The relation between patients' outcomes and the volume of cardioverter-defibrillator implantation procedures performed by physicians treating Medicare beneficiaries

Is conduction system pacing a panacea for pacemaker therapy?

INTRODUCTION

While supported by robust evidence and decades of clinical experience, right ventricular apical pacing for bradycardia is associated with a risk of progressive left ventricular dysfunction. Cardiac resynchronization therapy for heart failure with reduced ejection fraction can result in limited electrical resynchronization due to anatomical constraints and epicardial stimulation. In both settings, directly stimulating the conduction system below the atrio-ventricular node (either the bundle of His or the left bundle branch area) has potential to overcome these limitations. Conduction system pacing has met with considerable enthusiasm in view of the more physiological electrical conduction pattern, is rapidly becoming the preferred option of pacing for bradycardia, and is gaining momentum as an alternative to conventional biventricular pacing.

AREAS COVERED

This article provides a review of the current efficacy and safety data for both people requiring treatment for bradycardia and the management of heart failure with conduction delay and discusses the possible future roles for conduction system pacing in routine clinical practice.

EXPERT OPINION

Conduction system pacing might be the holy grail of pacemaker therapy without the disadvantages of current approaches. However, hypothesis and enthusiasm are no match for robust data, demonstrating at least equivalent efficacy and safety to standard approaches.

Prevention and Management of Cardiac Implantable Electronic Device Infections: State-of-the-Art and Future Directions

Cardiac implantable electronic device (CIED) infection is an increasingly common complication of device therapy. CIED infection confers significant patient morbidity and health care expenditure, hence it is essential that clinicians recognise the contemporary strategies for predicting, reducing and treating these events. Recent technological advances-in particular, the development of antimicrobial envelopes, leadless devices and validated risk scores-present decision-makers with novel strategies for managing this expanding patient population. This review summarises the key issues facing CIED patients and their physicians, and explores the supporting evidence for the latest therapeutic developments in this field.

Inequality between women and men in ICD implantation

Background

The impact of sex on ICD implantation practice and survival remain a topic of controversy. To assess sex-specific differences in ICD implantation practice we compared clinical characteristics and survival in women and men.

Methods

From a nationwide registry, all new ICD implantations performed between 01/02/2010 and 31/01/2019 in Belgian patients were analyzed retrospectively. Baseline characteristics and survival rates were compared between sexes. To identify predictors of mortality, multivariable Cox regression was performed.

Results

Only 3096 (20.9%) of 14,787 ICD implantations were performed in women. Within each type of underlying cardiomyopathy, the proportion women were lower than men. The main indication in men was ischemic vs dilated cardiomyopathy in women. Women were overall younger (59.1 ± 15.1 vs 62.6 ± 13.1 years; p < 0.001) and had less comorbidities except for oncological disease. More women functioned in NYHA-class III (33.6% vs 27.9%; p < 0.001) and had a QRS > 150 ms (29.4% vs 24.3%; p < 0.001), consistent with a higher use of CRT-D devices (31.7% vs 25.1%; p < 0.001). Women had more complications, reflected by the need to more re-interventions within 1 year (4.3% vs 2.7%, p < 0.001). After correction for covariates, sex-category was not a significant predictor of mortality (p = 0.055).

Conclusion

There is a significant sex-disparity in ICD implantation rates, not fully explained by epidemiological differences in the prevalence of cardiomyopathies, which could imply an undertreatment of women. Women differ from men in baseline characteristics at implantation suggesting a selection bias. Further research is necessary to evaluate if women receive equal sudden cardiac death prevention.

Canadian Heart Rhythm Society Task Force Report on Physician Training and Maintenance of Competency for Cardiovascular Implantable Electronic Device Therapies: Executive Summary

Physicians engaged in cardiovascular implantable electronic device (CIED)-related practice come from diverse training backgrounds with variable degrees of CIED implant training. The objective of the Canadian Heart Rhythm Society Task Force on CIED Implant Training was to establish a common structure and content for training programs in CIED implantation, related activities and maintenance of competency. This executive summary presents the essence of the report with key recommendations included, with the complete version made available in a linked supplement. The goals are to ensure that future generations of CIED implanters are better prepared for continuously evolving CIED practice and quality care for all Canadians.

Epidemiology of cardiac implantable electronic device infections: incidence and risk factors

Cardiac implantable electronic device (CIED) infection is a potentially devastating complication of CIED procedures, causing significant morbidity and mortality for patients. Of all CIED complications, infection has the greatest impact on mortality, requirement for re-intervention and additional hospital treatment days. Based on large prospective studies, the infection rate at 12-months after a CIED procedure is approximately 1%. The risk of CIED infection may be related to several factors which should be considered with regards to risk minimization. These include technical factors, patient factors, and periprocedural factors. Technical factors include the number of leads and size of generator, the absolute number of interventions which have been performed for the patient, and the operative approach. Patient factors include various non-modifiable underlying comorbidities and potentially modifiable transient conditions. Procedural factors include both peri-operative and post-operative factors. The contemporary PADIT score, derived from a large cohort of CIED patients, is useful for the prediction of infection risk. In this review, we summarize the key information regarding epidemiology, incidence and risk factors for CIED infection.

