Arrhythmias Research Articles

Atrial septal defect (ASD), trans-catheter closure – case report

Atrial septal defect (ASD) is one of the most common types of congenital heart defects, occurring in about 25% of children. An atrial septal defect occurs when there is a failure to close the communication between the right and left atria. It encompasses defects involving both the true septal membrane and other defects that allow for communication between both atria. There are five types of atrial septal defects ranging from most frequent to least: patent foramen ovale, ostium secundum defect, ostium primum defect, sinus venosus defect, and coronary sinus defect. Small atrial septal defects usually spontaneously close in childhood. Large defects that do not close spontaneously may require percutaneous or surgical intervention to prevent further complications such as stroke, dysrhythmias, and pulmonary hypertension. This activity describes the evaluation, diagnosis, and management of atrial septal defect and highlights the role of team-based interprofessional care for affected patients. Atrial septal defects are frequently asymptomatic. The characteristic murmur is a soft, systolic ejection murmur over the pulmonic area (second intercostal space) combined with a wide, fixed splitting of S2. Many ASDs go undiagnosed until adulthood; therefore, treatment, especially of large defects, is often delayed. Untreated large defects can cause exercise intolerance, cardiac dysrhythmias, palpitations, increased incidence of pneumonia, pulmonary hypertension and increased mortality.

HPB SO22 - Clinical outcomes following radical cholecystectomies, a single centre experience in review

Abstract Background Gallbladder carcinoma (GBC) is a rare disease with dismal prognosis. The majority of cases are identified at an advanced state that preclude curative approaches which would usually necessitate removal of the gallbladder with en-block wedge hepatectomy of segment 4b/5 as well as periportal lymphadenectomy. The purpose of this study was to analyze our outcomes for patients undergoing a radical cholecystectomy for suspected GBC. Method A retrospective analysis of patients who underwent radical cholecystecomies at Queen’s Medical Centre, Nottingham, UK between 1st January 2014 and October 2023 was performed. Patients with concomitant primaries, incidental GBC or completion liver resection following index cholecystectomy were excluded. Results 41 patients were eligible for analysis, those were comprised of 13 males and 28 females with a median age of 67 (IQR 57-72) years. The incidence of malignancy on histology was 31.7% (GBC n=11, metastatic renal carcinoma n=1, metastatic melanoma n=1). Cystic margin assessment by frozen section was performed in 41% of cases. In cases with confirmed gallbladder cancer, the median tumour size was 30mm, positive periportal lymph nodes were identified in two patients while R0 resection was achieved in all cases. The median length of stay following surgery was 5 days (IQR 5-7) while Clavien Dindo complication grade ≥ III were experienced in 12% ( return to theatre for leak from repaired cholecysto-duodenal fistula n=1, IR drainage of post operative collection n=3, ITU stay for cardiac arrhythmia n=1). The pathologies encountered in benign cases (n=28) were compatible with chronic cholecystitis (53.5%, n=15), concurrent chronic cholecystitis and adenomyomatosis (21.4%, n=6), xanthogranulomatous cholecystitis (10.7%, n=3), adenomyomatosis (7.1%, n=2), follicular cholecystitis (3.5%, n=1), benign GB polyps (3.5%, n=1). Conclusion Radical cholecystectomy remains the standard of care for suspected GBC however sufficient preoperative counselling is prudent given likelihood of benign disease on histology.

Abstract 4137177: A pharmacovigilance investigation from the FAERS database on patients using pembrolizumab and its association with cardiac arrhythmias

Background: Arrhythmia is always a concern in oncological treatments. The advent of immune checkpoint inhibitors (ICIs) has revolutionized cancer treatment, enhancing the immune system's ability to combat malignancies. They are being more frequently used, revealing a range of immune-related adverse events (irAEs). This study aims to investigate the incidence of cardiac arrhythmias in patients receiving Pembrolizumab. Methods: We conducted a retrospective analysis of the FDA Adverse Event Reporting System (FAERS) database, focusing on reports submitted between 2006 to 2024. Cases involving patients treated with ICs were identified, and information related to cardiac arrhythmias was extracted using the Medical Dictionary for Regulatory Activities (MedDRA). Patients ≥ 18 years of age treated with ICIs were included in this study. A disproportionality analysis was conducted to identify arrhythmia events associated with pembrolizumab by comparing it with other immune checkpoint inhibitors (nivolumab, ipilimumab, and atezolizumab) and the entire FAERS database using the reporting odds ratio (ROR) and information component (IC). Results: A comprehensive analysis of 61,236 reported cases of pembrolizumab use revealed a total of 3,901 cases with cardiac complications. Among these, 672 cases (17.22 %) of arrhythmias were reported, with 452 individuals (67.26%) requiring hospitalization and 172 cases (25.59%) resulting in fatalities. Atrial fibrillation emerged as the most prevalent arrhythmia (49.7%). The occurrence of ventricular tachycardia with an ROR of 1.67 (1.18–2.35) and an IC of 0.44 (0.01–1.46) and complete atrio-ventricular block with an ROR of 1.57 (1.19–2.08) and an IC of 0.40 (0.04–1.24) were statistically significant. The reported arrhythmias associated with pembrolizumab are tabulated in Table 1 . The majority of events were reported in males, as shown in Figure 1 . Conclusion: This research offers significant insights into the connection between ICIs and cardiac arrhythmias, utilizing real-world data from the FAERS database. Healthcare providers should monitor cardiac events in patients receiving ICIs and aim to achieve a balance between anticancer effectiveness and cardiovascular safety. Further investigation is necessary to better understand the underlying mechanisms of arrhythmia and enhance risk stratification strategies for this specific patient group.

