Anticoagulant use for the prevention of stroke in patients with atrial fibrillation: findings from a multi-payer analysis

Primary care provider payment models and adherence to anticoagulation in patients with atrial fibrillation

BACKGROUND: Oral anticoagulation (OAC) is recommended for the prevention of stroke in atrial fibrillation (AF). However, only 50%-60% of AF patients in the United States are treated with OAC, and 60% of them adhere to OAC therapy over time. OBJECTIVES: To (1) compare adherent use of OAC between AF patients who received primary care from practices involved in shared-savings models and patients who received care from practices not involved in shared savings and (2) examine the trend of adherence to OAC over time. Because OAC can save downstream medical costs associated with averted stroke events, we hypothesized that OAC adherence would be higher among patients receiving care from practices involved in shared savings. METHODS: Using 2014-2019 claims data from a health insurer in western Pennsylvania, we identified 20,637 AF patients from 2015-2018. Patients were followed from the first AF diagnosis (index date) for 12 months or until disenrollment. We categorized patients according to the payment model of the practice from which they received primary care: shared savings (n = 8,844) and no shared savings (n = 11,793). The primary outcome was adherent use of OAC therapy, which was defined as having at least 80% of the followup period covered with OAC. Secondary outcomes included adherent use of direct oral anticoagulants (DOACs) and adherent use of warfarin. We constructed logistic regression models to assess the association between involvement in shared savings and adherent use of OAC, while controlling for demographics, clinical characteristics, and index year. RESULTS: 34% of patients in the shared-savings group adhered to OAC, compared with 32.7% in the no shared-savings group (P = 0.04). After adjustment, adherence was higher for the shared-savings group for OAC (adjusted odds ratio [aOR] = 1.07, 95% CI = 1.01-1.14) and warfarin (aOR = 1.11, 95% CI = 1.02-1.20) compared with the no shared-savings group. However, the odds of adherent use of DOACs did not statistically differ between shared savings and no shared savings (aOR = 0.99, 95% CI = 0.91-1.08). The odds of adherent OAC use increased over time: the aOR of adherent use of OAC was 1.21 (95% CI = 1.09-1.34) for index year 2016; 1.50 (95% CI = 1.36-1.67) for 2017; and 1.78 (95% CI 1.60-1.98) for 2018, all compared with 2015. CONCLUSIONS: Receipt of primary care from a practice involved in shared savings was associated with a higher adherent use of OAC and warfarin for patients with atrial fibrillation. Furthermore, adherent use of OAC improved over time for both treatment groups. Our research demonstrates that the alignment of financial incentives between providers and insurers may improve the use of therapies with downstream cost-saving potential. DISCLOSURES: This project was funded by the National Heart, Lung and Blood Institute (grant number K01HL142847). Hernandez has received consulting fees from Pfizer and BMS, outside of the submitted work. The other authors have nothing to disclose.

Joint Latent Class Analysis of Oral Anticoagulation Use and Risk of Stroke or Systemic Thromboembolism in Patients with Atrial Fibrillation

BACKGROUND

Oral anticoagulation (OAC) is recommended to reduce the risk of stroke or systemic thromboembolism (TE) in atrial fibrillation (AF). In this study, we applied novel joint latent class mixed models to identify heterogeneous patterns of trajectories of OAC use and determined how these trajectories are associated with risks of thromboembolic outcomes.

METHODS AND RESULTS

We used 2013-2016 claims data from a 5% random sample of Medicare beneficiaries, obtained from the Centers for Medicare and Medicaid Services. Our study sample included 16,399 patients newly diagnosed with AF in 2014-2015 who were followed for 12 months after the first AF diagnosis and filled at least one OAC prescription in this time period. OAC use was defined as the number of days covered with OACs every 30-day interval after the first AF diagnosis. We used a joint latent class mixed model to simultaneously evaluate the longitudinal patterns of OAC use and time to stroke or TE, while adjusting for age, race, CHAD2S2-VASc score and HAS-BLED score. Five classes of OAC use patterns were identified: late users (17.8%); late initiators (12.5%); early discontinuers (18.6%); late discontinuers (15.4%); and continuous users (35.6%). Compared with continuous users, the risk of stroke or TE was higher for participants in the late initiators (hazard ratio [HR] 1.73, 95% confidence interval [CI] 1.49-2.01) and late discontinuers (HR 1.23, 95% CI 1.04-1.45) classes.

