Single-coil Implantable Cardioverter Defibrillator Research Articles

Analysis of 1051 ICD Leads Extractions in Search of Factors Affecting Procedure Difficulty and Complications: Number of Coils, Tip Fixation and Position-Does It Matter?

Background: Implantable cardioverter-defibrillator (ICD) leads are considered a risk factor for major complications (MC) during transvenous lead extraction (TLE). Methods: We analyzed 3878 TLE procedures (including 1051 ICD lead extractions). Results: In patients with ICD lead removal, implant duration was almost half as long (69.69 vs. 114.0 months; p < 0.001), procedure complexity (duration of dilatation of all extracted leads, use of more advanced tools or additional venous access) (15.13% vs. 20.78%; p < 0.001) and MC (0.67% vs. 2.62%; p < 0.001) were significantly lower as compared to patients with pacing lead extraction. The procedural success rate was higher in these patients (98.29% vs. 94.04%; p < 0.001). Extraction of two or more ICD leads or additional superior vena cava (SVC) coil significantly prolonged procedure time, increased procedure complexity and use of auxiliary or advanced tools but did not influence the rate of MC. The type of ICD lead fixation and tip position did not affect TLE complexity, complications and clinical success although passive fixation reduces the likelihood of procedural success (OR = 0.297; p = 0.011). Multivariable regression analysis showed that ICD lead implant duration ≥120 months (OR = 2.956; p < 0.001) and the number of coils in targeted ICD lead(s) (OR = 2.123; p = 0.003) but not passive-fixation ICD leads (1.361; p = 0.149) or single coil ICD leads (OR = 1.540; p = 0.177) were predictors of higher procedure complexity, but had no influence on MC or clinical and procedural success. ICD lead implant duration was of crucial importance, similar to the number of leads. Lead dwell time >10 years is associated with a high level of procedure difficulty and complexity but not with MC and procedure-related deaths. Conclusions: The main factors affecting the transvenous removal of ICD leads are implant duration and the number of targeted ICD leads. Dual coil and passive fixation ICD leads are a bit more difficult to extract whereas fixation mechanism and tip position play a much less dominant role.

51 Outcomes with single-coil versus dual-coil implantable cardioverter-defibrillators: a meta-analysis

AimsDual-coil implantable cardioverter defibrillator (ICD) leads have traditionally been used over single-coil leads due to concerns regarding high defibrillation thresholds (DFT) and consequent poor shock efficacy. However, accumulating evidence suggests...

Outcomes with single-coil versus dual-coil implantable cardioverter defibrillators: a meta-analysis.

Dual-coil implantable cardioverter defibrillator (ICD) leads have traditionally been used over single-coil leads due to concerns regarding high defibrillation thresholds (DFT) and consequent poor shock efficacy. However, accumulating evidence suggests that this position may be unfounded and that dual-coil leads may also be associated with higher complication rates during lead extraction. This meta-analysis collates data comparing dual- and single-coil ICD leads. Electronic databases were systematically searched for randomized controlled trials (RCT) and non-randomized studies comparing single-coil and dual-coil leads. The mean differences in DFT and summary estimates of the odds-ratio (OR) for first-shock efficacy and the hazard-ratio (HR) for all-cause mortality were calculated using random effects models. Eighteen studies including a total of 138,124 patients were identified. Dual-coil leads were associated with a lower DFT compared to single coil leads (mean difference -0.83J; 95% confidence interval [CI] -1.39--0.27; P = 0.004). There was no difference in the first-shock success rate with dual-coil compared to single-coil leads (OR 0.74; 95%CI 0.45-1.21; P=0.22). There was a significantly lower risk of all-cause mortality associated with single-coil leads (HR 0.91; 95%CI 0.86-0.95; P < 0.0001). This meta-analysis suggests that single-coil leads have a marginally higher DFT but that this may be clinically insignificant as there appears to be no difference in first-shock efficacy when compared to dual-coil leads. The mortality benefit with single-coil leads most likely represents patient selection bias. Given the increased risk and complexity of extracting dual-coil leads, centres should strongly consider single-coil ICD leads as the lead of choice for routine new left-sided ICD implants.

Abstract 17550: Predictors of High DFT in Single and Dual Coil Leads: Is There Still a Role for DFT Testing in Current Practice?

