Trends in antithrombotic therapy for atrial fibrillation: Data from the Veterans Health Administration Health System

Long duration of atrial high-rate episode is more favorable in predicting ischemic stroke than high CHA2 DS2 -VASc score

OBJECTIVE

This study aimed to explore the roles of duration and burden of atrial high-rate episode (AHRE) on ischemic stroke in patients with pacemaker implantation.

METHODS

Patients with pacemaker implantation for bradycardia from 2013 to 2017 were consecutively enrolled. Data such as gender, age, combined diseases, type of AF, left atrial size, left ventricular size, left ventricular ejection fraction, CHA2 DS2 -VASc score, and anticoagulants were collected. The burden and duration of AHRE based on different interval partition were also recorded in detail to evaluate the impacts on ischemic stroke. Cox regression analysis with time-dependent covariates was conducted.

RESULTS

A total of 220 patients with AHRE were enrolled. The average follow-up time was 48.42 ± 17.20 months. Univariate regression analysis showed that diabetes (p = .024), high CHA2 DS2 -VASc score (≥ 2) (p = .021), long mean AHRE burden (p = .011), long maximal AHRE burden (p = .015), long AHRE duration lasting≥48 h (p = .001) or 24 h (p = .001) or 12 h (p = .005) were prone to ischemic stroke. Further multivariate regression analysis showed that long duration of AHRE (≥48 h) (HR 10.77; 95% CI 3.22-55.12; p = .030) were significantly correlated with stroke in patients with paroxysmal AF. There was no significant correlation between the type of AF and stroke (p = .927).

CONCLUSION

The longer duration of AHRE (≥48 h) was more favorable in predicting ischemic stroke than high CHA2 DS2 -VASc score (≥2).

Elective Hand Surgery and Antithrombotic Use in Veterans

Background

Patients undergoing plastic surgery have traditionally been instructed to avoid anticoagulants and antiplatelets during the perioperative period to avoid bleeding that could lead to painful hematomas, skin necrosis, unplanned procedures, and blood transfusions. Many veterans are currently prescribed anticoagulants for prevention of life- and limb-threatening embolic and thrombotic events. In early 2015, the plastic surgery service began to instruct patients undergoing elective hand surgery to stay on their prescription anticoagulant perioperatively. The objective of this study was to determine the postoperative bleeding complication rate, if any, over a 7.5-year period in patients who did not interrupt their prescription anticoagulants.

Methods

Health records at the Malcom Randall Veterans Affairs Medical Center in Gainesville, Florida, were queried for all plastic surgery cases performed from January 1, 2015, through June 30, 2022. Elective hand cases were identified based on the operation description and included carpal tunnel decompression (endo and open), cubital tunnel decompression (in situ), trigger finger release, trapeziectomy, small-joint fusion, neurectomy, elective amputations, and benign neoplasm removals. Patient history and physicals notes were reviewed for mention of a prescription anticoagulant on their medication list and for instructions to not discontinue blood thinner use. The postoperative notes were reviewed for up to 30 days to look for evidence of postoperative bleeding complications.

Results

One hundred seventy-eight patients were identified for maintaining prescription blood thinners during their elective hand surgery. There was 1 major complication (0.6%) when a patient had to return to surgery for emergent control of bleeding. This was an in situ cubital tunnel release on clopidogrel and aspirin. There were 4 minor bleeding complications (2.2%) that were treated in the clinic with compression, wound care, or expedited follow-up for reassurance.

Conclusions

Continuing prescription anticoagulants and antiplatelets during the perioperative period for elective hand surgery is a safe practice with an acceptably low local complication rate.

Prescribing Trends of Oral Anticoagulants in US Patients With Cirrhosis and Nonvalvular Atrial Fibrillation