CONCLUSION

Late initiators and late discontinuers had a higher risk of stroke or TE than continuous users. Early initiation and continuous OAC use is important in preventing stroke and TE among patients diagnosed with AF.

Non-warfarin oral anticoagulant copayments and adherence in atrial fibrillation: A population-based cohort study

BACKGROUND

In patients with atrial fibrillation, incomplete adherence to anticoagulants increases risk of stroke. Non-warfarin oral anticoagulants (NOACs) are expensive; we evaluated whether higher copayments are associated with lower NOAC adherence.

METHODS

Using a national claims database of commercially-insured patients, we performed a cohort study of patients with atrial fibrillation who newly initiated a NOAC from 2012 to 2018. Patients were stratified into low (<$35), medium ($35-$59), or high (≥$60) copayments and propensity-score weighted based on demographics, insurance characteristics, comorbidities, prior health care utilization, calendar year, and the NOAC received. Follow-up was 1 year, with censoring for switching to a different anticoagulant, undergoing an ablation procedure, disenrolling from the insurance plan, or death. The primary outcome was adherence, measured by proportion of days covered (PDC). Secondary outcomes included NOAC discontinuation (no refill for 30 days after the end of NOAC supply) and switching anticoagulants. We compared PDC using a Kruskal-Wallis test and rates of discontinuation and switching using Cox proportional hazards models.

RESULTS

After weighting patients across the 3 copayment groups, the effective sample size was 17,558 patients, with balance across 50 clinical and demographic covariates (standardized differences <0.1). Mean age was 62 years, 29% of patients were female, and apixaban (43%), and rivaroxaban (38%) were the most common NOACs. Higher copayments were associated with lower adherence (P < .001), with a PDC of 0.82 (Interquartile range [IQR] 0.36-0.98) among those with high copayments, 0.85 (IQR 0.41-0.98) among those with medium copayments, and 0.88 (IQR 0.41-0.99) among those with low copayments. Compared to patients with low copayments, patients with high copayments had higher rates of discontinuation (hazard ratio [HR] 1.13, 95% confidence interval [CI] 1.08-1.19; P < .001).

CONCLUSIONS

Among atrial fibrillation patients newly initiating NOACs, higher copayments in commercial insurance were associated with lower adherence and higher rates of discontinuation in the first year. Policies to lower or limit cost-sharing of important medications may lead to improved adherence and better outcomes among patients receiving NOACs.

Identification of Circular RNA-MicroRNA-Messenger RNA Regulatory Network in Atrial Fibrillation by Integrated Analysis

BACKGROUND

Circular RNA (circRNA) is a noncoding RNA that forms a closed-loop structure, and its abnormal expression may cause disease. We aimed to find potential network for circRNA-related competitive endogenous RNA (ceRNA) in atrial fibrillation (AF).

METHODS

The circRNA, miRNA, and mRNA expression profiles in the heart tissue from AF patients were retrieved from the Gene Expression Omnibus database and analyzed comprehensively. Differentially expressed circRNAs (DEcircRNAs), differentially expressed miRNAs (DEmiRNAs), and differentially expressed mRNAs (DEmRNAs) were identified, followed by the establishment of DEcircRNA-DEmiRNA-DEmRNA regulatory network. Functional annotation analysis of host gene of DEcircRNAs and DEmRNAs in ceRNA regulatory network was performed. In vitro experiment and electronic validation were used to validate the expression of DEcircRNAs, DEmiRNAs, and DEmRNAs.

RESULTS

A total of 1611 DEcircRNAs, 51 DEmiRNAs, and 1250 DEmRNAs were identified in AF. The DEcircRNA-DEmiRNA-DEmRNA network contained 62 circRNAs, 14 miRNAs, and 728 mRNAs. Among which, two ceRNA regulatory pairs of hsa-circRNA-100053-hsa-miR-455-5p-TRPV1 and hsa-circRNA-005843-hsa-miR-188-5p-SPON1 were identified. In addition, six miRNA-mRNA regulatory pairs including hsa-miR-34c-5p-INMT, hsa-miR-1253-DDIT4L, hsa-miR-508-5p-SMOC2, hsa-miR-943-ACTA1, hsa-miR-338-3p-WIPI1, and hsa-miR-199a-3p-RAP1GAP2 were also obtained. MTOR was a significantly enriched signaling pathway of host gene of DEcircRNAs. In addition, arrhythmogenic right ventricular cardiomyopathy, dilated cardiomyopathy, and hypertrophic cardiomyopathy were remarkably enriched signaling pathways of DEmRNAs in DEcircRNA-DEmiRNA-DEmRNA regulatory network. The expression validation of hsa-circRNA-402565, hsa-miR-34c-5p, hsa-miR-188-5p, SPON1, DDIT4L, SMOC2, and WIPI1 was consistent with the integrated analysis.

