Knight, Bradley P.

A 32-fold accelerated real-time cine MRI sequence (radial sampling) demonstrated better temporal resolution and image quality than a 16-fold sequence (Cartesian sampling) in patients with cardiac implantable electronic devices and arrhythmias.

Background: The prevalence of cardiac implantable electronic devices (CIED) is increasing, with over 300,000 new implants annually in the U.S. Stress cardiac magnetic resonance (CMR) has proven as a powerful modality for myocardial characterization, enabling accurate diagnosis of different cardiac conditions. In patients without devices, CMR findings have also demonstrated prognostic value for major adverse cardiovascular events (MACE) and guide clinical decision-making. However, its use in CIED patients has historically been limited due to safety and image quality concerns. Hypothesis: We aimed to evaluate the prognostic value of CMR imaging using wideband sequences in CIED patients. Methods: CIED patients referred for clinical CMR were included prospectively and retrospectively between January 2020 and February 2025. All patients underwent a stress CMR protocol, which included cine, wideband late gadolinium enhancement (LGE), wideband T1 mapping, and wideband stress/rest perfusion imaging. Clinical follow-up is ongoing. The primary endpoint was the occurrence of MACE, defined as the composite of myocardial infarction, heart failure hospitalization, implantable cardioverter defibrillator (ICD) therapy, cardiac death, revascularization, or heart transplant. Results: A total of 89 patients were included (median age 69.0 [58.0–75.5] years; 62.9% male). Device types included pacemakers (33.7%), ICDs (48.3%), and cardiac resynchronization therapy devices (16.9%). Over a median of follow-up of 613 days [355-991], 21 patients experienced a MACE. In unadjusted models, higher left ventricular ejection fraction (LVEF) (per 5%) was significantly associated with a lower risk of MACE (odds ratio [OR] 0.80, 95% confidence interval [CI] 0.65–0.95; p=0.016), as was higher stress myocardial blood flow (MBF) (per 0.25 mL/g/min increase: OR 0.78, 95% CI 0.60–0.98; p=0.05). In contrast, greater LV myocardial mass (per 10 g) was significantly associated with a higher risk of MACE (OR 1.27, 95% CI 1.08–1.52; p = 0.006), figure 1. Conclusion: The use of wideband sequences enabled the assessment of prognostic imaging value in CIED patients. LVEF remains a strong and consistent predictor of MACE in this population and LV mass was significantly associated with higher rates of MACE reflecting the influence of underlying cardiomyopathy. While stress perfusion CMR imaging showed promising trends, further studies with longer follow-up are needed to clarify its prognostic value in this population.

Background Recent technologies enable real‐time 3‐dimensional intracardiac echocardiography (ICE) with the advantages of 2‐dimensional ICE and imaging capabilities of transesophageal echocardiography. The purpose of this study is to evaluate the real‐world, multicenter safety and performance of a novel 3‐dimensional ICE system in a variety of cardiac interventions used in standard clinical practice. Methods This prospective, multicenter, observational, single‐arm study enrolled patients who were scheduled for an invasive cardiac procedure involving guidance with ICE and followed until discharge or ≤48 hours postprocedure. Intracardiac imaging was performed with the 3‐dimensional ICE catheter, VeriSight Pro (Philips Inc.). Fluoroscopy was used in all cases and transesophageal echocardiography was used in some cases. The primary safety end point was device‐related adverse events. The primary efficacy end point included technical success, imaging success, and clinical success. Results Between October 2021 and November 2022, 155 patients were enrolled and screened. Percutaneous interventions performed included atrial septal defect/patent foramen ovale closures, left atrial appendage occlusion, catheter ablations, and valve procedures. No adverse events were related to the device or procedure. The technical, imaging, and clinical success rates were 98.7% (95% CI, 95.4%–99.8%), 96.1% (95% CI, 91.8%–98.6%), 94.8% (95% CI, 91.8%–98.6%), respectively. Overall, the VeriSight Pro ICE image quality was assessed to be “acceptable” or greater in relation to reference image modality among 96.2% (149 of 155) of procedures. Conclusions VeriSight ICE imaging is safe and effective in the guidance of a wide variety of percutaneous cardiovascular procedures and has provided successful and high‐quality imaging of cardiac structures.

AbstractPurposeOverall there is a lack of evidence on the accuracy and precision of phase‐contrast (PC) MRI in patients with cardiac implantable electronic devices (CIEDs). The purpose of this study is to determine whether aortic velocity measurements are influenced by a CIED.MethodsWe scanned 21 adult patients and 8 pediatric volunteers using clinical standard PC and real‐time PC (rt‐PC) sequences with and without a CIED generator taped on human subjects (below the left clavicle for adults and children; also on the abdomen for children) to mimic image artifacts. Peak and mean velocities above the aortic valve were calculated.ResultsThe Bland–Altman analyses on peak velocity measurements in pediatric subjects showed that both the accuracy and precision worsen as the distance between the CIED and aortic valve decreases (i.e., from abdomen to below the left clavicle). Specifically, both the bias and the coefficient of variation (CV) for both clinical PC and rt‐PC increased from the abdominal position (clinical: bias = −1.1%, CV = 4.3%; rt‐PC: bias = −0.3%, CV = 3.4%) to the clavicle position (clinical: bias = −4.0%, CV = 8.1%; rt‐PC: bias = 8.2%, CV = 7.3%). A similar trend was observed for mean velocity. The mean difference in peak and mean velocity measurements between rt‐PC with CIED (either position) and clinical standard PC with no CIED was within 7.5%. In adult patients, the mean difference between rt‐PC with CIED and clinical standard PC with CIED in peak velocity was 6.9%, and the CV was 7.9%.ConclusionThis study demonstrates that aortic velocity measurements are influenced by CIED in both adult and pediatric subjects.

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.

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.