Background: Two recent changes in implantable cardioverter defibrillator (ICD) practice are the increased use of single coil leads and less frequent defibrillation threshold (DFT) testing at implantation. Single coil leads have higher mean DFTs which is of unclear clinical significance. Such leads were used in only a minority of subjects in SIMPLE, which showed no benefit of DFT testing. Hypothesis: Clinical characteristics can be used to predict patients at increased risk of an inadequate defibrillation safety margin with single coil leads. Methods: This analysis included 174 consecutive patients undergoing de novo left pectoral, single coil ICD implantation. A standardized modified step down testing algorithm at implantation was used to determine the delivered energy DFT. Logistic regression was used to assess predictors of DFT and of a high DFT (&gt; 25 J). Results: The patient population was 71.3 percent male and 35 percent African American (AA). The mean age was 60.8 ± 14.3 years and ejection fraction was 34.3 ± 15.6 percent. Of twelve clinical factors assessed, the univariate predictors of DFT were age (p &lt; 0.001), male sex (p &lt; 0.001) and AA race (p &lt; 0.001). After covariate adjustment, race, age and ejection fraction were found to be associated with a high DFT. The mean DFT (J) among AA was 16.1 ± 8.8 compared with 13.3 ± 6.5 for the rest of the cohort (p &lt; 0.05). Moreover, 13.1% of AAs had a high DFT compared with 1.7% for the rest of the cohort (p &lt; 0.005). Conclusions: Age, race and sex predict DFTs with single coil leads. AA are at increased risk for a high DFT and thus an inadequate defibrillation safety margin (&lt; 10 J) and should be considered for dual coil leads and/or defibrillation testing at implantation.

Failure Rates of Single- Versus Dual-Coil Nonrecalled Sprint Quattro Defibrillator Leads

Electrical failure is more common in single-coil compared with dual-coil implantable cardioverter defibrillator (ICD) leads in the case of the recalled Riata lead. Single-coil leads are however favored in most patients given their lower risk of extraction. We therefore evaluated the failure-free survival of single- versus dual-coil ICD leads not included in Food and Drug Administration recalls. All patients receiving a Medtronic transvenous Sprint Quattro single- or dual-coil ICD lead were included in this analysis. Leads were followed to the end point of electrical failure. A total of 1,020 dual-coil and 631 single-coil ICD leads were implanted at our institution from November 2000 to March 2014. As expected, dual-coil leads had a longer follow-up time (3.4 ± 2.6 years vs 1.3 ± 1.0 years, p <0.001) because they were approved many years earlier by the Food and Drug Administration. The overall lead survival rates free from electrical failure at 1, 2, and 3 years after implantation were 98.8%, 98.2%, and 95.1%, respectively, for the single-coil leads versus 99.7%, 99.4%, and 99.3%, respectively, for the dual-coil leads (p = 0.0013). In conclusion, single-coil leads are associated with higher electrical failure rates compared with dual-coil leads even for nonrecalled lead models from the same family and manufacturer. These findings have implications on the choice of ICD lead at the time of device implantation.

Clinical Impact, Safety, and Efficacy of Single- versus Dual-Coil ICD Leads in MADIT-CRT

Current data on efficacy, safety and impact on clinical outcome of single- versus dual-coil implantable cardioverter-defibrillator (ICD) leads are limited and contradictory. Defibrillation threshold (DFT) at implantation and first shock efficacy were compared in patients implanted with single- versus dual-coil ICD leads in MADIT-CRT. The risk for atrial tachyarrhythmias and all-cause mortality were evaluated. Short- (< 30 days after the implantation) and long-term (throughout the entire study duration) complications were assessed. Patients with dual-coil ICD leads had significantly lower DFTs compared to patients with single-coil ICD leads (17.6 ± 5.8 J vs 19.4 ± 6.1 J, P < 0.001). First shock efficacy was similar among patients with dual and single-coil ICD leads (89.6% vs 92.3%, P= 1.00). When comparing patients with dual versus single-coil ICD leads, there was no difference in the risk of atrial tachyarrhythmias (HR= 1.57, 95% CI: 0.81-3.02, P= 0.18), or in the risk of all-cause mortality (HR= 1.10, 95% CI: 0.58-2.07, P= 0.77). Patients implanted with single- or dual-coil ICD lead had similar short and long-term complication rates (short-term HR= 0.96, 95% CI: 0.56-1.65, P= 0.88, long-term procedure-related HR= 0.99, 95% CI: 0.62-1.59, P= 1.00, long-term ICD lead related: HR= 1.2, 95% CI: 0.5-2.9, P= 0.68) during the mean follow-up of 3.3 years. Patients with single-coil ICD leads have slightly higher DFTs compared to those with dual-coil leads, but the efficacy, safety, and clinical impact on atrial tachyarrhythmias, and mortality is similar. Implantation of single-coil ICD leads may be favorable in most patients.

