Author + information
- William H. Maisel, MD, MPH⁎ ( and )
- Daniel B. Kramer, MD
- ↵⁎Reprint requests and correspondence:
Dr. William H. Maisel, Medical Device Safety Institute, 185 Pilgrim Road, Baker 4, Boston, Massachusetts 02215
Implantable cardioverter-defibrillators (ICDs) provide life-saving therapy for selected patients at increased risk of sudden cardiac death. In the 3 decades since the first human implant, millions of patients have undergone ICD implantation, and innumerable lives have been saved. Critical to the widespread acceptance, distribution, and safe implantation of the device have been remarkable design and engineering advances that have greatly reduced the risks associated with device implantation. The low implant risk in combination with strong scientific evidence supporting ICD implantation in numerous primary prevention populations has produced a growing “chronic” ICD population. As a result, clinicians are increasingly faced with ICD lead management issues related to lead performance, infection, or the need for device upgrade.
Removal or extraction of a previously implanted ICD lead is sometimes required. Significant efforts to develop tools and techniques for the removal of problematic leads were first undertaken in the 1980s. As a result, a substantial “toolbox” is now available to the extracting physician, including traction devices such as locking stylets and snares, and a variety of specialized sheaths that use mechanical, laser-assisted, or electrosurgical methods to assist with removal of fibrotic tissue that impedes lead extraction.
Given the significant advances in extraction technology and the increasing experience of the operators, overreliance on outdated extraction studies that describe extraction-associated morbidity and mortality could provide a misleading perspective. In this issue of the Journal, Maytin et al. (1) report on a retrospective cohort of 348 patients undergoing 349 ICD lead extractions (mean implant duration of 27.5 months) at 5 high-volume extraction centers between May 2005 and August 2009. All extractions were performed to manage recalled Medtronic (Minneapolis, Minnesota) Sprint Fidelis ICD leads, nearly one-half with evidence of lead fracture and one-fourth with evidence of infection before extraction. Simple traction was used in 49.7% of cases, with additional specialized extraction tools required in the remainder. The authors report complete removal of the index lead in every case with no major complications or deaths. Minor complications were observed in only 0.57% of patients.
Although the authors are to be congratulated for their remarkable clinical performance, it is critical to understand that this report stands in contrast to other large studies of lead extraction. Older registry data from the U.S. and Europe presented in 2000 and involving 7,823 extraction procedures and involving close to 12,833 pacemaker and ICD leads demonstrated a major complication rate of 1.6% (2). Implant duration of the oldest lead, ICD leads (compared with pacemaker leads), female sex, low-volume extraction hospitals, and the need for laser assistance were identified as risk factors for adverse outcomes (2). Byrd et al. (3) reported the results of the PLEXES (Pacemaker Lead Extraction With the Excimer Sheath) trial, involving >2,561 pacemaker and ICD leads in 1,684 patients undergoing laser lead extraction. They experienced a major complication rate of 1.9% and an in-hospital mortality rate of 0.8%.
More recently, Wazni et al. (4) reported a 97.7% clinical success rate, a 1.4% major adverse event rate, a 0.28% procedure-related mortality rate, and a 1.86% in-hospital mortality rate among 2,405 laser-assisted lead extractions performed in 1,449 patients. Interestingly, the Wazni et al. report (4) includes some of the same authors and institutions as the Maytin et al. report (1) during an overlapping time frame, suggesting that some patients may appear in both reports. A review of device-assisted lead extraction adverse events reported to U.S. Food and Drug Administration revealed 57 deaths and 48 serious cardiovascular injuries between 1995 and 2008, with nearly 40% occurring in the final 2 study years (5). Most notable was the conclusion that some extraction injuries cannot be mitigated by emergency cardiac surgery.
