Pacing and Department of Radiology, Sestre milosrdnice University Hospital Centre to guide and ease the management of patients with CIED undergoing MRI. Also, we propose a unified protocol and checklist that could be used in Croatian hospitals.

Cardiac Implantable Electronic Device Interrogation at Forensic Autopsy: An Underestimated Resource?

BACKGROUND: Postmortem interrogations of cardiac implantable electronic devices (CIEDs), recommended at autopsy in suspected cases of sudden cardiac death, are rarely performed, and data on systematic postmortem CIED analysis in the forensic pathology are missing. The aim of the study was to determine whether nonselective postmortem CIED interrogations and data analysis are useful to the forensic pathologist to determine the cause, mechanism, and time of death and to detect potential CIED-related safety issues. METHODS: From February 2012 to April 2017, all autopsy subjects in the department of forensic medicine at the University Hospital Charité who had a CIED underwent device removal and interrogation. Over the study period, 5368 autopsies were performed. One hundred fifty subjects had in total 151 CIEDs, including 109 pacemakers, 35 defibrillators, and 7 implantable loop recorders. RESULTS: In 40 cases (26.7%) time of death and in 51 cases (34.0%) cause of death could not be determined by forensic autopsy. Of these, CIED interrogation facilitated the determination of time of death in 70.0% of the cases and clarified the cause of death in 60.8%. Device concerns were identified in 9 cases (6.0%), including 3 hardware, 4 programming, and 2 algorithm issues. One CIED was submitted to the manufacturer for a detailed technical analysis. CONCLUSIONS: Our data demonstrate the necessity of systematic postmortem CIED interrogation in forensic medicine to determine the cause and timing of death more accurately. In addition, CIED analysis is an important tool to detect potential CIED-related safety issues.

[Feasibility and safety of new "blind" axillary vein puncture technique in pacemaker implantation].

Objective: To explore the feasibility and safety of a newly developed simple and rapid axillary vein puncture technique based on the surface landmarks for pacemaker implantation. Methods: From January to November 2018, we enrolled 110 patients who underwent pacemaker implantation in Beijing Anzhen Hospital. Basic clinical characteristics, such as gender, age, major diagnosis, type of pacemaker, and His-purkinje system pacing, were collected. The success rate of this axillary vein puncture technique, complications, and technical parameters of present puncture method were analyzed. Results: There were 58 (52.7%) male patients in this cohort and the average aged was (70.26±10.45) years old. This "blind" axillary vein puncture method was successful in 105 out of 110 patients (95.5%). The relevant puncture-related parameters included: the distance between points "a and b" was (3.89±0.40) cm, the first angle α was (25.84±5.54)° and the second angle ß was (66.18±10.26)°. There were no puncture-related complications, such as hematoma, pneumothorax and hemothorax. Conclusion: The new "blind" axillary vein puncture approach is a simple, effective and safe technique for pacemaker implantation, which is easy to learn and practice and suitable for promotion.

Outcomes Associated With Extraction Versus Capping and Abandoning Pacing and Defibrillator Leads.

BACKGROUND: Lead management is an increasingly important aspect of care in patients with cardiac implantable electronic devices; however, relatively little is known about long-term outcomes after capping and abandoning leads. METHODS: Using the 5% Medicare sample, we identified patients with de novo cardiac implantable electronic device implantations between January 1, 2000, and December 31, 2013, and with a subsequent lead addition or extraction ≥12 months after the de novo implantation. Patients who underwent extraction for infection were excluded. Using multivariable Cox proportional hazards models, we compared cumulative incidence of all-cause mortality, device-related infection, device revision, and lead extraction at 1 and 5 years for the extraction versus the cap and abandon group. RESULTS: Among 6859 patients, 1113 (16.2%) underwent extraction, whereas 5746 (83.8%) underwent capping and abandonment. Extraction patients tended to be younger (median, 78 versus 79 years; P<0.0001), were less likely to be male (65% versus 68%; P=0.05), and had shorter lead dwell time (median, 3.0 versus 4.0 years; P<0.0001) and fewer comorbidities. Over a median follow-up of 2.4 years (25th, 75th percentiles, 1.0, 4.3 years), the overall 1-year and 5-year cumulative incidence of mortality was 13.5% (95% confidence interval [CI], 12.7-14.4) and 54.3% (95% CI, 52.8-55.8), respectively. Extraction was associated with a lower risk of device infection at 5 years relative to capping (adjusted hazard ratio, 0.78; 95% CI, 0.62-0.97; P=0.027). There was no association between extraction and mortality, lead revision, or lead extraction at 5 years. CONCLUSIONS: Elective lead extraction for noninfectious indications had similar long-term survival to that for capping and abandoning leads in a Medicare population. However, extraction was associated with lower risk of device infections at 5 years.