CONCLUSION

We speculated that hsa-circRNA-100053-hsa-miR-455-5p-TRPV1 and hsa-circRNA-005843-hsa-miR-188-5p-SPON1 interaction pairs may be involved in AF.

Motivational Interviewing to Support Oral AntiCoagulation adherence in patients with non-valvular Atrial Fibrillation (MISOAC-AF): a randomized clinical trial

AIMS

We aimed to assess the impact of an educational, motivational intervention on the adherence to oral anticoagulation (OAC) in patients with non-valvular atrial fibrillation (AF).

METHODS AND RESULTS

Hospitalized patients with non-valvular AF who received OAC were randomly assigned to usual medical care or a proactive intervention, comprising motivational interviewing, and tailored counselling on medication adherence. The primary study outcome was adherence to OAC at 1 year, which was evaluated according to proportion of days covered (PDC) by OAC regimens and was assessed through nationwide registers of prescription claims. Secondary outcomes included the rate of persistence to OAC, gaps in treatment, and clinical events. A total of 1009 patients were randomized, 500 in the intervention group and 509 in the control group. At 1-year follow-up, 77.2% (386/500) of patients in the intervention group were adherent (PDC > 80%), compared with 55% (280/509) in the control group [adjusted odds ratio (aOR) 2.84, 95% confidence interval (CI) 2.14-3.75; P < 0.001]. Mean PDC ± standard deviation was 0.85 ± 0.26 and 0.75 ± 0.31, respectively (P < 0.001). Patients that received the intervention were more likely to persist in their OAC therapy at 1 year (aOR 2.42, 95% CI 1.71-3.41; P < 0.001). Usual medical care was associated with more major (≥3 months) treatment gaps (aOR 2.39, 95% CI 1.76-3.26; P < 0.001). Clinical events over a median follow-up period of 2 years did not differ among treatment groups.

CONCLUSION

In patients receiving OAC therapy for non-valvular AF, a multilevel motivational intervention significantly improved medication adherence and rate of therapy persistence, and reduced major gaps in treatment. No significant impact on clinical outcomes was observed.

TRIAL REGISTRATION NUMBER

NCT02941978.

Adherence to Anticoagulation and Risk of Stroke Among Medicare Beneficiaries Newly Diagnosed with Atrial Fibrillation

INTRODUCTION

The objective of this study was to compare the risk of stroke in atrial fibrillation (AF) with adherent use of oral anticoagulation (OAC), non-adherent use, and non-use of OAC.

METHODS

Using 2013-2016 Medicare claims data, we identified patients newly diagnosed with AF in 2014-2015 and collected prescriptions filled for OAC in the 12 months after AF diagnosis (n = 39,272). We categorized participants each day into three time-dependent exposures: adherent use (≥ 80% of the previous 30 days covered with OAC), non-adherent use (0-80% covered with OAC), and non-use (0%). We constructed Cox proportional hazards models to estimate the association between time-dependent exposures and time to stroke, adjusting for demographics and clinical characteristics.

RESULTS

The sample included 39,272 patients. Study participants spent 35.0% of the follow-up period in the adherent use exposure category, 10.9% in the non-adherent category, and 54.0% in the non-use category. OAC adherent use [hazard ratio (HR) 0.62; 95% confidence interval (CI) 0.52-0.74] and non-adherent use (HR 0.74; 95% CI 0.57-0.95) were associated with lower hazards of stroke than non-use. Adherent use of DOAC (HR 0.54; 95% CI 0.42-0.69) and warfarin (HR 0.70; 95% CI 0.56-0.89) was associated with lower risk of stroke than non-use, but the risk of stroke did not statistically differ between DOAC and warfarin adherent use (HR 0.77; 95% CI 0.56-1.04).

DISCUSSION

Although adherence to OAC reduces stroke risk by nearly 40%, newly diagnosed AF patients in Medicare adhere to OAC on average only one third of the first year after AF diagnosis.

