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Aims The aim of our study was to assess differences in post-ablation atrial fibrillation (AF) recurrence and burden and to quantify the change in LVEF across different congestive heart failure (CHF) subcategories of the DECAAF-II population. Methods and results Differences in the primary outcome of AF recurrence between CHF and non-CHF groups was calculated. The same analysis was performed for the three subgroups of CHF and the non-CHF group. Differences in AF burden after the 3-month blanking period between CHF and non-CHF groups was calculated. Improvement in LVEF was calculated and compared across the three CHF groups. Improvement was also calculated across different fibrosis stages. There was no significant differences in AF recurrence and AF burden after catheter ablation between CHF and non-CHF patients and between different CHF subcategories. Patients with heart failure with reduced ejection fraction (HFrEF) experienced the greatest improvement in EF following catheter ablation (CA, 16.66% ± 11.98, P < 0.001) compared to heart failure with moderately reduced LVEF, and heart failure with preserved EF (10.74% ± 8.34 and 2.00 ± 8.34 respectively, P-value < 0.001). Moreover, improvement in LVEF was independent of the four stages of atrial fibrosis (7.71 vs. 9.53 vs. 5.72 vs. 15.88, from Stage I to Stage IV respectively, P = 0.115). Conclusion Atrial fibrillation burden and recurrence after CA is similar between non-CHF and CHF patients, independent of the type of CHF. Of all CHF groups, those with HFrEF had the largest improvement in LVEF after CA. Moreover, the improvement in ventricular function seems to be independent of atrial fibrosis in patients with persistent AF.

Lower neighborhood median household income (nMHI) is associated with increased adverse outcomes in patients with atrial fibrillation (AF). However, its effect on mortality is yet unknown.Data from the regional United States (U.S.) electronic medical records database, Research Action for Health Network (REACHnet), was extracted for adult patients with AF at Tulane Medical Center over 10 years. Annual nMHIneighborhood high school graduation (HSG) data was collected from the US Census bureau. Only African Americans (AA) and Caucasians (CC) who had socioeconomic data were included. Low nMHI and low HSG were defined as ≤$25,00090% respectively. High nMHI and HSG were defined as$50,000≥90% respectively. Primary endpoints were all cause and cardiovascular (CV) mortality. Cox-proportional hazard ratios were used to evaluate the endpoints.We included 4616 patients diagnosed with AF. During a median follow up of 4.6 years, 434 patients died of which 32.7% patients had CV mortality. There was a stepwise decrease in incidence of both all-cause and CV mortality as nMHI increased. Patients with low nMHI had the greatest risk of all-cause mortality (HR 1.9, C.I. 1.2-3.2, P 0.004). The association between low nMHI and all-cause mortality persisted after adjusting for age, sex, race, HSG and stroke risk factors using CHALow nMHI is an independent risk factor for all cause and CV mortality in AF. Higher burden of co-morbidities is the driving force behind this disparity. Future studies should evaluate the role of educational and therapeutic intervention in these populations to reduce mortality.

UNSTRUCTURED The rise of mobile electrocardiogram (ECG) devices came with the rise of frequent large magnitudes of noise in their recordings. Several artificial intelligence (AI) models have had great success in denoising, but the model’s generalizability and the enhancement in clinical interpretability are still questionable. We propose Cardio-NAFNet, a novel AI-based approach to ECG denoising by employing a modified version of Non-Linear Activation Free Network (NAFNET). We conducted three experiments for quantitative and qualitative evaluation of denoising, clinical implications and generalizability. In the first experiment, Cardio-NAFNet achieved 53.74dB average signal to noise ratio across varying magnitude of noise in beat-to-beat denoising, which is a significant improvement over the current state of the art model in ECG denoising. In the second experiment, we tested the enhancement in clinical interpretation of the ECG signals by utilizing a pretrained ECG classifier using 8 second long noise-free ECG signals. When the classifier was tested using noisy ECG signals and their denoised counterparts, Cardio-NAFNet's denoised signals provided 26% boost in classification results. Lastly, we provide an external validation dataset composed of single-lead mobile ECG signals along with signal quality evaluation from physician experts. Our paper suggests a settling method to capture and reconstruct critical features of ECG signals not only in terms of quantitative evaluation, but also through generalizable qualitative evaluation.

