Necessity for surgical revision of defibrillator leads implanted long-term: causes and management

Left bundle branch pacing lead for sensing ventricular arrhythmias in implantable cardioverter-defibrillator: A pilot study (LBBP-ICD study)

BACKGROUND

Left bundle branch pacing (LBBP) has been suggested as an alternative modality for biventricular pacing in cardiac resynchronization therapy (CRT)-eligible patients. As it provides stable R-wave sensing, LBBP has been recently used to provide sensing of ventricular arrhythmia in patients receiving implantable cardioverter-defibrillator (ICD) with CRT.

OBJECTIVE

The aim of this study was to analyze the long-term safety and efficacy of the LBBP lead for appropriate detection of ventricular arrhythmia and delivery of antitachycardia pacing (ATP) in patients requiring defibrillator therapy with CRT.

METHODS

CRT-eligible patients who underwent successful LBBP-optimized ICD and LBBP-optimized CRT with defibrillator were enrolled. The LBBP lead was connected to the right ventricular-P/S port after capping the IS-1 connector plug of the DF-1-ICD lead. LBBP-optimized ICD or LBBP-optimized CRT with defibrillator was decided on the basis of correction of conduction system disease. Documented arrhythmic episodes and therapy delivered were analyzed.

RESULTS

Thirty patients were enrolled. The mean age was 59.7 ± 10.5 years. LBBP resulted in an increase in left ventricular ejection fraction from 29.9% ± 4.6% to 43.9% ± 11.2% (P < .0001). During a mean follow-up of 22.9 ± 12.5 months, 254 ventricular arrhythmic events were documented. Appropriate events (n = 225 [89%]) included nonsustained ventricular tachycardia (VT) (n = 212 episodes [94%]), VT (n = 8 [3.5%]), and ventricular fibrillation (n = 5 [2.5%]). ATP efficacy in terminating VT was 75%. Eleven percent of episodes (n = 29) were inappropriately detected because of T-wave oversensing. Inappropriate therapy (ATP) was delivered for 14 episodes (5.5%). Three patients (10%) had worsening of tricuspid regurgitation.

CONCLUSION

Sensing from the LBBP lead for arrhythmia detection is safe as ∼90% of the episodes were detected appropriately. Future studies with a dedicated LBBP-defibrillator lead along with algorithms to avoid oversensing can help in combining defibrillation with conduction system pacing.

Stepping back for good reasons: a reappraisal of the DF-1 connector for defibrillator leads

The DF-4 defibrillator standard has been rapidly adopted due to its convenience at implantation. There are however trade-offs compared to the traditional DF-1 standard that are underappreciated. This viewpoint outlines the advantages and limitations of current defibrillator lead standards that should be kept in mind, as they impact the options that are available to deal with issues that may arise.

Long-term follow-up of patients undergoing add-on pacing/sensing lead vs. ICD lead implantation for failed IS-1/DF-1 ICD leads: a single centre experience

BACKGROUND

Intracardiac defibrillator/cardioverter (ICD) is a cornerstone device for prevention of sudden cardiac death. Lead failure (LF) is one of the most important long-term complications. In this study, we sought to investigate mid-to-long term clinical, device and lead characteristics of patients who have undergone pacing sensing lead (PSL) implantation for an ICD LF and compare them to the patients who have undergone a new ICD lead implantation.

METHODS

In this retrospective, single centre, case-control study, we have screened all ICD patients presenting with LF. Patients with IS-1/DF-1 ICD leads with intact high-voltage conductor were included in the study group, while other patients were included in the control arm. Study group patients underwent PSL implantation, control group patients underwent ICD lead implantation.

RESULTS

Thirty patients were included in each arm of the study. The mean duration of follow-up after intervention was similar in both groups (47.6 months ± 20.4 vs. 46.1 months ± 25.7, p = .808). The total failure rate was not different between two groups (p = .640). Rate of high-voltage conductor disfunction was also similar between two arms: 1 (3.3%) in PSL arm and 0 in control arm (p = .303).

CONCLUSIONS

Addition of a PSL for IS-1/DF-1 ICD LF with normal high-voltage conductor measurements is a viable treatment option with similar long-term results to addition of a new ICD lead. This approach is potentially less costly, technically less demanding, and, in case of concomitant extraction procedure, associated with less acute complication risk.

Transvenous lead extraction in patients with systemic cardiac device-related infection-Procedural outcome and risk prediction: A GALLERY subgroup analysis

BACKGROUND

Transvenous lead extraction (TLE) has evolved as one of the most crucial treatment options for patients with cardiac device-related systemic infection (CDRSI).

OBJECTIVE

The aim of this study was to characterize the procedural outcome and risk factors of patients with CDRSI undergoing TLE.

METHODS

A subgroup analysis of patients with CDRSI of the GALLERY (GermAn Laser Lead Extraction RegistrY) database was performed. Predictors for complications, procedural failure, and all-cause mortality were evaluated.

RESULTS

A total of 722 patients (28.6%) in the GALLERY had "systemic infection" as extraction indication. Patients with CDRSI were older (70.1 ± 12.2 years vs 67.3 ± 14.3 years; P < .001) and had more comorbidities than patients with local infections or noninfectious extraction indications. There were no differences in complete procedural success (90.6% vs 91.7%; P = .328) or major complications (2.5% vs 1.9%; P = .416) but increased procedure-related (1.4% vs 0.3%; P = .003) and all-cause in-hospital mortality (11.1% vs 0.6%; P < .001) for patients with CDRSI. Multivariate analyses revealed lead age ≥10 years as a predictor for procedural complications (odds ratio [OR] 3.23; 95% confidence interval [CI] 1.58-6.60; P = .001). Lead age ≥10 years (OR 2.57; 95% CI 1.03-6.46; P = .04) was also a predictor for procedural failure. We identified left ventricular ejection fraction <30% (OR 1.70; 95% CI 1.00-2.99; P = .049), age ≥75 years (OR 2.1; 95% CI 1.27-3.48; P = .004), chronic kidney disease (OR 1.92; 95% CI 1.17-3.14; P = .01), and overall procedural complications (OR 5.15; 95% CI 2.44-10.84; P < .001) as predictors for all-cause mortality.

