Viable Prediction for Atrial Fibrillation Recurrence After Catheter Ablation

Introduction: Atrial fibrillation (AF) is the most common heart rhythm abnormality and the leading cause of stroke. Radiofrequency catheter ablation is used to treat AF but recurrence can occur after the ablation procedure, requiring repeat procedure. A new model to predict AF recurrence after ablation was developed through multivariate analysis. Methods: The variables include demographic, electrocardiographic, echocardiographic, and clinical parameters. In a retrospective review (n=82), 41 patients who underwent repeat ablation for recurrent AF were compared to 41 controls that underwent ablation only once. Results: Of the analyzed parameters, age, female gender and left atrial enlargement were not predictive, but P wave duration (PWD) and obstructive sleep apnea (OSA) were significant predictors of repeat ablation (p-value = 0.0003 and 0.0023, respectively). Based on the analyses, a simple decision tree model was developed, achieving a prediction accuracy of 87% (sensitivity=83%, specificity=90%). Conclusion: The developed PWD and OSA 2-predictor model has good accuracy and sensitivity, both of which make it a viable prediction model for AF recurrence after catheter ablation. The developed model will help doctors: 1) Avoid repeat procedure in patients at high risk of recurrence by exploring alternative treatments (2) Reduce costs by avoiding repeat procedure (3) Correct underlying issues prior to procedure in those at high risk (4) Objectively inform patients about recurrence so they can make an informed decision about whether to undergo the procedure. Adopting predictive models such as ours may therefore improve quality care and reduce costs for AF patients undergoing ablation.

A randomised study of comfort during bronchoscopy comparing conscious sedation and anaesthetist controlled general anaesthesia, including the utility of Bispectral Index (BIS) monitoring

BackgroundThe difference in patient comfort with conscious sedation (CS) versus general anaesthesia (GA) for bronchoscopy has not been adequately assessed in a randomised trial. This study aimed to assess if patient comfort during bronchoscopy with CS is non-inferior to GA.Methods96 subjects were randomized to receive CS or GA for bronchoscopy. The primary outcome was subject comfort. Secondary outcomes included: Willingness to undergo a repeat procedure if necessary andlevel of sedation assessed clinically and by Bispectral Index (BIS) monitoring.ResultsThere was no significant difference between subject comfort scores (difference −0.01 (95% CI −0.63, 0.61 on a 10 point scale,, p=0.97) or willingness to undergo a repeat procedure (97.7% versus 91.8%, (95% CI −4.8%, 15.5%); p=0.37). Deeper levels of sedation in the GA cohort was confirmed with both clinical and BIS. There was no significant difference in diagnostic accuracy (CS: 93.9% (95% CI 80.4%, 98.3%) versus GA: 86.5% (95% CI 72.0%, 94.1%); p=0.43). There were more complications (29.6% (95% CI 18.2%, 44.2%) versus 6.1% (95% CI 2.1%, 16.5%); p<0.01) in the GA group. There was no relationship between high BIS scores and subject discomfort. BIS levels of less than 40 during a procedure was associated with increased complications.ConclusionCS is not inferior to GA in providing patient comfort during bronchoscopy despite lighter sedation and is associated with fewer complications and comparable diagnostic accuracy. BIS monitoring may have a role in preventing complications associated with deeper sedation.

Abstract 15059: Prevalence of Recovery of Conduction in the Left Atrial Appendage Following Electrical Isolation of the Appendage in Patients With Atrial Fibrillation

Background: Electrical isolation of the left atrial appendage (LAAEI) is considered in patients presenting with recurrence following effective PV isolation. Objective: We evaluated the prevalence of LAA reconnection following LAAEI in patients undergoing repeat procedure for AF recurrence. Methods: Consecutive AF patients undergoing repeat ablation for arrhythmia recurrence following LAAEI were included in this analysis. Transesophageal echocardiogram (TEE) was performed in all at baseline to evaluate LAA function. Isoproterenol infusion up to 30 μg/min for 10 to 15 min was administered to detect LAA triggers. Re-isolation of the LAA was performed if triggers were detected. Off-drug success rate was assessed in all. Results: A total of 594 post-LAAEI patients with recurrent AF were included in the analysis. At the redo, PVs were found to be electrically silent in all. LAA reconnection was detected in 214 (36%) patients. Baseline TEE revealed normal LAA contractility and flow-velocity in all. Re-isolation of the LAA was performed in these 214 patients. In patients with no LAA reconnection (n=380), non-PV triggers from other sites were targeted for ablation. There was no difference in the clinical characteristics of patients with vs. without LAA reconnection (Table). At 2 years after the repeat procedure, 201 (94%) patients with and 351 (92.3%) without LAA reconnection were arrhythmia-free off-drugs (p=0.47). Conclusion: In this series, LAA reconnection rate was 36% after single LAAEI procedure and re-isolation of the appendage led to high success rate. Additionally, normal LAA functions detected by TEE correctly predicted recovery of conduction in the LAA.

