AGE AND GEOGRAPHIC VARIATIONS OF PACEMAKER IMPLANTATION IN BC

Abstract

utility in the assessment of the Biotronik Linox family of leads has not been studied. METHODS: We conducted a retrospective chart study at our center to assess the performance of LIA for lead system events (LSE) and lead failure in Linox leads. LIA-enabled Medtronic devices connected to an active Linox lead were included in the study. LIA is triggered in the presence of 2 of the following: abrupt change in pacing or shocking lead impedance, frequent short R-R intervals (<140ms) or 2 ICD-defined episodes of rapid non-sustained ventricular tachycardia (NSVT) (R-R<220ms). The alerts were adjudicated by two electrophysiologists and correlated with clinical data. RESULTS: Between 2008-2012, 364 Linox (S65, n1⁄498 and SD65, n1⁄4111) leads were implanted. Data from 209 patients with 509 patients-years of follow-up were available for LIA analysis. Information from 155 patients was not analyzed (absence of non LIA-enabled ICD and follow-up at another center). Mean age at implantation was 59 16 years (88% males). The mean lead dwell-time at the last follow-up visit was 2.6 1.2 years. Nineteen LIA triggers were noted in 18 different patients (1 patient had 2 Linox leads) during the study period (9.1%). The median dwelltime until LIA trigger was 31 months (range 5-44 months). One LIA event was false positive (electrocautery noise during surgery). All other alerts were true LSEs (18/209, 8.6%). Most common triggers were short V-V intervals (10/19[53%]) followed by NSVT in 9/19 (47%) patients. Abrupt changes of the ICD-lead impedance occurred in 5 cases (26%). Abnormal sensing integrity counters (SIC) were significantly more often triggered in patients with positive LIA (78%vs24%; p<0.001). Inappropriate ICDshocks were strongly associated with a positive LIA (28% vs6%; p1⁄40.009). Fourteen patients with Linox leads underwent 15 lead extractions based on LIA data (1 patient had 2 extractions). Most affected leads had significant macroscopic abnormality at explant. The values for sensitivity, specificity and positive predictive value for lead failure in the presence of a LIA trigger were 100%, 99.5% and 94.7% respectively. CONCLUSION: The Lead Integrity Alert algorithm is useful for the assessment of Linox lead performance. A positive LIA trigger in Biotronik Linox leads is highly predictive of lead failure.