European Heart Rhythm Association (EHRA) international consensus document on how to prevent, diagnose, and treat cardiac implantable electronic device infections-endorsed by the Heart Rhythm Society (HRS), the Asia Pacific Heart Rhythm Society (APHRS), the Latin American Heart Rhythm Society (LAHRS), International Society for Cardiovascular Infectious Diseases (ISCVID) and the European Society of Clinical Microbiology and Infectious Diseases (ESCMID) in collaboration with the European Association for Cardio-Thoracic Surgery (EACTS)

Pacemakers, implantable cardiac defibrillators, and cardiac resynchronization therapy devices are potentially life-saving treatments for a number of cardiac conditions, but are not without risk. Most concerning is the risk of a cardiac implantable electronic device (CIED) infection, which is associated with significant morbidity, increased hospitalizations, reduced survival, and increased healthcare costs. Recommended preventive strategies such as administration of intravenous antibiotics before implantation are well recognized. Uncertainties have remained about the role of various preventive, diagnostic, and treatment measures such as skin antiseptics, pocket antibiotic solutions, anti-bacterial envelopes, prolonged antibiotics post-implantation, and others. Guidance on whether to use novel device alternatives expected to be less prone to infections and novel oral anticoagulants is also limited, as are definitions on minimum quality requirements for centres and operators and volumes. Moreover, an international consensus document on management of CIED infections is lacking. The recognition of these issues, the dissemination of results from important randomized trials focusing on prevention of CIED infections, and observed divergences in managing device-related infections as found in an European Heart Rhythm Association worldwide survey, provided a strong incentive for a 2019 International State-of-the-art Consensus document on risk assessment, prevention, diagnosis, and treatment of CIED infections.

European Heart Rhythm Association (EHRA) international consensus document on how to prevent, diagnose, and treat cardiac implantable electronic device infections-endorsed by the Heart Rhythm Society (HRS), the Asia Pacific Heart Rhythm Society (APHRS), the Latin American Heart Rhythm Society (LAHRS), International Society for Cardiovascular Infectious Diseases (ISCVID) and the European Society of Clinical Microbiology and Infectious Diseases (ESCMID) in collaboration with the European Association for Cardio-Thoracic Surgery (EACTS)

Pacemakers, implantable cardiac defibrillators, and cardiac resynchronization therapy devices are potentially life-saving treatments for a number of cardiac conditions, but are not without risk. Most concerning is the risk of a cardiac implantable electronic device (CIED) infection, which is associated with significant morbidity, increased hospitalizations, reduced survival, and increased healthcare costs. Recommended preventive strategies such as administration of intravenous antibiotics before implantation are well recognized. Uncertainties have remained about the role of various preventive, diagnostic, and treatment measures such as skin antiseptics, pocket antibiotic solutions, anti-bacterial envelopes, prolonged antibiotics post-implantation, and others. Guidance on whether to use novel device alternatives expected to be less prone to infections and novel oral anticoagulants is also limited, as are definitions on minimum quality requirements for centres and operators and volumes. Moreover, an international consensus document on management of CIED infections is lacking. The recognition of these issues, the dissemination of results from important randomized trials focusing on prevention of CIED infections, and observed divergences in managing device-related infections as found in an European Heart Rhythm Association worldwide survey, provided a strong incentive for a 2019 International State-of-the-art Consensus document on risk assessment, prevention, diagnosis, and treatment of CIED infections.

European Heart Rhythm Association (EHRA) international consensus document on how to prevent, diagnose, and treat cardiac implantable electronic device infections-endorsed by the Heart Rhythm Society (HRS), the Asia Pacific Heart Rhythm Society (APHRS), the Latin American Heart Rhythm Society (LAHRS), International Society for Cardiovascular Infectious Diseases (ISCVID), and the European Society of Clinical Microbiology and Infectious Diseases (ESCMID) in collaboration with the European Association for Cardio-Thoracic Surgery (EACTS)

Pacemakers, implantable cardiac defibrillators, and cardiac resynchronization therapy devices are potentially lifesaving treatments for a number of cardiac conditions but are not without risk. Most concerning is the risk of a cardiac implantable electronic device (CIED) infection, which is associated with significant morbidity, increased hospitalizations, reduced survival, and increased health care costs. Recommended preventive strategies such as administration of intravenous antibiotics before implantation are well-recognized. Uncertainties have remained about the role of various preventive, diagnostic, and treatment measures such as skin antiseptics, pocket antibiotic solutions, antibacterial envelopes, prolonged antibiotics post-implantation, and others. When compared with previous guidelines or consensus statements, the present consensus document gives guidance on the use of novel device alternatives, novel oral anticoagulants, antibacterial envelopes, prolonged antibiotics post-implantation, as well as definitions on minimum quality requirements for centres and operators and volumes. The recognition that an international consensus document focused on management of CIED infections is lacking, the dissemination of results from new important randomized trials focusing on prevention of CIED infections, and observed divergences in managing device-related infections as found in an European Heart Rhythm Association worldwide survey, provided a strong incentive for a Novel 2019 International State-of-the-art Consensus document on risk assessment, prevention, diagnosis, and treatment of CIED infections.

Comparison of new implantation of cardiac implantable electronic device between tertiary and non-tertiary hospitals: a Korean nationwide study

This study compared the characteristics and mortality of new implantation of cardiac implantable electronic device (CIED) between tertiary and non-tertiary hospitals. From national health insurance claims data in Korea, 17,655 patients, who underwent first and new implantation of CIED between 2013 and 2017, were enrolled. Patients were categorized into the tertiary hospital group (n = 11,560) and non-tertiary hospital group (n = 6095). Clinical outcomes including in-hospital death and all-cause death were compared between the two groups using propensity-score matched analysis. Patients in non-tertiary hospitals were older and had more comorbidities than those in tertiary hospitals. The study population had a mean follow-up of 2.1 ± 1.2 years. In the propensity-score matched permanent pacemaker group (n = 5076 pairs), the incidence of in-hospital death (odds ratio [OR]: 0.76, 95% confidence interval [CI]: 0.43–1.32, p = 0.33) and all-cause death (hazard ratio [HR]: 0.92, 95% CI 0.81–1.05, p = 0.24) were not significantly different between tertiary and non-tertiary hospitals. These findings were consistently observed in the propensity-score matched implantable cardioverter-defibrillator group (n = 992 pairs, OR for in-hospital death: 1.76, 95% CI 0.51–6.02, p = 0.37; HR for all-cause death: 0.95, 95% CI 0.72–1.24, p = 0.70). In patients undergoing first and new implantation of CIED in Korea, mortality was not different between tertiary and non-tertiary hospitals.

