Think Before You Choose: The Case Against the Routine Use of Dual Coil ICD Leads

Transvenous lead management begins before the implantation of an implantable cardioverter-defibrillator (ICD). Individualized patient and hardware selection is mandatory. Far too often, selections are made because “that is what I have always done,” without much thought. Once implanted, patients may live for many years with a lead, and removal, if required, can be associated with morbidity and even mortality. 

The vast majority of implanted ICD leads are dual coil. In fact, it is estimated that single coil lead implantation in the United States accounts for only 5.4–13.2% of device implants.¹ One may question why this is the standard practice of so many operators. Is there data suggesting that dual coil leads result in better outcomes for our patients? I would argue the exact opposite. Data suggests there is no actual benefit to dual coil ICD leads in the vast majority of cases and there may be a clear detriment when it comes to removal of these leads. Therefore, why so many dual coil ICD leads? I believe it is habit. The first transvenous ICD leads required two leads be implanted and tunneled to an abdominal pocket, the RV pace-sense/shocking lead and the separate SVC coil. The advent of the dual coil transvenous ICD lead greatly simplified implantation and was a welcome addition. Since that time there have been many improvements. Devices are now pectoral and have an active can, eliminating the need for a second shocking coil. Devices are now biphasic, with dramatically lower defibrillation thresholds (DFTs) and a high rate of first shock efficacy. Despite these advances, many have clearly not adjusted their practice with the changing technology and continue to implant what they had learned to implant. Others believe that dual coil leads offer a benefit when it comes to DFTs and, therefore, extrapolate this to patient outcomes. As will be reviewed below, there is no data to support this belief.

DFT

There is a broad misconception that adding a SVC coil results in better DFTs. Early, small studies of older technology suggested a small DFT benefit of dual coil ICD leads.^2-5 More recent, larger studies of contemporary ICDs have demonstrated equivalent defibrillation efficacy in patients with single and dual coil ICD leads.^6-9 In most patients there is no difference; in others, the difference is almost always very small and can be improvement or worsening of the DFT. In addition, many now question the value of DFT testing.¹⁰ The 10J safety margin was an arbitrary standard that has never been tested. Studies have now demonstrated that DFT testing can be eliminated with equivalent patient outcomes.¹¹ Moreover, some studies suggest that even patients with “high” DFTs left as is, do as well as patients in whom attempts are made to lower the DFT.¹² Therefore, the preoccupation with DFTs seems to be waning and can no longer be supported as an argument for dual coil ICD leads.

First Shock Efficacy/Mortality

As opposed to DFTs, what really matter to patients are outcomes. Does the device terminate the arrhythmia with a single shock? Does the device improve mortality? Data from the SCD-HeFT trial demonstrated not only no difference in DFTs, but also a trend toward higher first shock efficacy and better survival in patients receiving single coil ICD leads.⁸ This is the exact population, i.e. heart failure patients, that many argue require dual coil leads due to “big hearts” and “poor ejection fraction.” In addition, the ALTITUDE study demonstrated no difference in DFT, first shock efficacy and mortality for a very large cohort of patients.¹³ As has been true throughout the history of medicine, beliefs that seem to “make sense” are not always true.

Risk of Extraction

For years those of us who extract leads have felt that dual coil ICD leads were more difficult and dangerous to remove.^14-16 There is now data to support that belief. Fibrosis develops in areas of direct contact between the lead and both the vasculature and endocardium, as well as other leads. The defibrillator coils of ICD leads enable vigorous fibrous tissue in-growth, resulting in dense vascular and myocardial adhesions and adding to the challenge of extraction.^17-20 Aggressive fibrosis of an SVC coil, which often lies in an area at high risk for vascular injury, presents additional potential for problems. A recent study reported the risk of major complications and difficulty associated specifically with the extraction of dual coil ICD leads.²¹ Transvenous lead extraction of ICD leads with an SVC coil was associated with a 1.0% major complication rate as compared with no major complications during removal of single coil ICD leads despite longer lead implant durations among the single coil leads. In addition to a markedly higher observed complication rate, dual coil ICD leads were 2.57 times more difficult to remove (more frequent use of powered sheaths and longer extraction times) after adjusting for age, gender, implant duration, TLE indication, the presence of ePTFE-coated or backfilled ICD coils, fixation mechanism and number of leads removed. These findings are supported by findings related to laser extraction of leads. When considering extraction complications of all leads, a Spectranetics post-market surveillance study found an astonishing 72% of all major adverse events and 79% of mortality were associated with the removal of dual coil ICD leads.²² One could argue that simply eliminating the use of dual coil ICD leads could dramatically reduce the risk of lead extraction.

