Lead Integrity Alert Is Useful for Assessment of Performance of Biotronik Linox Leads.

INTRODUCTION: Medtronic's Lead Integrity Alert (LIA) software algorithm is useful for detecting abnormal parameters across various ICD-lead families. However, its utility in the assessment of the Biotronik Linox™ family of high-voltage (HV) leads is unknown. METHODS: We conducted a retrospective cohort study to assess the performance of the LIA algorithm to detect abnormalities and lead failure in Linox ICD-leads. All LIA-enabled Medtronic devices connected to an active Linox lead were included. The alerts were adjudicated by 2 blinded electrophysiologists and correlated with clinical data. RESULTS: Between 2008 and 2012, data from 208 patients with 564 patient-years of follow-up were available for analysis. The median follow-up duration was 32 (IQR 21-41 months). Twenty-one LIA triggers were noted in 20 different patients. The median delay until a positive LIA was 32 months (IQR 21-41 months) postimplant with a 5-year lead survival free from LIA of 76%. Ninety-five percent (19/20) LIA alerts were true lead failures. The most common LIA triggers were short V-V intervals (85%) and nonsustained ventricular tachycardia (85%). Abrupt changes of the ICD-lead impedance occurred in 5/20 triggers. Inappropriate ICD-shocks were strongly associated with a positive LIA (30% vs. 7.4%; P = 0.006). Of the explanted Linox leads 53% had visible abnormalities. The sensitivity, specificity, and positive predictive value for lead failure in the presence of a LIA trigger were 87%, 99.5%, and 95.2%, respectively. CONCLUSIONS: A positive LIA trigger in Biotronik Linox ICD-leads is highly predictive of lead failure. LIA is useful in ongoing surveillance of lead performance.

Characteristics of patients and implantable defibrillators associated with failure to sense device alert systems.

AIMS: In the era of increasing implantable cardioverter defibrillator (ICD) complexity, the ICD patient alert is deemed to be an important feature in the early detection of ICD system malfunction and is either an audible or a vibratory alert. We sought to evaluate the patient's ability to detect these ICD alerts in the device clinic setting as a surrogate endpoint of clinical utility. METHODS AND RESULTS: From 1 November 2006 to 31 March 2008, 563 patients with an ICD equipped with either an audible patient alert (APA, Medtronic and Guidant; n = 485) or a vibratory monitoring alert ([VMA, St Jude Medical; n = 78) had their alarm demonstrated in the quiet clinic setting. The ability to recognize the alert was analysed and then stratified by gender, age, manufacturer, type of alert, and pocket location. The average patient age was 63.3 (± 13.6) years and 82.8% of patients were male. Implantable cardioverter defibrillator manufacturers were Medtronic (n = 464), Boston Scientific (n = 21), and SJM (n = 78). The APA was heard in 86.0% of patients. This was less likely in patients who were older, male, and where the device was placed in the submuscular position. Every patient with a VMA sensed their alert. CONCLUSION: In the current ICD alert technology, the ability to sense the ICD alert in the device clinic appears to be higher for the VMA than for the APA. In particular, older patients and male patients are less likely to sense the APA.