Impact of Atrial Fibrillation Burden on Health Care Costs and Utilization.

BACKGROUND: Integrating patient-specific cardiac implantable electronic device (CIED)-detected atrial fibrillation (AF) burden with measures of health care cost and utilization allows for an accurate assessment of the AF-related impact on health care use. OBJECTIVES: The goal of this study was to assess the incremental cost of device-recognized AF vs no AF; compare relative costs of paroxysmal atrial fibrillation (pAF), persistent atrial fibrillation (PeAF), and permanent atrial fibrillation (PermAF) AF; and evaluate rates and sources of health care utilization between cohorts. METHODS: Using the de-identified Optum Clinformatics U.S. claims database (2015-2020) linked with the Medtronic CareLink database, CIED patients were identified who transmitted data ≥6 months postimplantation. Annualized per-patient costs in follow-up were analyzed from insurance claims and adjusted to 2020 U.S. dollars. Costs and rates of health care utilization were compared between patients with no AF and those with device-recognized pAF, PeAF, and PermAF. Analyses were adjusted for geographical region, insurance type, CHA2DS2-VASc score, and implantation year. RESULTS: Of 21,391 patients (mean age 72.9 ± 10.9 years; 56.3% male) analyzed, 7,798 (36.5%) had device-recognized AF. The incremental annualized increased cost in those with AF was $12,789 ± $161,749 per patient, driven by increased rates of health care encounters, adverse clinical events associated with AF, and AF-specific interventions. Among those with AF, PeAF was associated with the highest cost, driven by increased rates of inpatient and outpatient hospitalization encounters, heart failure hospitalizations, and AF-specific interventions. CONCLUSIONS: Presence of device-recognized AF was associated with increased health care cost. Among those with AF, patients with PeAF had the highest health care costs. Mechanisms for cost differentials include both disease-specific consequences and physician-directed interventions.

Promises and Perils of Consumer Mobile Technologies in Cardiovascular Care: JACC Scientific Statement.

Direct-to-consumer (D2C) wearables are becoming increasingly popular in cardiovascular health management because of their affordability and capability to capture diverse health data. Wearables may enable continuous health care provider-patient partnerships and reduce the volume of episodic clinic-based care (thereby reducing health care costs). However, challenges arise from the unregulated use of these devices, including questionable data reliability, potential misinterpretation of information, unintended psychological impacts, and an influx of clinically nonactionable data that may overburden the health care system. Further, these technologies could exacerbate, rather than mitigate, health disparities. Experience with wearables in atrial fibrillation underscores these challenges. The prevalent use of D2C wearables necessitates a collaborative approach among stakeholders to ensure effective integration into cardiovascular care. Wearables are heralding innovative disease screening, diagnosis, and management paradigms, expanding therapeutic avenues, and anchoring personalized medicine.

Comparative effectiveness and healthcare utilization for ambulatory cardiac monitoring strategies in Medicare beneficiaries.

BACKGROUND: Objective data comparing the diagnostic performance of different ambulatory cardiac monitors (ACMs) are lacking. OBJECTIVES: To assess variation in monitoring strategy, clinical outcomes and healthcare utilization in patients undergoing ambulatory monitoring without a pre-existing arrhythmia diagnosis. METHODS: Using the full sample (100%) of Medicare claims data, we performed a retrospective cohort study of diagnostic-naïve patients who received first-time ACM in 2017 to 2018 and evaluated arrhythmia encounter diagnosis at 3-months, repeat ACM testing at 6 months, all-cause 90-day emergency department (ED) and inpatient utilization, and cost of different strategies: Holter; long-term continuous monitor (LTCM); non-continuous, event-based external ambulatory event monitor (AEM); and mobile cardiac telemetry (MCT). We secondarily performed a device-specific analysis by manufacturer, identified from unique claim modifier codes. RESULTS: ACMs were used in 287,789 patients (AEM = 10.3%; Holter = 53.8%; LTCM = 13.3%; MCT = 22.5%). Device-specific analysis showed that compared to Holter, AEM, MCT, or other LTCM manufacturers, a specific LTCM (ZioⓇ XT 14-day patch, iRhythm Technologies, San Francisco, CA) had the highest adjusted odds of diagnosis and lowest adjusted odds of ACM retesting. Findings were consistent for specific arrhythmia diagnoses of ventricular tachycardia, atrioventricular block, and paroxysmal atrial fibrillation. As a category, LTCM was associated with the lowest 1-year incremental health care expenditures (mean Δ$10,159), followed by Holter ($10,755), AEM ($11,462), and MCT ($12,532). CONCLUSIONS: There was large variation in diagnostic monitoring strategy. A specific LTCM was associated with the highest adjusted odds of a new arrhythmia diagnosis and lowest adjusted odds of repeat ACM testing. LTCM as a category had the lowest incremental acute care utilization. Different monitoring strategies may produce different results with respect to diagnosis and care.