Durable pulmonary vein (PV) isolation at repeat atrial fibrillation (AF) ablation procedure: a comparison between 4 ablation technologies

Background Durable PV isolation is the sought-after endpoint to obtain long term success after AF catheter ablation. Evolution in technology improves efficiency, safety and effectiveness in AF catheter ablation. Purpose To investigate the effectiveness of different catheter technologies in obtaining durable PV isolation in a real-world practice. Methods Retrospective analysis of prospectively collected data of patients undergoing repeat procedures for recurrence of AF or atrial flutter at our institution was performed. Incidence of all PVs being isolated at repeat procedure was recorded and patients 4 groups created based on catheter technology used during index AF ablation procedure (SF: multipored, irrigated catheter; ST: contact force sensor catheter; Cryo: 2nd generation cryobaloon; and STSF: multipored, irrigated, contact force sensing catheter). Results We identified 269 subjects undergoing repeat ablation from May 2014 to September 2019. Mean age was 67±9.7 years, 54.6% were males, 74.4% non-paroxysmal AF at the index procedure. The mean CHA2DS2Vasc score was 2.5±0.26, LA size 4.2±0.6 cm, EF 55.3±10%. The mean time from index to redo procedure was 374±331 days. At repeat procedure all veins were isolated in 24% (6/25) who were initially ablated using SF; 36% (8/22) with Cryo; 44% (47/108) with ST; and 74% (84/114) with STSF catheter. (Figure) Conclusion Patients undergoing index ablation with STSF catheter technology were significantly more likely to have all 4 PVs isolated at repeat procedure compared to previous generation technology. Funding Acknowledgement Type of funding source: Private grant(s) and/or Sponsorship. Main funding source(s): Biosense Webster

Low Fetal Fraction of Cell-free DNA Identified by Non-invasive Prenatal DNA Testing: Possible Causes, Clinical Significance, and Tactics

Study Objective: To compare the rates of fetal chromosomal abnormalities (CA) detected during initial non-invasive prenatal DNA testing (NIPT) with the rates of CA found through repeat NIPT in patients with low fetal fraction or low quality of cell-free embryonic DNA. Study Design: This was a retrospective cohort study. Materials and Methods: Twenty-one thousand forty-two women who underwent NIPT in Russia between 2013 and 2018 were included in the study. The main group comprised 1,025 of the 1,044 patients with uninformative results (low fetal fraction result, making it impossible to assess the risk of CA), who consented to repeat NIPT. The control group was made up of 19,998 women who had informative results of initial NIPT. The exclusion group comprised women with low fetal fraction who declined repeat screening. The study method was targeted NIPT. Blood samples were taken from a vein and centrifuged to obtain plasma. Fetal cell-free DNA was analyzed by next-generation sequencing (NGS), a method patented by Natera for sequencing single nucleotide polymorphisms. Study Results: Initial NIPT was uninformative in 1,044 (5%) of the patients and repeat procedure yielded informative results in 821 (80.1%) out of 1,025 patients. Among the patients with informative results from the initial study, the rate of chromosomal aneuploidies was 2.4%. In the group of women with informative results from the repeat procedure, fetal CA were detected in 27 (3.3%) cases. In the subgroup of women with informative results only after a third NIPT, the prevalence of CA was 9.3% (seven out of 75 cases). The study showed that in women carrying fetuses with trisomy 18 or 13 or monosomy X, mean fetal fraction in the first trimester was significantly lower than normal. In the second trimester, significantly lower than normal fetal fraction was observed in women carrying fetuses with trisomy 18 or monosomy X. There was a statistically significant difference in fetal fraction levels between patients with body weight <50 kg and those with body weight 80-89 kg or above (р<0.05). Conclusion: The probability of detecting CA by repeat NIPT is significantly higher than in an initial procedure. If initial testing is not informative, it should be repeated. If the second procedure also fails to yield informative results, invasive prenatal diagnosis should be considered. Fetal fraction levels are lower in heavier women. Thus, other methods of prenatal diagnosis should be recommended for overweight and obese women. Keywords: non-invasive prenatal DNA testing, fetal fraction, prenatal diagnosis, Down syndrome.