CONCLUSION

Patients with CDRSI undergoing TLE demonstrate an increased rate of all-cause in-hospital, as well as procedure-related mortality, despite having comparable procedural success rates. Given these data, it seems paramount to develop preventive strategies to detect and treat CDRSI in its earliest stages.

Outcome and safety of intraoperative defibrillation testing during device replacement: the Simpler trial

AIMS

Intraoperative defibrillation testing (DT) during implant or replacement of implantable cardioverter-defibrillators (ICDs) has been a matter of debate for many years. This debate was put to rest by the Simple and Nordic ICD trials, and the practice of testing during new implantations has essentially been almost abandoned. Old registries demonstrated an increased incidence of significant findings in DT during replacements. The aim of the present study was to evaluate frequency of significant findings and safety of DT in subjects undergoing device replacement.

METHODS AND RESULTS

A prospective observational multi-centre study included consecutive patients undergoing ICD generator replacement. The primary outcome was a failure to terminate induced ventricular fibrillation (VF) with a single shock 10 J below the maximal capacity of the device. Secondary outcomes included complications of DT. Patients were followed-up at 1- and 6-months post-procedure.  A total of 92 patients were eligible, and consented to the study, of which 84 underwent DT during battery replacement. The median age was 68 years and 79.8% were males. Induction of VF was successful in 84 patients as was a successful conversion on the first attempt in all. There were no procedure-related complications. During follow up one patient had two appropriate ICD shock events. In four patients, ICD programming was changed. None suffered inappropriate shock. There was no evidence of lead malfunction. Two deaths occurred, none of which was related to arrhythmia.

CONCLUSION

The present study found DT was not associated with complications in patients undergoing ICD generator replacement but produced no clinically important information.

Long-term follow-up of abandoned transvenous defibrillator leads: a nationwide cohort study

AIMS

Commonly, a dysfunctional defibrillator lead is abandoned and a new lead is implanted. Long-term follow-up data on abandoned leads are sparse. We aimed to investigate the incidence and reasons for extraction of abandoned defibrillator leads in a nationwide cohort and to describe extraction procedure-related complications.

METHODS AND RESULTS

All abandoned transvenous defibrillator leads were identified in the Danish Pacemaker and ICD Register from 1991 to 2019. The event-free survival of abandoned defibrillator leads was studied, and medical records of patients with interventions on abandoned defibrillator leads were audited for procedure-related data. We identified 740 abandoned defibrillator leads. Meantime from implantation to abandonment was 7.2 ± 3.8 years with mean patient age at abandonment of 66.5 ± 13.7 years. During a mean follow-up after abandonment of 4.4 ± 3.1 years, 65 (8.8%) abandoned defibrillator leads were extracted. Most frequent reason for extraction was infection (pocket and systemic) in 41 (63%) patients. Procedural outcome after lead extraction was clinical success in 63 (97%) patients. Minor complications occurred in 3 (5%) patients, and major complications in 1 (2%) patient. No patient died from complication to the procedure during 30-day follow-up after extraction.

CONCLUSION

More than 90% of abandoned defibrillator leads do not need to be extracted during long-term follow-up. The most common indication for extraction is infection. Abandoned defibrillator leads can be extracted with high clinical success rate and low risk of major complications at high-volume centres.

Multi-lead cephalic venous access and long-term performance of high-voltage leads

BACKGROUND

Cardiac resynchronization therapy-defibrillator (CRT-D) implantation via the cephalic vein is feasible and safe. Recent evidence has suggested a higher implantable cardioverter-defibrillator (ICD) lead failure in multi-lead defibrillator therapy via the cephalic route. We evaluated the relationship between CRT-D implantation via the cephalic and ICD lead failure.

METHODS

Data was collected from three CRT-D implanting centers between October 2008 and September 2017. In total 633 patients were included. Patient and lead characteristics with ICD lead failure were recorded. Comparison of "cephalic" (ICD lead via cephalic) versus "non-cephalic" (ICD lead via non-cephalic route) cohorts was performed. Kaplan-Meier survival and a Cox-regression analysis were applied to assess variables associated with lead failure.

RESULTS

The cephalic and non-cephalic cohorts were equally male (81.9% vs. 78%; p = .26), similar in age (69.7 ± 11.5 vs. 68.7 ± 11.9; p = .33) and body mass index (BMI) (27.7 ± 5.1 vs. 27.1 ± 5.7; p = .33). Most ICD leads were implanted via the cephalic vein (73.5%) and patients had a mean of 2.9 ± 0.28 leads implanted via this route. The rate of ICD lead failure was low and statistically similar between both groups (0.36%/year vs. 0.13%/year; p = .12). Female gender was more common in the lead failure cohort than non-failure (55.6% vs. 17.9%, respectively; p = .004) as was hypertension (88.9% vs. 54.2%, respectively, p = .038). On multivariate Cox-regression, female sex (p = .008; HR, 7.12 [1.7-30.2]), and BMI (p = .047; HR, 1.12 [1.001-1.24]) were significantly associated with ICD lead failure.

CONCLUSION

CRT-D implantation via the cephalic route is not significantly associated with premature ICD lead failure. Female gender and BMI are predictors of lead failure.

Surgical Techniques, Complications, and Long-Term Health Effects of Cardiac Implantable Electronic Devices

Cardiovascular implantable electronic device (CIED) has helped with advanced technological improvement in the cardiac field and has been a long-term alternative to medical management. There are different forms of CIEDs such as pacemakers, implantable cardioverter-defibrillators, and cardiac resynchronization therapy. These devices are efficient in establishing near-normal hemodynamics and circulation that ultimately aid physicians to improve the quality of life for their patients. However, there are risk factors that can result in postoperative complications, including infection, lead and pulse generator complications, heart complications, medication-related complications, and psychosocial complications. To ensure optimal outcome of CIED placement, preprocedural measures need to be in place such as matching the right candidate and using appropriate devices. This review aims to highlight the surgical techniques for CIEDs, the associated postoperative complications, and long-term health effects.

