The World-wide Randomized Antibiotic Envelope Infection Prevention (WRAP-IT) trial: Long-term follow-up

Effects of envelopes on cardiac implantable electronic device pocket healing: A head-to-head preclinical evaluation

BACKGROUND

The healing response to cardiac implantable electronic device (CIED) implantation results in inflammation that can lead to fibrous pocket formation, which may disrupt pocket healing or complicate future interventions.

OBJECTIVE

The purpose of this study was to assess CIED pocket healing with use of the second-generation TYRX absorbable antibacterial envelope (T2), the next-generation (NG) TYRX absorbable antibacterial envelope under development, and the CanGaroo® extracellular matrix envelope (ECM) compared to no envelope.

METHODS

A total of 110 CIEDs were implanted in an ovine model, either with (T2, NG, or ECM) or without envelopes. Histopathologic and morphometric analyses were completed at several timepoints after implant (3 days, 7 days, 4 weeks, 12 weeks, 24 weeks). An independent pathologist completed a blinded histopathology assessment of the pockets.

RESULTS

TYRX (T2/NG) pockets showed similar inflammatory and healing profiles to controls with more rapid provisional matrix formation compared to controls and ECM. ECM pockets exhibited increased acute (3 and 7 days) and chronic (24 weeks) inflammation. T2/NG had almost complete (T2) or complete (NG) absorption by week 12. ECM remained present at week 24 and was associated with significantly thicker capsules (ECM 0.80 ± 0.14 mm; NG 0.37 ± 0.10 mm; control 0.56 ± 0.17 mm).

CONCLUSION

Compared to ECM, pockets with TYRX showed less inflammation, more rapid provisional matrix formation, faster absorption, and thinner capsules. TYRX pockets had low inflammation comparable to controls with accelerated provisional matrix deposition and tissue adhesion. The healing response to CIEDs used with TYRX fosters the formation of a well-healed pocket, which may bring patient benefit beyond its proven infection reduction.

Do Antibiotic-Impregnated Envelopes Prevent Deep Brain Stimulation Implantable Pulse Generator Infections? A Prospective Cohort Study

INTRODUCTION

Infection after deep brain stimulation (DBS) implanted pulse generator (IPG) replacement is uncommon but when it occurs can cause significant clinical morbidity, often resulting in partial or complete DBS system removal. An antibiotic absorbable envelope developed for cardiac implantable electronic devices (IEDs), which releases minocycline and rifampicin for a minimum of 7 days, was shown in the WRAP-IT study to reduce cardiac IED infections for high-risk cardiac patients. We aimed to assess whether placing an IPG in the same antibiotic envelope at the time of IPG replacement reduced the IPG infection rate.

METHODS

Following institutional ethics approval (UnitingCare HREC), patients scheduled for IPG change due to impending battery depletion were prospectively randomised to receive IPG replacement with or without an antibiotic envelope. Patients with a past history of DBS system infection were excluded. Patients underwent surgery with standard aseptic neurosurgical technique [J Neurol Sci. 2017;383:135-41]. Subsequent infection requiring antibiotic therapy and/or IPG removal or revision was recorded.

RESULTS

A total of 427 consecutive patients were randomised from 2018 to 2021 and followed for a minimum of 12 months. No patients were lost to follow-up. At the time of IPG replacement, 200 patients received antibiotic envelope (54 female, 146 male, mean age 72 years), and 227 did not (43 female, 184 male, mean age 71 years). The two groups were homogenous for risk factors of infection. The IPG replacement infection rate was 2.1% (9/427). There were six infections, which required antibiotic therapy and/or IPG removal, in the antibiotic envelope group (6/200) and three in the non-envelope group (3/227) (p = 0.66).

CONCLUSION

This prospective randomised study did not find that an antibiotic envelope reduced the IPG infection rate in our 427 patients undergoing routine DBS IPG replacement. Further research to reduce IPG revisions and infections in a cost-effective manner is required.

Translation of Tools and Techniques from the Adult Electrophysiology World to Pediatric Cardiac Implantable Electronic Devices

This article reviews various opportunities to translate established and novel tools and techniques used in adult electrophysiology to pediatrics and the adult congenital heart disease population. There is a specific focus on preoperative management of special population, implantation techniques, and postoperative programming of devices.

REducing INFectiOns thRough Cardiac device Envelope: insight from real world data. The REINFORCE project

AIMS

Infections resulting from cardiac implantable electronic device (CIED) implantation are severely impacting on patients' and on health care systems. The use of TYRXTM absorbable antibiotic-eluting envelope has proven to decrease major CIED infections within 12 months of CIED surgery. The aim is to evaluate the impact of the envelope use on infection-related clinical events in a real-world contemporary patient population.

METHODS AND RESULTS

Data on patients undergoing CIED surgery were collected prospectively by participating centers of the One Hospital ClinicalService project. Patients were divided into two groups according to whether TYRXTM absorbable antibiotic-eluting envelope was used or not. Out of 1819 patients, 872 (47.9%) were implanted with an absorbable antibiotic-eluting envelope and included in the Envelope group and 947 (52.1%) patients who did not receive an envelope were included in the Control group. Compared to control, patients in the Envelope group had higher thrombo-embolic or hemorrhagic risk, higher BMI, lower LVEF and more comorbidities. During a mean follow-up of 1.4 years, the incidence of infection-related events was significantly higher in the control compared to the Envelope group (2.4% vs. 0.8%, P = 0.007). The five-year cumulative incidence of infection-related events was 8.1% in the control and 2.1% in the Envelope group (HR: 0.34, 95%CI: 0.14-0.80, P = 0.010).

CONCLUSION

In our analysis, the use of an absorbable antibiotic-eluting envelope in the general CIED population was associated with a lower risk of systemic and pocket infection.

Use of a taurolidine containing antimicrobial wash to reduce cardiac implantable electronic device infection

AIMS

TauroPace (Tauropharm, Bavaria Germany), a taurolidine solution for combating cardiac implantable electronic device (CIED) infection, was compared with a historical control of 3% hydrogen peroxide (H2O2) in a prospective observational study.