Comparison of Biplane Area-Length Method and 3D Volume Quantification by Using Cardiac MRI for Assessment of Left Atrial Volume in Atrial Fibrillation.

Purpose: To compare maximum left atrial (LA) volume (LAV) from the routinely used biplane area-length (BAL) method with three-dimensional (3D)-based volumetry from late gadolinium-enhanced MRI (3D LGE MRI) and contrast-enhanced MR angiography (3D CE-MRA) in patients with atrial fibrillation (AF). Materials and Methods: Sixty-four patients with AF (mean age, 63 years ± 9 [SD]; 40 male patients) were retrospectively included from a prospective cohort acquired between October 2018 and February 2021. All patients underwent a research MRI examination that included standard two- and four-chamber cine acquisitions, 3D CE-MRA, and 3D LGE MRI performed prior to the atrial kick. Contour delineation on cine imaging and LA 3D segmentations were performed by a radiologist. Maximum LAV (BALmax) was extracted from the BAL volume-time curve and compared with LAV from 3D CE-MRA and 3D LGE MRI. The Kruskal-Wallis test was performed, followed by the Dunn post hoc test and Bland-Altman analyses. Interobserver variability was assessed in 10 patients. Results: BALmax underestimated LAV compared with 3D CE-MRA (bias: -23.5 mL ± 46.2, P < .001) and 3D LGE MRI (bias: -31.3 mL ± 58.3, P < .001), whereas 3D LGE MRI volumes showed no evidence of a difference from 3D CE-MRA (bias: 7.8 mL ± 45.7, P = .38). Interobserver variability yielded excellent agreement for each method (intraclass correlation coefficient, 0.96-0.98). Conclusion: BALmax underestimated LAV in patients with AF compared with 3D LGE MRI and 3D CE-MRA, suggesting that the geometric assumption of an ellipsoidal LA shape in BAL does not reflect LA geometry in patients with AF.Keywords: Left Atrial Volume, Biplane Area-Length, Late Gadolinium-enhanced 3D MRI, Contrast-enhanced 3D MR Angiography, Atrial Fibrillation Supplemental material is available for this article. © RSNA, 2023.

Assessment of Beat-To-Beat Variability in Left Atrial Hemodynamics Using Real Time Phase Contrast MRI in Patients With Atrial Fibrillation.

BACKGROUND: Hemodynamic assessment of left atrial (LA) flow using phase contrast MRI provides insight into thromboembolic risk in atrial fibrillation (AF). However, conventional flow imaging techniques are averaged over many heartbeats. PURPOSE: To evaluate beat-to-beat variability and LA hemodynamics in patients with AF using real time phase contrast (RTPC) MRI. STUDY TYPE: Prospective. SUBJECTS: Thirty-five patients with history of AF (68 ± 10 years, nine female), 10 healthy controls (57 ± 19 years, four female). FIELD STRENGTH/SEQUENCE: 5T, 2D RTPC with through-plane velocity-encoded gradient echo sequence and 4D flow MRI with three-directional velocity-encoded gradient echo sequence. ASSESSMENT: RTPC was continuously acquired for a mid-LA slice in all subjects. 4D flow data were interpolated at the RTPC location and normally projected for comparison with RTPC. RR intervals extracted from RTPC were used to calculate heart rate variability (HRV = interquartile range over median × 100%). Patients were classified into low (<9.7%) and high (>9.7%) HRV groups. LA peak/mean velocity and stasis (%velocities < 5.8 cm/sec) were calculated from segmented 2D images. Variability in RTPC flow metrics was quantified by coefficient of variation (CV) over all cycles. STATISTICAL TESTS: Pearson's correlation coefficient (r), Bland-Altman analysis, Kruskal-Wallis test. A P value < 0.05 was considered statistically significant. RESULTS: RTPC and 4D flow measurements were strongly/significantly correlated for all hemodynamic parameters (R2  = 0.75-0.83) in controls. Twenty-four patients had low HRV (mean = 4 ± 2%) and 11 patients had high HRV (27 ± 9%). In patients, increased HRV was significantly correlated with CV of peak velocity (r = 0.67), mean velocity (r = 0.51), and stasis (r = 0.41). A stepwise decrease in peak/mean velocity and increase in stasis was observed when comparing controls vs. low HRV vs. high HRV groups. Mean velocity and stasis differences were significant for control vs. high HRV groups. CONCLUSIONS: RTPC may be suitable for assessing the impact of HRV on hemodynamics and provide insight for AF management in highly arrhythmic patients. EVIDENCE LEVEL: 1 TECHNICAL EFFICACY: Stage 2.