Novel two-lead cardiac resynchronization therapy system provides equivalent CRT responses with less complications than a conventional three-lead system: Results from the QP ExCELs lead registry

Introduction

The novel two‐lead cardiac resynchronization therapy (CRT)‐DX system utilizes a floating atrial dipole on the implantable cardioverter‐defibrillator lead, and when implanted with a left ventricular (LV) lead, offers a two‐lead CRT system with AV synchrony. This study compared complication rates and CRT response among subjects implanted with a two‐lead CRT‐DX system to those subjects implanted with a standard three‐lead CRT‐D system.

Methods and Results

A total of 240 subjects from the Sentus QP—Extended CRT Evaluation with Quadripolar Left Ventricular Leads postapproval study were selected to identify 120 matched pairs based on similar demographic characteristics using a Greedy algorithm. The complication‐free rate was evaluated as the primary endpoint. All‐cause mortality, heart failure hospitalizations, device diagnostic data, New York Heart Association (NYHA) class improvement, and defibrillator therapy were evaluated from clinical data, in‐office interrogations, and remote monitoring throughout the follow‐up period. Complication‐free survival favored the CRT‐DX group with 92.5% without a major complication compared to 85.0% in the CRT‐D cohort (P = .0495; 95% confidence interval: 0.1%‐14.9%) over a mean follow‐up of 1.3 and 1.4 years, respectively. Incidence of all‐cause mortality, heart failure hospitalizations, NYHA changes at 6 months postimplant, and percent of LV pacing during CRT therapy were similar in both device cohorts. Inappropriate shocks were more frequent in the CRT‐D cohort with 5.8% of subjects receiving an inappropriate shock vs 0.8% in the CRT‐DX cohort.

Conclusion

The results of this subanalysis demonstrate that the CRT‐DX system can provide similar CRT responses and significantly fewer complications when compared to a similar cohort with a conventional three‐lead CRT‐D system.

Analysis of Outcomes in 8304 Patients Undergoing Lead Extraction for Infection

Background Patients undergoing lead extraction for infected devices have worse outcomes compared with those with noninfected devices. We assessed predictors of in-hospital mortality and procedure-related major adverse events (MAEs) in a large cohort undergoing lead extraction. Methods and Results Deidentified hospital records procedure from 7 states between 1994 and 2013 were aggregated and International Classification of Disease, Ninth Revision (ICD-9) procedure codes were used to identify hospital records reporting lead extraction. MAEs included death, cardiac tamponade, hemothorax, and need for emergent cardiac surgery. Predictors of in-hospital MAEs for infected compared with noninfected leads were identified using multivariate regression. Associations between outcomes and specific microbe were also assessed. In total, 57 220 discharges specified lead extraction. Infected leads accounted for the minority of total lead extractions compared with fractured leads (16.1 versus 59.8%, 25.7% not reported). There were 3298 MAEs (5.8%) including 980 deaths (1.7%). Multivariate predictors of MAE included black race, atrial fibrillation, anemia, heart failure, and admission via either hospital transfer or emergency department versus home (all P<0.001). Infected leads were associated with an increased risk of death (4.6% versus 0.9%, P<0.001) compared with leads with fracture only. Among patients with microbial data, staphylococcal infection was most common, whereas streptococcal infection was associated with the worst outcomes. Conclusions Patients undergoing extraction of infected leads have higher in-hospital mortality and adverse events compared with noninfected leads. Streptococcus, anemia, and heart failure are predictors of adverse outcomes.

Strategies to Prevent Cardiac Implantable Electronic Device Infection

The association between the risk of mortality and cardiovascular implantable electronic device (CIED) infections has been well-established in the literature. As CIED implantations have increased in frequency in the past few decades, the incidence of CIED-related infections has also risen. Given the morbidity, mortality, and health-care costs associated with CIED infections, the prevention of device-related infection is a critical goal. Risk factors for developing CIED infections can be categorized as patient-, procedure-, or device-related. Numerous studies have highlighted different strategies for preventing CIED-related infections, which include patient optimization, device selection, and periprocedural preparation and treatment. Nonetheless, as the comorbidity burden of patients undergoing CIED implantation continues to increase, significant challenges in the successful elimination of CIED-related infections remain. This review provides a comprehensive overview of available evidence-based approaches and strategies to reduce the risk of CIED infections.

Institutional Variation in Quality of Cardiovascular Implantable Electronic Device Implantation: A Cohort Study

BACKGROUND

Cardiovascular implantable electronic devices (CIEDs) are associated with procedure-related complications, yet little is known about variation in complication rates among institutions that may suggest disparities in care quality.

OBJECTIVE

To assess institutional variation in risk-standardized complication rates (RSCRs) for CIED.

DESIGN

Cohort study.

SETTING

174 hospitals in Australia and New Zealand, 98 of which implanted at least 25 CIEDs during the study period.

PARTICIPANTS

81 304 patients older than 18 years (mean, 74.7 years [SD, 12.4]; 37.9% female) who received a new CIED (65 711 permanent pacemakers [PPMs] and 15 593 implantable cardioverter-defibrillators [ICDs]) in 2010 to 2015.

