Temporary cardiac pacemakers used in periods of need during surgical recovery involve percutaneous leads and externalized hardware that carry risks of infection, constrain patient mobility and may ...damage the heart during lead removal. Here we report a leadless, battery-free, fully implantable cardiac pacemaker for postoperative control of cardiac rate and rhythm that undergoes complete dissolution and clearance by natural biological processes after a defined operating timeframe. We show that these devices provide effective pacing of hearts of various sizes in mouse, rat, rabbit, canine and human cardiac models, with tailored geometries and operation timescales, powered by wireless energy transfer. This approach overcomes key disadvantages of traditional temporary pacing devices and may serve as the basis for the next generation of postoperative temporary pacing technology.
This study sought to define contemporary trends in permanent pacemaker use by analyzing a large national database.
The Medicare National Coverage Determination for permanent pacemaker, which ...emphasized single-chamber pacing, has not changed significantly since 1985. We sought to define contemporary trends in permanent pacemaker use by analyzing a large national database.
We queried the Nationwide Inpatient Sample to identify permanent pacemaker implants between 1993 and 2009 using the International Classification of Diseases-Ninth Revision-Clinical Modification procedure codes for dual-chamber (DDD), single-ventricular (VVI), single-atrial (AAI), or biventricular (BiV) devices. Annual permanent pacemaker implantation rates and patient demographics were analyzed.
Between 1993 and 2009, 2.9 million patients received permanent pacemakers in the United States. Overall use increased by 55.6%. By 2009, DDD use increased from 62% to 82% (p < 0.001), whereas single-chamber ventricular pacemaker use fell from 36% to 14% (p = 0.01). Use of DDD devices was higher in urban, nonteaching hospitals (79%) compared with urban teaching hospitals (76%) and rural hospitals (72%). Patients with private insurance (83%) more commonly received DDD devices than Medicaid (79%) or Medicare (75%) recipients (p < 0.001). Patient age and Charlson comorbidity index increased over time. Hospital charges ($2011) increased 45.3%, driven by the increased cost of DDD devices.
There is a steady growth in the use of permanent pacemakers in the United States. Although DDD device use is increasing, whereas single-chamber ventricular pacemaker use is decreasing. Patients are becoming older and have more medical comorbidities. These trends have important health care policy implications.
A leadless intracardiac transcatheter pacing system has been designed to avoid the need for a pacemaker pocket and transvenous lead.
In a prospective multicenter study without controls, a ...transcatheter pacemaker was implanted in patients who had guideline-based indications for ventricular pacing. The analysis of the primary end points began when 300 patients reached 6 months of follow-up. The primary safety end point was freedom from system-related or procedure-related major complications. The primary efficacy end point was the percentage of patients with low and stable pacing capture thresholds at 6 months (≤2.0 V at a pulse width of 0.24 msec and an increase of ≤1.5 V from the time of implantation). The safety and efficacy end points were evaluated against performance goals (based on historical data) of 83% and 80%, respectively. We also performed a post hoc analysis in which the rates of major complications were compared with those in a control cohort of 2667 patients with transvenous pacemakers from six previously published studies.
The device was successfully implanted in 719 of 725 patients (99.2%). The Kaplan-Meier estimate of the rate of the primary safety end point was 96.0% (95% confidence interval CI, 93.9 to 97.3; P<0.001 for the comparison with the safety performance goal of 83%); there were 28 major complications in 25 of 725 patients, and no dislodgements. The rate of the primary efficacy end point was 98.3% (95% CI, 96.1 to 99.5; P<0.001 for the comparison with the efficacy performance goal of 80%) among 292 of 297 patients with paired 6-month data. Although there were 28 major complications in 25 patients, patients with transcatheter pacemakers had significantly fewer major complications than did the control patients (hazard ratio, 0.49; 95% CI, 0.33 to 0.75; P=0.001).