It is difficult to reconcile the absence of “major” complications and the <1% rate of “minor” complications for a procedure as complex as a lead extraction, as reported by Maytin et al. (1), when reports of large well-conducted studies repeatedly cite “major” complication rates related to simpler procedures such as ICD implantation and generator changes that exceed 4% (6,7). One explanation may relate to terminology: even “minor” extraction complications can be clinically important. For example, the Heart Rhythm Society Transvenous Lead Extraction Consensus Document (2) defines minor complications as including hematoma at the implant site requiring reoperation, venous thrombosis of implant veins requiring medical intervention, vascular repair at the extraction site, blood loss requiring transfusion, pulmonary embolism not requiring surgical intervention, and hemodynamically significant air embolism. Long-term studies have demonstrated that immediate post-procedure complications associated with ICD implantation are associated with increased mortality at 180 days, suggesting that focusing only on major complications may provide a misleading perspective on the safety of the extraction procedure (6).
Clinical management of patients with Medtronic Sprint Fidelis leads remains a challenge. Medtronic's February 2010 update estimates a 7.9% lead failure rate at 57 months post-implantation (8), whereas other studies suggest an increasing annual risk of Fidelis failure (9). When leads do fail, inappropriate shocks are experienced by more than one-half of the patients, although algorithms have been developed that can identify impending fractures earlier, reducing the risk of inappropriate shocks and other untoward clinical events (10,11).
How should patients with a Medtronic Sprint Fidelis lead be managed in light of the Maytin et al. (1) report in this issue of the Journal? First, it is important to recognize that this study was not an evaluation of prophylactic Fidelis explantation. Indeed, nearly three-fourths of the patients had a bona fide indication for lead removal, either a lead fracture or infection. Second, although the failure rate of the Fidelis lead is high compared with historical standards, it is the minority of patients who are affected by actual lead performance issues. Therefore, a strategy that includes prophylactic extraction of all Fidelis leads is not only likely to result in unnecessary extraction-related deaths, but will also needlessly expose numerous patients to potentially unnecessary procedures and the attendant complications. More specifically, if the 143,000 patients in the U.S. who still have Fidelis leads implanted (12) were to undergo prophylactic lead explantation with an estimated mortality rate of 0.25% to 0.50%, 350 to 720 procedure-related deaths would be expected. To date, 13 deaths “possibly” or “likely” related to Fidelis failure have been confirmed, and 4 of the 13 were related to lead extraction (13).
Because unique patient and clinician factors affect the calculus of which clinical approach is best for individual patients, clinical recommendations must be individualized, as advised by the Heart Rhythm Society Task Force on Lead Performance and Policies (14). A number of factors should contribute to the clinical decision making, including patient prognosis, surgical risk of the revision/replacement procedure, patient anxiety over lead failure, history of ventricular arrhythmia, and estimated future risk of arrhythmia. Perhaps most important among patient risk factors is the degree of pacemaker dependence because lead failure in a pacemaker-dependent patient is more likely to result in life-threatening complications.
Currently, it appears advisable to consider patients who are pacemaker dependent (defined as a hemodynamically unstable rhythm in the absence of pacing) or who have confirmed or suspected Fidelis fractures for system revision. In most cases, lead extraction with implantation of a new ICD lead will be the preferred method, although the addition of a new ICD lead with abandonment/capping of the old Fidelis lead may be an option in some patients. Notably, however, for the majority of patients who have normally functioning leads at follow-up, active remote monitoring with automated lead integrity checks remains a viable, appropriate management option.
The tools and techniques for ICD lead extraction have greatly improved. However, it is critical that clinicians and patients have realistic expectations regarding clinical outcomes after extraction and recognize that life-threatening complications can and do occur. Patient care must be individualized. It is gratifying to see that lead extraction can be performed with increasingly good results, but this is not a prescription for extracting every normally functioning Fidelis lead.
The authors have reported that they have no relationships to disclose.
↵⁎ Editorials published in the Journal of the American College of Cardiology reflect the views of the authors and do not necessarily represent the views of JACC or the American College of Cardiology.
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