Abstract 4138507: Uncovering Risk Factors for Myocarditis and Cardiac Arrhythmia in Youth Post-SARS-CoV-2 Infection: Insights from the N3C Database and Advanced Machine Learning

Background: SARS-CoV2 infection has been associated with cardiovascular consequences, including myocarditis and cardiac arrhythmias. Myocarditis secondary to SARS-CoV2 infection and cardiac arrhythmias may often go unrecognized and can present with late and nonspecific symptoms. Predicting those at risk allows for prompt treatment and prevention of their potentially life-threatening consequences. Methods: The National COVID Cohort Collaborative (N3C) database was used to identify patients aged 0-30 years with COVID-19 index date between 1/1/2020 and 3/31/2022, whose sites provided data for at least six months beyond the index date. Outcomes included myocarditis and new arrythmias within 6 months of the index visit. Patients with known cardiac comorbidities were excluded. Predictors included gender, race, COVID severity as an ordinal scale, vaccination status, clinical comorbidities, and Area Deprivation Index (ADI). The data were stratified by age groups (0-4, 5-17, 18-30). Random forest models were used for data analysis and SHapley Additive exPlanations (SHAP) method was applied to optimize results. These analyses were conducted using the NCATS N3C Data Enclave. Results: Of the 1,487,741 patients in our study population, 4,105 (0.28%) had the measured outcomes; 404 had myocarditis only, 3,634 had arrhythmia only and 67 had both. Severity of COVID (SHAP 0.2344 for 0-4 years, 0.2114 for 5-17, 0.1370 for 18-30) was identified as the most important risk factor for de-novo myocarditis and arrhythmias overall. Increase in ADI (indicating lower socioeconomic status) was the second most important risk factor for the 0-4 and 5-17 age groups (SHAP: 0.0370, 0.0223). Among the 18-30 age group, race (SHAP 0.0321) and gender (SHAP 0.0289) were the second and third most important risk factors, with White and Black patients more likely to develop an event and Hispanic patients less likely. Women were less likely to develop a cardiac outcome than men. Conclusion: The severity of COVID was identified as the most important risk factor for the occurrence of myocarditis or cardiac arrhythmia within 6 months of infection. ADI, race, and gender were also identified as important, though less influential, risk factors.

Abstract 4117406: The Safety and Efficacy of Surgical Cardiac Sympathetic Denervation for Ventricular Arrhythmias: An Updated Systematic Review&Meta-Analysis

Objectives: This meta-analysis sought to explore the long-term arrhythmic outcomes of cardiac sympathetic denervation (CS) by measuring event rates of recurrent ventricular arrhythmias (VA) and implantable cardiac defibrillator shocks (ICD) post CSD. Background: The role of sympathetic nervous system in the beginning and continuation of ventricular arrhythmias (VAs) is well known. CS has been associated with improved arrhythmic outcomes in patients with refractory ventricular arrhythmias. However, whether CSD lowers shock event rates after the procedure is still uncertain and therefore, we performed a systematic review and meta-analysis to evaluate this. Methods&Materials: A comprehensive literature search was performed at Medline and Embase until March 2023. Our primary outcome was event rate of ICD shocks at 30 days, 90 days, and 1 year following CS. All analysis was conducted using Comprehensive Meta-Analysis software. Results: The initial search found 1,324 articles. After all articles were examined, a total of 29 studies fit our criteria. ICD shocks 1 year post CSD had a pooled event rate of 66.5% with a 95% confidence interval (CI) of 57.7% to 74.3% and the I-squared (I2) statistics. ICD shocks at 6 months had an event rate at 61.7% with a 95% confidence interval of 53.3% to 69.4% with I2 at 46. VA in one year post CSD had a pooled event rate of 62.5 with a 95% with a CI of 53.3% to 69.1% and I2 at 22%. At 6 months the event rate was 64.2 with a 95% CI of 56.3% to 71.4% with I2 at 33% Mortality from cardiac arrhythmia and classified 0-30 days (short term), 21-364 days (medium term), and >365 days (long term). The pooled event rate for short term morality was 6.8% with a 95% CI of 4.2%-11.0% with I2 at 0%, medium term was 5.2% with a 95% CI of 2.9% to 8.9% with I2 at 0%, and long term was 5.0% with a 95% CI of 2.7% to 9.2% and I2 at 0%. Conclusion: CSD may be an alternative form of therapy that reduces shock event rates and recurrent VA in patients that are refractory to ablation and medical therapy. However larger prospective studies are needed to further evaluate the usefulness and safety of CSD.

