Citations

Background: Previous animal studies have shown no significant vascular injury from pulsed electrical field (PEF) ablation. We sought to assess the effect of PEF on swine coronary arteries. Methods: We performed intracoronary and epicardial (near the coronary artery) PEF ablations in swine pretreated with dual antiplatelet and antiarrhythmic therapy. Intracoronary PEF was delivered using MapiT catheters (Biotronik, Berlin), whereas epicardial PEF was delivered using EPT catheters (Boston Scientific, MA). PEF pulse duration was microseconds (Nanoknife 3.0, Angio Dynamics, NY) or nanoseconds (CellFX, Pulse Biosciences, CA). Results: We performed 39 intracoronary ablations in 10 swine and 20 epicardial-pericoronary ablations in 4 separate swine. Intracoronary PEF was delivered at higher energy compared with epicardial PEF (46 [interquartile range, IQR 20–85] J versus 10 [IQR 10–11] J, P < 0.01). Reversible coronary spasm occurred in 49% intracoronary ablations and 45% epicardial ablations ( P =0.80). At the end study, fixed coronary stenosis was demonstrated in 44% intracoronary ablations (80% for microsecond PEF and 18% for nanosecond PEF) and 0% epicardial ablations. Visible hemorrhagic and/or fibrotic myocardial lesions were observed at necropsy with similar frequency between intracoronary and epicardial PEF (45% versus 50%, P =0.70). Nanosecond PEF (49 ablations in 11 swine), when compared with microsecond PEF (10 intracoronary ablations in 3 swine), resulted in lower energy delivery (21 [IQR 10–46] J versus 129 [IQR 24–143] J, P =0.03) and less incidence of fixed coronary stenosis (18% versus 80%, P =0.04). Conclusions: In the swine model, intracoronary PEF resulted both in significant coronary spasm and fixed coronary stenosis. Epicardial PEF, delivered at lower energy, resulted in reversible spasm but no fixed coronary stenosis.

AbstractIntroductionCardiac sarcoidosis (CS) is a nonischemic cardiomyopathy (NICM) characterized by infiltration of noncaseating granulomas involving the heart with highly variable clinical manifestations that can include conduction abnormalities and systolic heart failure. Cardiac resynchronization therapy (CRT) has shown significant promise in NICM, though little is known about its efficacy in patients with CS.ObjectiveTo determine if CRT improved cardiac remodeling in patients with CS.MethodsWe retrospectively reviewed all patients with a clinical or histological diagnosis of CS who underwent CRT implantation at the Mayo Clinic enterprise from 2000 to 2021. Baseline characteristics, imaging parameters, heart failure hospitalizations and need for advanced therapies, and major adverse cardiac events (MACE) were assessed.ResultsOur cohort was comprised of 55 patients with 61.8% male and a mean age of 58.7 ± 10.9 years. Eighteen (32.7%) patients had definite CS, 21 (38.2%) had probable CS, while 16 (29.1%) had presumed CS, and 26 (47.3%) with extracardiac sarcoidosis. The majority underwent CRT‐D implantation (n = 52, 94.5%) and 3 (5.5%) underwent CRT‐P implantation with 67.3% of implanted devices being upgrades from prior pacemakers or implantable cardioverter defibrillators. At 6 months postimplantation there was no significant improvement in ejection fraction (34.8 ± 10.9% vs. 37.7 ± 14.2%, p = .331) or left ventricular end‐diastolic diameter (58.5 ± 10.2 vs. 57.5 ± 8.1 mm, p = .236), though mild improvement in left ventricular end systolic diameter (49.1 ± 9.9 vs. 45.7± 9.9 mm, p < .0001). Within the first 6 months postimplantation, 5 (9.1%) patients sustained a heart failure hospitalization. At a mean follow‐up of 4.1± 3.7 years, 14 (25.5%) patients experienced a heart failure hospitalization, 11 (20.0%) underwent cardiac transplantation, 1 (1.8%) underwent left ventricular assist device implantation and 7 (12.7%) patients died.ConclusionsOur findings suggest variable response to CRT in patients with CS with no overall improvement in ventricular function within 6 months and a substantial proportion of patients progressing to advanced heart failure therapies.