In this historical comparison study, the transcatheter pacemaker met the prespecified safety and efficacy goals; it had a safety profile similar to that of a transvenous system while providing low and stable pacing thresholds. (Funded by Medtronic; Micra Transcatheter Pacing Study ClinicalTrials.gov number, NCT02004873.).
In the second part of this 2-part series on pacemakers, we present recent advances in pacemakers and preview future developments. Cardiac resynchronization therapy (CRT) is a potent treatment for ...heart failure in the setting of ventricular dyssynchrony. Successful CRT using coronary venous pacing depends on appropriate patient selection, lead implantation, and device programming. Despite optimization of these factors, nonresponse to CRT may occur in one-third of patients, which has led to a search for alternative techniques such as multisite pacing, His bundle pacing, and endocardial left ventricular pacing. A paradigm shift in pacemaker technology has been the development of leadless pacemaker devices, and on the horizon is the development of batteryless devices. Remote monitoring has ushered in an era of greater safety and the ability to respond to device malfunction in a timely fashion, improving outcomes.
The presence of a cardiovascular implantable electronic device has long been a contraindication for the performance of magnetic resonance imaging (MRI). We established a prospective registry to ...determine the risks associated with MRI at a magnetic field strength of 1.5 tesla for patients who had a pacemaker or implantable cardioverter-defibrillator (ICD) that was "non-MRI-conditional" (i.e., not approved by the Food and Drug Administration for MRI scanning).
Patients in the registry were referred for clinically indicated nonthoracic MRI at a field strength of 1.5 tesla. Devices were interrogated before and after MRI with the use of a standardized protocol and were appropriately reprogrammed before the scanning. The primary end points were death, generator or lead failure, induced arrhythmia, loss of capture, or electrical reset during the scanning. The secondary end points were changes in device settings.
MRI was performed in 1000 cases in which patients had a pacemaker and in 500 cases in which patients had an ICD. No deaths, lead failures, losses of capture, or ventricular arrhythmias occurred during MRI. One ICD generator could not be interrogated after MRI and required immediate replacement; the device had not been appropriately programmed per protocol before the MRI. We observed six cases of self-terminating atrial fibrillation or flutter and six cases of partial electrical reset. Changes in lead impedance, pacing threshold, battery voltage, and P-wave and R-wave amplitude exceeded prespecified thresholds in a small number of cases. Repeat MRI was not associated with an increase in adverse events.
In this study, device or lead failure did not occur in any patient with a non-MRI-conditional pacemaker or ICD who underwent clinically indicated nonthoracic MRI at 1.5 tesla, was appropriately screened, and had the device reprogrammed in accordance with the prespecified protocol. (Funded by St. Jude Medical and others; MagnaSafe ClinicalTrials.gov number, NCT00907361 .).
The European Lead Extraction ConTRolled Registry (ELECTRa), is a prospective registry of consecutive transvenous lead extraction (TLE) procedures conducted by the European Heart Rhythm Association ...(EHRA) in order to identify the safety and efficacy of the current practice of TLE.
European centres performing TLE, invited by the organizing committee on behalf of EHRA, prospectively recruited all consecutive patients undergoing TLE at their institution. The primary endpoint was TLE safety defined by pre-discharge major procedure-related complications including death. Secondary endpoints included clinical and radiological success and overall complication rates. Outcomes were compared between Low Volume (LoV) vs. High Volume (HiV) centers (LoV < 30 and HiV ≥ 30 procedures/year). A total of 3555 consecutive patients (pts) of whom 3510 underwent TLE at 73 centres in 19 European countries were enrolled between November 2012 and May 2014. The primary endpoint of in-hospital procedure-related major complication rate was 1.7% 95% CI 1.3-2.1% (58/3510 pts) including a mortality of 0.5% 95% CI 0.3-0.8% (17/3510 pts). Approximately two-thirds (37/58) of these complications occurred during the procedure and one-third (21/58) in the post-operative period. The most common procedure related complications were those requiring pericardiocentesis or chest tube and/or surgical repair (1.4% 95% CI 1.0-1.8%). Complete clinical and radiological success rates were 96.7% 95% CI 96.1-97.3% and 95.7% 95% CI 95.2-96.2%, respectively. The all cause in-hospital major complications and deaths were significantly lower in HiV centres vs. LoV centres (2.4% 95% CI 1.9-3.0% vs. 4.1% 95% CI 2.7-6.0%, P = 0.0146; and 1.2% 95% CI 0.8-1.6% vs. 2.5% 95% CI 1.5-4.1% P = 0.0088), although those related to the procedure did not reach statistical significance. Radiological and clinical successes were more frequent in HiV vs. LoV centres.