Abstract 4134668: Title: Mandibular advancement device versus CPAP on cardiovascular health and quality of life in OSA a pre-specified 12 months follow up of outcomes

Background: Obstructive sleep apnoea (OSA) is a significant cause of hypertension. ACC/AHA Guidelines recommended screening and treatment of OSA in patients with hypertension; however, evidence comparing mandibular advancement devices (MAD) to continuous positive airway pressure (CPAP) on cardiovascular health is lacking. We present the complete 12 months follow-up data on the comparative effectiveness of MAD versus CPAP in ambulatory BP reduction, QoL, cardiac arrhythmia, and myocardial remodelling. Method: In a randomized, non-inferiority trial (margin 1.5 mmHg), 321 participants, aged over 40, with hypertension and high cardiovascular risk were recruited. Of these, 220 participants with OSA (apnoea–hypopnea index ≥15 events/h) were randomized to either MAD or CPAP (1:1). Pre-specified secondary outcomes include: ambulatory BP, quality of life (QoL) (sleep-specific: ESS, SAQLI, FOSQ; non-sleep-specific: SF-36, EQ-5D), ambulatory ECG monitoring, and cardiac MRI. Results: A total of 89 (80.9% of 110) participants from MAD, and 91 (82.7% of 110) participants from CPAP completed 12 months follow-up. The median daily usage was 5.5 hours for MAD and 4.9 hours for CPAP. The between-group difference in 24h mean BP from baseline to 12 months was - 0.57 mmHg (95% confidence interval: (-2.53 to 1.39, non-inferiority P < 0.001). Compared with the CPAP group, MAD group demonstrated a larger reduction in all the 24h with the most pronounced differences observed in the asleep BP parameters (Table 1). Both the MAD and CPAP improved QoL (Table 2). CPAP had greater improvement in FOSQ from sleep-specific questionnaires (P=0.038), and social QoL in SF-36 from non-sleep-specificl questionnaires (P=0.013). The ambulatory ECG monitoring (MAD: 2.8 ± 1.0 days, CPAP: 2.3 ± 1.1 days) showed no between-group differences in % atrial fibrillation(P=0.209), % ventricular ectopic isolated count (P=0.790) and % supraventricular ectopic isolated count (P= 0.333). The cardiac MRI sub-study (101 participants : MAD= 45, CPAP= 56) showed CPAP had greater improvement in right ventricular stroke volume (P=0.023) and MAD had greater improvement in circumferential strain favours the MAD group (P=0.015) (Table 3). Conclusion: At 12 months , MAD was non-inferior to CPAP for reducing 24h mean arterial BP. MAD showed greater reduction in 24h BPs, especially during asleep. While both the MAD and CPAP are effective in improving QoL, CPAP is more effective in improving FOSQ and social QoL (SF-36).

Abstract 4115541: Association of Glucagon-like Peptide 1 Receptor Agonist Use with Incident Atrial Fibrillation

Background: Glucagon-like peptide 1 receptor agonists (GLP-1RAs) have shown efficacy for reducing cardiovascular morbidity and mortality in patients with diabetes mellitus (DM), but conflicting evidence exists regarding their impact on cardiac arrhythmias. Whereas some studies suggested a possible association between GLP-1RA use and arrhythmogenesis, other studies suggested decreased association with atrial fibrillation (AF). Overall, large-scale real-world data evaluating risk of AF in association with GLP-1RAs are lacking. Objective: To compare risk of incident AF after initiation of GLP1-RA vs Dipeptidyl peptidase-4 inhibitors (DPP4i), as active comparators, in patients with DM. Methods: This retrospective propensity score-matched cohort study was conducted within the Veterans Health Administration from fiscal years 2006 to 2021. The study included U.S. veterans aged 35 years or older who initiated either GLP1-RA or DPP4i prescriptions. The primary outcome assessed was a composite outcome of atrial fibrillation (AF), defined as a diagnosis of AF/flutter based on administrative codes or undergoing an AF procedure. Results: Out of 116,235 GLP1-RA users and 217,668 DPP4i users, we propensity score-matched 80,948 pairs, on 88 characteristics, including demographics, comorbidities, vital signs, cardiovascular risk score, healthcare utilization, DM control, laboratory investigation, and medications. Composite outcome of AF was similar in GLP-1RA group (4.1%) and DPP4i group (4.3%); odds ratio (OR) 0.96, 95% confidence interval (CI) 0.92-1.01. Secondary analyses stratified by medication use duration showed no significant differences in composite AF risk (P>0.05). Notably, individuals achieving weight loss of 2%, 5%, or 10% of baseline body weight had significantly lower AF incidence, whereas no significant differences were observed in those with no weight loss or weight gain (OR 0.99, 95% CI 0.91-1.07). Conclusions: Use of GLP1-RA in patients with DM was not associated with a decreased risk of AF when compared with the use of DPP4i. In the subgroup analysis, significantly lower AF risk was seen in the GLP-1 RA group who achieved weight loss vs. DPP4i and this highlights weight loss as a potential modifier of cardiovascular outcomes in DM.

Abstract 4134655: Clinical Outcomes of Patients with Alcoholic Cirrhosis and Acute STEMI Undergoing PCI