Abstract Background: Atrial fibrillation (AF) is relatively less frequent in younger patients (age<50). Recently, studies have suggested that early restoration of sinus rhythm may lead to improved outcomes compared with rate control. Methods: We included all hospitalized patients between 18 and 50 years with a diagnosis of AF from the Nationwide Readmission Database 2016-2017 from the Healthcare Cost and Utilization Project. Demographic and comorbidity data were collected and analyzed. Outcomes assessed included one-year AF readmission rates, all-cause readmission, ischemic stroke, and all-cause mortality. Subgroup analyses were performed for all demographic and comorbidity variables.Results: Overall, 52,598 patients (medium age 44, interquartile range 38-48, female 25.7%) were included in the study, including 2,146 (4.0%) who underwent catheter ablation for AF. Patients who underwent catheter ablation had a significantly lower rate of readmission for AF or any cause at one year (adjusted hazard ratios (HR) of 0.52 [95% confidence interval (CI): 0.43-0.63] and HR of 0.81 [95% CI: 0.72 - 0.89], respectively). There was no difference in 1-year readmission for stroke or all-cause mortality between the two groups. Subgroup analyses showed a consistent reduction in the risk of AF readmission among major demographic and comorbidity subgroups.Conclusion: Catheter ablation in young patients with AF was associated with a reduction in 1-year AF related and all-cause readmissions. These data merit further prospective investigation for validation.

Introduction: In the last two decades, risk factors, prevalence, and mortality due to coronary artery disease in young adults is on the rise. Hypothesis: Assess the prevalence, trends, and economic burden of ventricular tachycardia (VT) in young adults (18-44 years). Methods: The Nationwide Inpatient Sample was explored for hospitalizations with VT in patients (Age 19-44) between 2005-2018 and divided among 3 groups of the quadrennial period using validated ICD-9 and ICD-10 CM codes. The Pearson chi-square test and Student’s t-test were used for categorical and continuous variables, respectively. We assessed the temporal trends of mortality in VT as well as trends of VT stratified by age, sex, and race by the linear-by-linear association test (Figure 1). Results: Out of 5,156,326 patients were admitted with VT between 2005-2018, 309,636 were in young adults. Among them, 102,433 were admitted between 2005-2009 (mean age 36.1±6.99; 61% male, 58.5% white), 109,591 between 2010-2014 (mean age 35.5±7.16; 59% male, 54.2% white), and 97,495 between 2015-2018 (mean age 35.4±7.00; 60% male, 52.3% white) (p<0.0001). In the young adults with VT, all-cause mortality was 7.37% from 2005-2009, 7.85% from 2010-2014 (6.5% relative increase from 2005-2009), and 8.98% from 2015-2018 (relative increase of 14.4% from 2010-2014) (p<0.0001). Inflation adjusted cost increased over the years [$12,177 in 2005-2009; $13,249 in 2010-2014; $15,807 in 2015-2018; p<0.0001)]. Conclusions: The prevalence of VT in young individuals is rising. VT-related mortality and healthcare utilization costs are on the rise in the study period. VT burden and poor outcomes were notable for Black males. Further studies are required for targeted screening and preventative measures in young adults.

Introduction: Real-world data on the significance of adding a defibrillator to cardiac resynchronization therapy (CRT-D) in patients with nonischemic cardiomyopathy (NICM) are limited. Hypothesis: CRT-D is associated with a lower risk of mortality and heart failure (HF) readmissions compared to CRT-P in NICM. Methods: We identified patients with NICM who underwent CRT-D and CRT without an ICD (CRT-P) by analyzing the nationwide readmission database from October 2015- December 2018 and using appropriate ICD-10 CM codes. Propensity score matching was performed to adjust for the confounders. Kaplan Meier curves were utilized for time to event analysis. Cox proportional hazard regression was used to generate hazard ratios. All-cause mortality at 6 months was the primary outcome whereas readmission due to HF and any other cause at 6 months were defined as secondary outcomes. Results: Post-PSM, 3054 patients with NICM underwent CRT-P, and 2863 patients underwent CRT-D placement. CRT-D did not show any benefit over CRT-P in reducing all-cause mortality at 6 months (2.92% vs. 2.79%, HR: 0.84, 95% CI: 0.61-1.16, p=0.29). Similarly, there was no difference in terms of readmissions due to other causes among both groups of patients (36.25% vs. 31.85%, HR: 0.98, 95% CI: 0.89-1.08, p=0.77). However, patients with CRT-P implantations had a lower risk of HF readmissions compared to the CRT-D group (10.05% vs. 14.25%, HR: 0.67, 95% CI: 0.58-0.79, p<0.0001). Conclusions: The addition of a defibrillator to CRT failed to show a survival benefit in patients with NICM. Moreover, HF readmissions were higher in CRT-D patients compared to CRT-P.