Permanent Leadless Cardiac Pacemaker Therapy: A Comprehensive Review.

A new technology, leadless pacemaker therapy, was recently introduced clinically to address lead- and pocket-related complications in conventional transvenous pacemaker therapy. These leadless devices are self-contained right ventricular single-chamber pacemakers implanted by using a femoral percutaneous approach. In this review of available clinical data on leadless pacemakers, early results with leadless devices are compared with historical results with conventional single-chamber pacing. Both presently manufactured leadless pacemakers show similar complications, which are mostly related to the implant procedure: cardiac perforation, device dislocation, and femoral vascular access site complications. In comparison with conventional transvenous single-chamber pacemakers, slightly higher short-term complication rates have been observed: 4.8% for leadless pacemakers versus 4.1% for conventional pacemakers. The complication rate of the leadless pacemakers is influenced by the implanter learning curve for this new procedure. No long-term outcome data are yet available for the leadless pacemakers. Larger leadless pacing trials, with long-term follow-up and direct randomized comparison with conventional pacing systems, will be required to define the proper clinical role of these leadless systems. Although current leadless pacemakers are limited to right ventricular pacing, future advanced, communicating, multicomponent systems are expected to expand the potential benefits of leadless therapy to a larger patient population.

Conduction Disturbances After Transcatheter Aortic Valve Replacement: Current Status and Future Perspectives.

Transcatheter aortic valve replacement (TAVR) has become a well-accepted option for treating patients with aortic stenosis at intermediate to high or prohibitive surgical risk. TAVR-related conduction disturbances, mainly new-onset left bundle-branch block and advanced atrioventricular block requiring permanent pacemaker implantation, remain the most common complication of this procedure. Furthermore, improvements in TAVR technology, akin to the increasing experience of operators/centers, have translated to a major reduction in periprocedural complications, yet the incidence of conduction disturbances has remained relatively high, with perhaps an increasing trend over time. Several factors have been associated with a heightened risk of conduction disturbances and permanent pacemaker implantation after TAVR, with prior right bundle-branch block and transcatheter valve type and implantation depth being the most commonly reported. New-onset left bundle-branch block and the need for permanent pacemaker implantation may have a significant detrimental association with patients' prognosis. Consequently, strategies intended to reduce the risk and to improve the management of such complications are of paramount importance, particularly in an era when TAVR expansion toward treating lower-risk patients is considered inevitable. In this article, we review the available evidence on the incidence, predictive factors, and clinical association of conduction disturbances after TAVR and propose a strategy for the management of these complications.

[Bachmann bundle pacing]. / Bachmann-Bündel-Pacing.