Original research: Background: The objective is to evaluate the outcomes of percutaneous coronary intervention (PCI) in patients with alcoholic cirrhosis presenting with ST-segment elevation myocardial infarction (STEMI). Methods: We analyzed data from the National Inpatient Sample (NIS) for the years 2016-2020. Our cohort included patients admitted with STEMI and a secondary diagnosis of alcoholic cirrhosis, excluding those under 18 or those not receiving PCI. Propensity score matching using a kernel method was applied to adjust for 22 variables, including patient demographics, hospital characteristics, and comorbid conditions. Results: Among 119,799 patients, 98 had alcoholic cirrhosis. These patients exhibited higher mortality (18% vs. 5%) and longer hospital stays (5.4 days vs. 3.6 days). They also had increased risks of acute blood loss anemia (13% vs. 3.5%) and gastrointestinal bleeding (18% vs. 2%). Additionally, acute kidney injury was more prevalent in the cirrhosis group (25.5% vs. 14%). Although heart failure exacerbation and cardiac arrhythmias were more common, these were not statistically significant (Table 1). Conclusion: Our study indicates a significantly higher mortality rate among patients with alcoholic cirrhosis undergoing PCI for STEMI. These patients are also at increased risk of postoperative bleeding due to compromised liver function and hemostatic abnormalities, as reflected by higher incidences of acute blood loss anemia and gastrointestinal bleeding. Additionally, there is an elevated risk of acute kidney injury post-PCI, highlighting the need for renal-protective strategies. These findings stress the necessity for specialized care, vigilant monitoring, and tailored protocols to address the unique challenges faced by this population, aiming to reduce morbidity and mortality.

Abstract 4127664: Influences of Age on Improvement of Health-Related Quality of Life in Patients with Atrial Fibrillation following Initial Treatment

Background: The prevalence of Atrial Fibrillation (AF), the most cardiac common arrhythmia, increases with age. Various treatment strategies are available to improve health-related quality of life (HRQoL) in patients with AF; however, the impact of age on HRQoL treatment benefits is unknown. Aims: To investigate the association of age with HRQoL benefit across different treatment strategies. Methods: Using data from a multicenter registry for outpatients with early recognized AF, HRQoL at enrollment and 1 year later was measured with the Atrial Fibrillation Effect on Quality-of-life quesTionnaire (AFEQT). The association between age and the 1-year changes in AFEQT-overall summary (OS) and subdomain scores with either rate or rhythm control strategies were assessed using generalized additive models (GAM) to address non-linear relationships. To support clinical interpretation, multivariable linear regression models were performed with categories of age ranges. Results: Among 2786 patients (31.7% women, 54.7% rhythm control); 946 were <65 of age, 1019 were ≥65–75, and 821 were ≥75 years old. Rhythm (vs. rate) control was pursued in 76.6%, 58.0%, and 33.6% and mean AFEQT-OS changes were 11.1 (SD 16.6), 8.0 (17.0), and 4.7 (18.2) in those aged <65, 65–74, and ≥75, respectively. The GAM showed improvements in AFEQT-OS attenuated with advancing age with both treatment strategies ( Figure ). Linear regression analyses showed lesser improvements in AFEQT-OS as higher age categories (≥65–75 vs. <65, β -1.12 [95% CI, -2.33 – 0.09]; ≥75 vs. <65, β -3.86 [-5.29 – -2.42]), which were mainly driven by lesser improvement in AFEQT-daily activities scores, without differences in AFEQT scores for symptom or treatment concerns ( Table ). Conclusions: In AF patients, HRQoL benefits after treatment were attenuated by advancing age, primarily driven by less improvement in functional limitations, underscoring the need for further research to identify optimal treatment strategies for older adults.

Abstract 4124677: Left ventricular function and myocardial longitudinal strain analysis in patients with Chagas disease: case series and systematic literature review.

Introduction: Chagas disease is a significant cause of tropical disease-related mortality. It presents in acute, indeterminate, and chronic phases, with chronic cardiomyopathy being the most severe form, leading to heart failure, arrhythmias, and sudden cardiac death. Conventional echocardiography often fails to detect early subclinical dysfunction, whereas Global longitudinal strain (GLS) may provide earlier detection of myocardial strain abnormalities. Left ventricular dysfunction is an independent predictor of mortality and GLS is an emerging modality that may aid early detection of cardiac involvement. Objective: This study aims to compare left ventricular function using multiple echocardiographic parameters between patients with indeterminate and chronic forms of Chagas disease and to perform a systematic literature review. Methods: The observational study involved 11 patients (mean age 76.36 years) from a tertiary hospital in Brazil, classified as indeterminate (45%) or chronic (55%). Serological confirmation and detailed echocardiographic evaluations, including GLS, were performed. A systematic literature review was also conducted on GLS in Chagas cardiomyopathy. Results: Patients with chronic Chagas disease showed significantly lower LVEF and GLS compared to those with the indeterminate form. Segmental strain analysis revealed consistent contractility reductions across specific ventricular segments in both groups. Discussion: Chagas cardiomyopathy often leads to dilated cardiomyopathy with significant arrhythmias and heart failure. GLS can detect early myocardial changes even before a significant drop in LVEF, indicating its potential for early diagnosis and better management of Chagas cardiomyopathy. Literature review supports the use of GLS for detecting early cardiac involvement and predicting adverse outcomes. Conclusion: Incorporating GLS with conventional echocardiography offers enhanced early detection of myocardial changes in Chagas disease. While promising, further research is needed to establish the clinical significance and impact of these techniques in routine practice.

