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

BACKGROUND

Wearables to Investigate the Long Term Cardiovascular and Behavioral Impacts of COVID-19 (WEAICOR) study is a prospective observational study using 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 is to evaluate patients' compliance to wearable wristbands and determinants of compliance in a prospective COVID-19 cohort.

METHODS

Biostrap 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 in the study. Univariate correlation was performed between compliance, days in the study and age, BMI, sex, symptom severity, and number of complications/comorbidites as independent variables. Also, multivariate linear regression was then performed with days in the study as a dependent variable to assess the power of different parameters in determining days in the study.

RESULTS

On hundred twenty-two patients were included in the study. Patients were on average 43 years old and 32% were female. Age was found to be correlated with compliance (r=0.23, P=0.01). In addition, age (r=0.30, P=0.001), BMI (r=0.19, P=0.03) and severity of symptoms (r=0.19, P=0.03) were found to be correlated with days spent in the study. On multivariate analysis with days spent in the study as a dependent variable, only increased age was a significant determinant of compliance with wearables (adjusted R2 = 0.1, β = 1.6, P= 0.01).

CONCLUSIONS

Compliance is a major obstacle in remote monitoring studies and the reasons for a lack thereof 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.

Exploring factors associated with health disparities in asthma and poorly controlled asthma among school-aged children in the U.S

Objective: Certain populations suffer disproportionately from asthma and asthma morbidity. The objective was to provide a national descriptive profile of asthma control and treatment patterns among school-aged children (SAC: aged 6-17) in the U.S. Methods: This was a cross-sectional analysis using the nationally representative 2007-2014 Medical Expenditure Panel Survey. Among SAC with asthma, indicators of poor control included: exacerbation/asthma attack; >3 canisters short-acting beta agonist (SABA)/3 months; and asthma-specific Emergency Department or inpatient visits (ED/IP). Results: Non-Hispanic black, non-Hispanic multiple races, Puerto Rican, obese, Medicaid, poor, ≥2 non-asthma chronic comorbidities (CC), and family average CC ≥ 2 were associated with higher odds of having asthma. The following had significantly higher odds ratios (OR) of excessive SABA use compared to non-Hispanic whites [OR; CI; p < 0.05]: Puerto Rican (3.8; 2.1-6.9), Mexican (3.6; 2.0-6.4), Central/South American (3.0; 1.2-7.7), Hispanic-other (3.1; 1.1-9.0), non-Hispanic black (2.5; 1.6-3.9), and non-Hispanic Asian (4.0; 1.7-9.2). SABA OR were also significant for Spanish spoken at home (2.5; 1.6-3.8), obese (2.1; 1.3-3.3), Medicaid (2.9; 2.0-4.1), no medical insurance (2.1; 1.1-4.1), no prescription insurance (2.5; 1.8-3.5), poor (2.8; 1.7-4.7), CC ≥ 2 (2.1; 1.6-2.8), parent-without high-school degree (2.5; 1.8-3.6), parent-SF-12 Physical Component Scale <50 (1.6; 1.2-2.1) and Mental Component Scale <50 (1.5; 1.1-2.0). Significant differences also existed across subgroups for ED/IP visits. Conclusions: There are disparities in asthma control and prevalence among certain populations in the U.S. These results provide national data on disparities in several indicators of poor asthma control beyond the standard race/ethnicity groupings.

The national burden of poorly controlled asthma, school absence and parental work loss among school-aged children in the United States

OBJECTIVE

The degree of poorly controlled asthma and its association with missed school days and parental missed work days is not well understood.

METHODS

This was a retrospective analysis of missed school days and missed work days for school-aged children (SAC; aged 6-17) and their caregivers in the nationally representative 2007-2013 Medical Expenditure Panel Survey (MEPS). Indicators of poor asthma control included: exacerbation in previous 12 months; use of >3 canisters of short-acting beta agonist (SABA) in 3 months; and annual asthma-specific (AS) Emergency Department (ED) or inpatient (IP) visits. Negative binomial regression was used for missed school days, and a Heckman two-step selection model was used for missed work days. All analyses controlled for sociodemographics and other covariates.

RESULTS

There were 44,320 SAC in MEPS, of whom 5,890 had asthma. SAC with asthma and an indicator of poor control missed more school days than SAC without asthma: exacerbation (1.8 times more; p < 0.001); >3 canisters SABA (2.7 times more; p < 0.001) and ED/IP visit (3.8 times more; p < 0.001). The parents/caregivers of SAC with asthma and an exacerbation missed 1.2 times more work days (p < 0.05), while those with SAC with asthma and an ED/IP visit missed 1.8 times more work days (p < 0.01) than the parents of SAC without asthma.

