Knight, Bradley P.

AbstractBackgroundTransvenous implantable cardioverter defibrillators (TV ICD) provide life‐saving therapy for millions of patients worldwide. However, they are susceptible to several potential short‐ and long‐ term complications including cardiac perforation and pneumothorax, lead dislodgement, venous obstruction, and infection. The extravascular ICD system's novel design and substernal implant approach avoids the risks associated with TV ICDs while still providing pacing features and similar generator size to TV ICDs.Study DesignThe EV ICD pivotal study is a prospective, multicenter, single‐arm, nonrandomized, premarket clinical study designed to examine the safety and acute efficacy of the system. This study will enroll up to 400 patients with a Class I or IIa indication for implantation of an ICD. Implanted subjects will be followed up to approximately 3.5 years, depending on when the patient is enrolled.ObjectiveThe clinical trial is designed to demonstrate safety and effectiveness of the EV ICD system in human use. The safety endpoint is freedom from major complications, while the efficacy endpoint is defibrillation success. Both endpoints will be assessed against prespecified criteria. Additionally, this study will evaluate antitachycardia pacing performance, electrical performance, extracardiac pacing sensation, asystole pacing, appropriate and inappropriate shocks, as well as a summary of adverse events.ConclusionThe EV ICD pivotal study is designed to provide clear evidence addressing the safety and efficacy performance of the EV ICD System.

Introduction: Practice guidelines recommend use of subcutaneous implantable cardioverter-defibrillators (ICD) in patients (pts) at risk of sudden cardiac death and high risk for infection. This has prompted a need to better identify pts at high risk of infection to assist in de novo device selection. The objective of this study is to estimate infection incidence in de novo transvenous (TV) ICD implants and assess risk factors associated with infection in a large Medicare population. Methods: A retrospective cohort study was conducted using 100% Medicare administrative and claims data to identify pts who underwent de novo TV-ICD implantation between 7/2016 and 1/2018. Device-related infection within 2 years of implantation was identified using ICD-10 diagnosis and procedure codes. Baseline pt factors associated with infection were identified by univariable logistic regression analysis of all variables of interest, including factors in Charlson and Elixhauser comorbidity indices, followed by stepwise selection criteria with a p≤0.25 for inclusion in a multivariable model and a backwards, stepwise elimination process with p≤0.1 to remain in the model. A time-to-event analysis was also conducted. Results: Among 26,742 pts with de novo TV-ICD, 519 (1.9%) had a device-related infection over 2 years. The mean pt age with and without infection was 68 and 71 years, respectively. While more than half (54%) of infections occurred within 90 days post implant, infections continued to be diagnosed with 16% of infections occurring between years 1 and 2. Multivariable analysis revealed several significant predictors of infection (Figure) including age <70 years, end stage renal disease with chronic dialysis and diabetes with complications. Conclusion: The rate of de novo TV-ICD infection in a large real-world Medicare population is clinically significant. The factors associated with increased infection risk identified here can be used to help determine device selection.

Background: Transvenous implantable cardiac defibrillators (TV ICD) provide life-saving therapy for millions of patients worldwide. However, they are susceptible to several potential short- and long- term complications including cardiac perforation and pneumothorax, lead dislodgement, venous obstruction, and infection. The extravascular ICD (EV ICD) system’s novel design and substernal implant approach avoids the risks associated with TV ICDs while still providing pacing features and similar generator size to TV ICDs. Study Design: The EV ICD pivotal study is a prospective, multi-center, single-arm, non-randomized, pre-market clinical study designed to examine the safety and acute efficacy of the system. This study will enroll up to 400 patients with a Class I or IIa indication for implantation of an ICD. Implanted subjects will be followed up to approximately 3.5 years, depending on when the patient is enrolled. Objective: The clinical trial is designed to demonstrate safety and effectiveness of the EV ICD system in human use. The safety endpoint is freedom from major complications, while the efficacy endpoint is defibrillation success. Both endpoints will be assessed against prespecified criteria. Additionally, this study will evaluate antitachycardia pacing (ATP) performance, electrical performance, extracardiac pacing sensation, asystole pacing, appropriate and inappropriate shocks, as well as a summary of adverse events. Conclusion: The EV ICD pivotal study is designed to provide clear evidence addressing the safety and efficacy performance of the EV ICD System.

AbstractBackgroundInfection is a well‐recognized complication of cardiovascular implantable electronic device (CIED) implantation, including the more recently available subcutaneous implantable cardioverter‐defibrillator (S‐ICD). Although the AHA/ACC/HRS guidelines include recommendations for S‐ICD use, currently there are no clinical trial data that address the diagnosis and management of S‐ICD infections. Therefore, an expert panel was convened to develop consensus on these topics.MethodsA process mapping methodology was used to achieve a primary goal – the development of consensus on the diagnosis and management of S‐ICD infections. Two face‐to‐face meetings of panel experts were conducted to recommend useful information to clinicians in individual patient management of S‐ICD infections.ResultsPanel consensus of a stepwise approach in the diagnosis and management was developed to provide guidance in individual patient management.ConclusionAchieving expert panel consensus by process mapping methodology in S‐ICD infection diagnosis and management was attainable, and the results should be helpful in individual patient management.