Remote monitoring and telemedicine in heart failure: implementation and benefits

PURPOSE OF REVIEW

Remote monitoring (RM) of cardiac implantable electronic devices (CIEDs) is recommended as part of the individualized multidisciplinary follow-up of heart failure (HF) patients. Aim of this article is to critically review recent findings on RM, highlighting potential benefits and barriers to its implementation.

RECENT FINDINGS

Device-based RM is useful in the early detection of CIEDs technical issues and cardiac arrhythmias. Moreover, RM allows the continuous monitoring of several patients' clinical parameters associated with impending HF decompensation, but there is still uncertainty regarding its effectiveness in reducing mortality and hospitalizations. Implementation of RM strategies, together with a proactive physicians' attitude towards clinical actions in response to RM data reception, will make RM a more valuable tool, potentially leading to better outcomes.

Erosion of Cardiovascular Implantable Device: Conservative Therapy or Extraction?

The standard of care for device infection is normally a complete removal of the implantable system, including lead extraction in local or systemic infection cases. Despite the importance of lead extraction techniques, these techniques are complex and have some major risks. Success rates were high, but they are less favorable in patients with several comorbidities. An 80-year-old male presented for device erosion. The patient is known to have several cardiac comorbidities: a transcatheter aortic valve replacement (TAVR), mitral clips for severe aortic stenosis, mitral regurgitation, dual-chamber implantable cardioverter defibrillators (ICD) for secondary prevention. Several weeks ago, he noted tenderness and redness at the site of his device pocket, and his physician, after checking his wound, suggested a possible skin irritation with no systemic infection and started antibiotics treatment. Two weeks later, he noted thinning of the skin around the device with a hematoma and ecchymosis, and slight skin erosion. Strategies for assessment of the wound and pocket cleaning were taken. The strategy was to remove the left-sided device and keep the leads since the patient lately has no elevated inflammatory labs, negative cultures, no fever, nor signs of vegetation on transesophageal echocardiography (TEE) and refused any additional examination as positron emission tomography (PET) scan, and reimplant a new system on the contralateral side. The procedure was divided into two sequences: extracting the device and after one-week implantation of a right-sided new system. In this case, chronic antibiotics were discussable to decrease the recurrence rate, but they did increase the severity of the patient's thrombocytopenia. Despite extraction being the gold standard of treatment in most cases of devices with local and systemic infection, there are some frail patients with several comorbidities where extraction is unbearable due to its major risks and complex procedure. In these specific cases with local infection and device erosion with no signs of any systemic infection, conservative therapy could be a viable option.

Air Entrapment Causing Inappropriate Shock From a Subcutaneous Implantable Cardioverter Defibrillator

Subcutaneous implantable cardioverter defibrillator (S-ICD) is an accepted alternative to conventional transvenous devices. Their efficacy in arrhythmia management is comparable to ICDs. However, those devices also have limitations such as lack of anti-tachycardia pacing capability or higher occurrence of device oversensing associated with inappropriate shocks. Air entrapment inside one or more of subcutaneous pockets has been reported as one of uncommon causes of device malfunction. It is important to recognize the wandering or drifting baseline signals during device interrogation for timely diagnosis and appropriate treatment.

Effectiveness of single- vs dual-coil implantable defibrillator leads: An observational analysis from the SIMPLE study

INTRODUCTION

Dual-coil leads (DC-leads) were the standard of choice since the first nonthoracotomy implantable cardioverter/defibrillator (ICD). We used contemporary data to determine if DC-leads offer any advantage over single-coil leads (SC-leads), in terms of defibrillation efficacy, safety, clinical outcome, and complication rates.

METHODS AND RESULTS

In the Shockless IMPLant Evaluation study, 2500 patients received a first implanted ICD and were randomized to implantation with or without defibrillation testing. Two thousand and four hundred seventy-five patients received SC-coil or DC-coil leads (SC-leads in 1025/2475 patients; 41.4%). In patients who underwent defibrillation testing (n = 1204), patients with both lead types were equally likely to achieve an adequate defibrillation safety margin (88.8% vs 91.2%; P = 0.16). There was no overall effect of lead type on the primary study endpoint of "failed appropriate shock or arrhythmic death" (adjusted HR 1.18; 95% CI, 0.86-1.62; P = 0.300), and on all-cause mortality (SC-leads: 5.34%/year; DC-leads: 5.48%/year; adjusted HR 1.16; 95% CI, 0.94-1.43; P = 0.168). However, among patients without prior heart failure (HF), and SC-leads had a significantly higher risk of failed appropriate shock or arrhythmic death (adjusted HR 7.02; 95% CI, 2.41-20.5). There were no differences in complication rates.

CONCLUSION

In this nonrandomized evaluation, there was no overall difference in defibrillation efficacy, safety, outcome, and complication rates between SC-leads and DC-leads. However, DC-leads were associated with a reduction in the composite of failed appropriate shock or arrhythmic death in the subgroup of non-HF patients. Considering riskier future lead extraction with DC-leads, SC-leads appears to be preferable in the majority of patients.