Background Many patients with cirrhosis have concurrent nonvalvular atrial fibrillation (NVAF). Data are lacking regarding recent oral anticoagulant (OAC) usage trends among US patients with cirrhosis and NVAF. Methods and Results Using MarketScan claims data (2012-2019), we identified patients with cirrhosis and NVAF eligible for OACs (CHA2DS2-VASc score ≥2 [men] or ≥3 [women]). We calculated the yearly proportion of patients prescribed a direct OAC (DOAC), warfarin, or no OAC. We stratified by high-risk features (decompensated cirrhosis, thrombocytopenia, coagulopathy, chronic kidney disease, or end-stage renal disease). Among 32 487 patients (mean age=71.6 years, 38.5% women, 15.1% with decompensated cirrhosis, mean CHA2DS2-VASc=4.2), 44.6% used OACs within 180 days of NVAF diagnosis, including DOACs (20.2%) or warfarin (24.4%). Compared with OAC nonusers, OAC users were less likely to have decompensated cirrhosis (18.6% versus 10.7%), thrombocytopenia (19.5% versus 12.5%), or chronic kidney disease/end-stage renal disease (15.5% versus 14.0%). Between 2012 and 2019, warfarin use decreased by 21.0% (32.0% to 11.0%), whereas DOAC use increased by 30.6% (7.4% to 38.0%), and among all DOACs between 2012 and 2019, apixaban was the most commonly prescribed (46.1%). Warfarin use decreased and DOAC use increased in all subgroups, including in compensated and decompensated cirrhosis, thrombocytopenia, coagulopathy, chronic kidney disease/end-stage renal disease, and across CHA2DS2-VASc categories. Among OAC users (2012-2019), DOAC use increased by 58.9% (18.7% to 77.6%). Among DOAC users, the greatest proportional increase was with apixaban (61.2%; P<0.001). Conclusions Among US patients with cirrhosis and NVAF, DOAC use has increased substantially and surpassed warfarin, including in decompensated cirrhosis. Nevertheless, >55% of patients remain untreated, underscoring the need for clearer treatment guidance.

Association of Race and Ethnicity and Anticoagulation in Patients with Atrial Fibrillation Dually Enrolled in VA and Medicare: Effects of Medicare Part D on Prescribing Disparities

Background: Racial and ethnic disparities in anticoagulation exist in atrial fibrillation (AF) management in Medicare and the Veterans Health Administration (VA), but the influence of dual VA and Medicare enrollment is unclear. We compared anticoagulant initiation by race and ethnicity in dually enrolled patients and assessed the role of Medicare Part D enrollment on anticoagulation disparities. Methods: We identified patients with incident AF (2014-2018) dually enrolled in VA and Medicare. We assessed any anticoagulant initiation (warfarin or direct-acting oral anticoagulants, DOACs) within 90 days of AF diagnosis and DOAC use among anticoagulant initiators. We modeled anticoagulant initiation, adjusting for patient, provider, and facility factors, including main effects for race and ethnicity and Medicare Part D enrollment and an interaction term for these variables. Results: In 43,789 patients, 8.9% were Black, 3.6% Hispanic, and 87.5% White; 10.9% participated in Medicare Part D. Overall, 29,680 (67.8%) patients initiated any anticoagulant, of which 17,568 (59.2%) initiated DOACs. Lower proportions of Black (65.2%) than Hispanic (67.6%) or White (68.0%) patients initiated any anticoagulant (p= 0.001), and lower proportions of Black (56.3%) and Hispanic (55.9%) than White (59.6%) patients (p=0.001) initiated DOACs. Compared to White patients, Black patients had significantly lower initiation of any anticoagulant, adjusted odds ratio (aOR) 0.89; 95% CI 0.82-0.97. The aORs for DOAC initiation were significantly lower for Black (0.72; 95% CI, 0.65-0.81) and Hispanic (0.84; 95% CI, 0.70-1.00) than White patients.The interaction between race and ethnicity and Medicare Part D enrollment was non-significant for any anticoagulant (p=0.99) and DOAC (p=0.27) therapies. Conclusions: In dually enrolled VA and Medicare patients with AF, Black patients were less likely to initiate any anticoagulant and Black and Hispanic patients were less likely to initiate DOACs. Medicare Part D enrollment did not moderate the associations between race and ethnicity and anticoagulant therapies.

Trends in Atrial Fibrillation Incidence Rates Within an Integrated Health Care Delivery System, 2006 to 2018

IMPORTANCE

Atrial fibrillation (AF) is the most common cardiac arrhythmia, and multiple studies have reported increasing AF incidence rates over time, although the underlying explanations remain unclear.

OBJECTIVES

To estimate AF incidence rates from 2006 to 2018 in a community-based setting and to investigate possible explanations for increasing AF by evaluating the changing features of incident AF cases and the pool of patients at risk for AF over time.

