Extraction of Implantable Cardiac Electronic Devices

In-vitro model for bacterial growth inhibition of compartmentalized infection treated by an ultra-high concentration of antibiotics

BACKGROUND

Pseudomonas aeruginosa (P. aeruginosa), Escherichia coli (E. coli), and Staphylococcus aureus (S. aureus) are common pathogens encountered in infected cardiovascular-implantable electronic device (CIED). Continuous, in-situ targeted, ultra-high concentration antibiotic (CITA) treatment is a novel antibiotic treatment approach for localized infections. CITA provides sufficient local antibiotic concentrations to heavily infected cavities while avoiding systemic toxicity.

AIM

In-vitro confirmation of the efficacy of the CITA treatment approach in simulated compartmentalized infections.

MATERIALS AND METHODS

A rapid automated bacterial culture analyzing system) Uro4 HB&L™ (was applied to compare the efficacy of selected antibiotics at a standard minimal inhibitory concentration (1MIC), 4MIC, and CITA at 103MIC, for growth inhibition of high bacterial loads (106 colony-forming-units/ml) of ATCC strains of P. aeruginosa, E. coli, and S. aureus.

RESULTS

The addition of gentamicin and amikacin at 1MIC concentrations only temporarily inhibited the exponential growth of E. coli and P. aeruginosa. 4MIC level extended the delay of exponential bacterial growth. Increasing concentrations of vancomycin similarly temporarily delayed S. aureus growth. All tested antibiotics at CITA of 103MIC totally inhibited the exponential growth of the tested bacteria through 72 hours of exposure. (P<0.001).

CONCLUSION

In this in-vitro model, CITA at 103MIC effectively inhibited exponential bacterial growth of high loads of P. aeruginosa, E. coli, and S. aureus. This model offers preliminary laboratory support for the benefit of the in-situ antibiotic treatment, providing ultra-high concentrations directly at the compartmentalized infection site, not achievable by the conventional intravenous and oral routes.

Transvenous extraction of permanent pacemaker and defibrillator leads: Reduced procedural complexity and higher procedural success rates in patients with infective versus noninfective indications

INTRODUCTION

Transvenous lead extraction (TLE) is critical in the long-term management of patients with cardiac implanted electronic devices (CIEDs). The aim of the study is to evaluate the outcomes of TLE and to investigate the impact of infection.

METHODS AND RESULTS

Data of patients undergoing extraction of permanent pacemaker and defibrillator leads during October 2014-September 2019 were prospectively analyzed. Overall, 242 consecutive patients (aged 71.0 ± 14.0 years, 31.4% female), underwent an equal number of TLE operations for the removal of 516 leads. Infection was the commonest indication (n = 201, 83.1%). Mean implant-to-extraction duration was 7.6 ± 5.4 years. Complete procedural success was recorded in 96.1%, and clinical procedural success was achieved in 97.1% of attempted lead extractions. Major complications occurred in two (0.8%) and minor complications in seven (2.9%) patients. Leads were removed exclusively by using locking stylets in 65.7% of the cases. In the subgroup of noninfective patients, advanced extraction tools were more frequently required compared to patients with CIED infections, to extract leads (success only with locking stylet: 55.8% vs. 67.8%, p = .032). In addition, patients without infection demonstrated lower complete procedural success rates (90.7% vs. 97.2%, p = .004), higher major complication rates (2.4% vs. 0.5%, p = .31) and longer procedural times (136 ± 13 vs. 111 ± 15 min, p = .001).

CONCLUSIONS

Our data demonstrate high procedural efficacy and safety and indicate that in patients with noninfective indications, the procedure is more demanding, thus supporting the hypothesis that leads infection dissolves and/or prohibits the formation of fibrotic adherences.

Computed Tomography-Guided Risk Assessment in Percutaneous Lead Extraction

OBJECTIVES

The aim of this study was to assess if pre-procedural computed tomography (CT) could identify high-risk operative features and predict increased procedural complexity.

BACKGROUND

Unpredictable lead adhesions can make lead extraction complicated. Adhesions are known to affect leads with longer indwelling time but can unpredictably affect newer leads.

METHODS

Consecutive patients who had CTs performed ≤90 days before their planned lead extraction (LE) were included. CTs were reviewed blinded to outcome according to a preset checklist. The outcome was a combined endpoint of procedural complexity and major complications.

