Diagnostic accuracy and performance of artificial intelligence in measuring left atrial volumes and function on multiphasic CT in patients with atrial fibrillation.

OBJECTIVES: To evaluate the effectiveness of a novel artificial intelligence (AI) algorithm for fully automated measurement of left atrial (LA) volumes and function using cardiac CT in patients with atrial fibrillation. METHODS: We included 79 patients (mean age 63 ± 12 years; 35 with atrial fibrillation (AF) and 44 controls) between 2017 and 2020 in this retrospective study. Images were analyzed by a trained AI algorithm and an expert radiologist. Left atrial volumes were obtained at cardiac end-systole, end-diastole, and pre-atrial contraction, which were then used to obtain LA function indices. Intraclass correlation coefficient (ICC) analysis of the LA volumes and function parameters was performed and receiver operating characteristic (ROC) curve analysis was used to compare the ability to detect AF patients. RESULTS: The AI was significantly faster than manual measurement of LA volumes (4 s vs 10.8 min, respectively). Agreement between the manual and automated methods was good to excellent overall, and there was stronger agreement in AF patients (all ICCs ≥ 0.877; p < 0.001) than controls (all ICCs ≥ 0.799; p < 0.001). The AI comparably estimated LA volumes in AF patients (all within 1.3 mL of the manual measurement), but overestimated volumes by clinically negligible amounts in controls (all by ≤ 4.2 mL). The AI's ability to distinguish AF patients from controls using the LA volume index was similar to the expert's (AUC 0.81 vs 0.82, respectively; p = 0.62). CONCLUSION: The novel AI algorithm efficiently performed fully automated multiphasic CT-based quantification of left atrial volume and function with similar accuracy as compared to manual quantification. Novel CT-based AI algorithm efficiently quantifies left atrial volumes and function with similar accuracy as manual quantification in controls and atrial fibrillation patients. KEY POINTS: • There was good-to-excellent agreement between manual and automated methods for left atrial volume quantification. • The AI comparably estimated LA volumes in AF patients, but overestimated volumes by clinically negligible amounts in controls. • The AI's ability to distinguish AF patients from controls was similar to the manual methods.

Patient characteristics, care patterns, and outcomes of atrial fibrillation associated hospitalizations in patients with chronic kidney disease and end-stage renal disease.

BACKGROUND: Chronic Kidney Disease (CKD) and end-stage renal disease (ESRD) are associated with poor outcomes in patients with cardiovascular disease. There is a paucity of contemporary data on in-hospital outcomes and care patterns of atrial fibrillation (AF) associated hospitalizations CKD and ESRD. METHODS: Outcomes and care patterns were evaluated in GWTG-AFIB database (Jan 2013-Dec 2018), including in-hospital mortality, use of a rhythm control strategy, and oral anticoagulation (OAC) prescription at discharge among eligible patients. Generalized logistic regression models with generalized estimating equations were used to ascertain differences in outcomes. Hospital-level variation in OAC prescription and rhythm control was also evaluated. RESULTS: Among 50,154 patients from 105 hospitals the median age was 70 years (interquartile range 61-79) and 47.3% were women. The prevalence of CKD was 36.0% while that of ESRD was 1.6%. Among eligible patients, discharge OAC prescription rates were 93.6% for CKD and 89.1% for ESRD. After adjustment, CKD and ESRD were associated with higher in-hospital mortality (odds ratio [OR] 3.08, 95% confidence interval [CI] 1.57-6.03 for ESRD and OR 2.02, 95% CI 1.52-2.67 for CKD), lower odds of OAC prescription at discharge (OR 0.59, 95% CI 0.44-0.79 for ESRD and OR 0.84, 95% CI 0.75-0.94 for CKD) compared with normal renal function. CKD was associated with lower utilization of rhythm control strategy (OR 0.92, 95% CI 0.87-0.98) with no significant difference between ESRD and normal renal function (OR 1.32, 95% CI 0.79-1.11). There was large hospital-level variation in OAC prescription at discharge (MOR 2.34, 95% CI 2.05-2.76) and utilization of a rhythm control strategy (MOR 2.69, 95% CI 2.34-3.21). CONCLUSIONS: CKD/ESRD is associated with higher in-hospital mortality, less frequent rhythm control, and less OAC prescription among patients hospitalized for AF. There is wide hospital-level variation in utilization of a rhythm control strategy and OAC prescription at discharge highlighting potential opportunities to improve care and outcomes for these patients, and better define standards of care in this patient population.

Same-day discharge after catheter ablation in patients with atrial fibrillation in a large nationwide administrative claims database.