MEASUREMENTS

RSCRs and frequencies of major device-related complications during hospitalization or within 90 days of discharge.

RESULTS

Of the cohort, 6664 patients (8.2%) had a major complication. Although complication rates were higher for ICDs than PPMs (10.04% vs. 7.76%), 76.5% of all complications were attributable to PPMs (5098 vs. 1566 for ICDs). Among hospitals that implanted at least 25 CIEDs, the median RSCR was 8.1%; however, rates varied from 5.3% to 14.3%, with 22 hospitals identified as having RSCRs that differed significantly from the national average. Similar variation was observed when RSCRs for PPM implantation (n = 96 hospitals) (median RSCR, 7.6% [range, 5.4% to 12.9%]) were considered separately from those for ICD placement (n = 68 hospitals) (median RSCR, 9.7% [range, 6.2% to 16.9%]) and persisted when only elective procedures were assessed (n = 88 hospitals) (median RSCR, 7.4% [range, 4.7% to 13.0%]).

LIMITATION

Possible unmeasured confounding from the use of administrative data.

CONCLUSION

CIED complications are common and vary among hospitals, suggesting institutional variation in CIED care quality. Concerted clinical and policy interventions are needed to address CIED-related complications. These efforts should preferentially target PPMs, because most CIED complications are attributable to these devices.

PRIMARY FUNDING SOURCE

The Hospitals Contribution Fund Research Foundation.

Implantable Cardioverter Defibrillators in Patients With Continuous Flow Left Ventricular Assist Devices: Utilization Patterns, Related Procedures, and Complications

Background

The effect of implantable cardioverter defibrillators (ICD) in patients with continuous flow left ventricular assist devices (LVADs) on outcomes has not been evaluated in a randomized clinical trial.

Methods and Results

This is a retrospective single‐center study that included patients who underwent continuous flow LVAD implantation at the Cleveland Clinic between October 2004 and March 2017. Patients were evaluated according to the presence or absence of ICD at the time of LVAD insertion. Among 486 patients in the study cohort, 387 (79.6%) had an ICD before LVAD insertion. Patients with ICD before LVAD were older and had lower use of pre‐LVAD inotropes, extracorporeal membrane oxygenation, and mechanical ventilation. There were 81 patients (21.4% of patients with ICD) who required 93 procedures after LVAD: 74 generator exchanges, 12 lead revisions, and 7 complete system removals because of infection. Of the 99 patients without ICD, 52 (53%) underwent ICD implantation: 29 for primary prevention and 23 for secondary prevention. Patients were followed for a median of 401 (interquartile range 150–966) days. The presence of a pre‐LVAD ICD was not associated with mortality in a multivariable model (hazard ratio 1.19, 95% CI 0.73–1.93, P=0.492), nor was the presence of an ICD at any point when analyzed as a time‐varying covariate (hazard ratio 1.05, 95% CI 0.50–2.20, P=0.907).

Conclusions

There is no apparent mortality benefit associated with an ICD in a contemporary cohort of patients with continuous flow LVADs to balance considerable morbidity involving ICD‐related procedures and complications.

Clinical and Procedural Effects of Transitioning to Contact Force Guided Ablation for Atrial Fibrillation

Background

A major innovation in atrial fibrillation (AF) ablation has been the introduction of contact force (CF) sensing catheters.

Objective

To evaluate procedural and clinical effects of transitioning to CF-guided AF ablation.

Methods

Consecutive AF ablation patients were studiedduring the period of time of transitioning from a non-CF to CF sensing catheter. Procedural data recorded was total radiofrequency time, time to isolate the left pulmonary veins (LPVs), and time to isolate the right pulmonary veins (RPVs). Clinically, the 3 and 12-month maintenance of sinus rhythm was noted and compared by: paroxysmal vs. persistent AF; CT scan LA volume more or less than 150 cc; CHA2DS2VASC more or less than 2; and LVEF more or less than 55%. Safety data was recorded as well.

Results

Total ablation times were shorter (113 vs.146 min, p=0.011)when using the CF catheters compared to non-CF ablations. This was driven by a decrease in both LPV (46 vs.72 min, p<0.001) and RPV time (54 vs. 75 min, p=0.002).The use of CF catheter did not change the overall percentage of patients in sinus rhythm at 3 and 12-months of follow up. However, sinus rhythm was more frequent at 12 months with CF ablation inpatients with an LA volume of more than 150 cc when compared to non-CF ablation (84.6% and 52.4%, p=0.03). There was no difference in outcomes with stratification by CHA2DS2VASC score or LVEF. No significant difference in complications was noted.

Conclusions

For AF ablation, the initial use of CF-sensing technology reduced procedure times with similar overall sinus rhythm maintenance at 3 and 12 months. CF improved 12-month outcomes in patients with an enlarged LA.

Physician network position and patient outcomes following implantable cardioverter defibrillator therapy

OBJECTIVE

To evaluate two novel measures of physician network centrality and their associations with implantable cardioverter defibrillator (ICD) procedure volume and health outcomes.

DATA SOURCES

Medicare claims and the National Cardiovascular Data Registry data from 2007 to 2011.

STUDY DESIGN

We constructed a national cardiovascular disease patient-sharing physician network and used network analysis to characterize physician network centrality with two measures: within-hospital degree centrality (number of connections within a hospital) and across-hospital degree centrality (number of connections across hospitals). The primary outcome was risk-adjusted 2-year case fatality. Hierarchical logistic regression estimated the effects of physician's within-hospital and across-hospital degree centrality on case fatality. We included 105 109 ICD therapy patients and 3474 ICD implanting physicians in our analyses.