DESIGN, SETTING, AND PARTICIPANTS

This cohort study included 500 684 patients who received primary care and other health care services for more than 2 years through a single integrated health care delivery network in Pennsylvania. Data collection was conducted from January 2003 to December 2018. The base study population had no documentation of AF in the electronic medical record for at least 2 years prior to baseline. Data analysis was conducted from May to December 2019.

MAIN OUTCOMES AND MEASURES

Incident AF cases were identified through diagnostic codes recorded at inpatient or outpatient encounters. Age- and sex-adjusted AF incidence rates were estimated by calendar year from 2006 to 2018 both overall and across subgroups, including according to diagnostic setting (inpatient vs outpatient) and priority (primary vs secondary diagnosis).

RESULTS

Among 514 293 patients meeting criteria for the base study population, the mean (SD) age at baseline was 47 (18) years and 282 103 (54.9%) were women; 13 609 (2.6%) met AF diagnostic criteria on or prior to the baseline date and were excluded. Among 500 684 patients free of AF at baseline, standardized AF incidence rates from 2006 to 2018 increased from 4.74 (95% CI, 4.58-4.90) to 6.82 (95% CI, 6.65-7.00) cases per 1000 person-years, increasing significantly over time (P < .001). Incidence rates increased in all age and sex subgroups, although absolute rate increases were largest among those aged 85 years or older. The fraction of incident AF cases among individuals aged 85 years or older increased from 135 of 1075 (12.6%) in 2006 to 451 of 2427 (18.6%) in 2017. Patients with incident AF were more likely over time to have high body mass index (1351 of 3389 patients [39.9%] in 2006-2008 vs 4504 of 9214 [48.9%] in 2015-2018; P < .001), hypertension (2764 [81.6%] in 2006-2008 vs 7937 [86.1%] in 2015-2018; P < .001), and ischemic stroke (328 [9.7%] in 2006-2008 vs 1455 [15.8%] in 2015-2018; P < .001), but less likely to have coronary artery disease (1533 [45.2%] in 2006-2008 vs 3810 [41.4%] in 2015-2018; P < .001). Among 22 077 new cases of AF, 9146 (41.4%) were diagnosed as inpatients and 5731 (26.0%) as the primary diagnosis. Incidence rates of AF increased significantly in all diagnostic setting and priority pairings (eg, inpatient, primary: rate ratio, 1.07; 95% CI, 1.06-1.08; P < .001). Among patients at risk for AF, high BMI and hypertension increased over time (BMI: 71 433 of 198 245 [36.0%] in 2007 to 130 218 of 282 270 [46.1%] in 2017; hypertension: 79 977 [40.3%] in 2007 to 134 404 [47.6%] in 2017). Documentation of short-term ECG increased over time (23 297 of 207 349 [11.2%] in 2008 to 45 027 [16.0%] in 2017); however, long-term ECG monitoring showed no change (1871 [0.9%] in 2007 to 4036 [1.4%] in 2017).

CONCLUSIONS AND RELEVANCE

In this community-based study, AF incidence rates increased significantly during the study period. Concurrent increases were observed in AF risk factors in the at-risk population and short-term ECG use.

Guideline-concordant initiation of oral anticoagulant therapy for stroke prevention in older veterans with atrial fibrillation eligible for Medicare Part D

OBJECTIVE

To characterize the rate of guideline-concordant initiation of oral anticoagulation (OAC) among elderly Veterans with atrial fibrillation (AF) and high stroke risk.

DATA SOURCES/STUDY SETTING

Veterans Health Administration (VHA) Corporate Data Warehouse (CDW) linked with Medicare claims 2011-2015.

STUDY DESIGN

We identified 6619 elderly, high stroke-risk patients with a new episode of AF initially diagnosed in the VHA during fiscal years 2012-2015. We used logistic regression to estimate marginal effects of associations between patient characteristics and OAC initiation within 90 days of the first AF episode.

DATA EXTRACTION METHODS

We identified OACs using generic drug names. We calculated comorbidities and risk scores using diagnosis codes from 1 year of baseline data.

PRINCIPAL FINDINGS

Overall, 66.5% of Medicare-eligible Veterans with AF at high risk of stroke initiated an OAC within 90 days. We found lower initiation rates for patients enrolled in Medicare Part D and those ineligible for drug co-payment subsidies. OAC initiation rates increased during the study among VHA-reliant patients but not among dual VHA-Part D enrollees.