In pacemaker and ICD therapy, atrial leads are usually implanted in the right atrial appendage (RAA). This is easy but associated with a risk of negative hemodynamic and electrophysiological effects. Atrial depolarization, atrial contraction, and atrioventricular conduction can be delayed and desynchronized by RAA pacing leading to atrial fibrillation, pacing-induced long first-degree AV block, right ventricular pacing and the development of heart failure. High-septal atrial pacing near Bachmann's bundle that connects the right and left atrium can prevent the negative effects of RAA pacing and synchronize atrial excitation as demonstrated by the shortening of the PQ time and P wave duration during Bachmann bundle pacing. This review presents techniques to implant atrial leads at Bachmann's bundle. Apart from fluoroscopy in left anterior oblique projection, no additional effort compared to RAA implantation is required. Clinical studies on Bachmann bundle pacing are sparse; our own results suggest beneficial effects in patients with sick sinus syndrome and paroxysmal atrial fibrillation who receive atrial pacing for ≥50% of the time. Bachmann bundle pacing represents an interesting and simple option for atrial pacing. It is desirable to make this technique known to a wider spectrum of implanters and to generate more data on its clinical potential.

[Leadless pacemakers and subcutaneously implantable cardioverter defibrillators]. / Sondenlose Schrittmacher und subkutan implantierbare Kardioverter-Defibrillatoren.

Although pacemakers and implantable defibrillators have become the standard treatment of bradycardic and tachycardic arrhythmias, long-term complications caused by the transvenously inserted pacing and defibrillation leads, such as electrode fracture, lead infection and tricuspid valve insufficiency are not uncommonly observed. Therefore, leadless pacemakers and purely subcutaneously implantable cardioverter defibrillators (S-ICDs) have been developed in recent years, which are implanted without transvenous electrodes with the aim to reduce long-term complications with these devices; however, currently available leadless pacemakers are limited to single chamber stimulation and S­ICDs are limited to pure defibrillation without antibradycardic, antitachycardic pacing or cardiac resynchronization capabilities. Thus, these devices cannot yet be used as multichamber pacemakers or defibrillators even though in these circumstances a higher complication rate is to be expected due to the multiple number of transvenous leads. This article summarizes the current state of knowledge on leadless pacemakers and ICDs, discusses the limitations of these devices and provides an outlook into their future development.

Association Between a Prolonged PR Interval and Outcomes of Cardiac Resynchronization Therapy: A Report From the National Cardiovascular Data Registry.

BACKGROUND: A prolonged PR interval is common among cardiac resynchronization therapy (CRT) candidates; however, the association between PR interval and outcomes is unclear, and the data are conflicting. METHODS: We conducted inverse probability weighted analyses of 26 451 CRT-eligible (ejection fraction ≤35, QRS ≥120 ms) patients from the National Cardiovascular Data Registry ICD Registry to assess the association between a prolonged PR interval (≥230 ms), receipt of CRT with defibrillator (CRT-D) versus implantable cardioverter defibrillator (ICD), and outcomes. We first tested the association between a prolonged PR interval and outcomes among patients stratified by device type. Next, we performed a comparative effectiveness analysis of CRT-D versus ICD among patients when stratified by PR interval. Using Medicare claims data, we followed up with patients up to 5 years for incident heart failure hospitalization or death. RESULTS: Patients with a PR≥230 ms (15%; n=4035) were older and had more comorbidities, including coronary artery disease, atrial arrhythmias, diabetes mellitus, and chronic kidney disease. After risk adjustment, a PR≥230 ms (versus PR<230 ms) was associated with increased risk of heart failure hospitalization or death among CRT-D (hazard ratio, 1.23; 95% confidence interval, 1.14-1.31; P<0.001) but not ICD recipients (hazard ratio, 1.08; 95% confidence interval, 0.97-1.20; P=0.17) (Pinteraction=0.043). CRT-D (versus ICD) was associated with lower rates of heart failure hospitalization or death among patients with PR<230 ms (hazard ratio, 0.79; 95% confidence interval, 0.73-0.85; P<0.001) but not PR≥230 ms (hazard ratio, 1.01; 95% confidence interval, 0.87-1.17; P=0.90) (Pinteraction=0.0025). CONCLUSIONS: A PR≥230 ms is associated with increased rates of heart failure hospitalization or death among CRT-D patients. The real-world comparative effectiveness of CRT-D (versus ICD) is significantly less among patients with a PR≥230 ms in comparison with patients with a PR<230 ms.