PRINCIPAL FINDINGS

After controlling for other physician and hospital characteristics, we observed greater risk-adjusted case fatality among patients treated by physicians in the highest across-hospital degree tertile compared to lowest tertile (OR [95% CI] = 1.10 [1.04-1.16], P = 0.001) and lowest tertile volume physicians compared with highest volume (OR [95% CI] = 0.90 [0.84-0.95], P < 0.001). Physician's within-hospital degree tertile was inversely associated with case fatality but not statistically significant.

CONCLUSIONS

Degree centrality measures capture information independent of procedure volume and raise questions about the quality of physicians with networks that predict worse health outcomes.

Cardiac implantable electronic device infections: Observational data from a tertiary care center in Lebanon

With increasing rates of device implantation, there is an increased recognition of device infection. We conducted a retrospective observational study in a tertiary care center in Lebanon, with data collected from medical records of patients presenting with cardiac implantable electronic device (CIED) infection from 2000 to 2017 with the purpose of identifying etiologies, risk factors and other parameters, and comparing them to available data from the rest of the world. We identified a total of 22 CIED infections. The most common microbial etiologies, including involvement in polymicrobial infection, were coagulase-negative staphylococci (45.5%) and Staphylococcus aureus (22.7%). Rare cases of Brucella melitensis, Sphingomonas paucimobilis, and Kytococcus schroeteri device infection were seen. Heart failure was seen in 77.3% of patients, hypertension in 68.2%, and chronic kidney disease in 50%. Skin changes were the most common presenting symptoms (86.4%). Antibiotics were given to all patients and all had their devices removed, with 36.4% undergoing new device implantation. This is the first study of CIED infections in Lebanon and the Middle East. Local epidemiology and occupational exposure must be considered while contemplating the microbial etiology of infection. Close monitoring after device implantation is important in preventing device infection that carries high risk of morbidity and mortality.

Infection Management

Cardiovascular implantable electronic devices (CIEDs) and the indications for their use have significantly risen over the past decades to include patients who are older with more medical comorbidities. Predictably, the rates of CIED infection have increased substantially. CIED infection is associated with high morbidity, mortality, and financial costs. This article discusses the appropriate management of CIED infections, which is imperative to limit the problems associated with infection.

Frequency of in-hospital adverse outcomes and cost utilization associated with cardiac resynchronization therapy defibrillator implantation in the United States

BACKGROUND

The utilization of cardiac resynchronization therapy defibrillator (CRT-D) has increased significantly, since its initial approval for use in selected patients with heart failure. Limited data exist as for current trends in implant-related in-hospital complications and cost utilization. The aim of our study was to examine in-hospital complication rates associated with CRT-D and their trends over the last decade.

METHODS AND RESULTS

Using the Nationwide Inpatient Sample, we estimated 378 248 CRT-D procedures from 2003 to 2012. We investigated common complications, including mechanical, cardiovascular, pericardial complications (hemopericardium, cardiac tamponade, or pericardiocentesis), pneumothorax, stroke, vascular complications (consisting of hemorrhage/hematoma, incidents requiring surgical repair, and accidental arterial puncture), and in-hospital deaths described with CRT-D, defining them by the validated International Classification of Diseases, Ninth Revision, Clinical Modification diagnosis code. Mechanical complications (5.9%) were the commonest, followed by cardiovascular (3.6%), respiratory failure (2.4%), and pneumothorax (1.5%). Age (≥65 years), female gender (OR, 95% CI; P value) (1.08, 1.03-1.13; 0.001), and the Charlson score ≥3 (1.52, 1.45-1.60; <0.001) were significantly associated with increased mortality/complications.

CONCLUSIONS

The overall complication rate in patients undergoing CRT-D has been increasing in the last decade. Age (≥65), female sex, and the Charlson score ≥3 were associated with higher complications. In patients who underwent CRT-D implantation, postoperative complications were associated with significant increases in cost.

Infective endocarditis and risk of death after cardiac implantable electronic device implantation: a nationwide cohort study

Aims

To determine the incidence, risk factors, and mortality of infective endocarditis (IE) following implantation of a first-time, permanent, cardiac implantable electronic device (CIED).

Methods and results

From Danish nationwide administrative registers (beginning in 1996), we identified all de-novo permanent pacemakers (PMs) and implantable cardioverter defibrillators (ICDs) together with the occurrence of post-implantation IE-events in the period from 2000-2012. Included were 43 048 first-time PM/ICD recipients. Total follow-up time was 168 343 person-years (PYs). The incidence rate (per 1000 PYs) of IE in PM was 2.1 (95% confidence interval [CI]: 1.7-2.6) for single chamber devices and 6.2 (95% CI: 4.5-8.7) for cardiac resynchronization therapy (CRT); similarly, the rate of IE in ICD was 3.7 (95% CI: 2.9-4.7) in single chamber devices and 6.3 (95% CI: 4.4-9.0) in CRT. In multivariable analysis, increased PM complexity served as independent risk factor for IE {dual chamber PM [hazard ratio (HR) 1.39; 95% CI: 1.07-1.80] and CRT [HR: 1.84; 95% CI: 1.20-2.84]}. During follow-up, generator replacement (HR: 2.79; 95% CI: 1.87-4.17) and lead revision (HR: 4.33; 95% CI: 3.25-5.78) in PMs were associated with increased risk. Corresponding estimates in ICDs were 2.49 (95% CI: 1.28-4.86) and 6.58 (95% CI: 4.49-9.63). Risk of death after IE was significantly increased in PM and ICD with HRs of 1.56 (95% CI: 1.33-1.82) and 2.63 (95% CI: 2.00-3.48), respectively.