METHODS AND RESULTS

The device pocket was irrigated, and all hardware accessible within (leads, suture sleeves, pulse generator) was wiped with H2O2, TauroPace, or taurolidine in a galenic formulation during any invasive CIED procedure at the study centre. Only CIED procedures covered by TauroPace or H2O2 from 1 January 2017 to 28 February 2022 were included for analysis. Patients who underwent >1 procedure were censored for the last treatment group and reassigned at the next procedure. The primary endpoint was major CIED infection within 3 months. The secondary endpoints were CIED infection beyond 3 months, adverse events potentially related to the antimicrobial solutions, CIED system, procedure, and death, till the end of follow-up. TauroPace covered 654 procedures on 631 patients, and H2O2 covered 551 procedures on 532 patients. The TauroPace group had more patient risk factors for infection than the H2O2 group (P = 0.0058) but similar device and procedure-specific risk factors (P = 0.17). Cardiac implantable electronic device infection occurred in 0/654 (0%) of the TauroPace group and 6/551 (1.1%) of the H2O2 group (P = 0.0075). Death occurred in 23/654 (3.5%) of the TauroPace group and 14/551 (2.5%) of the H2O2 group (P = 0.33). Non-infection related adverse events were rarer in the TauroPace (3.8%) than the H2O2 (6.0%) group (P = 0.0802).

CONCLUSION

TauroPace is safe but more effective than H2O2 in reducing CIED infection.

CLINICAL TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT05576194.

The European TauroPace™ Registry

BACKGROUND

Cardiac implantable electronic device (CIED) placement comes with certain complications. CIED infection is a severe adverse event related to CIED placement. In randomised controlled trials, the preoperative intravenous administration of antibiotics and the adjunctive use of an antibiotic mesh envelope resulted in significant reduction in infections related to cardiac implantable electronic devices. The adjunctive use of taurolidine for this purpose is relatively novel and not considered in the guidelines. The required evidence may consist of a set of clinical studies.

METHODS

The European TauroPaceTM registry (ETPR) prospectively evaluates every consecutive invasive procedure involving any CIED with adjunct TauroPace™ use in the contributing centres. As the estimation of the infection rate needs to be defensible, only interventions registered prior to the procedure will be followed-up. The endpoint is a major cardiac implantable electronic device infection according to the novel CIED infection criteria (1). Secondary endpoints comprise all-cause mortality, complications, adverse events of all grades, and major CIED infections during all follow-up examinations. The follow-up times are three months, twelve months, and eventually 36 months, as acute, subacute, and long-term CIED infections are of interest.

RESULTS

As the rate of CIED infections is expected to be very low, this registry is a multicentre, international project that will run for several years. Several reports are planned. The analyses will be included in the case number calculations for future randomised controlled trials.

CONCLUSIONS

The ETPR will accumulate large case numbers to estimate small event rates more precisely; we intend to follow up on participants for years to reveal possible late effects.

Strategies for surface coatings of implantable cardiac medical devices

Cardiac medical devices (CMDs) are required when the patient's cardiac capacity or activity is compromised. To guarantee its correct functionality, the building materials in the development of CMDs must focus on several fundamental properties such as strength, stiffness, rigidity, corrosion resistance, etc. The challenge is more significant because CMDs are generally built with at least one metallic and one polymeric part. However, not only the properties of the materials need to be taken into consideration. The biocompatibility of the materials represents one of the major causes of the success of CMDs in the short and long term. Otherwise, the material will lead to several problems of hemocompatibility (e.g., protein adsorption, platelet aggregation, thrombus formation, bacterial infection, and finally, the rejection of the CMDs). To enhance the hemocompatibility of selected materials, surface modification represents a suitable solution. The surface modification involves the attachment of chemical compounds or bioactive compounds to the surface of the material. These coatings interact with the blood and avoid hemocompatibility and infection issues. This work reviews two main topics: 1) the materials employed in developing CMDs and their key characteristics, and 2) the surface modifications reported in the literature, clinical trials, and those that have reached the market. With the aim of providing to the research community, considerations regarding the choice of materials for CMDs, together with the advantages and disadvantages of the surface modifications and the limitations of the studies performed.

Association of the Timing and Extent of Cardiac Implantable Electronic Device Infections With Mortality

Importance

Cardiac implantable electronic device (CIED) infection is a potentially devastating complication with an estimated 12-month mortality of 15% to 30%. The association of the extent (localized or systemic) and timing of infection with all-cause mortality has not been established.

Objective

To evaluate the association of the extent and timing of CIED infection with all-cause mortality.

Design, Setting, and Participants

This prospective observational cohort study was conducted between December 1, 2012, and September 30, 2016, in 28 centers across Canada and the Netherlands. The study included 19 559 patients undergoing CIED procedures, 177 of whom developed an infection. Data were analyzed from April 5, 2021, to January 14, 2023.

Exposures

Prospectively identified CIED infections.

Main Outcomes and Measures

Time-dependent analysis of the timing (early [≤3 months] or delayed [3-12 months]) and extent (localized or systemic) of infection was performed to determine the risk of all-cause mortality associated with CIED infections.

Results

Of 19 559 patients undergoing CIED procedures, 177 developed a CIED infection. The mean (SD) age was 68.7 (12.7) years, and 132 patients were male (74.6%). The cumulative incidence of infection was 0.6%, 0.7%, and 0.9% within 3, 6, and 12 months, respectively. Infection rates were highest in the first 3 months (0.21% per month), reducing significantly thereafter. Compared with patients who did not develop CIED infection, those with early localized infections were not at higher risk for all-cause mortality (no deaths at 30 days [0 of 74 patients]: adjusted hazard ratio [aHR], 0.64 [95% CI, 0.20-1.98]; P = .43). However, patients with early systemic and delayed localized infections had an approximately 3-fold increase in mortality (8.9% 30-day mortality [4 of 45 patients]: aHR, 2.88 [95% CI, 1.48-5.61]; P = .002; 8.8% 30-day mortality [3 of 34 patients]: aHR, 3.57 [95% CI, 1.33-9.57]; P = .01), increasing to a 9.3-fold risk of death for those with delayed systemic infections (21.7% 30-day mortality [5 of 23 patients]: aHR, 9.30 [95% CI, 3.82-22.65]; P < .001).

Conclusions and Relevance

Findings suggest that CIED infections are most common within 3 months after the procedure. Early systemic infections and delayed localized infections are associated with increased mortality, with the highest risk for patients with delayed systemic infections. Early detection and treatment of CIED infections may be important in reducing mortality associated with this complication.

