Deaths and cardiovascular injuries due to device-assisted implantable cardioverter-defibrillator and pacemaker lead extraction

The prevalence of methicillin resistant organisms among pacemaker and defibrillator implant recipients

INTRODUCTION

Pacemaker and defibrillator infections are an uncommon, but catastrophic complication of device implantation. The present study examined the prevalence of device-related infections, the patterns of antibiotic resistance, and the presence of methicillin resistant staphylococcus aureus (MRSA) nares colonization in device implant recipients.

METHODS

Two protocols were employed using a retrospective and a prospective analysis. A retrospective chart review of 218 patients with suspected device infection from 1/2000 to 1/2011 was performed. Demographics, infection rates, and patterns of antibiotic resistance were compared. The prospective analysis enrolled one hundred eighty two patients undergoing device implantations or generator replacements. The nares were swabbed and analyzed for the presence of staphylococcus aureus, and tested for methicillin sensitivity.

RESULTS

Over a period of ten years, 12,771 device implants/generator changes/system revisions were performed, with an infection rate of 1.2%. Methicillin resistance (MR) was identified in 98/218 (44.9%) of patients. Those with MR infection had more diabetes and cardiomyopathy. There was no significant increase in methicillin resistance over time (p=0.30). Our prospective analysis included 110 men. A total of 32 patients (17.6%) had positive cultures for SA: 6.6% with MRSA. Patients positive for MRSA nares colonization had a statistically significant greater length of hospital stay 8.5 days (mean) versus 4.4 days (P=0.049).

CONCLUSIONS

Methicillin resistant organisms appear to be emerging and persistent pathogens in device implants. The screening of MRSA colonization may identify new populations at risk. Further studies and analysis are needed to determine the cost effectiveness of a screening protocol.

Deaths caused by the failure of Riata and Riata ST implantable cardioverter-defibrillator leads

BACKGROUND

Riata and Riata ST leads (St Jude Medical, Sylmar, CA) were recalled in 2011. These leads are prone to externalized conductors. However, it is electrical malfunctions that may result in serious adverse events, including death.

OBJECTIVE

To assess the deaths of patients with Riata and Riata ST leads that have been reported to the Food and Drug Administration to determine whether they were due to lead malfunction. A similar analysis was performed for Quattro Secure leads (Medtronic, Inc, Minneapolis, MN).

METHODS

In February 2012, we searched the Food and Drug Administration's Manufacturers and User Facility Device Experience database for deaths associated with Riata, Riata ST, and Quattro Secure leads. A lead-related death was a sudden or unexpected death accompanied by evidence of lead malfunction; an indeterminate death was a death that was nonsudden or evidence of lead malfunction was not provided; a not lead-related death was a death that was nonsudden and/or there was no evidence that the lead contributed to the patient's demise.

RESULTS

The Manufacturers and User Facility Device Experience database search found 133 deaths; of these, 22 were caused by Riata or Riata ST lead failure and 5 were caused by Quattro Secure lead failure. Riata and Riata ST lead failure deaths were typically caused by short circuits between high-voltage components. No death was due to externalized conductors.

CONCLUSIONS

Riata and Riata ST implantable cardioverter-defibrillator leads are prone to high-voltage failures that have resulted in death. These failures appeared to have been caused by insulation defects that resulted in short circuiting between high-voltage components. Externalized conductors were not a factor in these deaths.

Transvenous extraction of pacemaker leads in infective endocarditis with vegetations ≥20 mm: our experience

BACKGROUND

According to published evidence, treatment of infective endocarditis (IE) associated with cardiovascular implantable electronic devices (CIEDs) should include complete removal of the system. Several publications have shown that transvenous removal is an effective and safe nonthoracotomy approach in patients with large vegetations, but experiences with vegetations larger than 20 mm have rarely been reported.

HYPOTHESIS

Our aim was to describe our experience in percutaneous removal of CIEDs in patients with IE with large vegetations.

METHODS

The data were collected retrospectively and analyzed prospectively. We evaluated in-hospital morbidity and mortality related to percutaneous removal of vegetations ≥20 mm. This included 8 cases with a follow-up period of 20 months. We removed 100% of leads in the study population.

RESULTS

Two patients experienced minor complications. No patient experienced subclavian vein laceration, hemothorax and lead fracture, or severe tricuspid regurgitation. After the removal procedure, 2 patients had symptoms compatible with pulmonary embolism. Both in-hospital mortality and mortality at follow-up were zero.