Frequency of Need for Antitachycardia or Antibradycardia Pacing or Cardiac Resynchronization Therapy in Patients With a Single-Chamber Implantable Cardioverter-Defibrillator

The subcutaneous implantable cardioverter-defibrillator (S-ICD) is unable to deliver antitachycardia pacing (ATP), bradycardia pacing, and cardiac resynchronization therapy (CRT). However, little is known about the proportion of patients that develop the need for 1 of these features. We evaluated the potential suitability for a S-ICD at the time of first replacement in a cohort of patients with a transvenous single-chamber device who did not need bradycardia pacing at the time of implantation. The study cohort consisted of patients who received a transvenous single-chamber ICD between 1998 and September 2017. The primary end point was a combined end point of the need for atrial or ventricular pacing, development of a CRT indication, or termination of ventricular arrhythmias by ATP delivery. During a mean follow-up of 5.6 ± 1.9 years, 78 of 254 patients (31%) reached the primary end point. The 7 years' cumulative S-ICD suitability rate was 65.6% (95% confidence interval [CI] 58.5% to 71.7%). Event rates were 9.5% (95% CI 6.5% to 13.9%) at 1-year follow-up, and 28.0% (95% CI 22.8% to 34.2%) at 5 years' follow-up. For individual end points, incidence rates were 1.8 (95% CI 1.2 to 2.6) per 100-patient-years for CRT, 0.3 (95% CI 0.1 to 0.8) per 100-patient-years for pacing-dependency, and 4.9 (95% CI 3.8 to 6.3) per 100-patient-years for appropriate ATP therapy. No baseline variables for predicting S-ICD unsuitability were found. In conclusion, at the time of the first replacement, 69% of the patients with a single-chamber device would have been clinically eligible for the S-ICD. Incidence rates of developing a bradycardia pacing and CRT indication are low.

Reimplantation After Lead Removal

The number of implanted cardiovascular implantable electronic devices (CIEDs) has increased significantly in the last 30 years, which has led to an upsurge in CIED complications, such as infection and lead malfunction requiring CIED extraction. The decision-making process of CIED reimplantation requires meticulous planning that includes careful consideration of several aspects: the reason for extraction, the indication for CIED reimplantation, patients' wishes, timing of reimplantation, the need for a bridging device, and the type and location of device to be reimplanted. In this article, the authors review this decision-making process and the necessary steps to achieve optimal patient outcomes.

Long-term reliability of the defibrillator lead inserted by the extrathoracic subclavian puncture

BACKGROUND

As the transvenous defibrillator lead is fragile and its failure may cause a life-threatening event, reliable insertion techniques are required. While the extrathoracic puncture has been introduced to avoid subclavian crush syndrome, the reports on the long-term defibrillator lead survival using this approach, especially the comparison with the cephalic cutdown (CD), remain scarce. We aimed to evaluate the long-term survival of the transvenous defibrillator lead inserted by the extrathoracic subclavian puncture (ESCP) compared with CD.

METHODS

Between 1998 and 2011, 324 consecutive patients who underwent an implantable cardioverter-defibrillator (ICD) implantation in Hokkaido University Hospital were included. ICD leads were inserted by CD from 1998 to 2003 and by contrast venography-guided ESCP thereafter. Lead failure was defined as a nonphysiologic high-rate oversensing with abnormal lead impedance or highly elevated sensing and pacing threshold.

RESULTS

Of 324 patients, CD was used in 37 (11%) and ESCP in 287 patients (89%). During the median follow-up of 6.2 years (IQR:3.2-8.3), 7 leads (2 in CD and 5 leads in ESCP group) failed. All patients with lead failure in ESCP group were implanted with either SJM Riata (n = 1) or Medtronic Fidelis lead (n = 4). Five-year lead survival was 93.8% (CI95%:77.3-98.4%) in CD compared with 99.1% (CI95%:96.6-99.8%) in ESCP group (P = 0.903). Univariate Cox regression analysis showed that the use of Fidelis or Riata lead was the strong predictor of the ICD lead failure (HR 13.8, CI95%:2.9-96.5; P = 0.001).

CONCLUSIONS

Contrast venography-guided extrathoracic puncture ensures the reliable long-term survival in the transvenous defibrillator leads.

What physicians do in case of a failure of the pace-sense part of a defibrillation lead : Survey in Germany, Austria and Switzerland

BACKGROUND

The possible treatment strategies for defects of the pace-sense (P/S) part of a defibrillation lead are either implantation of a new high-voltage (HV)-P/S lead, with or without extraction of the malfunctioning lead, or implantation of a P/S lead.

METHODS

We conducted a Web-based survey across cardiac implantable electronic device (CIED) centers to investigate their procedural practice and decision-making process in cases of failure of the P/S portion of defibrillation leads. In particular, we focused on the question of whether the integrity of the HV circuit is confirmed by a test shock before decision-making. The questionnaire included 14 questions and was sent to 951 German, 341 Austrian, and 120 Swiss centers.

RESULTS

The survey was completed by 183 of the 1412 centers surveyed (12.7% response rate). Most centers (90.2%) do not conduct a test shock to confirm the integrity of the HV circuit before decision-making. Procedural practice in lead management varies depending on the presentation of lead failure and whether the center applies a test shock. In centers that do not conduct a test shock, the majority (69.9%) implant a new HV-P/S lead. Most centers (61.7%) that test the integrity of the HV system implant a P/S lead. The majority of centers favor DF-4 connectors (74.1%) over DF-1 connectors (25.9%) at first CIED implantation.

CONCLUSION

Either implanting a new HV-P/S lead or placing an additional P/S lead are selected strategies if the implantable cardioverter-defibrillator lead failure is localized to the P/S portion. However, conducting a test shock to confirm the integrity of the HV component is rarely performed.

Sex differences in outcomes of primary prevention implantable cardioverter-defibrillator therapy: combined registry data from eleven European countries

Aims

Therapy with an implantable cardioverter defibrillator (ICD) is established for the prevention of sudden cardiac death (SCD) in high risk patients. We aimed to determine the effectiveness of primary prevention ICD therapy by analysing registry data from 14 centres in 11 European countries compiled between 2002 and 2014, with emphasis on outcomes in women who have been underrepresented in all trials.