Trajectories of Oral Anticoagulation Adherence Among Medicare Beneficiaries Newly Diagnosed With Atrial Fibrillation

Background

Only 50% of atrial fibrillation (AF) patients recommended for oral anticoagulation (OAC) use these medications, and less than half of them adhere to OAC. In a cohort of Medicare beneficiaries newly diagnosed with AF, we identified groups of patients with similar trajectories of OAC use and adherence, and evaluated patient characteristics affecting group membership.

Methods and Results

We selected continuously enrolled Medicare Part D beneficiaries with first AF diagnosis in 2014 to 2015 (n=34 898). We calculated the proportion of days covered with OAC over the first 12 months after diagnosis and identified OAC adherence trajectories using group‐based trajectory models. We constructed multinomial logistic regression models to evaluate how demographics, system‐level factors, and clinical characteristics were associated with group membership. We identified 4 trajectories of OAC adherence: patients who never used OAC (43.8%), late OAC initiators (7.6%), early OAC discontinuers (8.9%), and continuously adherent patients (40.1%). Predictors such as sex, black race, residence in the South, or HAS‐BLED score were associated with not only OAC use, but also the timing of initiation and the likelihood of discontinuation. For example, HAS‐BLED score ≥4 was associated with a higher likelihood of not using OAC (odds ratio 1.35; 95% CI, 1.14–1.62), of late initiation (1.55; 95% CI, 1.11–2.05), and of early discontinuation (odds ratio 1.35; 95% CI, 1.01–1.84).

Conclusions

We identified 4 distinct trajectories of OAC adherence after first AF diagnosis, with <45% of newly diagnosed AF patients belonging to the trajectory group characterized by continuous OAC adherence. Trajectories were associated not only with demographic and clinical characteristics but also with regional factors.

Integrative Analysis Reveals Key Circular RNA in Atrial Fibrillation

Circular RNAs (circRNAs) are an emerging class of RNA species that may play a critical regulatory role in gene expression control, which can serve as diagnostic biomarkers for many diseases due to their abundant, stable, and cell- or tissue-specific expression. However, the association between circRNAs and atrial fibrillation (AF) is still not clear. In this study, we used RNA sequencing data to identify and quantify the circRNAs. Differential expression analysis of the circRNAs identified 250 up- and 126 down-regulated circRNAs in AF subjects compared with healthy donors, respectively. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis of the parental genes of the dysregulated circRNAs indicated that the up-regulated parental genes may participate in the process of DNA damage under oxidative stress. Furthermore, to annotate the dysregulated circRNAs, we constructed and merged the competing endogenous RNA (ceRNA) network and protein-protein interaction (PPI) network, respectively. In the merged network, 130 of 246 dysregulated circRNAs were successfully characterized by more than one pathway. Notably, the five circRNAs, including chr9:15474007-15490122, chr16:75445723-75448593, hsa_circ_0007256, chr12:56563313-56563992, and hsa_circ_0003533, showed the highest significance by the enrichment analysis, and four of them were enriched in cytokine-cytokine receptor interaction. These dysregulated circRNAs may mainly participate in biological processes of inflammatory response. In conclusion, the present study identified a set of dysregulated circRNAs, and characterized their potential functions, which may be associated with inflammatory responses in AF. To our knowledge, this is the first study to uncover the association between circRNAs and AF, which not only improves our understanding of the roles of circRNAs in AF, but also provides candidates of potentially functional circRNAs for AF researchers.

Geographic Disparities in the Incidence of Stroke among Patients with Atrial Fibrillation in the United States

AIM

To determine whether regional variation in stroke incidence exists among individuals with AF.

METHODS

Using healthcare utilization claims from 2 large US databases, MarketScan (2007-2014) and Optum Clinformatics (2009-2015), and the 2010 US population as the standard, we estimated age-, sex-, race- (only in Optum) standardized stroke incidence rates by the 9 US census divisions. We also used Poisson regression to examine incidence rate ratios (IRR) of stroke and the probability of anticoagulation prescription fills across divisions.

RESULTS

Both databases combined included 970,683 patients with AF who experienced 15,543 strokes, with a mean follow-up of 23 months. In MarketScan, the age- and sex-standardized stroke incidence rate was highest in the Middle Atlantic and East South Central divisions at 3.8/1000 person-years (PY) and lowest in the West North Central at 3.2/1000 PY. The IRR of stroke and the probability of anticoagulation fills were similar across divisions. In Optum Clinformatics, the age-, sex-, and race-standardized stroke incidence rate was highest in the East North Central division at 5.0/1000 PY and lowest in the New England division at 3.3/1000 PY. IRR of stroke and the probability of anticoagulation fills differed across divisions when compared to New England.