Pocket histology at cardiac implantable electronic device replacement: What's new?

BACKGROUND

Repeated procedures involving the cardiac implantable electronic device (CIED) pocket increase the infection risk, and the extent of pocket adhesions may prolong the procedure time. Few data on pocket histology at the time of CIED replacement are available.

OBJECTIVE

The purpose of this study was to describe CIED pocket histology in a cohort of patients undergoing CIED replacement or upgrade.

METHODS

All consecutive patients undergoing CIED replacement or upgrade at our center between November 2019 and May 2020 were enrolled. Subclinical pocket infection was ruled out by physical inspection and laboratory parameters before the procedure. Pocket tissue specimens from the anterior and posterior pockets were obtained intraoperatively. A systematic histological analysis of capsular thickness, fibrous connective tissue, neovascularization, inflammation, and calcifications was performed.

RESULTS

Thirty patients (6 women, 20%) were enrolled. The mean capsular thickness was 0.8 ± 0.3 mm in the anterior wall and 1.1 ± 0.4 mm in the posterior wall. Subcapsular fibrosis was mild and multifocal in the anterior wall and moderate and focal in the posterior wall. Neovascularization was focal in most cases, and vessel remodeling mainly involved the tunica media. Chronic inflammation was usually mild and nongranulomatous, and in a quarter of cases, subacute exudative fibrous inflammation was detected in the posterior pocket wall.

CONCLUSION

The CIED pocket is a histopathologically dynamic environment, given the coexistence of both a subacute foreign body response and fibrous tissue growth, implying continuous remodeling due to an injury-repair mechanism. Strategies to interact with foreign body response might minimize inflammatory pocket activity, especially device encapsulation by tight fibrous tissue, and possibly complications related to repeated CIED procedures.

Preclinical evaluation of a third-generation absorbable antibacterial envelope

BACKGROUND

The TYRX (Medtronic) absorbable antibacterial envelope has been shown to stabilize implantable cardiac devices and reduce infection. A third-generation envelope was developed to reduce surface roughness with a redesigned multifilament mesh and enhanced form factor but identical polymer coating and antibiotic concentrations as the currently available second-generation envelope.

OBJECTIVE

The purpose of this study was to compare drug elution, bacterial challenge efficacy, stabilization, and absorption of second- vs third-generation envelopes.

METHODS

Antibiotic elution was assessed in vitro and in vivo. For efficacy against gram-positive/gram-negative bacteria, 40 rabbits underwent device insertions with or without third-generation envelopes. For stabilization (migration, rotation), 5 sheep were implanted with 6 devices each in second- or third-generation envelopes. Prespecified acceptance criteria were <83-mm migration and <90° rotation. Absorption was assessed via gross pathology.

RESULTS

Elution curves were equivalent (similarity factors ≥50 per Food and Drug Administration guidance). Third-generation envelopes eluted antibiotics above minimal inhibitory concentration (MIC) in vivo at 2 hours postimplant through 7 days, consistent with second-generation envelopes. Bacterial challenge showed reductions (P <.05) in infection with second- and third-generation envelopes. Device migration was 5.5 ± 3.5 mm (third-generation) vs 9. 9 ±7.9 mm (second-generation) (P <.05). Device rotation was 18.9° ± 11.4° (third-generation) vs 17.6° ± 15.1° (second-generation) and did not differ (P = .79). Gross pathology confirmed the absence of luminal mesh remainders and no differences in peridevice fibrosis at 9 or 12 weeks.

CONCLUSION

The third-generation TYRX absorbable antibacterial envelope demonstrated equivalent preclinical performance to the second-generation envelope. Antibiotic elution curves were similar, elution was above MIC for 7 days, infections were reduced compared to no envelope, and acceptance criteria for migration, rotation, and absorption were met.

An antibiotic envelope to reduce infections in deep brain stimulation surgery

The therapeutic benefits of Deep Brain Stimulation (DBS) surgery in patients with movement disorderssuch as Parkinson's Diseaseare life-altering. Surgical site infections (SSI), however, can result in increasedhospitalisations, prolonged antibiotics and neurological sequelae. We performed aretrospective review to evaluate the effectiveness of an antibiotic envelope to reduce SSI in DBS surgeries.This study includedall DBS surgeries performed between August 2020 to May 2022 using a single-use, multifilament, antibiotic-coated mesh envelope wrapped around the DBS implantable pulse generator (IPG)(TYRX™ Absorbable Antibacterial Envelope,Medtronic Fridley, MN, USA). Standardised infection-prevention measures were applied and various patient-specific and surgery-specific factors were analysed.44 patients were analysed with 26 (59.1 %) primary implantations and 18 (40.9 %) revision surgeries.The median age was 65 years old with an average follow-up of 13.5 months (range 3-24 months). The mean Body Mass Indexwas 24.0 (range 16.7-35.6). 8 (18.2 %) patients had underlying diabetes mellitus. There were only 2 (4.5 %) SSIs reported with neither involvingthe subcutaneous IPG and antibiotic envelope. 1 superficial-incisional SSI (2.3 %) was from a prior retro-auricular abscess around a lead-wirerequiring antibiotics and subcutaneous implanttransposition. The other was a deep-incisional SSI (2.3 %) from repetitive trauma causingdelayed scalp wound dehiscence and lead-wire extrusion, requiring antibiotics and wound revision. Both subjects were discharged well with no implants removed. Theantibioticenvelope therefore appears to be a safe and well-tolerated adjunct that may reduce SSIs in DBS surgery. Further prospective work withlarger sample sizes in a multi-institution setting is required.

Infection in patients with subcutaneous implantable cardioverter-defibrillator: Results of the S-ICD Post Approval Study

BACKGROUND

Early subcutaneous implantable cardioverter-defibrillator (S-ICD) studies included atypical cohorts of patients who were younger with fewer comorbidities. Recent S-ICD studies included patient populations with more comorbidities.

OBJECTIVES

The goals of this study were to determine the incidence and predictors of S-ICD-related infection over a 3-year follow-up period and to use these results to develop an infection risk score.

METHODS

The S-ICD Post Approval Study is a US prospective registry of 1637 patients. Baseline demographic characteristics and outcomes with 3-year postimplantation follow-up were compared between patients with and without device-related infection. A risk score was derived from multivariable proportional hazards analysis of 22 variables.