CONCLUSIONS

This study provides evidence of the significant national burden of poorly controlled asthma due to missed school and work days in the United States. More effective and creative asthma management strategies, with collaboration across clinical, community and school-based outreach, may help address this burden.

Predictors of psychological adjustment in school-age children infected with HIV

OBJECTIVE

To assess for significant differences in psychological functioning between HIV-infected children and a demographically matched healthy control group and to examine the utility of applying a stress and coping model to children with HIV disease.

METHODS

Participants included HIV-infected children (ages 6-16) and their caregivers (n = 36) and a control group of healthy children and their caregivers (n = 32). During routine clinic visits, children completed measures of psychological adjustment, health locus of control, and coping style, and caregivers completed measures of their own and their child's psychological adjustment.

RESULTS

Caregiver-reported and child self-reported psychological adjustment scores did not significantly differ between the HIV and control groups, with the exception of significantly more internalizing behavior problems reported in the control group. Hierarchical multiple regression analyses revealed that the stress and coping model accounted for 36% of the variance in HIV-infected children's self-reported psychological adjustment. In addition, child age and coping style were significant predictors of child self-reported psychological adjustment, but not of caregiver-reported child adjustment.

CONCLUSIONS

Approximately 25% of children with HIV disease exhibited clinically significant emotional or behavioral problems; however, even higher rates of psychological adjustment problems were found in healthy children. Children with HIV disease who have not been told their diagnosis and children who endorse more emotion-focused coping strategies tend to exhibit more psychological adjustment problems.

New treatments and the future role of immunotherapy: anti-IgE

OBJECTIVE

The review outlines an overview of anti-IgE, along with a description of the production and mechanism of action of the finished molecule. The immunologic effect of the drug and the drug complexes are detailed, and proof of efficacy is offered. The review also speculates about the role of anti-IgE in clinical use, along with potential future therapies, including gene substitution and genetic alteration.

DATA SOURCES

The author reviewed literature studying IgE and anti-IgE antibody.

STUDY SELECTION

The expert opinion of the author was used to select relevant data.

RESULTS

The injection of anti-IgE results in four proven reactions: free antibody is bound; not bound antibody is not dislodged to any degree; plasma B cell production of IgE drops; and high-affinity Fc epsilon RI and low-affinity Fc epsilon RII on mast cells and basophils are downregulated.

CONCLUSIONS

Based on observation of clinical reaction, anti-IgE is truly immunotherapy. Current opinion among clinical investigators about the impact of the impending approval of this new drug is that it will not replace standard immunotherapy. How it will fit into the armamentarium of physicians dealing with allergic disease, and protocols for its use, are still being debated.

Separation of alpha-adrenergic and imidazoline/guanidinium receptive sites (IGRS) activity in a series of imidazoline analogues of cirazoline

To characterize the structure-activity relationship between alpha 1-adrenergic receptors and the family of imidazoline/guanidinium receptive sites (IGRS), we synthesized and characterized a series of analogues of cirazoline, an imidazoline with high affinity for alpha 1-adrenergic receptors and IGRS. Analysis of potency, affinity and efficacy of the synthesized molecules indicate different structure-activity relationships for IGRS and alpha-adrenergic receptors. Cirazoline exhibits a 25-fold higher affinity for IGRS (pKi 7.9) than for alpha 1-adrenergic receptors. Replacement of the cyclopropyl ring with an isopropoxy group resulted in a molecule that was 20-fold more selective for alpha 1-adrenergic receptors than for IGRS, i.e. a 500-fold increase in selectivity relative to cirazoline. The unsubstituted derivative 3 and the methyl and allyl substituted analogues 4 and 12 are of particular interest: compounds 3 and 4 recognize IGRS with high affinity (pKi 7.83 and 8.17) and high selectivity (398 and 123) with respect to the alpha 1-adrenergic receptor; compound 12 also recognizes IGRS with high affinity (pKi 8.08) and high selectivity (228 and 138) with respect to the alpha 2B and alpha 2C-adrenergic receptor subtypes. Thanks to their IGRS selectivity, these compounds represent novel and valuable pharmacological tools for the characterization and elucidation of the physiological role of these novel sites.