Digital Health and the Care of the Patient With Arrhythmia: What Every Electrophysiologist Needs to Know.

The field of cardiac electrophysiology has been on the cutting edge of advanced digital technologies for many years. More recently, medical device development through traditional clinical trials has been supplemented by direct to consumer products with advancement of wearables and health care apps. The rapid growth of innovation along with the mega-data generated has created challenges and opportunities. This review summarizes the regulatory landscape, applications to clinical practice, opportunities for virtual clinical trials, the use of artificial intelligence to streamline and interpret data, and integration into the electronic medical records and medical practice. Preparation of the new generation of physicians, guidance and promotion by professional societies, and advancement of research in the interpretation and application of big data and the impact of digital technologies on health outcomes will help to advance the adoption and the future of digital health care.

Racial Disparity in the Prescription of Anticoagulants and Risk of Stroke and Bleeding in Atrial Fibrillation Patients.

BACKGROUND: Oral anticoagulant (OAC) therapy is proven to be effective at reducing risk of stroke in patients with atrial fibrillation (AF). However, racial minorities with AF are less likely to be prescribed vitamin K anticoagulants (VKA). There is little information on the racial disparity in the prescription of the non-vitamin K oral anticoagulants (NOACs) and the associated risks of stroke and bleeding. METHODS: We used data from the Northwestern Medicine Enterprise Data Warehouse - a joint initiative across 11 Northwestern Medicine affiliated healthcare centers within metropolitan Chicago, Illinois. Newly diagnosed AF patients between Jan, 2011 and Dec, 2017 with CHA2DS2VASc (congestive heart failure, hypertension, age ≥75 years, diabetes, stroke/transient ischemic attack, vascular disease, age 65 to 74 years, female sex) score of 2 or more and no prior history of stroke or major bleeding were eligible. Logistic regression was used to examine differences in the prescription of any OAC and NOACs by race. Racial differences in the associations of NOACs prescription with incident stroke (a composite of ischemic and hemorrhagic stroke and cerebral embolism) and major bleeding were evaluated using Cox regression. RESULTS: Among 11,575 newly diagnosed AF patients with CHA2DS2VASc score of 2 or more, 48.7% (47.8-49.6) were on any OAC and among those 40.1% (38.8.3-41.4) received any NOACs. After adjusting for age, gender, income, insurance status, and stroke risk factors, the odds of receiving any OAC was .69 (95% CI: .58-.83) in blacks, .74 (.53-1.903) in Hispanics, and .75 (.58-.95) in Asians compared to whites. Among anticoagulated patients, blacks and Hispanics had significantly lower odds of receiving NOACs: .72 (.53-.97) and .53 (.29-.99), respectively. Use of NOACs, as compared to VKAs, was associated with significantly lower risk of stroke [.52(.31-.85)] and bleeding [.72(.54-.95)] in whites but not in non-whites [stroke: .71 (.22-2.31); bleeding .83(.43-1.57)] independent of other risk factors. CONCLUSIONS: Racial minorities with AF who are at risk of stroke were less likely to receive any OAC and NOACs specifically compared to whites even after accounting for insurance status, income, and stroke risk factors. Independent of other risk factors, use of NOACs as compared to VKA was associated with significantly lower risk of stroke and bleeding only in whites but not in non-whites.

Atrial fibrillation burden, progression, and the risk of death: a case-crossover analysis in patients with cardiac implantable electronic devices.