CONCLUSIONS

Transvenous extraction of pacing leads with larger vegetations is a feasible technique. There was a tendency toward symptomatic pulmonary embolism in patients with vegetations larger than 20 mm; however, morbidity and mortality were not influenced. We agree with the consensus that this procedure is highly useful and that the selection of the removal techniques will depend not only on the size of vegetation but also on prior cardiopulmonary conditions, concomitant cardiac surgery, atrial septal defect with risk of paradoxical embolism, center experience, and the possibility of complete removal of the device.

Riata implantable cardioverter-defibrillator lead failure: analysis of explanted leads with a unique insulation defect

BACKGROUND

The Riata family of implantable cardioverter-defibrillator leads (St Jude Medical, Sylmar, CA) appears prone to a unique failure mechanism whereby the conductor cables wear through the silicone insulation from inside-out and are seen outside the lead body (externalized conductors).

OBJECTIVE

To assess the extent of Riata lead damage associated with inside-out insulation defects and their clinical consequences.

METHODS

In September 2011, we searched the U.S. Food and Drug Administration's Manufacturers and User Defined Experience medical device database for reports describing Riata lead failures that had been analyzed by the manufacturer.

RESULTS

The Manufacturers and User Defined Experience search identified 105 leads that had inside-out insulation defects. Eight-French single-coil Riata leads accounted for a higher-than-expected proportion (25.7%) of the leads with this defect. A total of 226 insulation defects were found in the 105 leads (2.2 defects per lead), including 143 inside-out defects (1.4 defects per lead). The most common location of insulation defects was distal to the proximal coil (n = 108). Twenty-eight leads (26.7%) had inside-out insulation defects underneath the shocking coils. Of 43 leads whose cables were assessed for the integrity of the ethylene-tetrafluoroethylene cable coating, 22 (51.2%) were found to be abraded, exposing the conductor surfaces. On X-ray radiography or fluoroscopy, 7 leads were found to have externalized cables; 2 of these leads had no electrical abnormalities, while 4 exhibited noise or increased impedance. Inappropriate shocks were experienced by 31 of the 105 patients (29.5%).

CONCLUSION

Riata leads that have inside-out insulation defects often have multiple defects, including additional inside-out abrasions along the body of the lead and beneath the shocking coils. Eight-French single-coil Riata models may be more prone to externalized cables than are dual-coil and 7-F designs. Externalized cables are but one manifestation of interior insulation damage. Our findings question the durability of the ethylene-tetrafluoroethylene cable coating on exposed cables.

Wireless communication with implanted medical devices using the conductive properties of the body

Many medical devices that are implanted in the body use wires or wireless radiofrequency telemetry to communicate with circuitry outside the body. However, the wires are a common source of surgical complications, including breakage, infection and electrical noise. In addition, radiofrequency telemetry requires large amounts of power and results in low-efficiency transmission through biological tissue. As an alternative, the conductive properties of the body can be used to enable wireless communication with implanted devices. In this article, several methods of intrabody communication are described and compared. In addition to reducing the complications that occur with current implantable medical devices, intrabody communication can enable novel types of miniature devices for research and clinical applications.

Patient safety problems associated with heathcare information technology: an analysis of adverse events reported to the US Food and Drug Administration

The objective of this paper is to analyze healthcare information technology (HIT) events associated with patient harm submitted to the US Food and Drug Administration (FDA) Manufacturer and User Facility Device Experience (MAUDE) database. We examined the problems in 46 relevant events submitted to MAUDE from January 2008 to July 2010 to identify natural categories of problems from a clinical perspective. CPOE and PACS were involved in 93% of the events. Adverse events were associated with medications in 41%, clinical processes in 33%, radiation in 15% and surgery in 11%. There were four deaths. Strategies to improve the safety of HIT should focus on designing safe user interfaces, integrated checks of key identifiers and decision support, and engineering safer clinical processes.

Using FDA reports to inform a classification for health information technology safety problems

OBJECTIVE

To expand an emerging classification for problems with health information technology (HIT) using reports submitted to the US Food and Drug Administration Manufacturer and User Facility Device Experience (MAUDE) database.

DESIGN

HIT events submitted to MAUDE were retrieved using a standardized search strategy. Using an emerging classification with 32 categories of HIT problems, a subset of relevant events were iteratively analyzed to identify new categories. Two coders then independently classified the remaining events into one or more categories. Free-text descriptions were analyzed to identify the consequences of events.

MEASUREMENTS

Descriptive statistics by number of reported problems per category and by consequence; inter-rater reliability analysis using the κ statistic for the major categories and consequences.