Summary

Given the lack of benefit of dual coil ICD leads in the vast majority of patients, coupled with the increased risk of extraction, I would suggest that single coil leads be the standard of care for most patients. If you are an implanting physician, ask yourself for each individual patient: “What lead should I implant?” If you are an allied professional in an EP lab or a representative of a cardiac rhythm management company, you should be asking if a dual coil ICD lead is really in the best interest of that patient. With the undeniable data available, the answers should be clear.

Disclosures: The author reports these disclosures: Speaker/Consultant: Spectranetics, Boston Scientific, Medtronic, St. Jude Medical; MAB: Spectranetics, Boston Scientific; Fellowship support: Boston Scientific, Medtronic, St. Jude Medical, Biosense Webster, Inc., Spectranetics.

References

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3. Gold MR, Olsovsky MR, Pelini MA, et al. Comparison of single- and dual-coil active pectoral defibrillation lead systems. J Am Coll Cardiol. 1998;31:1391-1394.
4. Gold MR, Olsovsky MR, DeGroot PJ, et al. Optimization of transvenous coil position for active can defibrillation thresholds. J Cardiovasc Electrophysiol. 2000;11:25-29.
5. Lubinski A, Lewicka-Nowak E, Zienciuk A, et al. Comparison of defibrillation efficacy using implantable cardioverter-defibrillator with single- or dual-coil defibrillation leads and active can. Kardiol Pol. 2005;63:234-241; discussion 242-233.
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8. Aoukar PS, Poole JE, Johnson GW, et al. No benefit of a dual coil over a single coil ICD lead: evidence from SCD-HeFT. Circulation. 2010;122:A13672.
9. Mokabberi R, Haftbaradaran A, Pranesh S, et al. Defibrillation thresholds in single versus dual coil ICD lead systems: is there any difference? Circulation. 2011;124:A17919.
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13. Altitude Clinical Study (personal communication).
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16. Cooper JM, Stephenson EA, Berul CI, et al. Implantable cardioverter defibrillator lead complications and laser extraction in children and young adults with congenital heart disease: implications for implantation and management. J Cardiovasc Electrophysiol. 2003;14:344-349.
17. Epstein AE, Kay GN, Plumb VJ, et al. Gross and microscopic pathological changes associated with nonthoracotomy implantable defibrillator leads. Circulation. 1998;98:1517-1524.
18. Hackler JW, Sun Z, Lindsay BD, et al. Effectiveness of implantable cardioverter-defibrillator lead coil treatments in facilitating ease of extraction. Heart Rhythm. 2010;7:890-897.
19. Di Cori A, Bongiorni MG, Zucchelli G, et al. Transvenous extraction performance of expanded polytetrafluoroethylene covered ICD leads in comparison to traditional ICD leads in humans. Pacing Clin Electrophysiol. 2010;33:1376-1381.
20. Segreti L, Di Cori A, Soldati E, et al. Mechanical transvenous extraction of endocardial implantable cardioverter defibrillating leads: feasibility, safety and determinants of success in the pisa experience. Heart Rhythm. 2010;7:S185.
21. Epstein LM, Love CJ, Wilkoff BL, et al. SVC defibrillator coils make transvenous lead extraction more challenging and riskier. JACC. (in press)
22. Spectranetics, Extraction Considerations for Managing Dual Coil ICD Leads, 2012.