RESULTS

Infection was observed in 55 patients (3.3%), with 69% of infections occurring within 90 days and a vast majority (92.7%) within 1 year of implantation. Late infections more likely involved device erosion; no infections occurred after year 2. The annual mortality rate postinfection was 0.6%/y. No lead extraction complications or bacteremia related to infection were observed. An infection risk score was created with diabetes, age, prior transvenous ICD implant, and ejection fraction as predictors. Patients with a risk score of ≥3 had an 8.8 hazard ratio (95% confidence interval 2.8-16.3) of infection compared with a 0 risk score.

CONCLUSION

Infection rates in the S-ICD Post Approval Study were similar to other S-ICD populations and not associated with systemic blood-borne infections. Late infection (>1 year) is uncommon and associated with system erosion. A high-risk infection cohort can be identified that may facilitate preventive measures.

Use of Antibacterial Envelopes for Prevention of Infection in Neuromodulation Implantable Pulse Generators

BACKGROUND

Neuromodulation unit placement carries a historic infection rate as high as 12%. Treatment of such requires surgical removal and a long course of systemic antibiotics. Antibiotic-impregnated envelopes have been effective in preventing infection in implantable cardiac devices. At our center, 1 surgeon uses these envelopes with all implanted neuromodulation units.

OBJECTIVE

To assess the efficacy of antibacterial envelopes in prevention of infection in neuromodulation device placement.

METHODS

We conducted a retrospective cohort study of consecutive implantable pulse generator (IPG) unit implantation with an antibacterial envelope at a single center between October 2014 and December 2019. We collected demographic data, including postoperative infections, reoperations, and complications, associated with the IPGs. This cohort was then compared with a historical cohort of consecutive patients undergoing surgery before envelope usage (October 2007-April 2014).

RESULTS

In the pre-envelope cohort of 151 IPGs placed in 116 patients, there were 18 culture-confirmed infections (11.9%). In the antibacterial envelope cohort of 233 IPGs placed in 185 patients, there were 5 culture-confirmed infections (2.1%). The absolute risk reduction of the antibacterial envelope was 9.85% (95% CI 4.3%-15.4%, P < .01). The number needed to treat was 10.1 (95% CI 6.5-23.1, P < .01) envelopes to prevent 1 IPG infection.

CONCLUSION

We saw a reduced rate of infections in the antibacterial envelope cohort. Although this is likely multifactorial, our results suggest a benefit of antibacterial envelopes on infection after neuromodulation surgery.

Cardiac Implantable Electronic Devices Infection Assessment, Diagnosis and Management: A Review of the Literature

The use of increasingly complex cardiac implantable electronic devices (CIEDs) has increased exponentially in recent years. One of the most serious complications in terms of mortality, morbidity and financial burden is represented by infections involving these devices. They may affect only the generator pocket or be generalised with lead-related endocarditis. Modifiable and non-modifiable risk factors have been identified and they can be associated with patient or procedure characteristics or with the type of CIED. Pocket and systemic infections require a precise evaluation and a specialised treatment which in most cases involves the removal of all the components of the device and a personalised antimicrobial therapy. CIED retention is usually limited to cases where infection is unlikely or is limited to the skin incision site. Optimal re-implantation timing depends on the type of infection and on the results of microbiological tests. Preventive strategies, in the end, include antibiotic prophylaxis before CIED implantation, the possibility to use antibacterial envelopes and the prevention of hematomas. The aim of this review is to investigate the pathogenesis, stratification, diagnostic tools and management of CIED infections.

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.

Complications in Device Therapy: Spectrum, Prevalence, and Management

PURPOSE OF REVIEW

Cardiac implantable electronic device implant numbers are continually increasing due to the expanding indications and ageing population. This review explores the complications associated with device therapy and discusses ways to minimise and manage such complications.

RECENT FINDINGS

Complications related to device therapy contribute to mortality and morbidity. Recent publications have detailed clear guidelines for appropriate cardiac device selection, as well as consensus documents discussing care quality and optimal implantation techniques. There have also been advances in device technologies that may offer alternative options to patients at high risk of/or already having encountered a complication. Adherence to guidelines, appropriate training, and selection of device, in addition to good surgical technique are key in reducing the burden of complications and improving acceptability of device therapy.

The utility of postoperative systemic antibiotic prophylaxis following cardiovascular implantable electronic device implantation: A systematic review and meta-analysis

BACKGROUND

There is insufficient evidence regarding postoperative systemic antibiotic prophylaxis use for more than 24 hours following cardiovascular implantable electronic devices (CIED) implantation and its impact on infection prevention. However, this strategy remains a common practice in many institutions.

METHODS

We conducted a systematic review and meta-analysis including studies that compared the outcomes of patients: 1) who received preoperative plus 24 hours or more of postoperative antibiotic prophylaxis (intervention group); and 2) who received either preoperative only or preoperative plus less than 24 hours of antibiotic prophylaxis (control group). Risk of bias was assessed with ROBINS-I and ROB-2 tools. Risk ratio (RR) was pooled using random-effect meta-analyses with inverse variance method.

RESULTS

Eight studies that included two randomized controlled trials (RCTs) and six cohort studies with a total of 26,187 patients were included in the analysis. Overall, there were no differences in outcomes between the two groups, which included rates of CIED infection (RR 0.77, 95% CI 0.42, 1.42), mortality (RR 1.19, 95% CI 0.69, 2.06), pocket hematoma (RR 1.15, 95% CI 0.44, 3.00) or reintervention (RR 0.87, 95% CI 0.22, 3.46). Of note, the results were primarily impacted by the larger RCT.

CONCLUSIONS

There was no benefit of postoperative antibiotic prophylaxis for more than 24 hours following CIED implantation in the current systematic review and meta-analysis. This supports the practice advocated by current guidelines which foster antibiotic stewardship and may result in reductions of adverse drug events, selection for antibiotic resistance, and financial costs of prolonged postoperative antibiotic prophylaxis. This article is protected by copyright. All rights reserved.

Risk factors for hematoma in patients undergoing cardiac device procedures: A WRAP-IT trial analysis

Background

Implant site hematoma is a known complication of cardiac device procedures and can lead to major consequences.

