Birgersdotter‐Green, Ulrika

ABSTRACT Background A novel individualized antitachycardia pacing (IATP) algorithm using the post‐pacing interval for real‐time control has been introduced. Performance information is limited to a small safety and feasibility study with additional single‐center and case studies. A larger‐scale analysis is needed to better understand algorithm performance. Methods Deidentified remote monitoring transmissions from devices with the IATP therapy applied were randomly selected. Rhythms were classified and effects of the novel algorithm were assessed. For monomorphic ventricular tachycardias (MVTs) proportions of successful therapy, shock‐free episodes, and acceleration were calculated using generalized estimating equations to correct for multiple episodes and compute statistics of the algorithm's performance. Results There were 2259 MVT episodes in 336 patients. IATP succeeded in 87.1% of MVT episodes with 89.9% of MVT episodes ultimately free of shock therapy. Based on multivariate analysis, significant factors in therapy success were programming of at least the recommended number of sequences (90% at least recommended vs 73%, p = 0.00088) and female sex (95% for females vs 86%, p = 0.002). A trend to higher success was found for MVT with a cycle length of 320 ms or greater (90% vs. 83%, p = 0.10). The IATP accelerated 3.6% of MVT episodes. None of the available factors was significantly associated with acceleration in the multivariate analysis. Conclusions The IATP algorithm succeeded in a large proportion of MVT episodes and with low acceleration in patients randomly selected from remote monitoring transmissions. Using at least the recommended number of sequences had the strongest association with successful therapy.

Abstract Background The extravascular implantable cardioverter defibrillator (EV ICD) has recently emerged as an option for guideline indicated ICD patients. Results from the EV ICD Pilot and Pivotal studies demonstrated that the device can provide safe and effective therapy through chronic follow up. Lead placement outside the vasculature has the potential to reduce systemic infections. Infection occurrence and management details from the Pivotal are reported. Purpose To report on details of infection occurrence and management from the EV ICD Pivotal study. Methods The EV ICD Pivotal study was an international, prospective, single-arm, premarket clinical study. Patients with a class I or IIa indication for a single-chamber ICD per ESC or ACC/AHA/HRS guidelines were enrolled. Results In the EV ICD Pivotal study, 316 patients had an implant attempt, (74.7% male, age 53.8±13.1 years, 82% primary prevention, LVEF of 38.9%±15.4%, and NYHA Class I [23.7%] or II/III [65.5%]), of which 15 had a system or procedure-related infection (4.7%, 9 - 737 days post-implant) through an average 16.2 months follow-up. Of these infections, 8 were classified as major complications, 3 as minor, and 4 as observations. Most (n=9) infections were addressed through medication with or without wound care (2.8% of patients) while 6 (1.9% of patients) resulted in system removal. There was a single lead-related infection addressed through system explant. However, there were no reports of mediastinitis, sepsis, or endocarditis. No system removal resulted in sequelae. Conclusions Infection rates observed in the EV ICD Pivotal study were similar to those reported in the subcutaneous implantable cardioverter defibrillator. The results from this study support that EV ICD related infections are treatable with antibiotic therapy or system removal. No system or procedure-related systemic infections such as mediastinitis, sepsis, or endocarditis have been reported in the Pivotal study.

BACKGROUND: Substernal lead placement of the extravascular implantable cardioverter defibrillator (EV ICD) permits both defibrillation at thresholds similar to those seen with transvenous implantable cardioverter defibrillators and effective anti-tachycardia pacing (ATP) while avoiding the vasculature and associated complications. The global Pivotal study has shown the EV ICD system to be safe and effective through 6 months, but long-term experience has yet to be published. Our aim was to report the performance and safety of the EV ICD system throughout the study. METHODS: The EV ICD Pivotal study was a prospective, global, single-arm, premarket clinical study. Individuals with a Class I or IIa indication for a single-chamber implantable cardioverter defibrillator per guidelines were enrolled. Freedom from major system- or procedure-related complications and appropriate and inappropriate therapy rates were assessed through 3 years with the Kaplan-Meier method. ATP success was calculated from simple proportions. RESULTS: An implantation was attempted in 316 patients (25.3% female; 53.8±13.1 years of age; 81.6% primary prevention; left ventricular ejection fraction, 38.9±15.4%). Of 299 patients with a successful implantation, 24 experienced 82 spontaneous arrhythmic episodes that were appropriately treated with ATP only (38, 46.3%), shock only (34, 41.5%), or both (10, 12.2%) for a Kaplan-Meier–estimated rate of first any appropriate therapy of 9.2% at 3 years. ATP was successful in 77.1% (37/48) of episodes, and ATP use significantly increased from discharge to last follow-up visit ( P <0.0001). Shock therapy was successful in 100% (27/27) of discrete, spontaneous ventricular arrhythmias. The inappropriate shock rates at 1 and 3 years were 9.8% and 17.5%, respectively, with P-wave oversensing the predominant cause. No major intraprocedural complications were reported, and the estimated freedom from system- or procedure-related major complications was 91.9% at 1 year and 89.0% at 3 years. The most common major complications were lead dislodgement (10 events; n=9 patients, 2.8%), postoperative wound or device pocket infection (n=8, 2.5%), and device inappropriate shock delivery (n=4, 1.3%). Twenty-four system revisions were performed as a result of major complications related to the EV ICD system or procedure. CONCLUSIONS: From implantation to study completion, the EV ICD Pivotal study demonstrated that a single integrated system with an extravascular lead placed in the substernal space maintains high ATP success, effective defibrillation, and a consistent safety profile. REGISTRATION: URL: https://www.clinicaltrials.gov ; Unique identifier: NCT04060680.