Background: Conduction tissue in the ventricles is closely intertwined with myocardium. Owing to high velocity of conduction, there is near simultaneous activation , making it difficult to discern. Restricted sampling rates and limited dynamic range make real time signal processing challenging for these signals in routine recording systems. Objectives: We aimed to use novel signal processing techniques in a new system to isolate the conduction tissue signals from the rest of the myocardial activation. Methods: We used the PURE-EP™ (BioSig Technologies, MN) signal processing system to record endocardial and epicardial signals from 6 anesthetized canines in an acute study setting. A novel filter based on proprietary algorithms to isolate the high frequency signal was applied at sites where the electrogram signals were thought to have a conduction tissue component to them. . In addition, ventricular fibrillation (VF) was induced at the end of the experiment and signals were then recorded from the endocardium and the conduction system. Results: This filter was successfully able to isolate conduction tissue signals in the myocardium from those of the ventricular muscle. It did over sense atrial signals at the basal left ventricular septum owing to the high frequency components of the atrial signal at this location. When applied to epicardial signals, it did not pick up any conduction tissue signals. In VF, we could discern signals originating from the conduction system endocardially. (Figure 1) Conclusions: This filter can isolate conduction tissue signals from those of the myocardium and may prove to be a useful adjunct in mapping arrhythmias originating near the conduction system.

Introduction: Cardiac Sarcoidosis (CS) is a non-ischemic cardiomyopathy (NICM) characterized by infiltration of non-caseating granulomas involving in the heart with highly variable clinical manifestations. Cardiac resynchronization therapy (CRT) has shown significant promise in NICM, though little is known about its effectiveness in patients with CS. Hypothesis: We sought to determine if CRT improved cardiac remodeling and reduced hospitalizations in patients with CS. Methods: We retrospectively reviewed all patients with a clinical or histological diagnosis of CS who underwent CRT implantation at a Mayo Clinic site from 2000-2021. Baseline characteristics, echocardiographic parameters, heart failure hospitalization, and major adverse cardiac events (MACE) were assessed. Results: Our cohort was comprised of 55 patients with 61.8% male and a mean age of 58.7 ± 10.9 years. At baseline, 38 (69.1%) patients had isolated CS, while 17 (30.9%) had evidence of CS with extra-cardiac sarcoidosis. The overwhelming majority underwent CRT-D implantation (n=52, 94.5%) with 67.3% of implanted devices upgrades from prior pacemaker or implantable cardioverter defibrillator. At 6 months post-implantation there was no significant different in ejection fraction (34.8 ± 10.9 % vs. 37.7 ± 14.2 %, p = 0.237), left ventricular end systolic diameter (49.1 ± 9.9 mm vs. 45.7 ± 9.9 mm, p = 0.077) or left ventricular end-diastolic diameter (58.5 ± 10.2 mm vs. 57.5 ± 8.1 mm, p = 0.574). Within the first 6 months post-implantation, 5 (9.1%) patients sustained a heart failure hospitalization. At a mean follow up of 4.1 ± 3.7 years, 14 (25.5%) patients experienced a heart failure hospitalization, 11 (20.0%) underwent cardiac transplantation, 1 (1.8%) underwent LVAD implantation and 7 (12.7%) patients died. Conclusions: Our findings suggest a poor response to CRT in patients with CS with no significant evidence of reverse remodeling within 6 months and a substantial proportion of patients progressing to advanced heart failure therapies.

Introduction: Mobile thrombi are commonly observed on endovascular leads at the time of catheter ablation. Transseptal puncture poses a risk of paradoxical embolism. We sought to examine the risk of stroke or systemic embolism after transseptal ablation in patients with and without cardiac implantable electronic devices (CIEDs). Methods: Using a large, national administrative claims database we identified 31,720 patients who underwent a catheter ablation requiring transseptal puncture between 1/1/2004 and 9/30/2014. We created two propensity-matched cohorts, matching on age, gender, race, household income, region, Charlson index, CHADS-Vasc score, and year and indication for ablation (5,533 patients with CIEDs and 11,300 patients without devices). Incidence rates (events/100 patient-years) and propensity score-matched cox proportional hazards models (with 95% confidence intervals) were used to estimate risk of stroke, transient ischemic attack, or systemic embolism for patients with or without CIEDs. We also examined the impact of presence of a CIED and oral anticoagulation (OAC) use on risk of stroke or systemic embolism within the matched cohort. Average follow up was 2.1 years. Results: The event rate was 1.5 per 100 person years in patients without device, and 1.9 per 100 person years in patients with device. Among patients not on OAC, presence of a cardiac device was associated with an increased risk of stroke or systemic embolism (HR 1.71 [1.24-2.35], P<0.01) whereas there was no association among patients treated with OAC (0.98 [0.75_1.28], p=ns) (Figure). Conclusions: Cardiac devices are associated with an increased risk of stroke or systemic embolism after transseptal ablation, but this risk is attenuated with post ablation OAC use. Anticoagulation should be considered for all patients with CIEDs post transseptal ablation, regardless of the presence of another compelling indication for anticoagulation.