CONCLUSIONS

These findings suggest regional differences in stroke incidence among AF patients follow a pattern that differs from the hypothesized trend found in the general population and that other factors may be responsible for this new pattern. Cross-database differences provide a cautionary tale for the identification of regional variation using health claims data.

Treatment and discharge patterns among patients hospitalized with non-valvular atrial fibrillation transitioning from the inpatient to outpatient setting

OBJECTIVE

To evaluate inpatient oral anticoagulant (OAC) treatment, discharge location, and post-discharge OAC treatment for patients hospitalized with non-valvular atrial fibrillation (NVAF).

RESEARCH DESIGN AND METHODS

Retrospective study using claims data linked to hospital electronic health records (EHR). Patients (n = 2,484) were hospitalized with a primary (38%) or secondary (62%) diagnosis of AF without evidence of mitral valvular heart disease or valve replacement between January 2009 and September 2013. Inpatient OAC treatment was identified from EHR data.

MAIN OUTCOME MEASURES

Inpatient and post-discharge OAC treatment [direct OAC (DOAC; apixaban, rivaroxaban, dabigatran), warfarin, no OAC] and discharge location (long-term care, home health-care, home self-care).

RESULTS

Mean age was 72.6 years, 61.2% were male, and 89.5% had a CHA2DS2-VASc score ≥2. Overall, 6.4% received a DOAC, 38.0% warfarin, and 55.6% no OAC during hospitalization. Compared to other treatment groups, patients receiving DOAC were younger and more likely to be male. The majority (72.2%) were discharged to home health-care, 13.2% home self-care, and 6.0% long-term care. Among patients who were treated with warfarin during hospitalization, 40.3% filled a warfarin prescription within 30 days post-discharge, whereas among patients who were treated with a DOAC, 52.4% filled a DOAC prescription within 30 days post-discharge. Some NVAF patients not treated with an OAC during hospitalization filled a prescription for warfarin (18.0%) or DOAC (1.9%) within 30 days post-discharge. Results were similar among patients with CHA2DS2-VASc score ≥2.

CONCLUSIONS

Most patients hospitalized for NVAF were discharged to home support, and the majority did not have OAC treatment during hospitalization or the 30 days post-discharge. Additional investigation should be conducted on trends beyond 30 days post-hospitalization, and the reasons for not receiving anticoagulation therapy in patients at moderate-to-severe risk of stroke or systemic embolism. Helping to avoid preventable strokes is an important goal for public health.

Association of insurance type with receipt of oral anticoagulation in insured patients with atrial fibrillation: A report from the American College of Cardiology NCDR PINNACLE registry

BACKGROUND

It is poorly understood whether insurance type may be a major contributor to the underuse of oral anticoagulation (OAC) among patients with atrial fibrillation (AF), particularly for novel oral anticoagulants (NOACs).

METHODS

We performed a retrospective cohort registry study of patients with insurance, AF, CHA₂DS₂-VASc ≥2, and at least one outpatient encounter recorded in the ACC NCDR's PINNACLE Registry between January 1, 2011 and December 31, 2014. We used hierarchical regression, adjusting for patient characteristics and clustering by physician, to evaluate the association of insurance type (Private, Military, Medicare, Medicaid, Other) with receipt of OAC (any OAC, warfarin, or NOAC).

RESULTS

In 363,309 patients (age 75±10; 48% female), we found a significant difference in proportions of OAC and NOAC prescription across insurance types (OAC: Military 53%, Private 53%, Medicare 52%, Other 41%, Medicaid 41%, P<.001; NOAC: Military 24%, Private 19%, Medicare 17%, Other 17%, Medicaid 8%, P<.001). After adjustment for patient characteristics and facility, private, Medicaid, and other insurance were independently associated with a lower odds of OAC prescription relative to Medicare, but military insured patients were not significantly different. After adjustment, military and private insurance were independently associated with a higher odds of NOAC prescription relative to Medicare, while Medicaid and other insurance were associated with a lower odds of NOAC prescription.

CONCLUSIONS

In a contemporary US AF population, there was significant variation of OAC prescription across insurance plans, with the highest among private and Medicare insured patients. These differences may indicate that insurance plan, and its associated pharmacy benefits, affect the pace of diffusion of new therapies.