Objectives

To evaluate risk factors for hematoma and further understand the relationship between anticoagulant (AC), antiplatelet (AP) use, and hematoma development.

Methods

We included 6800 patients from the WRAP-IT trial. To assess baseline and procedural characteristics associated with hematoma within the first 30 days postprocedure, a stepwise Cox regression model was implemented with minimal Akaike information criterion. Cox regressions were also used to evaluate AC/AP use and hematoma risk.

Results

The overall rate of hematoma was 2.2%. The model identified 11 baseline and procedural characteristics associated with hematoma risk. AC use (hazard ratio [HR]: 2.44, P < .001), lower body mass index (HR: 1.06, P < .001), and history of valve surgery (HR: 2.11, P < .001) were associated with the highest risk. AP use, male sex, history of coronary artery disease, existing pocket, history of nonischemic cardiomyopathy, number of previous cardiac implantable electronic device (CIED) procedures, procedure time, and lead revision were associated with moderate risk. Antithrombotic use was high overall (86%) and AC+AP use was highly predictive of hematoma risk. Regardless of AC status, AP use was associated with an almost doubling of risk vs no AP (HR = 1.85, P = .0006) in the general cohort. Interruption of AC was associated with the lowest hematoma risk (HR = 2.35) while heparin bridging (HR = 4.98) and AP use vs no AP use (HR = 1.85) was associated with the highest hematoma risk.

Conclusion

The results of this analysis highlight risk factors associated with the development of hematoma in patients undergoing CIED procedures and can inform antithrombotic management.

Surgical management of "Twiddler syndrome" in patients with deep brain stimulation: a technical note and review of the literature

Background

The Twiddler syndrome (TS) describes a situation in which the implanted impulse generator (IPG) rotates several times around its own axis in the subcutaneous pocket. This can lead to severe mechanical damage of the leads and extensions and to dislocations.

Method

Hereby, we report on a technique for revision surgery in patients diagnosed with Twiddler syndrome after undergoing previous deep brain stimulation (DBS) surgery. For revision surgery, the TYRX ™ Absorbable Antibacterial Envelope was used.

Conclusion

The TS can be treated well with the envelope TYRX ™ Absorbable Antibacterial Envelope TYRX ™.

Supplementary Information

The online version contains supplementary material available at 10.1007/s00701-022-05135-8.

Antibiotic-Eluting Envelopes for the Prevention of Cardiac Implantable Electronic Device Infections: Rationale, Efficacy, and Cost-Effectiveness

Infections related to cardiac implantable electronic devices (CIED) are associated with significant morbidity and mortality. Despite optimal use of antimicrobials and other preventive strategies, the incidence of CIED infections is increasing over time leading to considerable costs to the healthcare systems. Recently, antibiotic-eluting envelopes (AEEs) have been introduced as a promising technology to prevent CIED infections. This review will address the current evidence on stratification of CIED infection risk, present the rationale behind AEE, and summarize the currently available evidence for CIED infection prevention as well as demonstrate the cost-effectiveness of this novel technology.

Surgical Applications of Materials Engineered with Antimicrobial Properties

The infection of surgically placed implants is a problem that is both large in magnitude and that broadly affects nearly all surgical specialties. Implant-associated infections deleteriously affect patient quality-of-life and can lead to greater morbidity, mortality, and cost to the health care system. The impact of this problem has prompted extensive pre-clinical and clinical investigation into decreasing implant infection rates. More recently, antimicrobial approaches that modify or treat the implant directly have been of great interest. These approaches include antibacterial implant coatings (antifouling materials, antibiotics, metal ions, and antimicrobial peptides), antibacterial nanostructured implant surfaces, and antibiotic-releasing implants. This review provides a compendium of these approaches and the clinical applications and outcomes. In general, implant-specific modalities for reducing infections have been effective; however, most applications remain in the preclinical or early clinical stages.

Cost-Effectiveness of Antibiotic-Eluting Envelope for Prevention of Cardiac Implantable Electronic Device Infections in Heart Failure

BACKGROUND

Use of an antibiotic-eluting envelope (AEE) during cardiac implantable electronic device procedures reduces infection risk but increases procedural costs. We aim to estimate the cost-effectiveness of AEE use during cardiac implantable electronic device procedures among patients with heart failure.

METHODS

A state-transition cohort model of heart failure patients undergoing cardiac implantable electronic device implantation or generator replacement was developed with input parameters estimated from randomized trials, registries, surveys, and claims data. Effectiveness was estimated from the World-Wide Randomized Antibiotic Envelope Infection Prevention Trial. AEE was assumed to cost $953 per unit. The model projected mortality, quality-adjusted life-years, costs, and the incremental cost-effectiveness ratio of AEE use compared with usual care from a US healthcare sector perspective over a lifetime horizon. We assumed a cost-effectiveness threshold of $100 000 per quality-adjusted life-year gained.

RESULTS

Compared with usual care, AEE use in initial implantations produced an incremental cost-effectiveness ratio of $112 000 per quality-adjusted life-year gained (39% probability of being cost-effective). In generator replacement procedures, AEE use produced an incremental cost-effectiveness ratio of $54 000 per quality-adjusted life-year gained (84% probability of being cost-effective). Results were sensitive to the underlying rate of infection, cost of the AEE, and durability of AEE effectiveness.

CONCLUSIONS

Universal AEE use for cardiac implantable electronic device procedures in patients with heart failure with reduced ejection fraction is unlikely to be cost-effective, reinforcing the need for individualized risk assessment to guide uptake of the AEE in clinical practice. Selective use in patients at increased risk of infection, such as those undergoing generator replacement procedures, is more likely to meet health system value benchmarks.

Incidence of lead erosion in a real-world cohort and a case of successful treatment with an antimicrobial mesh

Cardiac implantable electronic device (CIED)-related infections are a major complication of CIED therapy and associated with high morbidity and mortality. The aim of the present study was to evaluate the incidence of lead erosion as one cause of the CIED-related infections and to provide detailed information about the therapy of two cases of lead erosion. We retrospectively screened the database of a large clinic specialized on patients with CIED (HIZ BERLIN Herzschrittmacher- und ICD-Zentrum, Berlin, Germany) for cases of lead erosion between 2015 and 2020. A total of 5971 outpatients were treated at the HIZ BERLIN - including 4782 patients with a one- or two-chamber pacemaker, 837 patients with an implantable cardioverter defibrillator (ICD) and 352 patients with a biventricular device for cardiac resynchronization therapy (CRT). The incidence of lead erosion was 0.033%. As one of the two patients, who suffered from lead erosions, had no signs of systemic infection, the patient received local therapy with an antimicrobial mesh and intravenous antibiotics. After twelve months, he showed a good clinical outcome without ongoing or recurring infection. In conclusion, the incidence of lead erosion is low. In case of lead erosions without signs of systemic infection, an antimicrobial mesh might be implanted as an off-label use in patients that decline complete device removal.