CONCLUSIONS

One-third of elderly Veterans at risk of stroke are not receiving recommended therapy. Increased coordination between Medicare and VHA providers may lead to improvements in anticoagulation quality and stroke prevention.

Real world adherence to oral anticoagulant in non-valvular atrial fibrillation patients in China

BACKGROUND AND OBJECTIVE

Adherence to oral anticoagulants is crucial for the prevention of ischemic stroke in atrial fibrillation patients; however, evidence of oral-anticoagulant adherence from developing countries is still lacking. This study aimed to evaluate the current situation and predictors of oral-anticoagulant adherence in non-valvular atrial fibrillation (NVAF) patients in China.

METHODS

Records of NVAF patients were obtained from a regional claims database. Both initiation and adherence to oral anticoagulants were calculated from linked records. Factors of oral-anticoagulant initiation were identified using Cox regression.

RESULTS

Among 33,463 NVAF patients, only 13.9% initialized warfarin treatment after the indexed hospital visit. Stratified by CHA₂DS₂-VASc scores, 20.9% of patients in the low-risk group were on warfarin, followed by 15.3% and 10.7% from the middle and high-risk groups, respectively. Among patients who initialized warfarin, only 40.4% filled the first repeat prescription within 3 months. Concurrent statin use, hypertension and heart failure were associated with higher warfarin initiation rate. Factors such as age above 75, female sex, manufacture workers, discharge from the primary-care center, antiplatelet use, and diabetes, ischemic and hemorrhagic stroke were associated with lower rate of warfarin initiation. Additionally, initiating warfarin treatment reduced risk of ischemic stroke in middle and high-risk patients.

CONCLUSION

Oral anticoagulation was significantly under-used in NVAF patients in China. Age, sex, concurrent drug usage, and disease history were associated factors. Improving warfarin adherence was promising to reduce ischemic stroke risk of NVAF patients.

Contemporary Trends in Oral Anticoagulant Prescription in Atrial Fibrillation Patients at Low to Moderate Risk of Stroke After Guideline-Recommended Change in Use of the CHADS2 to the CHA2DS2-VASc Score for Thromboembolic Risk Assessment: Analysis From the National Cardiovascular Data Registry's Outpatient Practice Innovation and Clinical Excellence Atrial Fibrillation Registry

BACKGROUND

Use of the CHA₂DS₂-VASc score instead of the CHADS₂ score for thromboembolic risk stratification and initiation of oral anticoagulation (OAC) was recommended in the 2014 American Heart Association/American College of Cardiology/Heart Rhythm Society atrial fibrillation (AF) guidelines. We sought to define the proportion of patients with AF qualifying for and receiving OAC in contemporary practice by applying the CHA₂DS₂-VASc score to patients with a low CHADS₂ score.

METHODS AND RESULTS

Among patients with AF enrolled in the American College of Cardiology National Cardiovascular Data Registry's outpatient Practice Innovation and Clinical Excellence registry (2008-2014) CHADS₂ score of 0 or 1, we calculated the impact of adoption of the CHA₂DS₂-VASc score on the proportion of patients with an indication for OAC. We examined trends in prescription of OAC overall, direct OAC (dabigatran/rivaroxaban/apixaban), and multivariable associations between clinical characteristics and OAC use. Of 346 068 patients with AF aged 65±12 years, 61% were men and 65% were white. In total, 24% of those with CHADS₂=0 and 81% of those with a CHADS₂=1 were reclassified as having a definite indication for OAC (CHA₂DS₂-VASc score ≥2). OAC use increased from 37% to 48% during the study period, and direct OAC use increased from 5% to 30%. Increasing CHA₂DS₂-VASc score (odds ratio, 2.07; 95% confidence interval, 1.97-2.19 for score of 4 versus 0) and rhythm control strategy (odds ratio, 1.34; 95% confidence interval, 1.30-1.39) were associated with increased OAC use.

CONCLUSIONS

Adoption of the CHA₂DS₂-VASc score reclassifies 64.5% of patients with AF with low CHADS₂ scores into a class I indication for OAC prescription. Overall OAC prescription increased between 2011 and 2014.