Author + information
- Published online November 29, 2017.
- aCardiology Division, Department of Medicine, Queen Mary Hospital, University of Hong Kong, Hong Kong SAR, China
- bDepartment of Medicine, Shenzhen Hong Kong University Hospital, Shenzhen, China
- cShenzhen Institutes of Research and Innovation, University of Hong Kong, Hong Kong SAR, China
- ↵∗Address for correspondence:
Dr. Chu-Pak Lau, Cardiology Division, Department of Medicine, Queen Mary Hospital, The University of Hong Kong, Suite 1303, Central Building, 1 Pedder Street, Central, Hong Kong.
Leaving uninfected leads, which may be either nonfunctional or unnecessary at the time of replacement or upgrade of a cardiovascular implantable electronic device (CIED) without connecting to their headers, inside patients is widely practiced. Lead extraction for such an abandoned lead is indicated if the lead posts a mechanical or electrical risk or if there is suboptimal vascular access for new lead replacement (1). The problems reported for abandoned leads include venous thrombosis and obstruction, mechanical effects on tricuspid valve, electrical interference between leads, and infection (1). With the broadened application of CIEDs, the increased longevity of patients who survive longer than their devices, lead abandonment has become an important problem. In one recent study (2), implantable cardioverter-defibrillator (ICD) or cardiac resynchronization ICD leads would fail in 17% of patients at 12 years. Infection of the lead or device is the most dreaded complication of abandoned leads (3). As lead abandonment often takes place during device replacement or upgrade, which carries a higher risk of infection than with a new implant (4), abandoned leads are prone to future infection.
Completed device and lead extraction is the recommended procedure for management of device-related infection (3). However, removal of infected leads has more complications than uninfected leads that are removed for other reasons (3). There are limited data for the risk of lead extraction of infected abandoned leads. The only available registry study, performed at the Cleveland Clinic (5), suggested that total transvenous lead extraction was more difficult and often required additional specialized tools including femoral station backup in those with abandoned units or leads than in those with no abandoned leads. This was translated to a higher incidence of incomplete lead extraction (13.0% vs. 3.7%, respectively). Although the authors did not directly assess the mortality differences due to abandoned leads, the presence of incomplete extraction was associated with mortality higher than 1 month than in those with complete extraction (7.4% vs. 2.9%, respectively). Limitations of that study (5), as commented on by the accompanying editorial (6), were the significant differences in age, diagnosis, and presence of lead vegetation between the 2 groups, which could have accounted for some of the differences observed. Furthermore, because the study was conducted in a single tertiary referral center, it is unclear whether the outcome could be applied generally.
In this issue of JACC: Clinical Electrophysiology, the study by Boyle et al. (7) addresses not only the risk of lead extraction but extends our understanding of the clinical presentation and clinical course of abandoned leads that had become infected. The MEDIC (Multicenter Electrophysiologic Device Infection Cohort) trial was an international multicenter study that involved 10 centers in the United States and abroad. Using a propensity matched analysis adjusting for comorbidities, oldest lead age, sex, and race, the authors compared the presentations and clinical outcomes after lead extraction in 264 patients. The study results showed that patients with abandoned leads presented with a higher number of pocket infections than the systemic infections that occurred in patients with no abandoned leads. Approximately one third in either group had infective endocarditis. Importantly, the abandoned leads were more difficult to extract and tended more often to need thoracotomies for removal (17.1% vs. 11.5%, respectively), and removal was often incomplete (13.4% vs. 6.4%, respectively). These results confirmed the complexity of management of patients with infected abandoned leads.
One unexpected finding in this study was the higher in-hospital mortality rate in those without abandoned leads. There was a significantly higher rate of infection by more aggressive microorganisms such as methicillin-resistant Staphylococcus aureus and enterococci in those without abandoned leads, which could account for some of the differences. It is also very likely attributed to referral bias. The authors concluded that the seriousness of CIED infection as identified in their study merits large prospective registries to determine the fate of the abandoned leads.
It is interesting to compare the current study data (7) with those of the study performed at the Cleveland Clinic (5). Both data sets are registry data from major centers of lead extraction in a large cohort of patients, and procedures were performed by a group of highly skilled physicians. On the other hand, the Cleveland Clinic registry was a single-center study, and there was no propensity matching of patients with abandoned versus nonabandoned leads. Indeed, those with abandoned leads were older, had more heart block and sinus node disease, and a longer lead dwell time. These differences might have accounted for the high risk of lead extraction in those with abandoned leads in their patients. However, both studies show that patients with abandoned leads had a higher incidence of pocket infections in addition to infective endocarditis, and extracting these leads were difficult and required more instrumentation and surgical means.