Burden of disease and costs of infections associated with cardiac implantable electronic devices

INTRODUCTION

Infections are complications of Cardiac Implantable Electronic Device (CIED) procedures, associated with high mortality (20-25% at 1 year), long hospitalizations (23-30 days), and high costs for health-care systems (often higher than 30.000 €). The incidence rates are around 1-4%. Prevention strategies appear to be the best approach for minimizing the occurrence of CIED infections, but in real-world, the recommendations for the best practices are not always followed. Among the recommended preventive measures, the antibacterial envelope has proven to be effective in reducing CIED-related infections.

AREAS COVERED

Published studies investigate the role of antibacterial envelopes in infection prevention and the use of infection risk scores to select high-risk patients undergoing CIED implantation/replacement who can benefit from additional preventive measures.

EXPERT OPINION

A proficient selection of the best candidates for the antibacterial envelope can be the basis for reducing the healthcare system's costs, in line with the principles of cost-effectiveness. Risk scores have been developed to select patients at high risk of CIED infections and their use appears simple and more complete than individual factors alone. Among them, the PADIT score seems to be effective in selecting patients eligible for antibacterial envelope insertion, with a good cost-effectiveness profile.

Risk Factors for CIED Infection After Secondary Procedures: Insights From the WRAP-IT Trial

OBJECTIVES

This study aimed to identify risk factors for infection after secondary cardiac implantable electronic device (CIED) procedures.

BACKGROUND

Risk factors for CIED infection are not well defined and techniques to minimize infection lack supportive evidence. WRAP-IT (World-wide Randomized Antibiotic Envelope Infection Prevention trial), a large study that assessed the safety and efficacy of an antibacterial envelope for CIED infection reduction, offers insight into procedural details and infection prevention strategies.

METHODS

This analysis included 2,803 control patients from the WRAP-IT trial who received standard preoperative antibiotics but not the envelope (44 patients with major infections through all follow-up). A multivariate least absolute shrinkage and selection operator machine learning model, controlling for patient characteristics and procedural variables, was used for risk factor selection and identification. Risk factors consistently retaining predictive value in the model (appeared >10 times) across 100 iterations of imputed data were deemed significant.

RESULTS

Of the 81 variables screened, 17 were identified as risk factors with 6 being patient/device-related (nonmodifiable) and 11 begin procedure-related (potentially modifiable). Patient/device-related factors included higher number of previous CIED procedures, history of atrial arrhythmia, geography (outside North America and Europe), device type, and lower body mass index. Procedural factors associated with increased risk included longer procedure time, implant location (non-left pectoral subcutaneous), perioperative glycopeptide antibiotic versus nonglycopeptide, anticoagulant, and/or antiplatelet use, and capsulectomy. Factors associated with decreased risk of infection included chlorhexidine skin preparation and antibiotic pocket wash.

CONCLUSIONS

In WRAP-IT patients, we observed that several procedural risk factors correlated with infection risk. These results can help guide infection prevention strategies to minimize infections associated with secondary CIED procedures.

Implantable Pulse Generators for Deep Brain Stimulation: Challenges, Complications, and Strategies for Practicality and Longevity

Deep brain stimulation (DBS) represents an important treatment modality for movement disorders and other circuitopathies. Despite their miniaturization and increasing sophistication, DBS systems share a common set of components of which the implantable pulse generator (IPG) is the core power supply and programmable element. Here we provide an overview of key hardware and software specifications of commercially available IPG systems such as rechargeability, MRI compatibility, electrode configuration, pulse delivery, IPG case architecture, and local field potential sensing. We present evidence-based approaches to mitigate hardware complications, of which infection represents the most important factor. Strategies correlating positively with decreased complications include antibiotic impregnation and co-administration and other surgical considerations during IPG implantation such as the use of tack-up sutures and smaller profile devices.Strategies aimed at maximizing battery longevity include patient-related elements such as reliability of IPG recharging or consistency of nightly device shutoff, and device-specific such as parameter delivery, choice of lead configuration, implantation location, and careful selection of electrode materials to minimize impedance mismatch. Finally, experimental DBS systems such as ultrasound, magnetoelectric nanoparticles, and near-infrared that use extracorporeal powered neuromodulation strategies are described as potential future directions for minimally invasive treatment.

Rate of device-related infections using an antibacterial envelope in patients undergoing cardiac resynchronization therapy reoperations

AIMS 

Cardiac resynchronization therapy (CRT) reoperations are associated with a particularly high risk of device-related infection (DRI). An antibacterial envelope reduces the occurrence of DRIs in a broad population of moderate-tohigh-risk patients. To investigate the efficacy of an antibacterial envelope in a very high-risk population of patients undergoing CRT reoperation.

METHODS AND RESULTS

In this Danish two-centre, observational cohort study, we included consecutive patients who underwent a CRT pacemaker- or defibrillator reoperation procedure between January 2008 and November 2019. We obtained data from the Danish Pacemaker and ICD Register and through systematic medical chart review. Follow-up was restricted to 2 years. A total of 1943 patients were included in the study of which 736 (38%) received an envelope. Envelope patients had more independent risk factors for infection than non-envelope patients. Sixty-seven (3.4%) patients met the primary endpoint of DRI requiring device system extraction; 50 in the non-envelope group and 17 in the envelope group [4.1% vs. 2.3%, adjusted hazard ratio (HR) 0.52, 95% confidence interval (CI) 0.30-0.90; P = 0.021]. This difference persisted in propensity score analysis (HR 0.51, 95% CI 0.29-0.90; P = 0.019).

CONCLUSION 

Use of an antibacterial envelope was associated with a clinically and statistically significant reduction in DRIs in patients undergoing CRT reoperations. Our results were comparable to those recently reported from a large randomized controlled trial, which is suggestive of a proportional effect of the envelope even in very high-risk patients.