The ELECTRa study is the largest prospective registry on TLE and confirmed the safety and efficacy of the current practice of TLE. Lead extraction was associated with a higher success rate with lower all cause complication and mortality rates in high volume compared with low volume centres.
The widespread use of cardiac implantable electronic devices and wearable monitors has led to the detection of subclinical atrial fibrillation in a substantial proportion of patients. There is ...evidence that these asymptomatic arrhythmias are associated with increased risk of stroke. Thus, detection of subclinical atrial fibrillation may offer an opportunity to reduce stroke risk by initiating anticoagulation. However, it is unknown whether long-term anticoagulation is warranted and in what populations. This scientific statement explores the existing data on the prevalence, clinical significance, and management of subclinical atrial fibrillation and identifies current gaps in knowledge and areas of controversy and consensus.
Advances in cardiac surgery toward the mid-20th century created a need for an artificial means of stimulating the heart muscle. Initially developed as large external devices, technological advances ...resulted in miniaturization of electronic circuitry and eventually the development of totally implantable devices. These advances continue to date, with the recent introduction of leadless pacemakers. In this first part of a 2-part review, we describe indications, implant-related complications, basic function/programming, common pacemaker-related issues, and remote monitoring, which are relevant to the practicing cardiologist. We provide an overview of magnetic resonance imaging and perioperative management among patients with cardiac pacemakers.
Objective
To characterize contemporary pacemaker procedure trends.
Methods
Nationwide analysis of pacemaker procedures and costs between 2008 and 2017 in Australia. The main outcome measures were ...total, age‐ and gender‐specific implant, replacement, and complication rates, and costs.
Results
Pacemaker implants increased from 12,153 to 17,862. Implantation rates rose from 55.3 to 72.6 per 100,000, a 2.8% annual increase (incidence rate ratio IRR 1.028; 95% CI, 1.02–1.04; p < .001). Pacemaker implants in the 80+ age group were 17.37‐times higher than the < 50 group (95% CI 16.24–18.59; p < .001), and in males were 1.48‐times higher than in females (95% CI 1.42–1.55; p < .001). However, there were similar increases according to age (p = .10) and gender (p = .68) over the study period. Left ventricular lead rates were stable (IRR 0.995; 95% CI 0.98–1.01; p = .53). Generator replacements decreased from 20.5 to 18.3 per 100,000 (IRR 0.975; 95% CI 0.97–0.98; p < .001). Although procedures for generator‐related complications were stable (IRR 0.995; 95% CI 0.98–1.01; p = .54), those for lead‐related complications decreased (IRR 0.985; 95% CI 0.98–0.99; p < .001). Rates for all pacemaker procedures were consistently greater in males (p < .001). Although annual costs of all pacemaker procedures increased from $178 million to $329 million, inflation‐adjusted costs were more stable, rising from $294 million to $329 million.
Conclusions
Increasing demand for pacemaker implants is driven by the ageing population and rising rates across all ages, while replacement and complication procedure rates appeared more stable. Males have consistently greater pacemaker procedure rates than females. Our findings have significant clinical and public health implications for healthcare resource planning.
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