Abstract 4122486: Multicenter Study of Primary Fetal Cardiomyopathy: Clinical Outcomes And Genetic Etiologies, A Fetal Heart Society Research Collaborative Study

Background: Fetal cardiomyopathy (FCM) affects 8 per 100,000 live births, often with unknown etiology. Progress in fetal cardiac screening, genetic testing and management may have impacted historically poor outcomes. Aims: We sought to investigate genetic associations and clinical outcomes of FCM in the current era. Methods: This was a retrospective Fetal Heart Society Research Collaborative cohort study of FCM cases diagnosed from January 2017-December 2021 in 39 centers. Cases of fetal myocardial disease attributable to maternal diabetes, structural heart disease, arrhythmia or extra-cardiac conditions were excluded. Data including outcomes to 1 year after birth were collected. Significance of genetic testing results and FCM subtype were classified by each center. Results: There were 138 FCM cases diagnosed at a median gestational age of 27 +4 weeks (range 13-39 weeks). Suspected fetal heart disease (41%, 56/138) was the most common referral indication. There was a known family history of CM in 19% (26/138). FCM phenotypes included 38% (52/138) dilated, 24% (33/138) hypertrophic, 17% (24/138) non-compacted, 10% (14/138) mixed, 5% (7/138) restrictive, 3% (4/138) ventricular aneurysm, 3% (4/138) unspecified. Hydrops was present at diagnosis in 15% (20/138) and by delivery or at fetal demise in 26% (36/138). Of 128 continued pregnancies, 7% (9/128) had a fetal demise, 92% (118/128) a live birth and one was lost to follow-up. Among live births, 10% (12/118) received only palliative care. Of 106 actively treated, 75% (80/106) survived to 1 year; 7% (7/106) required ECMO, and 22% (23/106) were listed for transplant with 18 of these successfully transplanted. Of the cohort, a total of 80% (110/138) had genetic testing (including 30 with invasive prenatal testing), with 38% (52/138) having a confirmed genetic etiology and 28% (38/138) with a variant of uncertain significance (VUS) (Figure 1). Transplant-free survival to 1 year was similar for those with and without a genetic diagnosis (40%,21/52 vs 47%,40/86, p=0.48). Conclusion: Outcomes remain poor in FCM, with <50% 1-year survival overall. Confirmed genetic etiologies are now identified in nearly 40%, highlighting the importance of genetic testing.

Abstract 4138622: Cardiac Rhabdomyosarcoma: An Updated Review of the English Literature From 1980 Through 2023

Cardiac Rhabdomyosarcoma (CR) is a rare malignant neoplasm of the heart occurring in all age groups and genders. It can arise anywhere in the heart with varied clinical presentation. Available data on CR are mainly from case reports and series that are limited by small sizes. The purpose of this study was to characterize the epidemiology, presentation, management, hospital course, and outcomes of CR published in the English literature from 1980-2023. Methods: We reviewed and included all published case reports with a diagnosis of CR in adult patients (age >18 years) on PubMed and Google Scholar using the keywords “primary cardiac tumor” and “cardiac rhabdomyosarcoma”. Data was extracted onto an Excel spreadsheet for analysis and the outcomes of interest were demographics, clinical presentation, diagnostic modalities, management, complications, and outcomes. We used descriptive statistics to analyze the data. Results: Among a total of 97 patients from 19 countries included in this study, 54% were males and the median age was 49 years (range 18-80). The main symptoms were dyspnea (37.1%), palpitations (23.7%), chest pains (16.5%) and syncope (6.5%). Hypotension or heart failure and arrhythmias were present in 10.3% and 9.3%, respectively and 5.2% had pericardial effusion. In addition to those with metastatic tumors, 22.7% had chronic co-morbidities. The majority of the cases were primary tumors (85.6%), and the remainder were (14.4%). All patients had at least one imaging modality including echocardiography (89%) and CT/MRI (84%). The commonest sites of cardiac involvement were the left atrium (35%), right atrium (33%), right ventricle (20%), and left ventricle (12%). Approximately 68% involved a single cardiac site while 32% involved multiple sites. Among the patients, 96% underwent surgery while 33% and 25% had chemotherapy and 25% radiotherapy, respectively. The median length of hospital stay was 11 days (range, 2-68 days), and mortality was recorded in 79.3% (77/97) of the patients. The median survival time was reported in 42 patients, and it was 6 months (range, 0-36 months). Conclusion: Cardiac rhabdomyosarcoma is a rare and aggressive malignant neoplasm. Most cases are primary tumors with poor outcomes such as a very short median survival time and a very high mortality rate despite the combination of surgery, chemotherapy, and radiotherapy. This calls for further research into the early diagnosis and optimal management strategies to improve outcomes.

Abstract 4118070: High Output Heart Failure After Leadless Pacemaker Placement In a Heart Transplant Recipient

