Abstract 13716: Implanting an Extravascular ICD in Patients With a Prior Subcutaneous ICD

Background: The Extravascular Implantable Cardioverter Defibrillator (EV ICD) has been demonstrated as an effective therapy to treat sudden cardiac death using a substernal lead position. Limited data regarding the use of EV ICD in patients with prior subcutaneous ICD (S-ICD) is available.

Methods: The EV ICD Pivotal study database was reviewed for subjects with a prior S-ICD. Procedure times were compared using the Wilcoxon rank-sum test.

Results: Of the 316 subjects that had an implant attempt in the EV ICD Pivotal study, 9 subjects at 3 sites had history of a prior implanted S-ICD. All were male with a mean age of 59.6 ± 14.4 years. Mean Body Mass Index (BMI) was 29.5 ± 4.7. Five subjects had secondary prevention indication. Mean follow up duration was 1.4 ± 0.7 years. The study protocol required S-ICD explant prior to study enrollment. The mean time between S-ICD explant and EV ICD implant was 35 ± 19 days. Procedure times were similar to denovo EV ICD implant. Median times from first incision to final suture, inclusive of defibrillation testing, for subjects with and without prior S-ICD were 79 (IQR, 69 to 108) and 60.5 (IQR, 52 to 84.5) minutes, respectively (P=0.10). All subjects were defibrillated with 30 J or less at implant. There were no major intraprocedural complications and only 1 major complication during the follow up period, an implant site infection at 18 months. The Florida Patient Acceptance Survey, issued at 6 months post-implant, demonstrated high device acceptance rate with little or no body image concerns. Two subjects each had an appropriately treated episode of spontaneous sustained monomorphic VT, one terminated by ATP and the other terminated by shock following ATP.

Conclusions: The EV ICD System can be successfully implanted in patients who previously had an S-ICD. History of S-ICD did not significantly increase procedure time. The EV ICD had a high acceptance in this subgroup and may provide advantage over S-ICD due to its smaller size, and ability to deliver ATP.