Prospective Assessment of Linox Implantable Cardioverter Defibrillator Leads for Structural or Electrical Abnormalities

LECOM (Lead Extraction COMplexity): A New Scoring System for Predicting a Difficult Procedure

(1) Background: Transvenous lead extraction (TLE) can become far more complex when unanticipated difficulties arise. The aim was to develop a simple scoring system that allows for the prediction of the difficulty and complexity of this significant procedure. (2) Methods: Based on analysis of 3741 TLE procedures with and without complicating factors (extended fluoroscopy time, need for second-line instruments, and advanced techniques and instruments), a five-point Complex Indicator of Difficulty of (TLE) Procedure (CID-TLEP) scale was developed. Two or more points on the CID-TLEP scale indicate a higher level of procedure complexity. (3) Results: Patient age below 51 years at first CIED implantation, number of abandoned leads, number of previous procedures, passive fixation and multiple leads to be extracted, and a ratio of dwell time of oldest lead to patient age during TLE of >0.13 are significant predictors of higher levels of lead extraction complexity. The ROC analysis demonstrates that a point total (being the sum of the odds ratios of the above variables) of >9.697 indicates a 21.83% higher probability of complex TLE (sensitivity 74.08%, specificity 74.46%). Finally, a logistic function was calculated, and we constructed a simple equation for lead extraction complexity that can predict the probability of a difficult procedure. The risk of complex extraction (as a percentage) is calculated as [1/(1 + 55.34 · 0.754X)] · 100 (p < 0.001). (4) Conclusion: The LECOM score can effectively predict the risk of a difficult transvenous lead extraction procedure, and predicting the probability of a more complex procedure may help clinicians in planning lead removal and improving patient management.

Performance of an implantable cardioverter-defibrillator lead family

BACKGROUND

Lead failure is the major limitation in implantable cardioverter-defibrillator (ICD) therapy. Long-term follow-up data for Biotronik Linox ICD leads are limited. Therefore, we analyzed the performance of all these leads implanted at our institution.

MATERIALS AND METHODS

All Linox and Linox Smart ICD leads implanted between 2006 and 2015 were identified. Lead failure was defined as electrical dysfunction (oversensing, abnormal impedance, exit block). Lead survival was described, according to Kaplan-Meier. Associations between lead failure and specific variables were examined. p < .05 was considered significant.

RESULTS

We included 417 ICD leads. The median follow-up time for Linox (n = 205) was 81 months and for Linox Smart (n = 212) 75 months. During that follow-up time, 30 Linox (14.6%) and 16 Linox Smart leads (7.6%) showed a malfunction. The 5-year lead survival probability was 97.4% for Linox and 95.2% for Linox Smart (log-rank test, p = .19). The 6- and 8-year lead survival probability for Linox was 93.6% and 84.6%, and for Linox Smart 93% and 91.9%. The only factor significantly associated with lead failure was younger patient age at implantation (hazard ratio/year: 0.97, 95% CI: 0.94-0.99, p = .002).

CONCLUSION

This relatively large study with a long follow-up period highlights a relevant failure rate of Biotronik Linox leads. The performance of Linox versus Linox Smart ICD leads was comparable. Although we show an acceptable 5-year lead survival probability, we observed a marked drop after just 1 more year of follow-up. In an era of improving heart failure survival probability, a prolonged follow-up of ICD leads is increasingly clinically relevant.

Long-term longevity and clinical outcomes of Linox S/SD implantable cardioverter-defibrillator leads: a single-center experience

PURPOSE

Since the introduction of the Biotronik Linox S/SD leads in 2006, there have been multiple reports of premature lead failure. The purpose of this study was to investigate the longevity of the Linox S/SD leads and to identify the possible predictors of lead failure in a single tertiary implant center.

METHODS

We retrospectively reviewed patients who underwent implantation of Linox S/SD leads or Sorin Vigila 1CR/2CR leads (the same Linox S/SD leads marketed by Sorin) at our center. The cumulative lead survival was estimated using the Kaplan-Meier curve, and variables associated with lead failure were assessed by Cox proportional hazard model.

RESULTS

A total of 187 patients (154 (82%) male) underwent Linox S/SD or Vigila 1CR/2CR implantation between 2007 and 2013. During follow-up with a median time of 75 months, nine lead failures were identified (4.8%). The mean and median times from lead implantation to lead failure were 70.7 ± 21 months and 64 (45-111) months, respectively. The cumulative survival probability for the Linox S/SD at 5 years was 97.1% and at 12 years was 90.3%. Non-physiological high-rate sensing was the most common type of lead failure in patients. In two-thirds of these patients, this led to inappropriate shock. We did not find any significant relationships between patients' clinical and procedural characteristics and lead failure.

CONCLUSIONS

At our center, the 5-year lead survival of the Linox S/SD has been better than reports from other centers. The majority of lead failures presented as non-physiological high-rate sensing with subsequent inappropriate therapy.

Comparison of the performance of implantable cardioverter-defibrillator leads among manufacturers

BACKGROUND

Leads are often considered the weakest link in implantable cardioverter-defibrillator (ICD) systems, and lead dysfunction is a major concern for ICD recipients. The aim of this study was to compare the lead performance from three different manufacturers.

METHODS

We retrospectively reviewed consecutive patients who underwent ICD system implantation at Chiba University Hospital, Japan, between March 2008 and September 2017. The following leads were implanted in our center: Durata (St. Jude Medical, St. Paul, MN, USA, now Abbott) (n = 105), Linox and Linox^Smart (Biotronik, Berlin, Germany) (n = 66), and Sprint Quattro (Medtronic, Minneapolis, MN, USA) (n = 126).

RESULTS

A total of 297 ICD leads were analyzed. Failure rates for Durata, Linox/Linox^Smart, and Sprint Quattro were 0.20%/patient year, 0.95%/patient year, and 1.84%/patient year, respectively, during a mean follow-up of 4.8, 6.4, and 3.0 years, respectively. The cumulative ICD lead survival probability was 98.9%, 100%, and 87.5%, after 5 years, respectively. The survival probability over the entire follow-up time as measured by the log-rank test was lower for Sprint Quattro leads than for either Durata (p = 0.011) or Linox/Linox^Smart (p = 0.028). The difference between Durata and Linox/Linox^Smart was not significant (p = 0.393).

CONCLUSIONS

In this single-center retrospective study, the performance of Sprint Quattro was lower than the performance of Linox/Linox^Smart and Durata leads. Large-scale, multi-center studies or manufacturer-independent registries may be necessary to confirm or reject self-reported survival probabilities from manufacturers' product performance reports.