RESULTS

Between January 1, 2015 and July 1, 2018, 143 patients underwent CT and LE. Median age was 68 years (interquartile range [IQR]: 54.4 to 76.5), and 35% were female. Median age of extracted leads was 111 months, and 126 (43%) were >10 years. CT detected lead perforation ≥5 mm (n = 13), <5 mm (n = 55), severe lead adhesions (n = 65), leads touching vessel wall >1 cm (n = 102), lead fracture (n = 8), and severe ipsilateral venous stenosis/occlusion (n = 36). The procedure was complex in 63 cases. There were 2 deaths, and 6 major complications. Patients with severe lead adhesions had more complex procedures (n = 36 vs 29; p = 0.04), whereas none of the other findings on CT were significantly associated with worse outcome. In patients with leads that had an indwelling time <10 years (n = 72), severe lead adhesions on CT was associated with worse outcome in multivariable analysis (odds ratio: 6.4; 95% confidence interval: 1.4 to 30.2; p = 0.02).

CONCLUSIONS

Pre-procedural CT can be used to locate severe lead adhesions in patients planned for lead extraction. In patients with indwelling leads <10 years, pre-procedural CT aids in identifying patients prone to complex extractions.

Use of Preprocedural MDCT for Cardiac Implantable Electric Device Lead Extraction: Frequency of Findings That Change Management

OBJECTIVE

Five percent of cardiac implantable electric devices (CIEDs) are removed each year. Percutaneous extraction is preferred but can be complicated if the leads adhere to the vasculature or perforate. The goal of this study is to assess the frequency of findings on dedicated MDCT that alter preprocedural planning for percutaneous CIED extraction.

MATERIALS AND METHODS

One hundred patients with CIEDs who underwent MDCT before percutaneous lead extraction were analyzed. Major findings that could preclude percutaneous removal, including lead course and termination, were distinguished from moderately significant findings that could alter but not preclude percutaneous removal, including endofibrosis of leads to the vasculature, lead termination abnormalities, central vein stenosis, or thrombus. Incidental findings were characterized separately. Findings were correlated with preprocedural decisions, the extraction procedure performed, and procedural outcomes.

RESULTS

Twenty-six women and 74 men with 125 right ventricular leads, 84 right atrial leads, and 26 coronary venous leads were evaluated. Major findings were present in 7% of patients, including six patients with lead perforation and one with a lead coursing outside a tricuspid annuloplasty ring. Moderately significant findings of endothelial fibrosis were found in 78% of patients. The central veins were narrowed or occluded in 42% of patients, and thrombus was present in 2% of patients. Thirty-six percent of patients had incidental findings, and 4% of patients had unexpected findings requiring immediate inpatient attention.

CONCLUSION

MDCT performed before CIED lead extraction is able to identify major and moderately significant findings that can alter either percutaneous extraction or preprocedural planning. The use of dedicated preprocedural MDCT can help to stratify patient risk, guide decision making by the proceduralist, and identify non-catheter-related findings that affect patient management.

Canadian Heart Rhythm Society and Canadian Association of Radiologists Consensus Statement on Magnetic Resonance Imaging with Cardiac Implantable Electronic Devices

Magnetic resonance imaging (MRI) has historically been considered contraindicated for individuals with cardiac implantable electronic devices (CIEDs) such as pacemakers and implantable defibrillators. Magnetic resonance scanners produce magnetic fields that can interact negatively with the metallic components of CIEDs. However, as CIED technology has advanced, newer MRI conditional devices have been developed that are now in clinical use and these systems have had demonstrated safety in the MRI environment. Despite the supportive data of such CIED systems, physicians remain reluctant to perform MRI scanning of conditional devices. This joint statement by the Canadian Heart Rhythm Society and the Canadian Association of Radiologists describes a collaborative process by which CIED specialists and clinics can work with radiology departments and specialists to safely perform MRI in patients with MRI conditional CIED systems. The steps required for patient and scanning preparation and the roles and responsibilities of the CIED and radiology departments are outlined. We also briefly outline the risks and a process by which patients with nonconditional CIEDs might also receive MRI in highly specialized centres. This document supports MRI in patients with MRI conditional CIEDs and offers recommendations on how this can be implemented safely and effectively.