Conclusion

The risk of IE increased with increasing PM complexity. Other important risk factors were subsequent generator replacement and lead revision. IE was associated with an increased risk of mortality in the area of CIED.

Application of an Infection Control Protocol (ICP) Reduced Cardiac Device Infection (CDI) in Low-Volume Centers

Background

Cardiac device infection (CDI) is a serious complication of cardiovascular implantable electronic device (CIED) implantations. Many risk factors have been identified, but several are still uncertain. This study aimed to identify and evaluate the risk factors. Moreover, an infection control protocol (ICP) was carried out, and its efficacy in reducing CDIs was investigated.

Material/Methods

A total of 1259 patients who received permanent pacemaker (PPM) implantations were enrolled in this study in a 3-year period in a high-volume center and low-volume centers in the central area of Shaanxi Province, China. Follow-up data of all enrolled patients were collected. The risk factors for CDIs were identified and analyzed. The ICP was adopted in the low-volume centers. Data, including CDI rates, medical costs, and microbiology, were collected and compared.

Results

Male gender, diabetes, CKD, operation duration, PPM replacement, and low center volume were identified as the risk factors for CDIs. Furthermore, CDI rates in low-volume centers were significantly higher than in high-volume centers. The adoption of an ICP dramatically reduced CDI rates in low-volume centers without significant increases in medical costs.

Conclusions

ICPs were easily carried out, effective, and economical in controlling CDIs in low-volume centers, which was identified as a risk factor of CDIs.

Can machine learning complement traditional medical device surveillance? A case study of dual-chamber implantable cardioverter-defibrillators

BACKGROUND

Machine learning methods may complement traditional analytic methods for medical device surveillance.

METHODS AND RESULTS

Using data from the National Cardiovascular Data Registry for implantable cardioverter-defibrillators (ICDs) linked to Medicare administrative claims for longitudinal follow-up, we applied three statistical approaches to safety-signal detection for commonly used dual-chamber ICDs that used two propensity score (PS) models: one specified by subject-matter experts (PS-SME), and the other one by machine learning-based selection (PS-ML). The first approach used PS-SME and cumulative incidence (time-to-event), the second approach used PS-SME and cumulative risk (Data Extraction and Longitudinal Trend Analysis [DELTA]), and the third approach used PS-ML and cumulative risk (embedded feature selection). Safety-signal surveillance was conducted for eleven dual-chamber ICD models implanted at least 2,000 times over 3 years. Between 2006 and 2010, there were 71,948 Medicare fee-for-service beneficiaries who received dual-chamber ICDs. Cumulative device-specific unadjusted 3-year event rates varied for three surveyed safety signals: death from any cause, 12.8%-20.9%; nonfatal ICD-related adverse events, 19.3%-26.3%; and death from any cause or nonfatal ICD-related adverse event, 27.1%-37.6%. Agreement among safety signals detected/not detected between the time-to-event and DELTA approaches was 90.9% (360 of 396, k=0.068), between the time-to-event and embedded feature-selection approaches was 91.7% (363 of 396, k=-0.028), and between the DELTA and embedded feature selection approaches was 88.1% (349 of 396, k=-0.042).

CONCLUSION

Three statistical approaches, including one machine learning method, identified important safety signals, but without exact agreement. Ensemble methods may be needed to detect all safety signals for further evaluation during medical device surveillance.

Defibrillators: Selecting the Right Device for the Right Patient

Advances in the field of defibrillation have brought to practice different types of devices that include the transvenous implantable cardioverter-defibrillator (ICD) with or without cardiac resynchronization therapy, the subcutaneous ICD (S-ICD), and the wearable cardioverter-defibrillator. To ensure optimal use of these devices and to achieve best patient outcomes, clinicians need to understand how these devices work, learn the characteristics of patients who qualify them for one type of device versus another, and recognize the remaining gaps in knowledge surrounding these devices. The transvenous ICD has been shown in several randomized clinical trials to improve the survival of patients resuscitated from near-fatal ventricular fibrillation and those with sustained ventricular tachycardia with syncope or systolic heart failure as a result of ischemic or nonischemic cardiomyopathy despite receiving guideline-directed medical therapy. Important gaps in knowledge regarding the transvenous ICD involve the role of the ICD in patient subgroups not included, or not well represented, in clinical trials and the need to refine the selection criteria for the ICD in patients who are indicated for it. S-ICDs were recently introduced into the clinical arena as another option for many patients who have an approved indication for a transvenous ICD. The main advantage of the S-ICD is a lower risk of infection and lead-related complications; however, the S-ICD does not offer bradycardia or antitachycardia pacing. The S-ICD may be ideal for patients with limited vascular access, high infection risk, or some congenital heart diseases. However, more data are needed regarding the efficacy and effectiveness of the S-ICD in comparison to transvenous ICDs, the extent of defibrillation testing required, and the use of the S-ICD with other novel technologies, including leadless pacemakers. Cardiac resynchronization therapy-defibrillators are indicated in patients with a left ventricular ejection fraction ≤35%, QRS width ≥130 ms, and New York Heart Association class II, III, or ambulatory IV symptoms despite treatment with guideline-directed medical therapy. Multiple randomized controlled trials have shown that the cardiac resynchronization therapy-defibrillator improves survival, quality of life, and several echocardiographic measures. One main challenge related to cardiac resynchronization therapy-defibrillators is the 30% nonresponse rate. Many initiatives are underway to address this challenge including improved cardiac resynchronization therapy and imaging technologies and enhanced selection of patients and device programming.