Introduction: The advent of leadless pacemaker (LP) technology has revolutionized cardiac rhythm management by minimizing risks associated with traditional transvenous pacemakers. LP use is expected to increase as dual-chamber LP systems emerge into clinical practice. The LP requires a large-bore venous sheath (27-Fr) through a femoral vein. One risk of large bore femoral cannulation is creation of an occult arteriovenous fistula (AVF), which can cause high output heart failure (HOHF) over time. In the LEADLESS II trial, the event rate for AVF was 0.2%. HOHF as a complication of LP implant has not been previously reported. We describe the first case of HOHF in a heart transplant (HT) recipient after LP. Case Presentation: An 82-year-old male with a history of HT 26 years earlier underwent leadless pacemaker for recurrent syncope, deemed associated with conduction system disease. He had no history of cardiac allograft rejection, angiographic coronary allograft vasculopathy or left ventricular dysfunction. Six months post-implant he presented with shortness of breath and bilateral lower extremity edema. Management: Evaluation included: 1) Chest X-ray which was suggestive of pulmonary edema 2) natriuretic peptide level of 5,500 pg/ml (6-fold increase from 6 months prior) 3) echocardiogram showing EF of 69%, and 4) bilateral lower extremity Doppler ultrasound where he was found to have a large AVF between the right superficial femoral artery and superficial femoral vein. Subsequent right heart catheterization was notable for a PCWP of 18 mmHg and a cardiac output/index of 11 L/min and 5.8 L/min/m2 respectively, hence confirming HOHF. Treatment with intravenous diuretic was initiated and percutaneous stent placement to correct the AVF was performed with symptomatic relief. Conclusion: This case highlights the rare but serious complication of unrecognized AVF following leadless pacemaker implant. Given that this event occurred in a HT recipient, a more exhaustive work-up was required to rule-out expected causes of congestion. To our knowledge there is only one other case report describing AVF post-LP implant for which no intervention was performed due to absence of symptoms at 6-month follow up and HOHF was not reported. Our case emphasizes that the differential diagnosis of new onset of signs and symptoms of heart failure that develop post LP implant in general and in HT recipients specifically, should include HOHF related to an unrecognized procedural AVF.

Abstract 4144567: Prevalence of Atrial Fibrillation in Amyloidosis and Their Association: A 5-Year Nationwide Analytical Cross-Sectional Study

Background: Atrial fibrillation (AF) is a common cardiac arrhythmia associated with significant morbidity and mortality. Amyloidosis (AM) is characterized by the accumulation of amyloid protein in various anatomical sites, including the heart, atria, and ventricles. This amyloid infiltration leads to adverse chamber remodeling, predisposing patients to tachyarrhythmias such as atrial fibrillation/flutter. This study aims to re-evaluate the association of AM with AF by using the large nationwide inpatient database over a total duration of 5 years. Methods: An analytical cross-sectional study was conducted utilizing the data from a survey-weighted national inpatient sample database covering admissions from Jan 2017 to Dec 2021. A total of 147,015,073 admissions of patients aged 18 years and above were included. Descriptive statistics and univariate logistic regression models were used to calculate prevalence rates and odds ratios (OR), respectively. The multivariate logistic regression model was then used to adjust various potential confounders, including age, gender, race, income, hypertension, diabetes, stage 3 or above chronic kidney disease (CKD), Charlson comorbidity index, and hospital-related factors. Results: The 5-year prevalence of AF was 36.73% and 15.42% in admissions with and without AM, respectively. Significant differences between the with AM and without AM groups were in mean ages (72.40 vs. 58.08), female (41.83% vs. 56.92%), race of Black (24.57% vs. 15.40%), and CKD stage 3+ (44.83% vs. 16.65%), respectively. The univariate logistic regression analysis showed an OR for AF of 3.18 (95%CI: 3.102 - 3.267, P<0.000) in admissions with AM compared to those without. After adjustment for the potential confounders, the OR for AF decreased to 1.64 (95%CI 1.597- 1.686; P<0.000) in patients with Amyloidosis compared to those without. Conclusion: This study confirms a significant association between amyloidosis and atrial fibrillation, demonstrating that patients with amyloidosis have a markedly higher prevalence of atrial fibrillation compared to those without. Univariate analysis showed an odds ratio of 3.18 for atrial fibrillation in amyloidosis patients, which remained significantly elevated at 1.64 after adjusting for confounders. These findings indicate the need for a comprehensive workup of suspected atrial fibrillation in amyloidosis patients. Further research should investigate the mechanisms behind this association and potential prevention.

Abstract 4141454: Atrial Fibrillation in American Indians: Comparative Analysis of Characteristics and Anticoagulation Use for Stroke Prevention of Atrial Fibrillation

Background: Atrial fibrillation (AF) is the most common cardiac arrhythmia in the United States, affecting individuals of all races. Anticoagulation (AC) therapy is recommended by the guidelines to reduce the risk of stroke in AF patients. Previous reports indicate that American Indians (AI) have a higher risk of AF and an increased risk of stroke from AF. Aim: To describe the demographic and clinical characteristics of the AI population with AF and compare their AC status with other racial groups. Methods: We retrospectively analyzed AF patients age >18 years hospitalized between January 2022 and October 2023 in two hospitals serving a large Navajo Nation AI population in rural Northern Arizona. We compared baseline characteristics, AC status and direct oral anticoagulant (DOAC) use between AI and other races. Between group statistical analysis was completed using a chi-square for categorical variables and a Mann-whiney U test for continuous variables, with statistical significance defined as a p-value ≤ 0.05. Results: In total, 9255 patients were admitted with AF: 871 (9.4%) were AI, with 696 (79.9%) being Navajo Nation AI and 8284 (89.5%) from other non-AI races. AI patients with AF were younger (average age 65±15.9 vs 75±11.2; p <0.0001), had fewer female patients (30.5% vs 39.3%; p <0.0001), and were less likely to be treated with oral anticoagulation (40.5% vs 50.9%; p <0.0001; OR 0.66; 95% CI: 0.57 to 0.76) compared to non-AI races (table 1). Among those anticoagulated, AI patients were less likely to receive a DOAC (38.0% vs 44.7%; p = 0.0002; OR 0.76; 95% CI: 0.66 to 0.88) compared to non-AI races (table 2). Conclusions: Our analysis, with a significant number of AI pts, reveal that AI patients develop AF at a younger age and despite an increased risk of stroke, have significantly lower rates of anticoagulation use, particularly with DOACs. Our findings underscore the need for guideline-adherent AC use in this AI population.