AbstractBackgroundComplications associated with cardiovascular implantable electronic devices may necessitate device and lead removal. An open approach to removal may be electively chosen in cases with high risk of complications or those requiring additional concomitant cardiac surgery. This study aimed to investigate outcomes of patients who underwent elective open lead extractions (OLE) at two large tertiary care centers.MethodsThe records of 29 patients undergoing elective OLE were analyzed through retrospective chart review.Results69 total leads were extracted from 29 patients (77% completely, 23% partially). The average age of the oldest leads was 13.3 ± 11.3 years. Infective endocarditis with severe valvular insufficiency requiring valvular intervention (41%)—an infectious etiology, and tricuspid valve intervention to correct RV lead‐related severe TR (38%)—a noninfectious etiology, were the most common reasons for OLE. 38% of the patients had additional co‐primary or secondary indications for open extraction, such as CABG and pericardiectomies. The rate of major complications and procedural failure was 3% each (1/29). 30‐day survival was 100%, and 1‐year survival was 92%. The average length of hospital stay was 15 days and higher among those undergoing OLE for infectious indications.ConclusionOpen lead extractions offered a similar clinical success rate (97%) to transvenous extractions in this cohort and may be a viable alternative for those necessitating valvular intervention or when the risk of complications from TLE is considered very high.

Abstract Aims The extravascular implantable cardioverter-defibrillator (EV ICD) has been shown to be safe and effective for patients at risk of sudden cardiac death, but little is known about EV ICD lead removal in humans. This analysis aimed to characterize the EV ICD lead removal experience thus far. Methods and results This was a retrospective analysis of lead removals from the EV ICD Pilot, Pivotal, and Continued Access Studies. Patients with a successful EV ICD implant who underwent lead removal were included. The main objective was lead removal success. Ancillary objectives included characterizing technique used, procedure complications, and reimplantation status. An EV ICD system was successfully implanted in 347 patients across the 3 studies (25.9% female; 53.4 ± 13.3 years; left ventricular ejection fraction: 39.7 ± 15.9). Of these patients, 29 (8.4%) underwent lead removal with a mean lead dwell time of 12.6 ± 14.3 months (0.2–58.4). The main reason for lead removal was lead dislodgement (n = 9, 31.0%). Lead removal was successful in 27/29 (93.1%) cases [100% (19/19) success rate &lt;1 year and 80% (8/10) success rate &gt;1 year post-implant]. Simple traction was used in 22/26 (84.6%) and extraction tools in 4/26 (15.4%) successful cases where technique was known. No complications were reported for any of the removal procedures. All 11 EV ICD reimplant attempts were successful. Conclusion Complete removal of the EV ICD lead was successful in 93.1% of cases, and simple traction was sufficient in most instances. Based on these results, lead removal from the substernal space was safe and achievable up to 3 years post-implant.