Methods and results

Retrospective data of 14 local registries of primary prevention ICD implantations between 2002 and 2014 were compiled in a central database. Predefined primary outcome measures were overall mortality and first appropriate and first inappropriate shocks. A multivariable model enforcing a common hazard ratio for sex category across the centres, but allowing for centre-specific baseline hazards and centre specific effects of other covariates, was adjusted for age, the presence of ischaemic cardiomyopathy or a CRT-D, and left ventricular ejection fraction ≤25%. Of the 5033 patients, 957 (19%) were women. During a median follow-up of 33 months (IQR 16-55 months) 129 women (13%) and 807 men (20%) died (HR 0.65; 95% CI: [0.53, 0.79], P-value < 0.0001). An appropriate ICD shock occurred in 66 women (8%) and 514 men (14%; HR 0.61; 95% CI: 0.47-0.79; P = 0.0002).

Conclusion

Our retrospective analysis of 14 local registries in 11 European countries demonstrates that fewer women than men undergo ICD implantation for primary prevention. After multivariate adjustment, women have a significantly lower mortality and receive fewer appropriate ICD shocks.

Prophylactic implantable cardioverter defibrillator in heart failure: the growing evidence for all or Primum non nocere for some?

Heart failure (HF) is a common health problem and has reached epidemic in many western countries. Despite the current era of HF treatment, the risk of sudden cardiac death (SCD) in HF remains significant. Implantable cardioverter defibrillator (ICD) support has been shown to reduce the risk of SCD in patients with HF and impaired left ventricular function. Prophylactic ICD implantation in HF patients seems a logical step to reduce mortality through a reduction in SCD. However, ICD implantation is an invasive procedure, and both short- and long-term complications can occur. This needs to be carefully considered when evaluating the risk-benefit ratio of ICD implantation for individual patients. As the severity of HF increases, the proportion of SCD compared with HF-related deaths decreases. The challenge lies in identifying patients with HF who are at significant risk of SCD and who would most benefit from an ICD in addition to other anti-arrhythmic strategies. This review offers insight on the applicability and practicability of ICD for this growing population.

Neointimal fibrotic lead encapsulation - Clinical challenges and demands for implantable cardiac electronic devices

Every tenth patient with a cardiac pacemaker or implantable cardioverter-defibrillator implanted is expected to have at least one lead problem in his lifetime. However, transvenous leads are often difficult to remove due to thrombotic obstruction or extensive neointimal fibrotic ingrowth. Despite its clinical significance, knowledge on lead-induced vascular fibrosis and neointimal lead encapsulation is sparse. Although leadless pacemakers are already available, their clinical operating range is limited. Therefore, lead/tissue interactions must be further improved in order to improve lead removals in particular. The published data on the coherences and issues related to lead associated vascular fibrosis and neointimal lead encapsulation are reviewed and discussed in this paper.

Interaction between shock coils increased the incidence of inappropriate therapies and lead failure in implantable cardioverter defibrillator

AIMS

Shock coil interaction in patients with multiple implantable cardioverter defibrillator (ICD) leads is occasionally observed. We aimed to evaluate the incidence of shock coil interaction and its clinical relevance.

METHODS AND RESULTS

All ICD patients (646 patients) who came to follow up control in our ICD ambulance between January 1, 2011, and December 31, 2011 in the department of cardiology in Bad Berka hospital were retrospectively evaluated in this study. All baseline demographic, clinical, and procedural characteristics and postoperative chest x ray in postero-anterior and lateral view as well as clinical and ICD follow up data were evaluated. Among 646 patients 42 had multiple ICD leads (6.5%) of whom 36 patients (5.5% of total cohort patients and 85.7% of patients with multiple ICD leads) had shock coil interaction and presented the study group (Group I). The control group (Group II) consisted of 610 patients without coil-coil interaction including patients with single shock lead (604 patients) or patients with multiple leads but without interaction between shock coils (6 patients). Inappropriate anti-tachycardia therapies and RV lead revisions were more frequent in patients with interaction between shock coils (Group I vs Group II: 27.7% and 5.7%; p = 0.049 and 30.6% vs 6.4; p = 0.0001, respectively).

CONCLUSIONS

Interaction between shock coils may be one of possible causes of lead failure and resulted in inappropriate therapies and subsequent lead revision.

Outcomes Associated With Extraction Versus Capping and Abandoning Pacing and Defibrillator Leads

Background:

Lead management is an increasingly important aspect of care in patients with cardiac implantable electronic devices; however, relatively little is known about long-term outcomes after capping and abandoning leads.

Methods:

Using the 5% Medicare sample, we identified patients with de novo cardiac implantable electronic device implantations between January 1, 2000, and December 31, 2013, and with a subsequent lead addition or extraction ≥12 months after the de novo implantation. Patients who underwent extraction for infection were excluded. Using multivariable Cox proportional hazards models, we compared cumulative incidence of all-cause mortality, device-related infection, device revision, and lead extraction at 1 and 5 years for the extraction versus the cap and abandon group.

Results:

Among 6859 patients, 1113 (16.2%) underwent extraction, whereas 5746 (83.8%) underwent capping and abandonment. Extraction patients tended to be younger (median, 78 versus 79 years; P <0.0001), were less likely to be male (65% versus 68%; P =0.05), and had shorter lead dwell time (median, 3.0 versus 4.0 years; P <0.0001) and fewer comorbidities. Over a median follow-up of 2.4 years (25th, 75th percentiles, 1.0, 4.3 years), the overall 1-year and 5-year cumulative incidence of mortality was 13.5% (95% confidence interval [CI], 12.7–14.4) and 54.3% (95% CI, 52.8–55.8), respectively. Extraction was associated with a lower risk of device infection at 5 years relative to capping (adjusted hazard ratio, 0.78; 95% CI, 0.62–0.97; P =0.027). There was no association between extraction and mortality, lead revision, or lead extraction at 5 years.

Conclusions:

Elective lead extraction for noninfectious indications had similar long-term survival to that for capping and abandoning leads in a Medicare population. However, extraction was associated with lower risk of device infections at 5 years.