Abstract 4135869: Local Ethanol Infusion after Pulsed Field Ablation Enhances Acute Efficacy of In Vivo Ventricular Electroporation

Background: Pulsed field ablation (PFA) has emerged as an innovative technology for treating cardiac arrhythmias. PFA increases cell permeability, which can lead to apoptosis. Greater PFA energy may be necessary to ablate ventricular myocardium for ventricular tachycardia circuits, but this carries risks of side effects such as gaseous formation (microbubbles) and hemolysis. Ethanol (EtOH) infusion has been used to ablate pathologic myocardial tissues in hypertrophic cardiomyopathy and for refractory arrhythmias. Hypothesis: We hypothesize that PFA in the ventricle can increase EtOH uptake through PFA-generated pores, thereby enhancing ablation efficacy, even at low powers, by utilizing the cell permeability effects of PFA. Aim: The aim of this study is to investigate the effect of local EtOH infusion after PFA on lesion size in porcine ventricles. Methods: The ventricles of five porcine subjects were ablated in vivo with a PFA low power setting (750 V, at 20 μs for 50 pulses separated by 200 ms) using a focal bipolar irrigated ablation catheter and BTX 830 electroporation generator (Harvard Apparatus). After PFA was performed, 2 ml of 90 % EtOH vs. saline (control) was infused through the catheter tip to the site of ablation. We compared the electrograms voltage amplitude reduction before and after PFA, and the ablation lesion characteristics. Results: A total of 10 lesions in the control group and 9 lesions in the EtOH group were analyzed. For the controls, the voltage after PFA was not reduced. In contrast, for the EtOH group, the voltage after PFA was significantly reduced ( Figure 1A ). On gross pathology, there were significant differences in ablation lesion depths and volumes between the 2 lesion sets ( Figure 1A-B ). Conclusion: Local EtOH infusion after ventricular PFA enhanced acute efficacy of electroporation. Concurrent PFA with local EtOH infusion has the potential to improve efficacy without requiring higher energy parameters, thereby reducing PFA risks. Future studies on chronic efficacy are warranted.

Abstract 4113854: Outcomes Of Atrial Fibrillation Ablation In Elderly: A Retrospective Cohort Study

Introduction: Atrial fibrillation (Afib) is a common cardiac arrhythmia that increases in prevalence with age. Ablation has been widely used for managing Afib, but its outcomes in octogenarians have been less thoroughly investigated. Research Question: This study aims to assess the in-hospital outcomes of Afib ablation in patients aged above 80 compared to those below 80 years old. Methods: Data was obtained from the Nationwide Inpatient Sample database from January 2016 to December 2020. The study included all adult patients with a primary discharge diagnosis of Afib who underwent catheter ablation during their hospitalization. These patients were then categorized into two groups based on age: below 80 and above 80 years. In-hospital outcomes for these groups were then looked at. The primary outcome was inpatient mortality. Secondary outcomes were the length of stay, cost of hospitalization, cardiac arrest, cardiac tamponade, arrhythmias, acute respiratory failure, acute renal failure, procedural complications as well as the need for dialysis, transfusions, pressors, ventilators, and tracheostomy. Results: Out of about 35 million admissions screened, 403,247 patients had Afib as their primary discharge diagnosis, of these, 17,927 patients underwent catheter ablations during their hospitalization. Amongst them, 3,051(17%) were above the age of 80 years. The in-hospital mortality was slightly higher in the elderly compared to the younger cohort (1.1% vs 0.5%, aOR: 1.87; 95% CI: 1.20-2.92, p=0.006). They had a longer hospital stay (5.14 days vs. 3.72 days, p<0.001) and lower hospitalization costs (USD 138,091 vs. USD 162,788, p<0.001). Complications such as acute respiratory failure and acute renal failure were more frequent in the older age group, while no significant differences were observed in cardiac arrest, cardiac tamponade, ventricular arrhythmias, and most device-related complications. The need for new dialysis, mechanical ventilation, and pressor use was significantly less in the above-80 group. Conclusion: Afib ablation in older adults, results in slightly higher in-hospital mortality and longer hospital stays compared to younger patients. Despite these differences, the overall complication rates are comparable, suggesting that age alone should not deter the selection of patients for Afib ablation. Further studies are needed to validate these findings and optimize management strategies for the elderly population.

Abstract 4123563: High Prevalence of Unrecognized Actionable Cardiac Arrhythmias in Patients with Moderate to Severe Chronic Obstructive Pulmonary Disease