Background Esophageal injury (EI) remains a concern when performing pulmonary vein isolation (PVI) using the high-power short-duration (HPSD) technique. Objective We aim to indicate that high esophageal temperature during HPSD PVI does not correlate with positive esophageal endoscopy (EGD) findings. Methods A retrospective observational study was performed on 43 patients undergoing PVI using HPSD (50 W for 6–7 seconds per lesion) at Tulane Medical Center from July 2020 to January 2021. Esophageal temperature was monitored throughout the procedure using a temperature probe and patients underwent EGD the following day. Small ulcers, nonbleeding erosions, erythema, and/or esophagitis were considered positive EGD findings. Results Mean age was 64.9 years; 46.5% of the patients were female. Eleven patients had positive EGD findings (group 1) and 32 patients had normal EGD (group 2). There was no statistical difference in mean esophageal peak temperature between group 1 and group 2 (43.9°C ± 2.9°C and 42.5°C ± 2.3°C, respectively, P = .17). There was no association between positive EGD results and esophageal temperature during PVI. Mean baseline esophageal temperature was similar in both groups (36.1°C, P = .78). Average contact force (P = .53), ablation time (P = .67), age (P = .3096), sex (P = .4), body mass index (P = .14), and other comorbidities did not correlate with positive endoscopy results. We found positive correlation between the distance of the left atrium (LA) to esophagus and positive EGD (P = .0001). Conclusion EI during HPSD PVI does not correlate to esophageal temperature changes during ablation. However, esophageal injury does correlate to a shorter proximity of the esophagus to the LA.

Introduction: Pulmonary vein isolation (PVI) using radiofrequency (RF) and cryoballoon (Cryo) ablation are standard approaches for rhythm control of symptomatic atrial fibrillation. Both strategies involve scar formation of the left atrium (LA). There have been few studies investigating the differences in residual fibrosis and scar formation in patients undergoing RF and Cryo using cardiac magnetic resonance imaging (CMR). Methods: The current study is a sub-analysis of the control arm of the Delayed-Enhancement MRI Determinant of Successful Catheter Ablation of Atrial Fibrillation study (DECAAF II). The study was a multicenter, randomized, controlled, single blinded trial that evaluated atrial arrhythmia recurrence (AAR) between PVI alone and PVI plus CMR atrial fibrosis guided ablation. Pre-ablation CMR and 3–6-month post ablation CMR were obtained to assess baseline LA fibrosis and scar formation respectively. Results: Of the 843 patients randomized in the DECAAF II trial, we analyzed the 408 patients in the primary analysis control arm that received standard PVI. Five patients received combined RF and Cryo ablations so were excluded from this sub-analysis. Of the 403 patients analyzed, 345 underwent RF and 58 Cryo. The average procedure duration was 146 minutes for RF and 103 minutes for Cryo (p = 0.001). The rate of AAR at ~15 months occurred in 151 (43.8%) patients in the RF group and 28 (48.3%) patients in the Cryo group (p = 0.62). On 3-month post CMR the RF arm had significantly more covered fibrosis (3.6% vs. 3.0%, p = 0.04) and scar (8.8% vs. 6.4%, p = 0.001) compared to Cryo. Patients with ≥ 6.5% LA scar on 3-month post CMR had less AAR independent of ablation technique (RF p = 0.009, Cryo p = 0.02). Cryo caused a greater percentage of right and left pulmonary vein (PV) scar (p = 0.04, p = 0.02) and less non-PV scar (p = 0.009) compared to RF. On Cox regression Cryo patients free of AAR had a greater percentage of left PV scar (p = 0.01) and less non-PV scar (p = 0.004) compared to RF free of AAR. Conclusion: In this sub-analysis of the control arm of the DECAAF II trial, there was no significant difference in the rate of AAR in patients undergoing PVI alone between RF vs. Cryo. Post ablation LA scar ≥ 6.5% predicted freedom from AAR, independent of ablation technique. Cryo formed a greater percentage of PV scar and less non-PV scar compared to RF, which may have prognostic implications.

The rise of mobile electrocardiogram (ECG) devices came with the rise of frequent large magnitudes of noise in their recordings. Several artificial intelligence (AI) models have had great success in denoising, but the model’s generalizability and the enhancement in clinical interpretability are still questionable. We propose Cardio-NAFNet, a novel AI-based approach to ECG denoising by employing a modified version of Non-Linear Activation Free Network (NAFNET). We conducted three experiments for quantitative and qualitative evaluation of denoising, clinical implications and generalizability. In the first experiment, Cardio-NAFNet achieved 53.74dB average signal to noise ratio across varying magnitude of noise in beat-to-beat denoising, which is a significant improvement over the current state of the art model in ECG denoising. In the second experiment, we tested the enhancement in clinical interpretation of the ECG signals by utilizing a pretrained ECG classifier using 8 second long noise-free ECG signals. When the classifier was tested using noisy ECG signals and their denoised counterparts, Cardio-NAFNet’s denoised signals provided 26% boost in classification results. Lastly, we provide an external validation dataset composed of single-lead mobile ECG signals along with signal quality evaluation from physician experts. Our paper suggests a settling method to capture and reconstruct critical features of ECG signals not only in terms of quantitative evaluation, but also through generalizable qualitative evaluation.