AbstractIntroductionA recent study reported that diffuse left ventricular (LV) fibrosis is a predictor of atrial fibrillation (AF) recurrence following catheter ablation, by measuring postcontrast cardiac T1 (an error prone metric as per the 2017 Society for Cardiovascular Magnetic Resonance consensus statement) using an inversion‐recovery pulse sequence (an error prone method in arrhythmia) in AF ablation candidates. The purpose of this study was to verify the prior study, by measuring extracellular volume (ECV) fraction (an accurate metric) using a saturation‐recovery pulse sequence (accurate method in arrhythmia).Methods and ResultsThis study examined 100 AF patients (mean age = 62 ± 11 years, 69 males and 31 females, 67 paroxysmal [pAF] and 33 persistent [peAF]) who underwent a preablation cardiovascular magnetic resonance (CMR) exam. LV ECV and left atrial (LA) and LV functional parameters were quantified using standard analysis methods. During an average follow‐up period of 457 ± 261 days with 4 ± 3 rhythm checks per patient, 72 patients maintained sinus rhythm. Between those who maintained sinus rhythm (n = 72) and those who reverted to AF (n = 28), the only clinical characteristic that was significantly different was age (60 ± 12 years vs 66 ± 9 years); for CMR metrics, neither mean LV ECV (25.1 ± 3.3% vs 24.7 ± 3.7%), native LV T1 (1093.8 ± 73.5 ms vs 1070.2 ± 115.9 ms), left ventricular ejection fraction (54.1 ± 11.2% vs 55.7 ± 7.1%), nor LA end diastolic volume/body surface area (42.4 ± 14.8 mL/m2 vs 43.4 ± 19.6 mL/m2) were significantly different (P ≥ .23). According to Cox regression tests, none of the clinical and imaging variables predict AF recurrence.ConclusionNeither LV ECV nor other CMR metrics predict recurrence of AF following catheter ablation.

Background: Efforts to improve prescription of oral anticoagulation (OAC) drugs in patients with atrial fibrillation have had limited success in improving guideline adherence. Methods: We evaluated adherence to the American College of Cardiology/American Heart Association performance measures for OAC in eligible patients with a CHA 2 DS 2 -VASc score ≥2 and trends in prescription over time in the American Heart Association’s Get With The Guidelines–AFIB (atrial fibrillation) registry. Adjusted associations with in-hospital outcomes were also determined. The cohort included 33 235 patients with a CHA 2 DS 2 -VASc score ≥2 who were admitted for atrial fibrillation and were enrolled at 115 sites between January 1, 2013, and September 31, 2017. Results: The median (25th, 75th percentile) age was 73 years (65, 81 years); 51% were female; and the median (25th, 75th percentile) CHA 2 DS 2 -VASc score was 4 (3, 5). At admission, 16 206 (59.5%) of 27 221 patients with a previous diagnosis of atrial fibrillation were taking OAC agents, and OAC drug use at admission was associated with a lower adjusted odds of in-hospital ischemic stroke (odds ratio, 0.38; 95% CI, 0.24–0.59; P <0.0001). At discharge, prescription of OAC in eligible patients (no contraindications) was 93.5% (n=25 499 of 27 270). In a sensitivity analysis, when excluding only strict contraindications (4.6%, n=1497 of 32 806), OAC prescription at discharge was 80.3%. OAC prescription at discharge was higher in those aged ≤75 years, men, those with heart failure, those with previous atrial fibrillation ablation, and those with rhythm control ( P <0.0001 for all). OAC use was lowest in Hispanic patients (90.2%, P <0.0001). Prescription of OAC at discharge in eligible patients improved over time from 79.9% to 96.6% ( P <0.0001). Conclusions: Among hospitals participating in the GWTG-AFIB quality improvement program, OAC prescription at discharge in eligible guideline-indicated patients increased significantly and improved consistently over time. These data confirm that high-level adherence to guideline-recommended stroke prevention is achievable.

Background— The Intracardiac Echocardiography Guided Cardioversion Helps Interventional Procedures study evaluated the concordance of intracardiac echocardiography (ICE) with transesophageal echocardiography (TEE) in patients with atrial fibrillation (AF). Methods and Results— Patients with AF undergoing right heart catheterization underwent left atrium (LA) and interatrial septal (IAS) imaging by TEE and ICE. A blinded comparison of the 2 modalities was performed at a core laboratory. Ninety-five patients aged 58±12 years completed the study. The LA was profiled in all patients with both techniques, and concordance for image quality was 96%. LA appendage (LAA) imaging was achieved in 85% with ICE and 96% with TEE. There was no difference in the presence of spontaneous echo contrast between ICE and TEE during LA imaging, but there was a trend toward a greater incidence in the LAA with TEE ( P =0.109). Intracardiac thrombus was uncommonly seen (TEE, 6.9%; ICE, 5.2%). The concordance for the presence or absence of thrombus was 97% in the LA and 92% in the LAA, but the latter was detected more frequently with TEE. IAS imaging was achieved in 91% with ICE and in 97% with TEE ( P =0.177). Concordance for patent foramen ovale and atrial septal aneurysms was 100% and 96%, respectively. A negative ICE examination was associated with absence of dense echo contrast or thrombus on TEE in 86%. Conclusions— This study provides validation for the use of ICE for LA and IAS imaging. ICE imaging was less sensitive compared to TEE for LAA thrombus identification. Clinical Trial Registration— URL: http://www.clinicaltrials.gov . Unique identifier: NCT00281073.