Background: Patients with chronic obstructive pulmonary disease (COPD) are at high risk for developing arrhythmias due to hypoxemia, right heart failure and use of beta-agonists inhalers. Symptoms related to arrhythmias can often be masked or confounded by symptoms related to COPD exacerbation and remain undiagnosed. Objective: To identify the incidence of actionable arrhythmias in patients with no prior cardiology follow-up and moderate–severe COPD with continuous monitoring. Methods: An automatic referral for electrophysiology (EP) consult was generated in patients with moderate-severe COPD if they answered yes to one of the following: palpitations, dizziness, abnormal ECG, near syncope. Upon consultation with EP specialist, implantation of loop reorder was discussed (ILR) with the patient. Patients were then monitored for 12 months via remote monitoring. Actionable arrhythmia was defined the arrhythmia that correlated with symptoms triggered by the patient, necessitated adjustment of medications (including initiation of anticoagulation), catheter ablation and implantation of implantable cardiac defibrillator (ICD) or permanent pacemaker (PPM). Results: Out of 62 patients referred 22 (35.5%) agreed to undergo ILR implantation. Of the 22 (50.0% female, 62 ± 9.5 years) patients implanted with an ILR, 15 (68.2%) had an actionable arrhythmia after a mean follow-up of 2.7± .3 months. These included 14 symptomatic events requiring medication adjustment (10 atrial tachycardias, 4 ventricular events), 7 cases of atrial fibrillation (requiring initiation of anticoagulation in all cases and catheter ablation in 1), 1 case of sinus node dysfunction requiring pacemaker implantation, and 1 episodes of sustained ventricular tachycardia requiring ICD implantation. Conclusion: Continuous monitoring had high yield in diagnosing significant arrhythmic events in patients with moderate-severe COPD. Awareness should be raised about the high arrhythmic risk of this population and the role of continuous monitoring should be sought in larger studies.

Abstract 4129195: Mechanisms of Healthy Aging in the Prevention of Atrial Fibrillation

Introduction: Atrial Fibrillation (AF) is the most frequent cardiac arrhythmia. AF can lead to severe complications such as myocardial infarction, strokes, and sudden death. With 70% of AF patients aged 65 and older, aging stands as the major risk factor for AF. Our group have recently contributed to reveal that old Wistar rats (20 months) are more susceptible to AF than younger rats (5 months). Interestingly, Lou/c/jall (LOU) rats, a model of healthy aging derived from Wistar rats, can live up to ~35 months old (equivalent to 100 human years). LOU rats have been identified as resistant to age-related diseases such as obesity, hypertension, and neurodegenerative disorders, which are major risk factors for AF. However, the susceptibility of LOU rats to AF have never been reported. Hypothesis: LOU rats may carry specific molecular adaptations conferring resistance to age-related cardiac remodeling and low AF vulnerability. Objectives: Characterize the vulnerability of very old LOU rats (32 months) to AF compared to old Wistar rats (22 months). Determine the atrial inflammatory profile of LOU rats and identify the molecular adaptations that may explain their resistance to AF Methods: Male and Female rats were divided into five groups: LOU and Wistar rats of 5 months (young), 20 months (old), and 32 months (very old: LOU/c rats only). AF inducibility was assessed in vivo using transesophageal electrophysiological study and cardiac structure and function were analyzed by in vivo echocardiography. Atrial electrical conduction was examined using ex vivo optical mapping. Histological analyses were performed to assess atrial fibrosis. Additionally, immunoblot analysis, qPCR, and RNA sequencing were employed to investigate the levels of biomarkers involved in atrial inflammation and fibrosis. Result: Old Wistar rats were more vulnerable to AF than young rats. Old and very old LOU were significantly more resistant to AF than old Wistar animals. LOU rats’ low susceptibility to AF was accompanied with absence of cardiac structural and functional remodeling and low levels of atrial fibrosis compared to old Wistar. Additionally, advanced age did not affect LOU rats’ atrial electrical conduction properties as compared to old Wistar rats. Conclusion: Promotion of healthy aging conditions mimicking LOU rats’ resistance to cardiac remodeling and reduction of atrial fibrosis may contribute to prevent AF in subjects with pathological aging.

Abstract 4144530: IL-37 promotes resolution of Right Heart Disease-induced inflammation and atrial fibrillation.

INTRODUCTION: Atrial Fibrillation (AF) is the most common cardiac arrhythmia. Hypertension, obesity, diabetes or right heart disease (RHD) are important risk factors for AF. Inflammation stands as a common denominator among most AF risk factors. Studies have shown that patients with AF present high levels of circulating IL-18. Our group recently described that inflammation-resolution may prevent AF in RHD, however, the mechanism remains unclear. To inhibit IL-18-induced inflammation, IL37, a specific antagonist of IL-18-receptor was shown to attenuate cardiac fibrosis in a mice model of myocardial infarction, but little is known about its efficacy to prevent AF. HYPOTHESIS: IL-37 curbs RHD-induced atrial inflammation and AF vulnerability. METHODS: To induce right-sided cardiac hypertrophy and dilation, pulmonary artery banding (PAB) was performed in male and female Wistar rats (250-300g). Sham animals did not receive the ligation. Animals were randomized into four groups: Sham and PAB treated or not with IL37 (100 ng/ml/kg). Electrophysiological studies and echocardiography were performed in vivo before sacrifices at day (D)0, D7, D14 and D21. To analyze the atrial conduction, right atrial (RA) optical mapping was performed on Langendorff-perfused hearts. Histology, western blot, and qPCR were performed to study the expression of proteins and genes involved in atrial inflammation, fibrosis, and electrical remodeling. RESULTS: Twenty-one days after surgery, PAB rats were more vulnerable to AF and developed severe right-sided hypertrophy and dilation compared to Sham. Reliable to clinical evidence, female rats might be more resistant to AF than males. AF was associated with increased RA levels of inflammatory biomarkers including IL18, IL1β, and IL6. IL37 treatment was associated with decreased atrial expression of inflammatory markers. CONCLUSION: IL37 is a potential new therapeutic strategy to reduce atrial inflammation and prevent AF vulnerability in RHD.