P4761Impact of focal ablation versus isolation of the coronary sinus in patients undergoing repeat radiofrequency catheter ablation of persistent atrial fibrillation

Introduction Non-pulmonary vein (PV) triggers originating from the coronary sinus (CS) are a common finding in atrial fibrillation (AF) patients. To date, no studies have investigated the clinical impact of focal ablation versus isolation of the CS in patients presenting triggers from this area. Purpose This study analyzed the effectiveness of two different approaches for CS ablation (total isolation vs focal ablation) in persistent AF patients undergoing repeat AF ablation. Methods Consecutive persistent AF patients undergoing repeat ablation were enrolled in this prospective analysis. All patients had triggers from the CS documented during high-dose isoproterenol. Pulmonary vein antrum isolation (PVAI) extended to the posterior wall (PW) plus superior vena cava (SVC) isolation was performed in all patients at first procedure. At repeat procedure, PV, PW, and SVC were re-isolated, if needed. Focal ablation or isolation of the CS was performed based on operator's choice either at first and/or repeat procedure, along with ablation of other non-PV triggers. Patients with triggers from left atrial appendage were excluded from the study. Results Overall, 628 consecutive patients (73.4% male, age 66.9±9.0 years) were enrolled. On the basis of the CS ablation strategy, patients were categorized into two groups: Group I received CS isolation (n=389) and Group II received CS focal ablation (n=239). Major clinical characteristics were not different between groups. PV reconnection was documented in 55 (14.1%) patients of Group I and 33 (13.8%) of Group II. The incidence of procedure-related complications was similar between the two groups (10 [2.6%] in Group I vs 6 [2.5%] in Group II; p=0.9). After a follow-up of 18±8 months, 276 (71%) patients in Group I and 115 (48%) in Group II remained arrhythmia-free (p<0.001, figure.1). After adjusting for age, gender and clinically relevant variables, CS isolation was associated with a significantly higher arrhythmia-free survival rate (HR: 0.47; 95% CI: 0.37–0.61, p-value<0.001). Conclusions In patients with documented triggers from the CS undergoing repeat ablation of persistent AF, isolation rather than focal ablation of the CS significantly increased freedom from atrial tachyarrhythmias in the long term.

Percutaneous pericardiocentesis versus pericardial window: A retrospective subset analysis in a cancer population.

e23093 Background: Malignant pericardial effusions (PEs) must often, and for a multitude of reasons, be managed invasively. Options for intervention include percutaneous or surgical drainage. There is a paucity of data directly comparing efficacy of these interventions. This study compares efficacy of surgical pericardial window (PW) percutaneous pericardiocentesis (PP) in cancer subjects with PEs, with respect to mortality, readmission, and repeat procedure. Methods: We performed a 5 year, retrospective, single center study at a major academic center. 79 patients were selected using ICD codes for PP (n = 19) and PW (n = 59) and grouped by first procedure performed. Log Rank Regression of Kaplan-Meier Curves was performed for major adverse events, as defined by repeat procedure, readmission, or mortality during the surveillance period. Results: Log Rank Tests of readmission and mortality were not statistically significant (P = 0.54, 0.656 respectively). Single Variate Log Rank Test of repeat procedure favored PW (P = 0.008, event rates: PP 21.1% vs PW 3.4%. Multivariate Log Rank Test of and all 3 events was not statistically significant (P = 0.168). Fig 1: Kaplan-Meier Analysis of PP (0) vs PW (1) by any event (repeat procedure, readmission, or mortality). Event Rate = 89.5% PC, 89.5% PW. Conclusions: PW patients had a lower incidence of repeat procedures. There were no differences in readmission, mortality, or a composite of all 3 events. Future aims will identify risk factors associated with repeat procedures in PCs and PWs.