Strategies for Transvenous Lead Extraction Procedures

Transvenous lead extraction (TLE) has undergone an explosive evolution since its inception as a rudimentary skill with limited technology and therapeutic options. Early techniques involved simple manual traction that frequently proved ineffective for chronically implanted leads, and carried a significant risk of myocardial avulsion, tamponade, and death. The morbidity and mortality associated with these early extraction techniques limited their application to use only in life-threatening situations, such as infection and sepsis. The past four decades, however, have witnessed significant advances in lead extraction technology, resulting in more efficacious techniques and tools, providing the skilled extractor with a well-equipped armamentarium. With the development of the discipline, we have witnessed a growth in the community of TLE experts coincident with a marked decline in the incidence of procedure-related morbidity and mortality, with recent registries at high-volume centers reporting high success rates with exceedingly low complication rates. Future developments in lead extraction are likely to focus on new tools that will allow for us to provide comprehensive device management, develop alternative systems for extraction training, and focus on the design of new leads conceived to facilitate future extraction.

Complete right bundle branch block and QRS-T discordance can be the initial clue to detect S-ICD ineligibility

BACKGROUND

In order to minimize inappropriate shocks of subcutaneous implantable cardioverter-defibrillators (S-ICD), it is important to recognize who is suitable for S-ICD indication. This study aimed to clarify what types of cardiac disease are likely to fulfill the S-ICD screening criteria and ineligible factors for S-ICD in the standard 12-lead electrocardiogram (ECG).

METHODS

A total of 348 patients with heart disease were enrolled. They were assessed by supine and standing ECG recording to simulate the 3 S-ICD sensing vectors and standard 12-lead ECG, simultaneously. Clinical and ECG characteristics were analyzed to compare the patients who are eligible and ineligible with S-ICD screening ECG indication.

RESULTS

The mean age of study patients was 49±21 years and 244 (70%) were men. Nineteen percent of patients were unsuitable for S-ICD. There was no significant difference in ineligibility for S-ICD among cardiac diseases (p=0.48). Univariate analysis showed complete right bundle branch block (CRBBB), QRS-T discordance in lead II, and QRS-T discordance in 3 leads (I, II, and aVF) were more frequent in patients who were ineligible for S-ICD than in the eligible group. Multivariate regression analysis showed CRBBB and QRS-T discordance in 3 leads were independent predictors for ineligibility of S-ICD.

CONCLUSION

There are no differences in eligibility of S-ICD among types of cardiac diseases. CRBBB and QRS-T discordance were independent predictors for ineligibility.

Long-Term Evaluation of Biotronik Linox and Linox(smart) Implantable Cardioverter Defibrillator Leads

INTRODUCTION

Expert consensus holds that post-market, systematic surveillance of ICD leads is essential to ensure confirmation of adequate lead performance. GALAXY (NCT00836589) and CELESTIAL (NCT00810264) are ongoing multicenter, prospective, non-randomized registries conducted to confirm the long-term safety and reliability of Biotronik leads.

METHODS AND RESULTS

ICD and CRT-D patients are followed for Linox and Linox(smart) ICD lead performance and safety for 5 years post-implant. All procedural and system-related adverse events (AEs) were assessed at each follow-up, along with lead electrical parameters. An independent CEC of EPs adjudicated AEs to determine AE category and lead relatedness. The analysis used categories of lead observations per ISO 5841-2 (Third edition). A total of 3,933 leads were implanted in 3,840 patients (73.0% male, mean age 67.0 ± 12.2 years) at 146 US centers. The estimated cumulative survival probability was 96.3% at 5 years after implant for Linox leads and 96.6% at 4 years after implant for Linox(smart) leads. A comparison of the Linox and Linox(smart) survival functions did not find evidence of a difference (P = 0.2155). The most common AEs were oversensing (23, 0.58%), conductor fracture (14, 0.36%), failure to capture (13, 0.33%), lead dislodgement (12, 0.31%), insulation breach (10, 0.25%), and abnormal pacing impedance (8, 0.20%).

CONCLUSIONS

Linox and Linox(smart) ICD leads are safe, reliable and infrequently associated with lead-related AEs. Additionally, estimated cumulative survival probability is clinically acceptable and well within industry standards. Ongoing data collection will confirm the longer-term safety and performance of the Linox family of ICD leads.

A novel use of EP catheter in extraction of trapped intracardiac devices: Two case reports

The decision to retrieve chronically implanted abandoned leads and trapped intracardiac devices percutaneously has been difficult and highly controversial. We present two case reports in which electrophysiological ablation catheter was used to retrieve infected abandoned pacemaker lead and trapped permacatheter (permacath) in right ventricle. We could avert major cardiovascular surgeries in both the patients by simply modifying the traditionally used techniques for extraction of intracardiac devices.

The Entirely Subcutaneous Defibrillator - A New Generation and Future Expectations

Although conventional implantable cardioverter-defibrillators (ICDs) have proved effective in the prevention of sudden cardiac death (SCD), they still appear to be limited by non-trivial acute and long-term complications. The recent advent of an entirely subcutaneous ICD (S-ICD) represents a further step in the evolution of defibrillation technology towards a less-invasive approach. This review highlights some historical and current issues concerning the S-ICD that may offer a viable therapeutic option in selected patients at high risk of SCD and in whom pacing is not required. After the CE Mark and US Food and Drug Administration (FDA) approvals, the S-ICD is being implanted worldwide with growing clinical data regarding its safety and efficacy (the EFFORTLESS Registry). The recently developed new generation of S-ICD (EMBLEM, Boston Scientific) demonstrates favourable features including a smaller device, longer longevity and remote-monitoring compatibility. Further innovations in the S-ICD system and potential integration with leadless pacing may play an important role in defibrillation therapy and prevention of SCD in the near future.