Prognostic factors of clinical endpoints in elderly patients with atrial fibrillation during a 2-year follow-up in China: An observational cohort study

This study aimed to reveal the incidence of clinical endpoints in elderly patients with atrial fibrillation (AF) during a 2-year follow-up and evaluate the related prognostic factors of these endpoints.In total, 200 elderly patients with AF and 400 age- and sex-matched patients without AF were enrolled in this prospective observational cohort study. The incidence of clinical endpoints, including thromboembolism, hemorrhage, and all-cause death, during the 2-year follow-up was analyzed. Other follow-up data, including disease history, laboratory examinations, medication status, and other clinical endpoints, were collected. The prognostic factors of these clinical endpoints were then evaluated by Cox-survival analysis. In addition, the predicative role of C-reactive protein (CRP) and platelet-activating factor (PAF) on these clinical endpoints was analyzed.The incidence of clinical endpoints, including thromboembolism, hemorrhage, and all-cause death, was significantly higher in patients with AF than in those without AF (27.8% vs 9.8%, 29.4% vs 12.7%, and 28.7% vs 11.6%, respectively; all P < .001). Antithrombotic therapy significantly reduced the incidences of all-cause deaths (P < .05). Body mass index (BMI) and digoxin were prognostic risk factors of thromboembolism; age, massive hemorrhage history, and digoxin were prognostic risk factors of hemorrhage and age, renal insufficiency history, massive hemorrhage history, and digoxin were prognostic risk factors of all-cause death (P < .05). Further, both CRP and PAF were prognostic risk factors of thromboembolism and massive hemorrhage (P < .05).Age, BMI, massive hemorrhage history, and digoxin appear to be prognostic risk factors of clinical endpoints in elderly patients with AF. Appropriate drug use during follow-up may be beneficial in preventing the occurrence of clinical endpoints in elderly patients with AF.

TRIAL REGISTRATION NUMBER

ChiCTR-OCH-13003479.

Increased Post-procedural Non-gastrointestinal Adverse Events After Outpatient Colonoscopy in High-risk Patients

BACKGROUND & AIMS

The incidence and predictors of non-gastrointestinal (GI) adverse events (AEs) after colonoscopy are not well-understood. We studied the effects of antithrombotic agents, cardiopulmonary comorbidities, and age on risk of non-GI AEs after colonoscopy.

METHODS

We performed a retrospective longitudinal analysis to assess the diagnosis, procedure, and prescription drug codes in a United States commercial claims database (March 2010-March 2012). Data from patients at increased risk (n = 82,025; defined as patients with pulmonary comorbidities or cardiovascular disease requiring antithrombotic medications) were compared with data from 398,663 average-risk patients. In a 1:1 matched analysis, 51,932 patients at increased risk, examined by colonoscopy, were compared with 51,932 matched (on the basis of age, sex, and comorbidities) patients at increased risk who did not undergo colonoscopy. We tracked cardiac, pulmonary, and neurovascular events 1-30 days after colonoscopy.

RESULTS

Thirty days after outpatient colonoscopy, non-GI AEs were significantly higher in patients taking antithrombotic medications (7.3%; odds ratio [OR], 10.75; 95% confidence interval, 10.13-11.42) or those with pulmonary comorbidities (1.8%; OR, 2.44; 95% confidence interval, 2.27-2.62) vs average-risk patients (0.7%) and in patients 60-69 years old (OR, 2.21; 95% confidence interval, 2.01-2.42) or 70 years or older (OR, 6.45; 95% confidence interval, 5.89-7.06), compared with patients younger than 50 years. The 30-day incidence of non-GI AEs in patients at increased risk who underwent colonoscopy was also significantly higher than in matched patients at increased risk who did not undergo colonoscopy in the anticoagulant group (OR, 2.31; 95% confidence interval, 2.01-2.65) and in the chronic obstructive pulmonary disease group (OR, 1.33; 95% confidence interval, 1.13-1.56).

CONCLUSIONS

Increased number of comorbidities and older age (older than 60 years) are associated with increased risk of non-GI AEs after colonoscopy. These findings indicate the importance of determining comorbid risk and evaluating antithrombotic management before colonoscopy.