AIMS: Atrial fibrillation (AF) is associated with increased mortality, but the temporal relationship between AF burden (AFB) and death among patients with cardiac implanted electronic devices is unknown. We sought to characterize the timing and progression of AFB before death. METHODS AND RESULTS: Using Merlin.netTM remote monitoring (RM) data, we analysed weekly AFB in patients age ≥55 years implanted with dual-chamber pacemaker, implantable cardioverter-defibrillator, or cardiac resynchronization therapy devices whose death was verified in the Social Security Death Index and who had continuous RM from 1 year to 4 weeks preceding death. Atrial fibrillation burden was defined as amount of time per week atrial rate exceeded a set threshold of 180 b.p.m. Case-crossover analysis was used to compare the AFB at every week to 6 control weeks at the start of the year before death. There were 3131 patients meeting analysis criteria (age at death 76 ± 8 years, 70% men). Weekly increase in AFB >6 h was associated with increased odds of death, which was greatest at 4 weeks before death [odds ratio (OR) 2.30, 95% confidence interval (CI) 2.09-2.53; P < 0.001]. Atrial fibrillation progression week-to-week >24 h was associated with the greatest odds of death (OR 12.95, 95% 8.72-19.22; P < 0.001). A combination of AFB >6 h per week and activity <0.5 h per day was associated with an increased odds of death. CONCLUSION: In this large patient cohort, AFB progression accelerated in the weeks leading to death. Continuous monitoring of AFB may help identify device patients who may be at risk for adverse outcomes, including death.

Cost Effectiveness of Implantable Cardiac Monitor-Guided Intermittent Anticoagulation for Atrial Fibrillation: An Analysis of the REACT.COM Pilot Study.

INTRODUCTION: Anticoagulation guidelines for patients with atrial fibrillation (AF) disregard AF burden. A strategy of targeted anticoagulation with novel oral anticoagulants (NOACs) based on continuous rhythm assessment with an implantable cardiac monitor (ICM) has recently been explored. We evaluated the potential cost-effectiveness of this strategy versus projected outcomes with continuous anticoagulation. METHODS AND RESULTS: We developed a Markov model using data from the Rhythm Evaluation for AntiCoagulaTion With COntinuous Monitoring (REACT.COM) pilot study (N = 59) and prior NOAC trials to calculate the costs and quality-adjusted life years (QALYs) associated with ICM-guided intermittent anticoagulation for AF versus standard care during a 3-year time horizon. Health state utilities were estimated from the pilot study population using the SF-12. Costs were based on current Medicare reimbursement. Over 14 ± 4 months of follow-up, 18 of 59 patients had 35 AF episodes. The ICM-guided strategy resulted in a 94% reduction in anticoagulant use relative to continuous treatment. There were no strokes, 3 (5.1%) TIAs, 2 major bleeding events (on aspirin) and 3 minor bleeding events with the ICM-guided strategy. The projected total 3-year costs were $12,535 for the ICM-guided strategy versus $13,340 for continuous anticoagulation. Projected QALYs were 2.45 for both groups. CONCLUSION: Based on a pilot study, a strategy of ICM-guided anticoagulation with NOACs may be cost-saving relative to expected outcomes with continuous anticoagulation, with similar quality-adjusted survival. This strategy could be attractive from a health economic perspective if shown to be safe and effective in a rigorous clinical trial.

Gender differences in outcomes after surgical ablation of atrial fibrillation.

BACKGROUND: Gender disparities have been established in patients who have atrial fibrillation (AF), and in their outcomes after medical treatment for AF. This study evaluated differences in outcome by gender in patients who underwent surgical treatment for AF. METHODS: From April 2004 to December 2012, a total of 936 patients had surgical treatment for AF. Outcomes were analyzed by gender using propensity score-matching methods. RESULTS: Of the 936 subjects, 571 (61%) were men; women were older (aged 68.6 ± 11.3 vs 66.9 ± 11.9 years; P = .033), had more heart failure (44% vs 37%; P = .024), more mitral valve surgery (72% vs 50%; P < .001) and more tricuspid valve surgery (41% vs 18%; P < .001). Men underwent more coronary artery bypass surgery (37% vs 19%; P < .001) and aortic valve surgery (38% vs 31%; P = .029). Women had higher late stroke rate per 10 person-years (0.15 vs 0.07; P = .035), fewer catheter ablations (6.0% vs 9.8%; P = .017), and a trend toward fewer cardioversions for recurrent AF (15.7% vs 19.2%; P = .20). After propensity-score matching, late stroke rates per 10 person-years trended higher in women (0.12 vs 0.04; P = .13). No significant gender differences were found in overall survival (5-year survival: 78.8% in men, and 81.0% in women; P = .40) or freedom from AF without antiarrhythmic drugs at last follow-up (71.8% in men vs 73.6% in women, P = .59). CONCLUSIONS: Women sought surgery treatment at older ages and with more heart failure. No gender-based differences were found in stroke, overall survival, or procedure success, after propensity-score matching.