BACKGROUND: Catheter ablation (CA) is a common treatment for atrial fibrillation (AF). This study evaluated outcomes of same day discharge (SDD) versus overnight stay (ONS) among AF patients undergoing outpatient CA. METHODS: The Optum SES Clinformatics Extended Data Mart database was used to identify patients ≥18 years of age undergoing outpatient CA for AF (2016-2020). Eligible patients were indexed to the date of first CA and classified into SDD and ONS groups based on the length of service. A 1:3 propensity score matching was used to create comparable SDD:ONS samples. The primary safety outcome was CA-related complications within 30 days of index procedure. The primary efficacy outcome was AF recurrence within 1 year. Cox proportional hazards models were estimated for outcome comparison. RESULTS: In the postmatch 30-day cohort for safety evaluation, there were 6600 patients (1660 [25.2%] SDD; 4940 [74.8%] ONS), with a mean age of 66.6 years. There was no significant difference in the 30-day composite rate of postablation complications (4.7% [78/1660] vs. 3.8% [187/4940]; p = 0.100) and 1-year composite rate of AF recurrence (14.3% [142/996] vs. 14.5% [430/2972]; p = 0.705) between the SDD and ONS groups. CONCLUSION: This study demonstrated that SDD following CA to treat patients with AF is safe, with low rates of postablation complications and AF recurrence, which were comparable to rates in patients with an ONS after CA.

Electrical delays in quadripolar leads with cardiac resynchronization therapy.

BACKGROUND: Pacing at sites of late intraventricular activation (QLV) or long interventricular conduction (right ventricle [RV]-left ventricular [LV]) have been associated with improved cardiac resynchronization therapy (CRT) outcomes. Quadripolar leads improve CRT outcomes by allowing for electrical repositioning to optimize pacing sites. However, little is known regarding the effect of such repositioning on electrical delay. OBJECTIVE: Determine the relationship between different electrical bipoles from a quadripolar lead and measures of electrical delay. METHODS: Forty-six patients underwent CRT with a quadripolar lead. The RV-LV and QLV intervals were measured for both the proximal and distal bipoles and the difference (Δ) between bipoles for each measure were calculated. Multivariate analyses were performed to identify predictors of electrical delays. RESULTS: This was a typical CRT population with a mean age of 65 years and ejection fraction of 27%, with left bundle branch block (LBBB) present in 70%. The regression model for ΔQLV was significant (p = .05), with both gender (p = .008) and LBBB status (p = .020) significant predictors. The overall regression model for ΔRV-LV was not significant. ΔQLV and ΔRV-LV were significant among LBBB patients. Among non-LBBB, only ΔRV-LV was significant (mean: 7.2 ms, p = .006). ΔRV-LV versus ΔQLV were strongly correlated in LBBB (R2 = .92) but not non-LBBB (R2 = .06). CONCLUSION: In LBBB, ΔRV-LV and ΔQLV are closely correlated suggesting that the proximal bipole and thus basal LV pacing sites should be selected when feasible. Greater variation in activation pattern is present in non-LBBB, so pacing sites should be individualized.

Impact of age on catheter ablation of premature ventricular contractions.

INTRODUCTION: Catheter ablation (CA) of frequent premature ventricular contractions (PVC) is increasingly performed in older patients as the population ages. The aim of this study was to assess the impact of age on procedural characteristics, safety and efficacy on PVC ablations. METHODS: Consecutive patients with symptomatic PVCs undergoing CA between 2015 and 2020 were evaluated. Acute ablation success was defined as the elimination of PVCs at the end of the procedure. Sustained success was defined as an elimination of symptoms, and ≥80% reduction of PVC burden determined by Holter-electrocardiogram during long-term follow. Patients were sub-grouped based on age (<65 vs. ≥65 years). RESULTS: A total of 114 patients were enrolled (median age 64 years, 71% males) and followed up for a median duration of 228 days. Baseline and procedural data were similar in both age groups. A left-sided origin of PVCs was more frequently observed in the elderly patient group compared to younger patients (83% vs. 67%; p = .04). The median procedure time was significantly shorter in elderly patients (160 vs. 193 min; p = .02). The rates of both acute (86% vs. 92%; p = .32) and sustained success (70% vs. 71%; p = .90) were similar between groups. Complications rates (3.7%) did not differ between the two groups. CONCLUSION: In a large series of patients with a variety of underlying arrhythmia substrates, similar rates of acute procedural success, complications, and ventricular arrhythmia-free-survival were observed after CA of PVCs. Older age alone should not be a reason to withhold CA of PVCs.