Overcoming global challenges in stroke prophylaxis in atrial fibrillation: The role of non-vitamin K antagonist oral anticoagulants

Atrial fibrillation is the world's most common sustained cardiac arrhythmia and is associated with a significantly increased risk of stroke. The global burden of atrial fibrillation is rising, commensurate with the ageing population. Well-controlled vitamin K antagonist-based anticoagulation has been shown to reduce the risk of stroke secondary to atrial fibrillation by two-thirds. However, patients with atrial fibrillation have frequently been denied anticoagulation because of a variety of perceived risks related to bleeding, falls, chronological age, and poor compliance. Even when vitamin K antagonists are used, maximum benefit and safety are only delivered when high quality control of therapy (TTR > 70%) is achieved, which has proven remarkably difficult in many health-care systems and amongst many patient groups. The non-vitamin K antagonist oral anticoagulants (NOACs) offer solutions to many of the challenges of achieving widespread, safe, and effective anticoagulation for stroke prophylaxis in atrial fibrillation, yet their uptake into routine clinical practice remains variable. The evidence supporting their more widespread use to overcome the challenges of stroke prophylaxis for atrial fibrillation is reviewed in this article.

Clinical Characteristics, Oral Anticoagulation Patterns, and Outcomes of Medicaid Patients With Atrial Fibrillation: Insights From the Outcomes Registry for Better Informed Treatment of Atrial Fibrillation (ORBIT-AF I) Registry

Background

Whereas insurance status has been previously associated with care patterns, little is currently known about the association between Medicaid insurance and the clinical characteristics, treatment, or outcomes of patients with atrial fibrillation (AF).

Methods and Results

We used data from adults with AF enrolled in the Outcomes Registry for Better Informed Treatment of AF (ORBIT‐AF), a national outpatient registry conducted at 176 community, multispecialty sites. The primary outcome of interest was the proportion of patients prescribed any oral anticoagulation (OAC; warfarin or novel oral anticoagulants [NOAC]). Secondary outcomes of interest included the proportion of patients prescribed NOACs (dabigatran or rivaroxaban); time in therapeutic range (TTR) for warfarin users, all‐cause mortality, stroke/systemic embolism, and major bleed. Of 10 133 patients, N=470 (4.6%) had Medicaid insurance. Medicaid patients were similarly likely to receive OAC at baseline (72.8% vs 76.3%; unadjusted P=0.079), but less likely to receive NOAC at baseline or follow‐up (12.1% vs 16.3%; unadjusted P=0.019). After risk adjustment, Medicaid status was associated with lower use of OAC at baseline among patients with high stroke risk (odds ratio [OR]=0.68; 95% CI=0.49, 0.94), but was not associated with OAC use overall (OR=0.82; 95% CI=0.61, 1.09). Among warfarin users, median TTR was lower among Medicaid patients (60% vs 68%; P<0.0001; adjusted TTR difference, −2.9; 95% CI=−5.7, −0.2; P=0.04). Use of an NOAC over 2 years of follow‐up was not statistically different by insurance. Compared with non‐Medicaid patients, Medicaid patients had higher unadjusted rates of mortality, stroke/systemic embolism, and major bleeding; however, these differences were attenuated following adjustment for clinical characteristics.

Conclusions

In a contemporary AF cohort, use of OAC overall and use of NOACs were not significantly lower among Medicaid patients relative to others. However, among warfarin users, Medicaid patients spent less time in therapeutic range compared with those with other forms of insurance.

Attitudes toward anticoagulant treatment among nonvalvular atrial fibrillation patients at high risk of stroke and low risk of bleed

BACKGROUND

Atrial fibrillation (AF) is associated with an increased risk of stroke. Anticoagulant (AC) therapies are effective at treating AF, but carry with them an increased risk of bleed. Research suggests that a large proportion of AF patients who have high risk of stroke and low risk of bleeding are not currently receiving AC treatment. The goal of this study was to understand the reasons why these patients do not engage in this potentially life-saving treatment.

METHOD

Through a self-report online survey, using validated instruments, 1,184 US adults who self-reported a diagnosis of AF were screened for the risk of stroke and bleed. Of these patients, 230 (19.4%) were at high risk of stroke, low risk of bleed, and not currently using an AC treatment, and were asked follow-up questions to assess their reasons for nontreatment, attitudes toward treatment, and attitudes toward dosing regimens.

RESULTS

The most common reasons patients stopped AC treatment were concerns regarding bleeding (27.8%) and other medical concerns (26.6%), whereas the most common reason cited for not being prescribed an AC in the first place was the use of antiplatelet therapy as an alternative (57.1%). In both cases, potentially erroneous decisions regarding perceived stoke and/or bleeding risk were also a factor. Finally, the largest factors regarding attitudes toward treatment and dosing regimen were instructions from an authority figure (eg, physician, pharmacist) and ease of use, respectively.