Structural and ligand recognition properties of imidazoline binding proteins in tissues of rat and rabbit

Imidazoline/guanidinium receptive sites (IGRS) belong to a family of membrane proteins that selectively recognize certain pharmacologically active compounds with an imidazoline or a guanidinium moiety. The role of such proteins in the cellular responses elicited by these compounds is unclear, but two members of this protein family are identical to isoforms of monoamine oxidase, an enzyme involved in the metabolism of monamine neurotransmitters. To characterize the structural and ligand recognition properties of the imidazoline binding proteins, we used the photoaffinity adduct [125I]iodoazidophe-noxymethylimidazoline ([125I]AZIPI) to label their ligand binding subunits in selected target tissues (kidney, pancreatic B cells, liver, and salivary gland). Photoaffinity labeling of membrane preparations or subcellular particulate fractions from various rat, rabbit, or hamster tissues indicated two labeled peptides of M(r) approximately 55,000 and approximately 61,000, the relative tissue distribution of which mirrored the expression of the A or B isoforms of monoamine oxidase. The ligand binding subunit of imidazoline binding proteins was identified on two peptides of M(r) approximately 55,000 and approximately 61,000 in rat and rabbit kidney, rat liver, rabbit salivary gland, and the pancreatic B cell line RIN-5AH, whereas only an M(r) approximately 61,000 peptide was observed in rat salivary gland and the hamster pancreatic B cell line HIT-T15. Saturation labeling experiments indicated that [125I]AZIPI exhibited similar affinity (Kd approximately 2-3 nM) for both the M(r) approximately 55,000 and approximately 61,000 peptides. However, competitive inhibition of photolabeling indicated that the two peptides were distinguished by their affinity for the guanidinium guanabenz or their interaction with potassium. Although some types of imidazoline binding sites are located on the enzyme monoamine oxidase, the nonisoform selective enzyme inhibitor pargyline did not alter photoaffinity labeling of either the M(r) approximately 55,000 or approximately 61,000 peptide, indicating that imidazolines/guanidiniums and active site inhibitors of monoamine oxidase interact with different domains on the enzyme. In rat kidney and liver, an additional photolabeled peptide of M(r) approximately 25,000 was observed, and its ligand recognition profile was distinct from the M(r) approximately 55,000 and approximately 61,000 species. In contrast with the mitochondrial location of the larger peptides, subcellular fractionation of liver homogenates indicated that the M(r) approximately 25,000 localized to the plasma membrane.

Use of high affinity, radioiodinated probes for identification of imidazoline/guanidinium receptive sites

Various pharmacologically active compounds with an imidazoline or guanidinium moiety are recognized by membrane bound proteins that appear structurally and functionally distinct from known hormone receptors. Such entities are termed imidazoline binding sites, I receptors, or imidazoline/guanidinium receptive sites (IGRS). To facilitate the identification and structural analysis of IGRS, we developed functionalized molecular probes exhibiting high affinity and selectivity for IGRS. The molecular probes are structurally related to cirazoline, and imidazoline that exhibits high affinity for IGRS in both central and peripheral tissues. The parent molecule 2-[3-aminophenoxy]methyl imidazoline (125I-AMIPI), which was used to identify IGRS in brain and peripheral tissues. 125I-AMIPI was converted to the photosensitive arylazide derivative (125I-AMIPI) and used to identify the M(r) of the ligand binding subunit of IGRS in various tissues including brain, pancreas, kidney, and liver. The results of these studies indicate that there are multiple binding proteins for these molecules that differ in their apparent molecular weight, tissue distribution, intratissue location, and ligand recognition properties.

Who is dying of asthma and why?

Recognition of the high rates of mortality from asthma over the past 20 years has spurred greater efforts to prevent death from this potentially controllable pulmonary process. Some suggest that inadequate assessment and delayed treatment account for this epidemic of asthma fatalities. Both the natural progression of this condition and the risk factors are discussed. Once patients at greatest risk have been identified and the pattern of episodes has been analyzed, clinicians can carry out "reversibility trials" using a variety of management techniques to optimize lung function. This program will allow an appropriate and individualized treatment plan to be formulated, with steps taken to ensure compliance and to carry out diligent follow-up.

Effect of hypoxia on laryngeal reflex apnea--implications for sudden infant death

Apnea was elicited by the application of chemical stimuli to the laryngeal region of 25 piglets from 1 to 70 days of age. Animals were tested under normoxic and hypoxic (Flo2 10%) conditions with water and solutions of graded acid and salt concentration. The chemoreflex was found to diminish with postnatal age. Fatal apneic episodes were confined to animals less than 3 weeks of age. Hypoxia consistently augmented the reflex, and in some cases elicited fatal apnea in animals that had survived similar stimulation under normoxic conditions. A direct relationship was also found between the strength of stimulus and respiratory response. Apnea increased with diminishing NaCl concentration or pH. The reflex was abolished by bilateral section of the superior laryngeal nerves. Fatal apnea elicited by laryngeal chemo-stimulation under the circumstance of hypoxia may provide further insight into the enigma of sudden infant death.