Electromagnetic interference from left ventricular assist devices in patients with subcutaneous implantable cardioverter-defibrillators.

INTRODUCTION: Interactions of left ventricular assist devices (LVADs) with transvenous implantable cardioverter-defibrillator systems (ICDs) have been widely reported. However, less is known regarding the impact of electromagnetic interference (EMI) from LVADs on subcutaneous ICD function. METHODS AND RESULTS: A comprehensive literature search was performed on PubMed, Cochrane central registry, and Google Scholar using the search terms "subcutaneous implantable cardioverter-defibrillator and left ventricular assist devices," "electromagnetic interference, LVAD, and subcutaneous ICD," "EMI and S-ICD," and "inappropriate shocks, LVAD, and ICD." Demographic and programming data were extracted from the reports and authors as needed. A total of seven cases of EMI in LVAD patients with subcutaneous ICD (S-ICD) devices were found. In addition three previously unreported cases from our center were included. All cases involved either a heartware ventricular assist device or HeartMate III LVAD with a pre-existing S-ICD. In all patients, both the primary and secondary vectors had inappropriate sensing due to EMI. Three patients were reprogramed to the alternate vector with appropriate sensing. The S-ICD was either inactivated or replaced with a transvenous device in six patients. A single patient was left sensing in the alternate vector. There were no reports of inability to interrogate S-ICD systems in patients with LVADs. CONCLUSION: The risk of inappropriate shocks from LVADs should be considered in pre-existing patients with S-ICD, particularly when the heartware ventricular assist device or HeartMate III LVAD device is present. Reprogramming of the sensing vector can occasionally avoid this issue but often the S-ICD needs to be inactivated.

Healthcare utilization and cost in patients with atrial fibrillation and heart failure undergoing catheter ablation.

BACKGROUND: Catheter ablation is an effective treatment for patients with atrial fibrillation (AF) and heart failure (HF). However, little is known about how healthcare utilization and cost change after ablation in this population. We sought to determine healthcare utilization and cost patterns among patients with AF and HF undergoing ablation. METHODS: Using a large United States administrative database, we identified (n = 1568) treated with ablation with a primary and secondary diagnosis of AF and HF, respectively, were evaluated 1-year pre- and postablation for outcomes including inpatient admissions (AF or HF), emergency department (ED) visits, cardioversions, length of stay (LOS), and cost. A secondary analysis was extended to 3-years postablation. RESULTS: Reductions were observed in AF-related admissions (64%), LOS (65%), cardioversions (52%), ED visits (51%, all values, p < .0001), and HF-related admissions (22%, p = .01). There was a 40% reduction in inpatient admission cost ($4165 preablation to $2510 postablation, p < .0001). In a sensitivity analysis excluding repeat-ablation patients, a greater reduction in overall AF management cost was observed compared to the full cohort (-43% vs. -2%). Comparing 1-year pre- to 3-years postablation, both total mean AF-management cost ($850 per-patient per-month 1-year pre- to $546 3-years postablation, p < .0001) and AF-related healthcare utilization was reduced. CONCLUSIONS: Catheter ablation in patients with AF and HF resulted in significant reductions in healthcare utilization and cost through 3-years of follow-up. This reduction was observed regardless of whether repeat ablation was performed, reflecting the positive impact of ablation on longer term cost reduction.

Real-world outcomes of ventricular tachycardia catheter ablation with versus without intracardiac echocardiography.

INTRODUCTION: By providing real-time monitoring of catheter-tissue interface and for complications, intracardiac echocardiography (ICE) during catheter ablation for ventricular tachycardia (VT) may improve outcomes. To test this hypothesis, we compared 12-month readmission rates (all-cause, cardiovascular [CV]-related, and VT-related), repeat ablation, and complications among patients with VT with structural heart disease undergoing ablation with versus without ICE. METHODS AND RESULTS: Using the 2008-2017 IBM MarketScan Commercial and Medicare Supplemental databases, patients with a history of implantable cardioverter defibrillator/cardiac resynchronization therapy (ICD/CRT-D) who underwent VT ablation with and without ICE use were identified. Propensity matching was performed and regression analysis was used to compare outcomes. After matching, 1324 patients were identified (ICE: 662; non-ICE: 662). The rate of 12-month VT-related readmission (18.13% vs 22.51%; P < .05) and repeat VT ablation (14.35% vs 19.34%; P = .02) postindex discharge were lower among patients in the ICE group compared with the non-ICE group, with a 24% lower risk of 12-month VT-related readmission (odds ratio [OR], 0.76; 95% confidence interval [CI], 0.58-0.99) and a 30% lower risk of repeat ablation (OR, 0.70; 95% CI, 0.52-0.93) vs non-ICE group. The 12-month all-cause (44.56% vs 43.20%; P = .62) and CV-related readmissions (35.20% vs 32.93%; P = 0.38) and complication rates were not significantly different between the two groups. CONCLUSIONS: VT ablation using ICE was associated with a lower likelihood of 12-month VT-related readmission and repeat ablation compared with non-ICE patients.