Abstract Background The extravascular implantable cardioverter defibrillator (EV ICD) has recently emerged as a new option for guideline indicated ICD patients. Previous study results from the EV ICD Pilot and Pivotal studies have demonstrated that the device can provide safe and effective therapy through chronic follow up. However, less has been reported regarding EV ICD lead removal. Purpose To report on the experience of lead removal in the EV ICD Pivotal Study. Methods The EV ICD Pivotal study was an international, prospective, single-arm, premarket clinical study. Patients with a class I or IIa indication for a single-chamber ICD per ESC or ACC/AHA/HRS guidelines were enrolled. Lead removal summary data was reported. Results Of 316 patients with an implant attempt, (74.7% male, age 53.8±13.1 years, 82% primary prevention, LVEF of 38.9%±15.4%, and NYHA Class I [23.7%] or II/III [65.5%]) 299 were fully implanted; 17 (5.7%) of which had a lead removal procedure (14–752 days post-implant, at 13 sites) with 3 of them having been implanted for more than 1 year. Reasons for lead removal were lead dislodgement (n=7), infection (n=5), high impedance alert due to lead fracture (n=2), pacing indication (n=1), cardiac transplant (n=1), or scheduled sternotomy (n=1). New EV ICD leads were placed in 7/17 (41.2%) patients. No serious adverse events were adjudicated as related to the explant procedures. There was a single observation of incision site haemorrhage, that was resolved with wound care. Additional details on lead removal will be included at the time of presentation. Conclusions The EV ICD lead was successfully removed 14-752 days post implant. Nine patients were re-implanted with either extravascular or transvenous systems. Longer term extraction data collection is ongoing through the EV ICD Pivotal study and through the EV ICD post-approval study and will continue to provide additional insights.Lead removed 24 months post-implant.

Introduction: Surgically implanted epicardial left ventricular (eLV) lead has been used as an alternative approach when implantation of transvenous LV (tLV) lead in patients requiring cardiac resynchronization therapy (CRT) has failed. Recent literatures noted similarities in clinical response between tLV and eLV-CRT patients. However, comparison between CRT patients with ischemic (ICM) and dilated cardiomyopathy (DCM) is currently lacking in eLV-CRT patients. Hypothesis: We hypothesize that DCM patients respond better to eLV-CRT than ICM patients. Methods: Of 1038 patients who underwent tLV-CRT implantation at UCSD and Mayo Clinics between 2002 and 2013, 44 (Age 63±15, 28M) had failed tLV lead placement and received eLV-CRT. Electronic Medical Records of these patients were reviewed. NYHA class and echocardiograph were assessed before and after successful CRT implantation. Results: Following eLV-CRT implantation, improvements were noted in LVEF (26% vs. 31%, p < 0.01), NYHA class (2.9 vs. 2.3, p < 0.01) and LVESD (57mm vs. 52mm, p = 0.03) in the study cohort. In patients with DCM (n=19), the NYHA class (3.0 vs. 2.3, p = 0.01), LVEF (24% vs. 30%, p = 0.02) and LVESD (57mm vs. 52mm, p = 0.04) had significantly improved following CRT implantation compared to baseline (figures). No statistically significant changes in NYHA class, LVEF and LVESD were observed in patients with ICM (all p > 0.05). Conclusion: In this two-center study, eLV-CRT patients with DCM benefited significantly after CRT, as compared to ICM patients. Although larger scaled studies are needed, eLV-CRT may be considered a viable alternative to tLV-CRT, especially in patients with DCM.

Introduction: Surgically implanted epicardial left ventricular (eLV) lead is an alternative approach when transvenous LV (tLV) lead implantation in CRT patients has failed. With advancement in surgical technique and free from limitations of cardiac venous anatomy, operators have the freedom to choose the most optimal LV pacing site. Recent literatures noted differential clinical response in tLV-CRT patients with different LV lead locations. However, to the best of the authors’ knowledge, no such analysis has been published for eLV-CRT patients. Hypothesis: We hypothesize that optimal LV lead location in eLV-CRT is similar to tLV-CRT and similar clinical response is expected. Methods: After unsuccessful attempt(s) of tLV-CRT implantation, 44 (Age 63±15, 28M) patients received eLV-CRT from UCSD and Mayo Clinics between 2002 and 2013. Two-view (PA, lateral) chest radiographs were used to determine lead location by blinded independent observers. 9 patients were partially excluded from lead location analysis due to congenital cardiac anomaly or unavailable lateral chest radiograph. eLV lead locations were classified as basal, mid, or apical on the PA view; and anterior, anterolateral, lateral, posterolateral, or posterior on the lateral view. Survival data were collected from the national death and location database. Results: During an average follow up of 65 months, 15 patients have died following eLV-CRT implant. No death was attributed to acute surgical complication to eLV-CRT implantation. Kaplan-Meyer survival estimate showed anterior and apical eLV lead positions had lower survival rate as compared to non-anterior (p<0.01, figure A) and non-apical location (p=0.07, figure B). Conclusion: In this two-center study, apical and anterior eLV lead locations were associated with significantly lower survival rate. The study implies apical and/or anterior locations should be avoided, if possible, during eLV-CRT implantation.