Re-evaluation of transvenous lead extraction with modified standard technique: a prospective study in 229 patients

As new-type powered sheaths are expensive and unavailable, the standard lead extraction techniques remain the mainstay in clinical applications in many countries. The purpose of this study was to re-evaluate the clinical application of the standard lead extraction techniques and equipment, and make some procedural modifications and innovations. In our center, between January 2006 and May 2012, 229 patients (median, 66 years) who underwent lead extraction due to infection and lead malfunction were registered and followed up prospectively with respect to clinical features, reasons for lead extraction, technical characteristics, and clinical prognosis. A total of 440 leads had to be extracted transvenously by using special tools from 229 patients (male, 72.1%). Vegetations ≥1 cm were detected in six patients. Locking Stylets were applied for 398 (90.5%) leads. Telescoping dilator polypropylene sheaths and counter traction technique were used for 202 (45.9%) leads due to lead adhesion, and the mean implant duration of the 202 leads was longer than the other 238 leads (48.9±22.6 vs. 26.6±17.8 months; P <0.01). In addition, modified isolation and snare techniques were used for 56 leads (12.7%). Minor and major procedure-related complications occurred in three (1.3%) and four (1.7%) cases respectively, including one death (0.4%). Severe lead residue occurred in one case. Complete procedural success rate was 96.1% (423/440), and clinical success rate was 98.9% (435/440). The median follow-up period was 18 (1-76) months. No infection- and procedure-related death occurred in our series. Our data demonstrated that high clinical success rate of transvenous lead extraction can be guaranteed by making full use of the standard lead extraction techniques and equipment with individualized modifications.

Tricuspid regurgitation in patients with pacemakers and implantable cardiac defibrillators: a comprehensive review

Implantable cardiac devices, including defibrillators and pacemakers, may be the cause of tricuspid regurgitation (TR) or may worsen existing TR. This review of the literature suggests that TR usually occurs over time after lead implantation. Diagnosis by clinical exam and 2-dimensional echocardiography may be augmented by 3-dimensional echocardiography and/or computed tomography. The mechanism may be mechanical perforation or laceration of leaflets, scarring and restriction of leaflets, or asynchronized activation of the right ventricle. Pacemaker-related TR might cause severe right-sided heart failure, but data regarding associated mortality are lacking. This comprehensive review summarizes the data regarding incidence, mechanism, and treatment of lead-related TR.

Implantable cardioverter defibrillator therapy in paediatric practice: a single-centre UK experience with focus on subcutaneous defibrillation

AIMS

Sudden cardiac death (SCD) risk can be managed by implantable cardioverter defibrillators (ICD). Defibrillation shocks can be delivered via ICD generator and/or intracardiac or subcutaneous coil configurations. We present our single-centre use of childhood ICDs.

METHODS AND RESULTS

Twenty-three patients had ICD implantation, with median age and weight of 12.96 years and 41.35 kg. Indications included eight long QT; four hypertrophic cardiomyopathy; three Brugada syndrome; two idiopathic ventricular fibrillation; two post-congenital heart repair; two family history of SCD with abnormal repolarization; one catecholaminergic polymorphic ventricular tachycardia; and one left ventricle non-compaction. Twelve had out of hospital cardiac arrests prior to implantation. Techniques included 13 conventional ICD implants (pre-pectoral device with endocardial leads), 7 with subcutaneous defibrillation coils (sensing via epicardial or endocardial leads tunnelled to the ICD), and 3 with exclusive subcutaneous ICD (sensing and defibrillation via the same subcutaneous lead). Satisfactory defibrillation efficacy and ventricular arrhythmia sensing was confirmed at implantation. Follow-up ranged from 0.17 to 11.08 years. One child died with the ICD in situ. Ten children received appropriate shocks; five on more than one occasion. Five received inappropriate shocks (for inappropriate recognition of sinus tachycardia or supraventricular tachycardia). Five children underwent six further interventions; all had intracardiac leads.

CONCLUSION

Innovative shock delivery systems can be used in children requiring an ICD. The insertion technique and device used need to accommodate the age and weight of the child, and concomitant need for pacing therapy. We have demonstrated effective defibrillation with shocks delivered via configurations employing subcutaneous coils in children.