Pragmatic Study of Clinician Use of a Personalized Patient Decision Aid Integrated into the Electronic Health Record: An 8-Year Experience.

Background: Patient decision aids (PDAs) facilitate shared decision-making (SDM) and are delivered in a variety of formats, including printed material or instructional videos, and, more recently, web-based tools. Barriers such as time constraints and disruption to clinical workflow are reported to impede usage in routine practice. Introduction: This pragmatic study examines use of PDAs integrated (iPDAs) into the electronic health record (EHR) over an 8-year period. Methods: A suite of iPDAs that personalize decision-making was integrated into an academic health system EHR. Clinician use was tracked using patient and clinician encrypted information, enabling identification of clinician types and unique uses for an 8-year period. Clinician feedback was obtained through survey. Results: Over 8 years, 1,209 identifiable clinicians used the iPDAs at least once ("aware"). Use increased over time, with 2,415 unique uses in 2010, and 23,456 in 2017. Clinicians who used an iPDA with at least 5 patients ("adopters"), increased by 82 clinicians each year (range 56-108); of clinicians who used the tool once, 54.3% became adopters. Of 261 primary care clinicians, 93.5% were aware, 86.2% were adopters, and 80.5% used the tools in the last 90 days. Clinicians perceived the iPDAs to be convenient, efficient, and encouraging of SDM. Discussion: We demonstrate that use of decision aids integrated into the EHR result in repeated use among clinicians over time and have the potential to overcome barriers to implementation. We noted a high degree of clinician satisfaction, without a sense of increase in visit time. Conclusion: Integration of PDAs into the EHR results in sustained use. Further research is needed to assess the impact of iPDAs on decisional quality.

Impact of a novel protocol for atrial fibrillation management in outpatient gastrointestinal endoscopic procedures: a retrospective cohort study.

BACKGROUND: Atrial fibrillation (AF) may result in procedure cancellations and emergency department (ED) referrals for patients presenting for outpatient GI endoscopic procedures. Such cancellations and referrals delay patient care and can lead to inefficient use of resources. METHODS: All consecutive patients presenting in AF for a colonoscopy or upper endoscopy to the University of Wisconsin Digestive Health Center between October 2013 and September 2014 were defined as the pre-intervention group (Group 1). In 2015, a protocol was initiated for peri-procedural management of patients presenting in AF, new onset or previously known. All consecutive patients after initiation of the protocol from October 2015 to September 2016 were analyzed as the post intervention group (Group 2). Patients with heart failure, hypotension, or chest pain were excluded from the protocol. RESULTS: One hundred nine and 141 patients were included in Groups 1 and Group 2, respectively. Following protocol initiation, patients were less likely to present to the ED (6.4% Group 1 vs. 1.4% Group 2, RR 0.22, p = 0.04). There was also a trend towards a reduction in procedure cancelations (5.5% Group 1 vs. 1.4% Group 2, RR 0.26, p = 0.08). All attempted procedures were completed and there were no complications in the intervention group. CONCLUSIONS: Implementation of a standardized protocol for management of atrial fibrillation in patients presenting for outpatient gastrointestinal endoscopic procedures resulted in a significant decrease in emergency department visits with an additional trend toward decreased procedural cancellations without an increased risk of complications.

Concealed Accessory Pathways with a Single Ventricular and Two Discrete Atrial Insertion Sites.

BACKGROUND: Atrioventricular reciprocating tachycardia (AVRT) utilizing a concealed accessory pathway is common. It is well appreciated that some patients may have multiple accessory pathways with separate atrial and ventricular insertion sites. METHODS: We present three cases of AVRT utilizing concealed pathways with evidence that each utilizing a single ventricular insertion and two discrete atrial insertion sites. RESULTS: In case one, two discrete atrial insertion sites were mapped in two separate procedures, and only during the second ablation was the Kent potential identified. Ablation of the Kent potential at this site remote from the two atrial insertion sites resulted in the termination of the retrograde conduction in both pathways. Case two presented with supraventricular tachycardia (SVT) with alternating eccentric atrial activation patterns without alteration in the tachycardia cycle length. The two distinct atrial insertion sites during orthodromic AVRT and ventricular pacing were targeted and each of the two atrial insertion sites were successfully mapped and ablated. In case three, retrograde decremental conduction utilizing both atrial insertion sites was identified prior to ablation. After mapping and ablation of the first discrete atrial insertion site, tachycardia persisted utilizing the second atrial insertion site. Only after ablation of the second atrial insertion site was SVT noninducible, and VA conduction was no longer present. CONCLUSIONS: Concealed retrograde accessory pathways with discrete atrial insertion sites may have a common ventricular insertion site. Identification and ablation of the ventricular insertion site or the separate discrete atrial insertion sites result in successful treatment.