BACKGROUND The WEAICOR (Wearables to Investigate the Long Term Cardiovascular and Behavioral Impacts of COVID-19) study was a prospective observational study that used continuous monitoring to detect and analyze biometrics. Compliance to wearables was a major challenge when conducting the study and was crucial for the results. OBJECTIVE The aim of this study was to evaluate patients’ compliance to wearable wristbands and determinants of compliance in a prospective COVID-19 cohort. METHODS The Biostrap (Biostrap USA LLC) wearable device was used to monitor participants’ biometric data. Compliance was calculated by dividing the total number of days in which transmissions were sent by the total number of days spent in the WEAICOR study. Univariate correlation analyses were performed, with compliance and days spent in the study as dependent variables and age, BMI, sex, symptom severity, and the number of complications or comorbidities as independent variables. Multivariate linear regression was then performed, with days spent in the study as a dependent variable, to assess the power of different parameters in determining the number of days patients spent in the study. RESULTS A total of 122 patients were included in this study. Patients were on average aged 41.32 years, and 46 (38%) were female. Age was found to correlate with compliance (r=0.23; P=.01). In addition, age (r=0.30; P=.001), BMI (r=0.19; P=.03), and the severity of symptoms (r=0.19; P=.03) were found to correlate with days spent in the WEAICOR study. Per our multivariate analysis, in which days spent in the study was a dependent variable, only increased age was a significant determinant of compliance with wearables (adjusted R2=0.1; β=1.6; P=.01). CONCLUSIONS Compliance is a major obstacle in remote monitoring studies, and the reasons for a lack of compliance are multifactorial. Patient factors such as age, in addition to environmental factors, can affect compliance to wearables.

BACKGROUND Patients with COVID-19 have increased sleep disturbances and decreased sleep quality during and after the infection. The current published literature focuses mainly on qualitative analyses based on surveys and subjective measurements rather than quantitative data. OBJECTIVE In this paper, we assessed the long-term effects of COVID-19 through sleep patterns from continuous signals collected via wearable wristbands. METHODS Patients with a history of COVID-19 were compared to a control arm of individuals who never had COVID-19. Baseline demographics were collected for each subject. Linear correlations among the mean duration of each sleep phase and the mean daily biometrics were performed. The average duration for each subject’s total sleep time and sleep phases per night was calculated and compared between the 2 groups. RESULTS This study includes 122 patients with COVID-19 and 588 controls (N=710). Total sleep time was positively correlated with respiratory rate (RR) and oxygen saturation (SpO2). Increased awake sleep phase was correlated with increased heart rate, decreased RR, heart rate variability (HRV), and SpO2. Increased light sleep time was correlated with increased RR and SpO2 in the group with COVID-19. Deep sleep duration was correlated with decreased heart rate as well as increased RR and SpO2. When comparing different sleep phases, patients with long COVID-19 had decreased light sleep (244, SD 67 vs 258, SD 67; P=.003) and decreased deep sleep time (123, SD 66 vs 128, SD 58; P=.02). CONCLUSIONS Regardless of the demographic background and symptom levels, patients with a history of COVID-19 infection demonstrated altered sleep architecture when compared to matched controls. The sleep of patients with COVID-19 was characterized by decreased total sleep and deep sleep.

Introduction: Larger left atrial appendage (LAA) ostium area and greater left atrial (LA) volume have been associated with an increased risk of ischemic stroke. Catheter ablation (CA) of atrial fibrillation (AF) leads to morphological and functional changes within the LA and LAA, some of which are not well studied. Here, we present findings regarding post-ablation changes of the LAA ostia and correlate them with various LA, LAA and left ventricular (LV) functional and morphological metrics. Methods: This retrospective analysis included patients scheduled to undergo first-time radiofrequency CA for AF. Catheter ablation techniques included PVI with or without additional ablations. Cardiac magnetic resonance imaging (CMR) was used to assess LA, LAA and LV morphology and function, including LAA ostium area, LA/LAA volume and volume index, LA ejection fraction, LA strain, and LV ejection fraction. A Kruskal-Wallis test was used for correlating LAA ostial dimensions with other LA morphological and functional metrics. The t-test or two-sample Wilcoxon test were used to compare LA and LAA morphological parameters. Results: A total of 101 patients with AF were included in this study. The mean age was 60.1 ± 11.1 years, 69% were male, the average BMI was 29.22 ± 5.08. The LAA ostial area reduced significantly from 3.84 ± 1.15 cm before ablation to 3.42 ± 0.96 cm after ablation (p=0.0004). This reduction was asymmetrical, as the minor axis length decreased from 1.92 cm to 1.77 cm without significant changes in the major axis. LVEF increased from a pre-ablation average of 48.26% to a post-ablation average of 53.62% (p=0.015). Correlation of pre-ablation LVEF and LAA ostium area showed a near-significant negative trend (r=-0.21, p=0.083). LAEF correlated negatively with LAA ostial area (r=-0.289, p=0.0057), total LA strain (r=-0.248, p=0.0185), and passive LA strain (r=-0.208, p=0.049). Conclusion: There is a significant asymmetrical reduction of the LAA ostial area after AF ablation that is independent of LVEF changes. Larger LAA ostial area was associated with lower LAEF and LA strain. Remodeling of the LAA after AF ablation may help account for reduced risk of stroke and increased cardiac function.