No benefit of a dual coil over a single coil ICD lead: Evidence from the Sudden Cardiac Death in Heart Failure Trial

Dual coil implantable cardioverter-defibrillator (ICD) leads with a superior vena cava (SVC) electrode have been considered standard of care despite sparse data suggesting improved ICD defibrillation efficacy. SVC coils increase lead complexity, cost, risk of lead failure, and lead removal. To compare all-cause mortality, sudden cardiac death, implant defibrillation threshold (DFT) test energies, appropriate shock rates, and first shock efficacy for ventricular tachyarrhythmias for dual coil vs single coil leads in the Sudden Cardiac Death in Heart Failure Trial (SCD-HeFT). In SCD-HeFT, 811 patients with heart failure received a single lead transvenous ICD (Medtronic model 7223) and underwent protocol-driven DFT testing. The selection of a dual vs single coil right ventricular (RV) lead was at the physician's discretion. DFT data were available in 717 patients. Dual coil leads were used in 563 and single coil in 246 patients. After 45.5-month follow-up, overall mortality was similar (19.4% for dual coil vs 21.5% for single coil; adjusted hazard ratio 0.95; 95% confidence interval 0.68-1.34; P = .78). Sudden cardiac death was also similar (3.6% for dual coil vs 3.7% for single coil; P = .96). First shock efficacy was 82.2% vs 91.9% (dual coil vs single coil; unadjusted odds ratio 0.41; 95% confidence interval 0.15-1.13; P = .085). Mean DFT was 12.1 ± 4.7 J vs 12.8 ± 4.8 J (dual coil vs single coil; P = .087). In the SCD-HeFT, the addition of an SVC coil for left-sided implants was not associated with improved outcome measures. We advocate returning to single coil RV ICD leads as the standard of care to decrease chronic lead complications.

Abstract 17919: Defibrillation Thresholds in Single Versus Dual Coil ICD Lead Systems: Is There Any Difference?

Background: Single coil implantable cardioverter defibrillator (ICD) lead systems are less often utilized even though no significant difference in defibrillation threshold (DFT) has been demonstrated in comparison to dual coil ICDs. The superior vena cava (SVC) coil is associated with an active fibrotic reaction within the SVC, which can increase complication risk during extraction. We compared DFTs between single vs. dual coil ICD leads at initial implantation. Methods: Two hundred and fifty three consecutive patients who underwent new ICD implantation from 9/2008 to 9/2010 at our institution were retrospectively analyzed. Mean follow-up was 14.6±7.3 months. Results: Single coil was used more frequently vs. dual coil (172 vs. 81 pts). Age was lower in single coil group (63.0 vs. 72.1, p&lt;0.001). There was no significant difference (single vs. dual coil, p&gt;0.05) in sex, LV EF (28.9 vs. 26.6%), body mass index, ischemic cardiomyopathy, primary prophylaxis indication, procedural complications, lead extraction during follow up, and mortality. DFT testing was performed in 92% and 86% of patients in each group. There was no significant difference in DFTs (16.6±2.8 vs. 17.3±3.2J, p=0.13), DFT safety margin (18.9±3.1 vs. 18.9±3.8J, p=0.96) and successful shocks during follow up between the two groups. The single coil group with ischemic cardiomyopathy had lower DFT (16.1±2.5 vs. 17.9±3.4J, p=0.002), but single coil group with non-ischemic cardiomyopathy had higher DFT (17.7±3.1 vs. 15.9±2.3J, p= 0.03). Right-sided implants in single coil group had lower DFTs (16.4±4 vs. 18.3±2.4J, p=0.008). Two BMI groups (BMI &lt;30 [25±2.5] vs. BMI ≥30 [35.5±4.2]) were analyzed. In BMI &lt;30 group, DFT was lower in single coil group (16.6±3.0J vs. 18.3±3.5J, p=0.008). In BMI ≥30 group, there was no significant difference in DFT between two groups (16.7±2.6 vs. 16.1±2.5, p=0.30). Conclusion: Single coil ICD leads offer adequate safety margins in patients with ischemic and non-ischemic cardiomyopathy irrespective of sex, LV function, implant site, and BMI. They should offer a better safety profile during lead extractions.