Targeted Anticoagulation for Atrial Fibrillation Guided by Continuous Rhythm Assessment With an Insertable Cardiac Monitor: The Rhythm Evaluation for Anticoagulation With Continuous Monitoring (REACT.COM) Pilot Study.

INTRODUCTION: Chronic anticoagulation is recommended for patients with AF and additional stroke risk factors, even during long periods of sinus rhythm. Continuous rhythm assessment with an insertable cardiac monitor (ICM) and use of rapid onset novel oral anticoagulants (NOACs) allow for targeted anticoagulation only around an AF episode, potentially reducing bleeding complications without compromising stroke risk. METHODS: This multicenter, single-arm study enrolled patients on NOAC with nonpermanent AF and CHADS2 score 1 or 2. After a 60-day run-in with no AF episodes ≥ 1 hour, NOACs were discontinued but reinitiated for 30 days following any AF episode ≥ 1 hour diagnosed through daily ICM transmissions. Major endpoints included time on NOAC, stroke, and bleeding. RESULTS: Among 59 enrollees, 75% were male, age 67 ± 8 years, 76% paroxysmal AF, 69% had prior AF ablation, and mean CHADS2 score 1.3 ± 0.5. Over 466 ± 131 mean days of follow-up there were 24,004 ICM transmissions with a compliance rate of 98.7%. A total of 35 AF episodes ≥ 1 hour occurred in 18 (31%) patients, resulting in a total time on NOAC of 1,472 days. This represents a 94% reduction in the time on NOAC compared to chronic anticoagulation. There were three traumatic bleeds (all on aspirin), three potential transient ischemic attacks (all on aspirin with CHADS2 score of 1), and no strokes or deaths. CONCLUSIONS: A targeted strategy of ICM-guided intermittent NOAC administration is feasible. A large-scale trial is necessary to evaluate the safety of this approach.

In vitro performance characteristics of reused ablation catheters.

BACKGROUND: Prior studies have found that there is a widespread practice of catheter reprocessing in cardiac electrophysiology laboratories. Effects of reprocessing of ablation catheters on temperature sensing and mechanical deflection are not fully known. METHODS: Twenty-four new and used ablation catheters were studied. Deviation of temperature sensing by catheters from the temperature of a heated saline bath was measured. The angle of deflection of digitally scanned catheters at 75% and 100% handle deflection was also measured. New and used catheters were compared with respect to their temperature sensing accuracy and deflection characteristics. RESULTS: Overall, there was 0.7 +/- 0.1 degrees C (mean +/- standard error) deviation of the sensed temperature from the bath temperature, with no significant difference between new and used catheters. Similarly, there was no significant difference in the angle of deflection between new (66.7 degrees +/- 6.2 degrees and 24.3 degrees +/- 6.8 degrees at 75% and 100% deflections, respectively) and used (59.6 degrees +/- 5.6 degrees and 28.7 degrees +/- 9.9 degrees at 75% and 100% deflections, respectively) catheters. The difference in the angle of deflection between matched new and used catheters was 18.9 degrees +/- 4.2 degrees and 10.9 degrees +/- 2.4 degrees at 75% and 100% deflections, respectively, with a relatively broad range (5.0 degrees -35.6 degrees and 0.4 degrees -19.0 degrees at 75% and 100% deflections, respectively). CONCLUSIONS: This study found no significant overall difference in temperature sensing accuracy and deflection angle of new and used ablation catheters. Nevertheless, individual differences in deflection characteristics between new and used catheters are occasionally seen and warrant screening of reprocessed catheters prior to their reuse.