Outcome after implantation of a cardioverter-defibrillator in patients with Brugada syndrome: a multicenter study-part 2.

BACKGROUND: Implantable cardioverter-defibrillator indications in Brugada syndrome remain controversial, especially in asymptomatic patients. Previous outcome data are limited by relatively small numbers of patients or short follow-up durations. We report the outcome of patients with Brugada syndrome implanted with an implantable cardioverter-defibrillator in a large multicenter registry. METHODS AND RESULTS: A total of 378 patients (310 male; age, 46±13 years) with a type 1 Brugada ECG pattern implanted with an implantable cardioverter-defibrillator (31 for aborted sudden cardiac arrest, 181 for syncope, and 166 asymptomatic) were included. Fifteen patients (4%) were lost to follow-up. During a mean follow-up of 77±42 months, 7 patients (2%) died (1 as a result of an inappropriate shock), and 46 patients (12%) had appropriate device therapy (5±5 shocks per patient). Appropriate device therapy rates at 10 years were 48% for patients whose implantable cardioverter-defibrillator indication was aborted sudden cardiac arrest, 19% for those whose indication was syncope, and 12% for the patients who were asymptomatic at implantation. At 10 years, rates of inappropriate shock and lead failure were 37% and 29%, respectively. Inappropriate shock occurred in 91 patients (24%; 4±4 shocks per patient) because of lead failure (n=38), supraventricular tachycardia (n=20), T-wave oversensing (n=14), or sinus tachycardia (n=12). Importantly, introduction of remote monitoring, programming a high single ventricular fibrillation zone (>210-220 bpm), and a long detection time were associated with a reduced risk of inappropriate shock. CONCLUSIONS: Appropriate therapies are more prevalent in symptomatic Brugada syndrome patients but are not insignificant in asymptomatic patients (1%/y). Optimal implantable cardioverter-defibrillator programming and follow-up dramatically reduce inappropriate shock. However, lead failure remains a major problem in this population.

Substrate Imaging Before Catheter Ablation of Ventricular Tachycardia: Risk Prediction for Acute Hemodynamic Decompensation.

BACKGROUND: The PAINESD (Pulmonary disease, Age, Ischemic cardiomyopathy, NYHA functional class, Ejection fraction, Storm, Diabetes mellitus) risk score has been validated as a predictor of periprocedural acute hemodynamic decompensation (AHD) in patients undergoing ventricular tachycardia (VT) ablation. Whether the addition of total scar volume (TSV) determined by preprocedure computed tomography imaging provides additional risk stratification has not been previously investigated. OBJECTIVES: The purpose of this study was to evaluate the impact of TSV on the risk of AHD and its adjunctive benefit to the PAINESD score newly modified as Pulmonary disease, Age, Ischemic cardiomyopathy, NYHA class, Ejection fraction, Storm, Scar volume, Diabetes mellitus (PAINES2D) based on the addition of scar volumes. METHODS: This was a retrospective analysis of all index VT ablations at a quaternary care center from 2017 to 2022. Associations between TSV and AHD were evaluated among patients with structural heart disease. RESULTS: Among 61 patients with TSV data, 13 (21%) had periprocedural AHD. TSV and PAINESD were independently associated with AHD risk. Both TSV and PAINESD were associated with AHD (P = 0.016 vs P = 0.053, respectively). The highest TSV tertile (≥37.30 mL) showed significant association with AHD (P = 0.018; OR: 4.80) compared to the other tertiles. The PAINESD and PAINES2D scores had significant impact on AHD (P = 0.046 and P = 0.010, respectively). The PAINES2D score had a greater impact on AHD compared to PAINESD (area under the curve: 0.73; P = 0.011; 95% CI: 0.56-0.91 and area under the curve: 0.67; P = 0.058; 95% CI: 0.49-0.85, respectively). CONCLUSIONS: Addition of TSV to a modified PAINESD score, PAINES2D, enhances risk prediction of AHD. Further prospective study is needed to assess benefit in various cardiomyopathy populations undergoing VT ablation.