Longevity of implantable cardioverter defibrillators: a comparison among manufacturers and over time

Aims

Longevity of implantable cardioverter defibrillators (ICDs) is crucial for patients and healthcare systems as replacements impact on infection rates and cost-effectiveness. Aim was to determine longevity using very large databases of two teaching hospitals with a high number of replacements and a rather homogeneous distribution among manufacturers.

Methods and results

The study population consists of all patients in whom an ICD was inserted in. All ICD manufacturers operating in Switzerland and the Netherlands and all implanted ICDs were included. Implantable cardioverter defibrillator replacements due to normal battery depletion were considered events, and other replacements were censored. Longevity was assessed depending on manufacturers, pacing mode, implant before/after 2006, and all parameters combined. We analysed data from 3436 patients in whom 4881 ICDs [44.2% VVI-ICDs, 27.4% DDD-ICDs, 26.3% cardiac resynchronization therapy (CRT)-ICDs, 2.0% subcutaneous ICDs] were implanted. The four major manufacturers had implant shares between 18.4 and 31.5%. Replacement due to battery depletion (27.4%) was performed for 1339 ICDs. Patient survival at 5 years was 80.1%. Longevity at 5 years improved in contemporary compared with elderly ICDs [63.9–80.6% across all ICDs, of 73.7–92.1% in VVIs, 58.2–76.1% in DDDs, and of 47.1–66.3% in CRT defibrillators, all P value < 0.05]. Remarkable differences were seen among manufacturers, and those with better performance in elderly ICDs were not those with better performance in contemporary ones.

Conclusion

Implantable cardioverter defibrillator longevity increased in contemporary models independent of manufacturer and pacing mode. Still, significant differences exist among manufacturers. These results might impact on device selection.

Heart Failure With Reduced Ejection Fraction And A Narrow QRS Complex: Combination Of A Subcutaneous Defibrillator With Cardiac Contractility Modulation

Cardiac contractility modulation (CCM) is a relatively new electrical therapy for heart failure patients with reduced ejection fraction. The majority of patients eligible for CCM will also need an implantable cardioverter-defibrillator (ICD). To-date, three pacing electrodes are mandatory for CCM therapy because the current CCM signal delivery algorithm requires sequential intracardiac sensing of a p-wave, followed by appropriately timed ventricular activation by the two ventricular septal leads. As there is no device combining CCM with ICD functions, most CCM patients will need multiple intracardiac electrodes, which increase the cumulative risk for complications such as systemic infections, thrombosis of central venous lines, insulation failures or lead fractures. The long-term complications associated with trans-venous ICD leads have led to the development of a totally subcutaneous implantable cardioverter-defibrillator (S-ICD). In this essay the two technologies CCM and S-ICD are reviewed. Additionally, we present their successful combination on the basis of a case report on the first patient receiving both devices.

Transvenous Implantable Cardioverter-Defibrillator (ICD) Lead Performance: A Meta-Analysis of Observational Studies

BACKGROUND

Despite the widespread use of implantable cardioverter-defibrillators (ICDs) in clinical practice, concerns exist regarding ICD lead durability. The performance of specific lead designs and factors determining this in large populations need clarification.

METHODS AND RESULTS

The Medline, Embase, and Cochrane Collaboration databases were searched for studies including ≥2 of the most commonly implanted leads. The Mantel-Haenszel random-effects model was used. Seventeen studies were selected, including a total of 49 871 patients-5538 implanted with Durata (St. Jude Medical Inc), 10 605 with Endotak Reliance (Boston Scientific), 16 119 with Sprint Quattro (Medtronic Corp), 11 709 with Sprint Fidelis (Medtronic Corp), and 5900 with Riata (St. Jude Medical Inc)-with follow-up of 136 509 lead-years. Although the Durata lead presented a numerically higher rate, no statistically significant differences in the mean incidence of lead failure (0.29%-0.45% per year) were observed in comparison of the 3 nonrecalled leads. A higher event rate was documented with the Riata (1.0% per-year increase) and Sprint Fidelis (>2.0% per-year increase) leads compared with nonrecalled leads. An indication of increased incidence of Durata lead failure versus Sprint Quattro and Endotak Reliance leads was observed in 1 of 3 included studies, allowing for comparison of purely electrical lead failure, but this requires further evaluation.

CONCLUSIONS

Endotak Reliance (8F), Sprint Quattro (8F), and Durata (7F) leads displayed low annual incidence of failure; however, long-term follow-up data are still scarce. More data are needed to clarify the performance and safety of the Durata lead.

Subcutaneous implantable cardioverter defibrillators in children, young adults and patients with congenital heart disease

The demonstration of severe complications in patients implanted with a transvenous implantable cardioverter defibrillator (ICD) has led to the development of devices equipped with a subcutaneous lead. This new technique offers numerous advantages but also certain disadvantages. Various studies or anecdotal clinical cases have specifically been conducted with this subcutaneous defibrillation system in children and/or patients with congenital heart disease. Results of these studies suggest: 1) a high feasibility despite being limited by a selection process that excludes patients requiring permanent pacing and patients declared ineligible during pre-screening; 2) good efficacy of electrical shocks in reducing induced or spontaneous ventricular arrhythmias; 3) in this specific subset of patients, 2 types of complications have been particularly described: a risk of device exteriorization and infection, and a large number of inappropriate therapies primarily related to T-wave oversensing. The subcutaneous ICD could therefore constitute the gold standard for patients with complex congenital heart disease with no venous access to the heart or with a persistent shunt increasing the risk of systemic emboli as well as in young patients with channelopathy or hypertrophic cardiomyopathy not requiring long-term pacing. Technological change (reduction in device size, better differentiation between R- and T-waves, possibility of pacing if device coupled with a leadless pacemaker) could reduce the limitations and complications and thereby increase the indications in this sub-group of patients.