Complications of Spinal Cord Stimulation and Peripheral Nerve Stimulation Techniques: A Review of the Literature

OBJECTIVE

Spinal cord and peripheral neurostimulation techniques have been practiced since 1967 for the relief of pain, and some techniques are also used for improvement in organ function. Neuromodulation has recognized complications, although very rarely do these cause long-term morbidity. The aim of this article is to present a review of complications observed in patients treated with neurostimulation techniques.

METHODS

A review of the major recent publications in the literature on the subjects of spinal cord, occipital, sacral, and peripheral nerve field stimulation was conducted.

RESULTS

The incidence of complications reported varies from 30% to 40% of patients affected by one or more complications. Adverse events can be subdivided into hardware-related complications and biological complications. The commonest hardware-related complication is lead migration. Other lead related complications such as failure or fracture have also been reported. Common biological complications include infection and pain over the implant. Serious biological complications such as dural puncture headache and neurological damage are rarely observed.

CONCLUSIONS

Spinal cord and peripheral neurostimulation techniques are safe and reversible therapies. Hardware-related complications are more commonly observed than biological complications. Serious adverse events such as neurological damage are rare.

Cardiac implantable electronic device infection due to Mycobacterium species: a case report and review of the literature

BACKGROUND

Infection of cardiac implantable electronic devices is a serious cardiovascular disease and it is associated with a high mortality. Mycobacterium species may rarely cause cardiac implantable electronic devices infection.

CASE PRESENTATION

We are reporting a case of miliary tuberculosis in an Arab patient with dilated cardiomyopathy and a cardiac resynchronization therapy-defibrillator device that was complicated with infection of his cardiac resynchronization therapy-defibrillator device. To our knowledge, this is the third case in the literature with such a presentation and all patients died during the course of treatment. This underscores the importance of early diagnosis and management. We also performed a literature review of reported cases of cardiac implantable electronic devices infection related to Mycobacterium species.

CONCLUSIONS

Cardiac implantable electronic devices infection due to Mycobacterium species is an uncommon but a well-known entity. Early diagnosis and prompt management may result in a better outcome.

A Subclavian Arteriovenous Fistula Associated with Implantable Cardioverter-Defibrillator Implantation

Subclavian arteriovenous fistulas (AVFs) should be considered in the differential diagnosis of a patient presenting with worsening CHF symptoms or unilateral edema immediately after device implantation. A palpable thrill may be present or a bruit may be auscultated in the region of the fistula. Ultrasonography has limitations in the subclavian region and definitive diagnosis is only made by angiogram. Percutaneous occlusion of the AVF is preferred as surgical repair is associated with significant morbidity and mortality.

Impact of early complications on outcomes in patients with implantable cardioverter-defibrillator for primary prevention

BACKGROUND

The lifesaving benefit of implantable cardioverter-defibrillators (ICDs) has been demonstrated. Their use has increased considerably in the past decade, but related complications have become a major concern.

OBJECTIVE

The purpose of this study was to assess the incidence and effect on outcomes of early (≤30 days) complications after ICD implantation for primary prevention in a large French population.

METHODS

We analyzed data from 5539 patients from the multicenter French DAI-PP (Défibrillateur Automatique Implantable-Prévention Primaire) registry (2002-2012) who had coronary artery disease or dilated cardiomyopathy and were implanted with an ICD for primary prevention.

RESULTS

Overall, early complications occurred in 707 patients (13.5%), mainly related to lead dislodgment or hematoma (57%). Independent factors associated with occurrence of early complications were severe renal impairment (odds ratio [OR] 1.66, 95% confidence interval [CI] 1.17-2.37, P = .02), age ≥75 years (OR 1.01, 95% CI 1.00-1.02, P = .03), cardiac resynchronization therapy (OR 1.58, 95% CI 1.16-2.17, P = .01), and anticoagulant therapy (OR 1.28, 95% CI 1.02-1.61, P = .03). During a mean ± SD follow-up of 3.1 ± 2.3 years, 824 (15.8%) patients experienced ≥1 late complication (>30 days), and 782 (14.9%) patients died. After adjustment, early complications remained associated with occurrence of late complications (OR 2.15, 95% CI 1.73-2.66, P < .0001) and mortality (OR 1.70, 95% CI 1.34-2.17, P = .003).

CONCLUSION

Early complications are common after ICD implantation for primary prevention, occurring in 1 in 7 patients, and are associated with an increased risk of late complications and overall mortality. Further studies are needed to investigate the underlying mechanisms of such associations.

Management of Cardiac Electronic Device Infections: Challenges and Outcomes

Cardiac implantable electronic device (CIED) infection is an increasing problem. Reasons for this are uncertain, but likely relate to an increasing proportion of implantable cardioverter defibrillator (ICD) and cardiac resynchronisation therapy (CRT) devices implanted, as well as implantations in 'higher risk' candidates, i.e. patients with heart failure, diabetes and renal failure. Challenges within the field of CIED infections are multiple with prevention being the most important challenge. Careful prescription of CIED treatment and careful patient preparation before implantation is important. Diagnosis is often difficult and delayed by subtle signs of infection. Treatment of CIED infection includes complete system removal in centres experienced in CIED extraction and prolonged antibiotic therapy. Meticulous planning and preparation before system extraction and later CIED re-implantation is essential for better patient outcome. Future strategies for reducing CIED infection should be tested in sufficiently powered, multicentre, randomised controlled trials.

Incidence of cardiac implantable electronic device infections and migrations in Japan: Results from a 129 institute survey

BACKGROUND

We conducted a survey of the infection burden associated with the implantation of cardiac implantable electronic devices (CIEDs) in Japan.