RESULTS

A search of 899 768 reports from January 2008 to July 2010 yielded 1100 reports about HIT. After removing duplicate and unrelated reports, 678 reports describing 436 events remained. The authors identified four new categories to describe problems with software functionality, system configuration, interface with devices, and network configuration; the authors' classification with 32 categories of HIT problems was expanded by the addition of these four categories. Examination of the 436 events revealed 712 problems, 96% were machine-related, and 4% were problems at the human-computer interface. Almost half (46%) of the events related to hazardous circumstances. Of the 46 events (11%) associated with patient harm, four deaths were linked to HIT problems (0.9% of 436 events).

CONCLUSIONS

Only 0.1% of the MAUDE reports searched were related to HIT. Nevertheless, Food and Drug Administration reports did prove to be a useful new source of information about the nature of software problems and their safety implications with potential to inform strategies for safe design and implementation.

The effect of device advisories on implantable cardioverter-defibrillator therapy

Implantable cardioverter-defibrillators have been shown to improve survival by terminating life-threatening ventricular tachyarrhythmias. As the devices have become more complex, there has been an increase in the incidence of device and lead malfunction. The device manufacturers issue advisories and recalls to alert physicians of the potential for malfunction. When patients are faced with a recalled device or lead, the initial question is whether or not to replace it. A rational approach to evaluating these patients and the associated advisory can help gauge the competing risks of elective device removal or extraction versus keeping the device in place. It is important to keep in mind that the risks of replacing devices or extracting leads are not insignificant and may outweigh the risks of death from malfunction. Despite the increasing number of advisories and attention to device and lead failure, the overall reliability and efficacy of these devices for appropriate patients remains high. In general, patients should be counseled prior to implant of the potential for device and lead malfunction, and careful consideration must be employed when decisions are made to replace generators or extract leads.

Complex percutaneous extraction of a 15-year-old atrial lead dislodged into the subclavian vein

We present a case of a 50-year-old patient with DDD pacing failure who underwent atrial lead extraction. The lead was implanted 15 years ago, and 4 months ago it dislodged into the subclavian vein following a fracture. The lead was removed via the femoral vein approach using a Cook Medical device (Byrd Femoral Workstation, Dotter basket) and pigtail catheter.

Implantable Cardioverter-Defibrillator Lead Extraction by Conventional Traction and Counter-Traction Technique

A 46-year-old man presented to our institution with inappropriate implantable cardioverter-defibrillator (ICD) shock delivery. The ICD (single chamber, dual shock coils) was implanted for sustained monomorphic ventricular tachycardia with unstable hemodynamics and underlying systolic left ventricular dysfunction. ICD interrogation revealed recurrent episodes of ICD shock due to noise sensing and increased impedance of right ventricular-lead. With the impression of lead fracture, ICD lead extraction was performed. The fractured ICD lead was completely removed by traction of locking stylet and counter-traction of polypropylene dilator sheath. A new lead was inserted and the patient was discharged without complications after 2 days. To our knowledge, this is the first report on ICD lead extraction by conventional traction and counter-traction technique in Korea.

Very-late proarrhythmia of a migrant pacemaker lead

The report is on a 49-year-old patient who experienced life-threatening ventricular tachyarrhythmias caused by a pacemaker lead that was abandoned 26 years ago, migrated with its proximal ending to the main pulmonary artery and remained there asymptomatically for at least 3 years.

Extraction of embolized lead tip from azygous vein using distal embolic protection device

Indwelling pacemaker or defibrillator leads are often extracted with use of a cutting laser sheath. We report embolization of a tined pacemaker lead tip into the azygous vein, with the use of a distal embolization protection device to retrieve the fragment. Creative and non-traditional use of a filter-based device may assist in retrieval of embolized material.

Implantable Cardioverter-Defibrillator Lead Extraction by Conventional Traction and Counter-Traction Technique

A 46-year-old man presented to our institution with inappropriate implantable cardioverter-defibrillator (ICD) shock delivery. The ICD (single chamber, dual shock coils) was implanted for sustained monomorphic ventricular tachycardia with unstable hemodynamics and underlying systolic left ventricular dysfunction. ICD interrogation revealed recurrent episodes of ICD shock due to noise sensing and increased impedance of right ventricular (RV)-lead. With the impression of lead fracture, ICD lead extraction was performed. The fractured ICD lead was completely removed by traction of locking stylet and counter-traction of polypropylene dilator sheath. A new lead was inserted and the patient was discharged without complications after 2 days. To our knowledge, this is the first report on ICD lead extraction by conventional traction and counter-traction technique in Korea.