Smartphone AF Burden During the Blanking Period Predicts Catheter Ablation Outcomes: Insights From DECAAF II.

BACKGROUND: Atrial fibrillation (AF) recurrence during the blanking period is under investigated. With the rise of smartphone-based electrocardiogram (ECG) monitoring, there's potential for better prediction and understanding of AF recurrence trends. OBJECTIVES: In this study the authors hypothesize that AF burden derived from a single-lead Smartphone ECG during the blanking period predicts recurrence of atrial arrhythmias after ablation. METHODS: 630 patients with persistent AF undergoing ablation were included from the DECAAF II (Effect of MRI-Guided Fibrosis Ablation vs Conventional Catheter Ablation on Atrial Arrhythmia Recurrence in Patients With Persistent Atrial Fibrillation) trial. Patients recorded daily ECG strips using a smartphone device. AF burden was defined as the ratio of ECG strips with AF to the total number of strips submitted. The primary outcome was the recurrence of atrial arrhythmia. RESULTS: Recurrence occurred in 301 patients during the 18-month follow-up period. In patients who developed recurrent arrhythmia after 90 days of follow-up, AF burden during the blanking period was significantly higher when compared with patients who remained in sinus rhythm (31.3% vs 7.5%; P < 0.001). AF burden during the blanking period was an independent predictor of arrhythmia recurrence (HR: 1.41; 95% CI: 1.36-1.47; P < 0.001). Through grid searching, an AF burden of 18% best discriminates between recurrence and no-recurrence groups, yielding a C-index of 0.748. After a follow-up period of 18 months, recurrence occurred in 33.7% of patients (147 of 436) with an AF burden <18% and in 79.4% of patients (154 of 194) with an AF burden >18% (HR: 4.57; 95% CI: 3.63-5.75; P < 0.001). CONCLUSIONS: A high AF burden derived from a smartphone ECG during the blanking period is a strong predictor of atrial arrhythmia recurrences after ablation.

Identifying the prognostic significance of early arrhythmia recurrence during the blanking period and the optimal blanking period duration: insights from the DECAAF II study.

OBJECTIVE: Early atrial arrhythmia recurrence following atrial fibrillation (AF) ablation is common. Current guidelines promulgate a 3-month blanking period. We hypothesize that early atrial arrhythmia recurrence during the blanking period may predict longer-term ablation outcomes. METHODS AND RESULTS: A total of 688 patients with persistent AF undergoing catheter ablation were included in the DECAAF II trial database. The primary endpoint of the study was the first confirmed recurrence of atrial arrhythmia. Recurrence was also monitored during the 90-day blanking period. A total of 287 patients experienced recurrent atrial arrhythmia during the blanking period, while 401 remained in sinus rhythm. Rates of longer-term arrhythmia recurrence were substantially higher among those who developed recurrence during the blanking period compared to those who remained in sinus rhythm throughout the blanking period (68% vs. 32%, P < 0.001). The study cohort was divided into three groups according to the timing of arrhythmia recurrence during the blanking period. Of those who had recurrent arrhythmia during the first month of the blanking period (Group 1), 43.9% experienced longer-term recurrence, compared to 61.6% who recurred during the second month of the blanking period (Group 2), and 93.3% of those who had arrhythmia recurrence during the third month (Group 3, P < 0.001). The risk of recurrent arrhythmia was highest in Group 3 (HR = 10.15), followed by Group 2 (HR = 2.35) and Group 1 (HR = 1.5). Receiver operating characteristic analysis was performed to assess the relationship between the timing of arrhythmia recurrence and the primary outcome (AUC = 0.746, P < 0.001). The optimal blanking period duration was identified as 34 days. Atrial fibrillation burden determined by smartphone electrocardiogram technology over the 18 months follow-up period was significantly higher in Group 3 (29%) compared to Groups 1 (6%) and 2 (7%) and in patients who stayed in sinus rhythm during the blanking period (5%) (P < 0.0001). CONCLUSION: Early atrial arrhythmia recurrence during the blanking period, particularly during the third month, is significantly associated with later recurrence. Although a blanking period is warranted, it should be abbreviated.

Compliance Challenges in a Longitudinal COVID-19 Cohort Using Wearables for Continuous Monitoring: Observational Study.

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; ß=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.

Effectiveness and Cost-effectiveness of Mailed FIT in a Safety Net Clinic Population.

BACKGROUND: Mailed fecal immunochemical testing (FIT) can increase colorectal cancer (CRC) screening rates, including for vulnerable patients, but its cost-effectiveness is unclear. OBJECTIVE: We sought to examine the effectiveness and cost-effectiveness of the initial cycle of our mailed FIT program from November 2017 to July 2019 in a federally qualified health center (FQHC) system in Central Texas. DESIGN: Single group intervention and economic analysis PARTICIPANTS: Eligible patients were those ages 50-75 who had been seen recently in a system practice and were not up to date with screening. INTERVENTION: The program mailing packet included an introductory letter in plain language, the FIT itself, easy to read instructions, and a postage-paid lab mailer, supplemented with written and text messaging reminders. MAIN MEASURES: We measured effectiveness based on completion of mailed FIT and cost-effectiveness in terms of cost per person screened. Costs were measured using detailed micro-costing techniques from the perspective of a third-party payer and expressed in 2019 US dollars. Direct costs were based on material supply costs and detailed observations of labor required, valued at the wage rate. KEY RESULTS: Of the 22,838 eligible patients who received program materials, mean age was 59.0, 51.5% were female, and 43.9% were Latino. FIT were successfully completed by 19.2% (4395/22,838) patients at an average direct cost of $5275.70 per 500-patient mailing. Assuming completed tests from the mailed intervention represent incremental screening, the direct cost per patient screened, compared with no intervention, was $54.83. Incorporating start-up and indirect costs increases total costs to $7014.45 and cost per patient screened to $72.90. Alternately, assuming 2.5% and 5% screening without the intervention increased the direct (total) cost per patient screened to $60.03 ($80.80) and $67.05 ($91.47), respectively. CONCLUSIONS: Mailed FIT is an effective and cost-effective population health strategy for CRC screening in vulnerable patients.