[The subcutaneous cardioverter-defibrillator: When less is more]

INTRODUCTION

In the last few decades, defibrillator therapy has revolutionized treatment of patients at risk for sudden cardiac death. Multiple clinical trials have shown the benefit of implantable cardioverter-defibrillators (ICD) for primary and secondary prevention of sudden cardiac death. Being an entirely subcutaneous system, the S-ICD® avoids important periprocedural and long-term complications associated with transvenous implantable cardioverter-defibrillator (TV-ICD) systems as well as the need for fluoroscopy during implant surgery.

METHODS AND RESULTS

In patients with challenging anatomic conditions or after infection, the S-ICD® might be reasonable. In multicenter studies and registries efficacy and safety of the S-ICD® was equal or better to transvenous implantable defibrillators. The cardiac rhythm is detected by the use of 1 of the 3 potential vectors. The S-ICD® automatically selects the most suitable vector for rhythm detection. If ventricular tachyarrhythmia is detected, the device is able to deliver up to five shocks of 80 J, while postshock pacing is available at 50 bpm for 30 s. The implantation technique is different from that of conventional ICDs, but easily learnable by experienced cardiologists. Initially observed hurdles (e.g., inappropriate shocks or infections) have been overcome by standardized implantation techniques, operator learning curves, and modification of algorithms.

CONCLUSIONS

The S-ICD® predominately might be suitable in all patients with ICD indication except patients with pacing or cardiac resynchronization therapy (CRT) indication, ventricular tachycardia < 170 bpm, negative screening, or in the occasional patient whose arrhythmia might be suppressed by overdrive pacing. The system received CE certification in 2009 and was approved by the FDA in 2012. Currently, in Germany the S-ICD® has been integrated into the DRG system and can be reimbursed as a single chamber ICD.

Transvenous implantable cardioverter-defibrillator lead reliability: implications for postmarket surveillance

Background

As implantable cardioverter-defibrillator technology evolves, clinicians and patients need reliable performance data on current transvenous implantable cardioverter-defibrillator systems. In addition, real-world reliability data could inform postmarket surveillance strategies directed by regulators and manufacturers.

Methods and Results

We evaluated Medtronic Sprint Quattro, Boston Scientific Endotak, and St Jude Medical Durata and Riata ST Optim leads implanted by participating center physicians between January 1, 2006 and September 1, 2012. Our analytic sample of 2653 patients (median age 65, male 73%) included 445 St Jude, 1819 Medtronic, and 389 Boston Scientific leads. After a median of 3.2 years, lead failure was 0.28% per year (95% CI, 0.19 to 0.43), with no statistically significant difference among manufacturers. Simulations based on these results suggest that detecting performance differences among generally safe leads would require nearly 10 000 patients or very long follow-up.

Conclusions

Currently marketed implantable cardioverter-defibrillator leads rarely fail, which may be reassuring to clinicians advising patients about risks and benefits of transvenous implantable cardioverter-defibrillator systems. Regulators should consider the sample size implications when designing comparative effectiveness studies and evaluating new technology for preventing sudden cardiac death.

Managing patients with advisory defibrillator leads: what can we learn from published data?

Defibrillator lead advisories stir a lot of emotions, both with patients and physicians, and this may influence lead management. We reviewed the literature for a more evidence-based approach to this issue.

From the complications of two of the current advisory leads, the Medtronic Sprint Fidelis and St. Jude Riata leads, and the consequences of possible interventions, we can conclude that a restrained approach to premature replacement is appropriate. It may be opportune to replace the leads during a scheduled generator replacement in case of a higher electrical failure rate, in order to prevent future premature interventions.

We found no support to extract non-functional advisory leads. In contrast, extraction is often more demanding than anticipated, and the risk substantially exceeds that of simply abandoning the leads.

The mismatch between patient life expectancy and the service life of implantable devices in current cardioverter-defibrillator therapy: a call for larger device batteries

In 2005, Bob Hauser published a paper in the Journal of the American College of Cardiology entitled "The growing mismatch between patient longevity and the service life of Implantable Cardioverter-Defibrillators". Now, nearly a decade later, I would like to perform a second look on the problem of a mismatching between ICD device service life and the survival of ICD recipients. Since 2005, the demographics of the ICD population has changed significantly. Primary prevention has become the dominant indication in defibrillator therapy and device implantation is indicated more and more in earlier stages of cardiac diseases. In former larger scale ICD trials, the patient average 5-year survival probability was in a range of 68-71%; in newer CRT-D trials in a range of 72-88%. Due to a progressively widened ICD indication and implantation preferentially performed in patients with better life expectancy, the problem of inadequate device service life is of growing importance. The early days of defibrillator therapy started with a generator volume of 145 ccm and a device service life <18 months. In this early period, the device miniaturization and extension of service life were similar challenges for the technicians. Today, we have reached a formerly unexpected extent of device miniaturization. However, technologic improvements were often preferentially translated in further device miniaturization and not in prolonging device service life. In his analysis, Bob Hauser reported a prolonged device service life of 2.3 years in ICD models with a larger battery capacity of 0.54 up to 0.69 Ah. Between 2008 and 2014, several studies had been published on the problem of ICD longevity in clinical scenarios. These analyses included "older" and currently used single chamber, dual chamber and CRT devices. The reported average 5-year device service life ranged from 0 to 75%. Assuming today technology, larger battery capacities will only result in minimal increase in device volume. Selected ICD patients may further benefit from device miniaturization-but the vast majority may much more benefit from a significant prolongation in device service life. All published cost-effectiveness analyses in ICD therapy show that device costs and device service life are the dominant determinants of the results. The performed "second look-nearly a decade later" revealed that there are still relevant limitations regarding the device service life in current defibrillator therapy. Technical improvements were preferentially transformed into device miniaturization but not into prolonging device service life. But this optimization is strongly enforced. The most feasible solution might be the use of device batteries with larger capacities. The economic burden, mainly caused by non-adequate device service life, may limit the future realization of ICD therapy in a progressively growing patient population. In the former years, physicians and device manufacturers have ignored the patient perspective in defibrillator therapy. However, it is the patient viewpoint that prolonged device service life is much more important than smaller generator size.