Economic evaluation of an absorbable antibiotic envelope for prevention of cardiac implantable electronic device infection

AIMS

Recent evidence suggests that an antibiotic impregnated envelope inserted at time of cardiac implantable electronic device (CIED) implantation may reduce risk of subsequent CIED infection compared with standard of care (SoC). The objective of the current work was to perform a cost-effectiveness analysis comparing an antibiotic impregnated envelope with SoC at time of CIED insertion.

METHODS AND RESULTS

Decision analytic models were used to project healthcare costs and benefits of two strategies, an antibiotic impregnated envelope plus SoC (Env+SoC) vs. SoC alone, in a cohort of patients undergoing CIED implantation over a 1-year time horizon. Evidence from published literature informed the model inputs. Probabilistic and deterministic sensitivity analyses were performed. The primary outcome was the incremental cost per infection prevented, assessed from the Canadian healthcare system perspective. Envelope plus SoC was associated with fewer CIED infection (7 CIED infections/1000 patients) at higher total costs ($29 033 000/1000 patients) compared with SoC (11 CIED infections and $27 926 000/1000 patients). The incremental cost per infection prevented over 1 year was $274 416. Use of Env+SoC was cost saving only when baseline CIED infection risk was increased to 6% (vs. base case of 1.2%).

CONCLUSIONS

A strategy of Env+SoC was not economically favourable compared with SoC alone, and the opportunity cost of widescale implementation should be considered. Future work is required to develop validated risk stratification tools to identify patients at greatest risk of CIED infection. The value proposition of Env+SoC improves when applying this intervention to patients at greatest infection risk.

Avoiding implant complications in cardiac implantable electronic devices: what works?

Nearly one in ten patients experience complications in relation to cardiac implantable electronic device (CIED) implantations. CIED complications have serious implications for the patients and for the healthcare system. In light of the rising rates of new implants and consistent rate of complications, primary prevention remains a major concern. To guide future efforts, we sought to review the evidence base underlying common preventive actions made during a primary CIED implantation.

Antibiotic eluting envelopes: evidence, technology, and defining high-risk populations

Cardiovascular implantable electronic devices (CIED) are effective and important components of modern cardiovascular care. Despite the dramatic improvements in the functionality and reliability of these devices, over time patients are at risk for developing several morbidities, the most feared of which are local and systemic infections. Despite significant financial investment and aggressive therapy with hospitalization, intravenous antibiotics, and transvenous lead extraction, the outcomes include a 1-year mortality rate as high as 25%. This risk of infection has increased over time, likely due to the increased complexity of the surgical interventions required to insert and replace these devices. The only way to reduce this morbidity and mortality is to prevent these infections, and other than preoperative antibiotics, there were little data supporting effective therapy until the WRAP-IT trial provided randomized data showing that pocket infections can be reduced by 60% at 12 months and major CIED infections reduced by 40% at 1 year with the use of the absorbable antibiotic eluting envelope in patient CIED procedures at high risk of infection. Not all CIED procedures are at high risk of infection and justify the use of the envelope, but cost-effectiveness data support the use of the antibiotic envelope particularly in patients with defibrillator replacements, revisions, and upgrades, such as to a resynchronization device and in patients with prior CIED infection, history of immunocompromise, two or more prior procedures, or a history of renal dysfunction.

Infectious consequences of hematoma from cardiac implantable electronic device procedures and the role of the antibiotic envelope: A WRAP-IT trial analysis

BACKGROUND

Hematoma is a complication of cardiac implantable electronic device (CIED) procedures and may lead to device infection. The TYRX antibacterial envelope reduced major CIED infection by 40% in the randomized WRAP-IT (World-wide Randomized Antibiotic Envelope Infection Prevention Trial) study, but its effectiveness in the presence of hematoma is not well understood.

OBJECTIVE

The purpose of this study was to evaluate the incidence and infectious consequences of hematoma and the association between envelope use, hematomas, and major CIED infection among WRAP-IT patients.

METHODS

All 6800 study patients were included in this analysis (control 3429; envelope 3371). Hematomas occurring within 30 days postprocedure (acute) were characterized and grouped by study treatment and evaluated for subsequent infection risk. Data were analyzed using Cox proportional hazard regression modeling.

RESULTS

Acute hematoma incidence was 2.2% at 30 days, with no significant difference between treatment groups (envelope vs control hazard ratio [HR] 1.15; 95% confidence interval [CI] 0.84-1.58; P = .39). Through all follow-up, the risk of major infection was significantly higher among control patients with hematoma vs those without (13.1% vs 1.6%; HR 11.3; 95% CI 5.5-23.2; P <.001). The risk of major infection was significantly lower in the envelope vs control patients with hematoma (2.5% vs 13.1%; HR 0.18; 95% CI 0.04-0.85; P = .03).

CONCLUSION

The risk of hematoma was 2.2% among WRAP-IT patients. Among control patients, hematoma carried a >11-fold risk of developing a major CIED infection. This risk was significantly mitigated with antibacterial envelope use, with an 82% reduction in major CIED infection among envelope patients who developed hematoma compared to control.

Cost-Effectiveness Analyses of an Absorbable Antibacterial Envelope for Use in Patients at Increased Risk of Cardiac Implantable Electronic Device Infection in Germany, Italy, and England

OBJECTIVES

To model the cost-effectiveness of the TYRX Absorbable Antibacterial Envelope when used in patients at increased risk of cardiac implantable electronic device (CIED) infection in the context of 3 European healthcare systems: Germany, Italy, and England.

METHODS

A decision tree model with a lifetime horizon was populated using data from the Worldwide Randomized Antibiotic Envelope Infection Prevention Trial, a large multicenter randomized controlled trial. Use of the antibacterial envelope adjunctive to standard of care was compared to standard of care infection prevention alone. Patients in the model were divided into subgroups based on presence of factors known to increase infection risk.

RESULTS

The antibacterial envelope had the most favorable cost-effectiveness profile when patients had previously experienced CIED infection, had a history of immunosuppressive therapy, or had a Prevention of Arrhythmia Device Infection Trial (PADIT) score indicating high risk of infection (scores ≥6) at cost-effectiveness thresholds of €50 000 in Germany (assumed in the absence of an official threshold), €40 000 in Italy, and £30 000 in England. Probabilistic sensitivity analysis indicated that the antibacterial envelope was likely to be cost-effective in patients with other risk factors (including replacement of high power CIEDs, generator replacement with lead modification, and PADIT scores indicating intermediate risk of infection) when used with some device types and in some countries.