How can we use these data? In both of the studies (5,7), pocket infections were a major presentation in patients with abandoned leads. Abandoned leads will likely make the pocket bulkier which may affect wound healing. Attention to pocket management should include hemostasis, proper pocket sizing, and application of local antimicrobial or antibiotic envelopes (8). Are these data adding weight to prophylactic lead extraction at the time of device replacement? The central question is whether abandoned leads are associated with a higher infection rate than if they are extracted. There are controversial outcomes among those reported in small retrospective studies (9) and a paucity of long-term data in the large registry (10). In a recently published article (11), among 6,859 patients, 16.2% underwent lead extraction and 5,746 (83.8%) underwent capping and abandonment. Patients with extracted leads were often males and younger and had shorter lead dwell time and fewer comorbidities. At a follow-up of 2.4 years, the 1-year and 5-year cumulative mortality rates were 13.5% and 54.3%, respectively, without significant differences between the groups. Extraction was associated with a lower risk of infection at 5 years relative to capping and lead abandonment (hazard ratio: 0.78; 95% confidence interval: 0.62 to 0.97; p = 0.027). However, the variations in clinical profiles between the 2 groups could have accounted for much of the difference.
Are these data enough to prompt us to extract leads at the time of upgrade or replacement? There is certainly a case to be made if there is no venous access or the abandoned leads pose a mechanical or electrical risk. There is also reason to consider future magnetic resonance imaging compatibility. Although the current guideline (12) does not recommend lead extraction to render magnetic resonance imaging compatibility, abandonment of a lead will convert a magnetic resonance imaging conditional system to an incompatible system. The likely higher risk of future infection and the more problematic clinical course of management once the CIED system with abandoned leads becomes infected should add weight to the consideration for earlier lead extraction.
What are the arguments against prophylactic extraction? Apart from additional costs, the additional risk is not low, especially if performed routinely in low volumes and by less experienced centers. In a meta-analysis of studies undertaken before 2013, Di Monaco et al. (13) reported a major complication rate of extractions of 1.6% and minor complications of 2.4%. The risk was increased in less experienced centers with fewer numbers of lead extractions performed per year and in earlier than in later publications. Indeed, in the Medicare population (10), subgroup analysis showed that the overall mortality was not different between extraction versus abandoned leads, but numerically higher at 1 year in the extraction group (11.39 vs 8.16, respectively; p = 0.06). Interestingly, 6-month infection rates also trended in the same direction (3.07 vs. 1.34%, respectively). Although these data are both short term and nonrandomized, they are thought provoking and give insight into the outcome of lead extraction when applied generally. Justification based on prophylactic extractions thus needs to balance overall risk of extraction with long-term risk of infection, for which we presently do not have percentages of risk with which to advise our patients. A survey (14) among European centers suggested that the main factors that strongly influenced decision making were patient’s age (most considered as <60 years of age), damaged leads, and lead dwell time. Most providers considered the maximum number of leads to implant in the subclavian vein to be ≥4 leads in older patients and ≥3 leads in younger patients.
We will need more data so that we can better inform our patients of the risk of abandoned leads. It would be useful to have some clinical subsets such as age and comorbidities that allow us to advise patients about the risk of extraction initially and the infection risk of abandoned leads in the future. Bringing down the risk of lead extraction by virtue of improved technology and expertise and, above all, institutional protocol to address complications promptly and efficiently will swing the balance in favor of extraction. Moreover, implanting leads that will be easier to extract such as single coil and polytetrafluoroethylene (Teflon)-coated ICD leads, and attention to pocket management at the time of replacement or upgrade should be useful. Finally, placing no transvenous lead, whether for pacing or defibrillation in the first place, as in leadless pacemaker and subcutaneous ICDs, may be a good way to mitigate this problem.
↵∗ Editorials published in JACC: Clinical Electrophysiology reflect the views of the authors and do not necessarily represent the views of JACC: Clinical Electrophysiology or the American College of Cardiology.
The authors have reported that they have no relationships relevant to the contents of this paper to disclose.
The authors attest they are in compliance with human studies committees and animal welfare regulations of the authors’ institutions and Food and Drug Administration guidelines, including patient consent where appropriate. For more information, visit the JACC: Clinical Electrophysiology author instructions page.
- 2017 American College of Cardiology Foundation
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