Faculty Bibliography

Leadless pacemakers are being used with increased frequency due to improvements in the technologies, and the recognition of the substantial benefits over traditional transvenous devices. Current information shows a substantial reduction in morbidity with leadless devices which has resulted in a significant expansion in the indication for these devices. Patient selection now includes a younger population as well as those commonly excluded from consideration. Understanding these new applications will allow a larger group of patients to benefit from the significant advantages of leadless devices while not compromising quality and effective pacing. Further improvements in this technology will result in even more availability of these transformative devices.

Existing deep learning algorithms for electrocardiogram (ECG) classification rely on supervised training approaches requiring large volumes of reliably labeled data. This limits their applicability to rare cardiac diseases like Brugada syndrome (BrS), often lacking accurately labeled ECG examples. To address labeled data constraints and the resulting limitations of supervised training approaches, we developed a novel deep learning model for BrS ECG classification using the Variance-Invariance-Covariance Regularization (VICReg) architecture for self-supervised pre-training. The VICReg model outperformed a state-of-the-art neural network in all calculated metrics, achieving an area under the receiver operating and precision-recall curves of 0.88 and 0.82, respectively. We used the VICReg model to identify missed BrS cases and hence refine the previously underestimated institutional BrS prevalence and patient outcomes. Our results provide a novel approach to rare cardiac disease identification and challenge existing BrS prevalence estimates offering a framework for other rare cardiac conditions.

BACKGROUND:Left atrial appendage occlusion (LAA-O) with Amulet and Watchman FLX are approved for reducing stroke risk in patients with atrial fibrillation when oral anticoagulation is not tolerated. Real world clinical outcomes reported along with imaging data are needed to help clinicians choose between these two technologies and manage device-related complications. METHODS:The study retrospectively analyzed clinical, transesophageal (TEE), and available computed tomography (CT) data from 364 FLX and 292 Amulet procedures performed at an academic medical center over a 4-year period. RESULTS:were included. TTE LAA-orifice area correlated with CT-derived measurements. There were more late pericardial effusions for Amulet (3.1%) compared to FLX (0.3%), though the majority were conservatively managed. Mean procedure times were similar (FLX 64 ± 24, Amulet 65 ± 21 min) as were the rates of device related thrombus (FLX 1% and Amulet 1.4%). Clinically relevant peridevice leak (PDL) on follow-up TEE imaging was greater for FLX (16%) compared to Amulet (10%). Combined AF ablation-LAA-occlusion procedures exhibited lower rates of PDL and late pericardial effusions compared to solo procedures. CONCLUSIONS:Based on retrospective analysis, an initial strategy with Watchman FLX in patients with favorable LAA anatomy would reduce the risk of late pericardial effusions at the expense of a higher rate of clinically relevant PDL compared to Amulet. Combined AF ablation and LAA-O procedures exhibit less PDL.

BACKGROUND:Recent evidence suggests atrial fibrillation (AF) causes cardiomyopathy due to remodeling driven by both irregular rate and rhythm. Atrial fibrillation (AF) ablation in patients with reduced ejection fraction (EF) ≤ 35% has been shown to improve EF and mortality. It is unknown whether the benefits of AF ablation among patients with reduced EF are affected by the degree of pre-ablation rate control. OBJECTIVES/OBJECTIVE:To evaluate AF ablation echocardiographic outcomes for patients who have EF ≤ 35% with varying degrees of pre-ablation rate control. METHODS:Single-center, retrospective study of patients with EF ≤ 35% undergoing first-time ablation of persistent AF. Primary analyses evaluated the degree to which pre-ablation rate control impacted echocardiographic outcomes. Rates of EF recovery to > 35% were compared at three different cutoffs: 110 bpm, 90 bpm, and 70 bpm. A linear regression analysis was then performed to evaluate whether baseline heart rate (HR) predicted change in EF. RESULTS: = 0.05, p = 0.07). CONCLUSIONS:Catheter ablation of persistent AF in patients with reduced EF frequently resulted in recovery in EF > 35%, irrespective of pre-ablation achieved rate control. While patients with HR > 70 bpm experienced a greater improvement in EF compared to those ≤ 70 bpm, patients with baseline HR below this target still experienced significant EF improvements. Further investigation into irregularity-mediated cardiomyopathy is warranted.