METHODS

The institutes were selected using annual device implantation data provided by Medtronic Japan Co., Ltd. The data sampling period was from January 1 to December 31, 2013. Institutes were classified into Group P, at which only pacemakers were implanted, and Group A, at which other CIEDs were implanted. Group P was further classified into three sub-groups by implantation number. The infection rate was compared between groups using logistic regression analysis.

RESULTS

A total of 129 of 138 institutes responded. The annual infection rate was 1.12% for overall CIEDs. The institute at which 15-29 pacemakers were implanted had a high infection rate (2.11%). No statistically significant difference was observed (adjusted p=0.1131). The overall migration rate was 0.50%. Complete removal of the CIED system was performed in 55.8% of patients who underwent implantation.

CONCLUSIONS

This survey was the first on CIED infection and migration in Japan. The CIED infection rate (1.12%) was similar to that previously reported. A high infection rate (2.77%) was observed in the infection experienced institutes.

Implantable cardioverter-defibrillator harm in young patients with inherited arrhythmia syndromes: A systematic review and meta-analysis of inappropriate shocks and complications

BACKGROUND

Implantable cardioverter-defibrillators (ICDs) are implanted with the intention to prolong life in selected patients with inherited arrhythmia syndromes, but ICD implantation is also associated with inappropriate shocks and complications.

OBJECTIVE

We aimed to quantify the rate of inappropriate shocks and other ICD-related complications to be able to weigh benefit and harm in these patients.

METHODS

We performed a systematic review and meta-analysis of inappropriate shock and/or other ICD-related complication rates, including ICD-related mortality, in patients with inherited arrhythmia syndromes, that is, arrhythmogenic right ventricular cardiomyopathy/dysplasia, Brugada syndrome, catecholaminergic polymorphic ventricular tachycardia, hypertrophic cardiomyopathy, dilated cardiomyopathy due to a mutation in the lamin A/C gene, long QT syndrome, and short QT syndrome. We searched MEDLINE and EMBASE from inception to May 30, 2014.

RESULTS

Of 2471 unique citations, 63 studies comprising 4916 patients with inherited arrhythmia syndromes (mean age of 39 ± 15 years) were included. Inappropriate shocks occurred in 20% of patients (crude annual rate of 4.7% per year), with a significantly higher rate in studies published before 2008 (6.1% per year vs 4.1% per year). Moreover, 22% experienced ICD-related complications (4.4% per year) and there was a 0.5% ICD-related mortality (0.08% per year).

CONCLUSION

ICD implantation carries a significant risk of inappropriate shocks and inhospital and postdischarge complications in relatively young patients with inherited arrhythmia syndromes. These data can be used to better inform patients and physicians about the expected risk of adverse ICD events and thereby facilitate shared decision making.

The learning curve associated with the introduction of the subcutaneous implantable defibrillator

Aims

The subcutaneous implantable cardioverter defibrillator (S-ICD) was introduced to overcome complications related to transvenous leads. Adoption of the S-ICD requires implanters to learn a new implantation technique. The aim of this study was to assess the learning curve for S-ICD implanters with respect to implant-related complications, procedure time, and inappropriate shocks (IASs).

Methods and results

In a pooled cohort from two clinical S-ICD databases, the IDE Trial and the EFFORTLESS Registry, complications, IASs at 180 days follow-up and implant procedure duration were assessed. Patients were grouped in quartiles based on experience of the implanter and Kaplan–Meier estimates of complication and IAS rates were calculated. A total of 882 patients implanted in 61 centres by 107 implanters with a median of 4 implants (IQR 1,8) were analysed. There were a total of 59 patients with complications and 48 patients with IAS. The complication rate decreased significantly from 9.8% in Quartile 1 (least experience) to 5.4% in Quartile 4 (most experience) (P = 0.02) and non-significantly for IAS from 7.9 to 4.8% (P = 0.10). Multivariable analysis demonstrated a hazard ratio of 0.78 (P = 0.045) for complications and 1.01 (P = 0.958) for IAS. Dual-zone programming increased with experience of the individual implanter (P < 0.001), which reduced IAS significantly in the multivariable model (HR 0.44, P = 0.01). Procedure time decreased from 75 to 65 min (P < 0.001). The complication rate and procedure time stabilized after Quartile 2 (>13 implants).

Conclusion

There is a short and significant learning curve associated with physicians adopting the S-ICD. Performance stabilizes after 13 implants.

Does Categorization Method Matter in Exploring Volume-Outcome Relation? A Multiple Categorization Methods Comparison in Coronary Artery Bypass Graft Surgery Surgical Site Infection

BACKGROUND

Volume-infection relation studies have been published for high-risk surgical procedures, although the conclusions remain controversial. Inconsistent results may be caused by inconsistent categorization methods, the definitions of service volume, and different statistical approaches. The purpose of this study was to examine whether a relation exists between provider volume and coronary artery bypass graft (CABG) surgical site infection (SSI) using different categorization methods.

METHODS

A population-based cross-sectional multi-level study was conducted. A total of 10,405 patients who received CABG surgery between 2006 and 2008 in Taiwan were recruited. The outcome of interest was surgical site infection for CABG surgery. The associations among several patient, surgeon, and hospital characteristics was examined. The definition of surgeons' and hospitals' service volume was the cumulative CABG service volumes in the previous year for each CABG operation and categorized by three types of approaches: Continuous, quartile, and k-means clustering.

RESULTS

The results of multi-level mixed effects modeling showed that hospital volume had no association with SSI. Although the relation between surgeon volume and surgical site infection was negative, it was inconsistent among the different categorization methods.

CONCLUSIONS

Categorization of service volume is an important issue in volume-infection study. The findings of the current study suggest that different categorization methods might influence the relation between volume and SSI. The selection of an optimal cutoff point should be taken into account for future research.