CONCLUSIONS

The absorbable antibacterial envelope was associated with cost-effectiveness ratios below European benchmarks in selected patients at increased risk of infection, suggesting the envelope provides value for European healthcare systems by reducing CIED infections.

Anti-biofilm activity of antibiotic-loaded Hylomate®

Introduction

Antibiotic envelopes are being developed for cardiac implantable electronic device (CIED) wrapping to reduce the risk of infections.

Methods

Fifteen CIED infection-associated bacterial isolates of Staphylococcus aureus, Staphylococcus epidermidis and Cutibacterium acnes were used to assess in vitro biofilm formation on Hylomate® compared to titanium, silicone and polyurethane coupons pre-treated with vancomycin (400 µg/ml), bacitracin (1000 U/ml) or a combination of rifampin (80 µg/ml) plus minocycline (50 µg/ml). Scanning electron microscopy (SEM) was performed to visualize bacteria on Hylomate®.

Results

There was significantly less (p < 0.05) S. aureus and S. epidermidis on Hylomate® pre-treated with vancomycin, bacitracin or rifampin plus minocycline after 24 h of incubation (≤1.00 log₁₀ CFU/cm²) compared with titanium, silicone or polyurethane pre-treated with vancomycin, bacitracin or rifampin plus minocycline. C. acnes biofilms were not detected (≤1.00 log₁₀ CFU/cm²) on pre-treated Hylomate® coupons.

Conclusions

This study showed that Hylomate® coupons pre-treated with antibiotics reduced staphylococcal and C. acnes biofilm formation in vitro.

A Review of Cardiac Implantable Electronic Device Infections for the Practicing Electrophysiologist

Cardiovascular implantable electronic device (CIED) infections are morbid, costly, and difficult to manage. This review explores the pathophysiology, diagnosis, and management of CIED infections. Diagnostic accuracy has been improved through increased awareness and improved imaging strategies. Pocket or bloodstream infection with virulent organisms often requires complete system extraction. Emerging prophylactic interventions and novel devices have expanded preventative strategies and options for re-implantation. A clear and nuanced understanding of CIED infection is important to the practicing electrophysiologist.

Antibiotic-Eluting Envelopes to Prevent Cardiac-Implantable Electronic Device Infection: Past, Present, and Future

Objective: Cardiac-implantable electronic device (CIED) infections are associated with significant morbidity and mortality. In this review, we describe the risk factors and pathogenesis of CIED infections and review the rationale and the evidence for the use of antibiotic-eluting envelopes (ABEs) in patients at increased risk for CIED infections.

Findings: The majority of CIED infections are caused by staphylococci that involve generator pocket and occur due to contamination of the device or the pocket tissues at the time of implantation. Clinical trials have shown that extending the duration of post-operative systemic antibacterial therapy is not beneficial in reducing CIED infection rate. However, ABEs that reduce device migration after implantation and provide sustained local delivery of prophylactic antibiotics at the pocket site, may provide benefit in reducing infection. Currently, there are two types of commercially available CIED envelope devices in the United States. The first ABE device (TYRX™, Medtronic Inc., Monmouth Junction, NJ) is composed of a synthetic absorbable mesh envelope that elutes minocycline and rifampin and has been shown to reduce CIED pocket infections in a large multi-center randomized clinical trial. The second ABE device (CanGaroo-G™, Aziyo Biologics, Silver Spring, MD) is composed of decellularized extracellular matrix (ECM) and was originally designed to stabilize the device within the pocket, limiting risk for migration or erosion, and providing a substrate for tissue ingrowth in a preclinical study. This device has shown promising results in a preclinical study with local delivery of gentamicin. Compared with artificial materials, such as synthetic surgical mesh, biologic ECM has been shown to foster greater tissue integration and vascular ingrowth, a reduced inflammatory response, and more rapid clearance of bacteria.

Conclusions and Relevance: ABE devices provide sustained local delivery of antibiotics at the generator pocket site and appear beneficial in reducing CIED pocket infections. Given the continued increase in the use of CIED therapy and resultant infectious complications, innovative approaches to infection prevention are critical.

Clinical Presentation, Timing, and Microbiology of CIED Infections: An Analysis of the WRAP-IT Trial

OBJECTIVES

This study characterized the microbiology of major cardiac implantable electronic device (CIED) infections that occurred during the WRAP-IT (Worldwide Randomized Antibiotic Envelope Infection Prevention Trial) study.

BACKGROUND

The WRAP-IT study offers a unique opportunity for further understanding of the pathogens involved in major CIED infections in a prospective dataset, with implications for clinical practice and infection management.

METHODS

A total of 6,800 patients randomized 1:1 to receive an antibacterial envelope or not (control subjects) were included in this analysis. Patient characteristics, infection manifestation (pocket vs. systemic), and infection microbiology were evaluated through all follow-up (36 months). Data were analyzed using Cox proportional hazards regression.

RESULTS

A total of 3,371 patients received an envelope, and 3,429 patients were control subjects. Major CIED infection occurred in 32 patients who received an envelope and 51 control subjects (36-month Kaplan-Meier estimated event rate, 1.3% and 1.9%, respectively; p = 0.046). A 61% reduction in major pocket infection was observed within 12 months of the procedure in the envelope group (hazard ratio: 0.39, 95% confidence interval: 0.21 to 0.73; p = 0.003). Among 76 patients with major infections who had a sample taken, causative pathogens were identified in 47 patients. Staphylococcus species were the predominate pathogen (n = 31) and envelope use resulted in a 76% reduction in Staphylococcus-related pocket infections (n = 4 vs. 17; p = 0.010). Envelope use was not associated with delayed onset of pocket infections and did not affect the presentation of infections.

CONCLUSIONS

Antibacterial envelope use resulted in a significant reduction of major CIED pocket infections and was particularly effective against Staphylococcus species, the predominant cause of pocket infections. (Worldwide Randomized Antibiotic Envelope Infection Prevention Trial [WRAP-IT]; NCT02277990).