BACKGROUND/UNASSIGNED:There have been limited data examining the temporal relationship between device-derived daily activity and ventricular arrhythmias (VAs). OBJECTIVE/UNASSIGNED:We aimed to assess whether activity predicted VAs or VAs predicted changes in activity. METHODS/UNASSIGNED:The CERTITUDE registry includes over 55,000 implanted devices active on Home Monitoring. Daily data on activity are captured by a 1-axis accelerometer. Temporal changes in activity during treated VAs were analyzed using the first event and 7-day activity windows (baseline, pre-event, and postevent). Baseline period was defined as 31 to 38 days prior to VA. VAs were categorized by heart rate (≤200 beats/min, >200 beats/min) and treatment (shock or antitachycardia pacing). Differences were assessed using the binomial proportion test and case-crossover analysis. RESULTS/UNASSIGNED:.003). Case-crossover analyses confirmed lower activity rates following for VA events >200 beats/min with shock. CONCLUSION/UNASSIGNED:In the CERTITUDE registry, we have shown a temporal decline in device-derived activity following VA events >200 beats/min and for VA events <200 beats/min treated with a shock, but we did not find changes in activity preceding a shock event.

BACKGROUND/UNASSIGNED:Catheter ablation (CA) for ventricular tachycardia (VT) can be a useful treatment strategy, however, few studies have compared CA to medical therapy (MT) in the sarcoidosis population. OBJECTIVE/UNASSIGNED:To assess in-hospital outcomes and unplanned readmissions following CA for VT compared to MT in patients with sarcoidosis. METHODS/UNASSIGNED:Data was obtained from the Nationwide Readmissions Database between 2010 and 2019 to identify patients with sarcoidosis admitted for VT either undergoing CA or MT during elective and non-elective admission. Primary endpoints were a composite endpoint of inpatient mortality, cardiogenic shock, cardiac arrest and 30-day hospital readmissions. Procedural complications at index admission and causes of readmission were also identified. RESULTS/UNASSIGNED: = 0.343). The most common cause of readmission were ventricular arrhythmias (VA) in both groups, however, those undergoing elective CA were less likely to be readmitted for VA compared to non-elective CA. The most common complication in the CA group was cardiac tamponade (4.8 %). CONCLUSION/UNASSIGNED:VT ablation is associated with similar rates of 30-day readmission compared to MT and does not confer increased risk of harm with respect to inpatient mortality, cardiogenic shock or cardiac arrest. Further research is warranted to determine if a subgroup of sarcoidosis patients admitted with VT are better served with an initial conservative management strategy followed by VT ablation.

BACKGROUND:Many patients with mildly to moderately reduced left ventricular ejection fraction (LVEF) who require permanent pacemaker (PPM) implantation do not have a concurrent indication for implantable cardioverter-defibrillator (ICD) therapy. However, the risk of ventricular tachycardia/ventricular fibrillation (VT/VF) in this population is unknown. OBJECTIVE:The aim of this study was to describe the risk of VT/VF after PPM implantation in patients with mildly to moderately reduced LVEF. METHODS:Retrospective analysis was performed of 243 patients with LVEF between 35% and 49% who underwent PPM placement and did not meet indications for an ICD. The primary end point was occurrence of sustained VT/VF. Competing risks regression was performed to calculate subhazard ratios for the primary end point. RESULTS:Median follow-up was 27 months; 73% of patients were male, average age was 79 ± 10 years, average LVEF was 42% ± 4%, and 70% were New York Heart Association class II or above. Most PPMs were implanted for sick sinus syndrome (34%) or atrioventricular block (50%). Of 243 total patients, 11 (4.5%) met the primary end point of VT/VF. Multivessel coronary artery disease (CAD) was associated with significantly higher rates of VT/VF, with a subhazard ratio of 5.4 (95% CI, 1.5-20.1; P = .01). Of patients with multivessel CAD, 8 of 82 (9.8%) patients met the primary end point for an annualized risk of 4.3% per year. CONCLUSION:Patients with mildly to moderately reduced LVEF and multivessel CAD undergoing PPM implantation are at increased risk for the development of malignant ventricular arrhythmias. Patients in this population may benefit from additional risk stratification for VT/VF and consideration for upfront ICD implantation.