CONCLUSION

Results suggest that many AF patients who are at high risk of stroke but at low risk of bleed may not be receiving AC due to potentially inaccurate beliefs about risk. This study also found that AF patients place trust in physicians above other factors such as cost when making treatment decisions. Increased education of patients by physicians on the risks and benefits may be a simple strategy to improve outcomes.

National Trends in Ambulatory Oral Anticoagulant Use

BACKGROUND

Four direct oral anticoagulants (DOACs) have been brought to market for the treatment of nonvalvular atrial fibrillation and venous thromboembolism. Many forces, including numerous positive trial results, emerging safety concerns, marketing, and promotion, may shape DOAC adoption by providers. However, relatively little is known regarding their ambulatory utilization compared with warfarin, as well as the degree to which they have decreased under-treatment of atrial fibrillation.

METHODS

We used the IMS Health National Disease and Therapeutic Index, a nationally representative audit of outpatient office visits, to estimate the use of warfarin and DOACs between 2009 and 2014.

RESULTS

Overall, visits with anticoagulation use increased from 2.05 (95% confidence interval [CI], 1.82-2.27) to 2.83 (95% CI, 2.49-3.17) million (M) quarterly visits (P < .001). Of these, DOAC use has grown to 4.21M (95% CI, 3.63M-4.79M; 38.2% of total) treatment visits in 2014 since their introduction in 2010. Use of all oral anticoagulants in treatment visits for atrial fibrillation has increased from 0.88M (95% CI, 0.74M-1.02M) to 1.72M (95% CI, 1.47M-1.97M; P < .001), with similar DOAC and warfarin use in 2014. Atrial fibrillation visits with anticoagulant use increased from 51.9% (95% CI, 50.4%-53.8%) to 66.9% (95% CI, 65.0%-69.3%) between 2009 and 2014 (P < .001). In 2014, rivaroxaban was the most commonly prescribed DOAC for atrial fibrillation (47.9% of office visits), followed by apixaban (26.5%) and dabigatran (25.5%).

CONCLUSIONS

Direct oral anticoagulants have been adopted rapidly, matching the use of warfarin, and are associated with increased use of oral anticoagulation for patients with atrial fibrillation.

Time to Cost-Effectiveness Following Stroke Reduction Strategies in AF: Warfarin Versus NOACs Versus LAA Closure

BACKGROUND

Left atrial appendage closure (LAAC) and nonwarfarin oral anticoagulants (NOACs) have emerged as safe and effective alternatives to warfarin for stroke prophylaxis in patients with nonvalvular atrial fibrillation (AF).

OBJECTIVES

This analysis assessed the cost-effectiveness of warfarin, NOACs, and LAAC with the Watchman device (Boston Scientific, Marlborough, Massachusetts) for stroke risk reduction in patients with nonvalvular AF at multiple time points over a lifetime horizon.

METHODS

A Markov model was developed to assess the cost-effectiveness of LAAC, NOACs, and warfarin from the perspective of the Centers for Medicare & Medicaid Services over a lifetime (20-year) horizon. Patients were 70 years of age and at moderate risk for stroke and bleeding. Clinical event rates, stroke outcomes, and quality of life information were drawn predominantly from PROTECT AF (Watchman Left Atrial Appendage System for Embolic Protection in Patients with Atrial Fibrillation) 4-year data and meta-analyses of warfarin and NOACs. Costs for stroke risk reduction therapies, treatment of associated acute events, and long-term care following disabling stroke were presented in 2015 U.S. dollars.

RESULTS

Relative to warfarin, LAAC was cost-effective at 7 years ($42,994/quality-adjusted life-years [QALY]), and NOACs were cost-effective at 16 years ($48,446/QALY). LAAC was dominant over NOACs by year 5 and warfarin by year 10. At 10 years, LAAC provided more QALYs than warfarin and NOACs (5.855 vs. 5.601 vs. 5.751, respectively). In sensitivity analyses, LAAC remained cost-effective relative to warfarin ($41,470/QALY at 11 years) and NOACs ($21,964/QALY at 10 years), even if procedure costs were doubled.

CONCLUSIONS

Both NOACs and LAAC with the Watchman device were cost-effective relative to warfarin, but LAAC was also found to be cost-effective and to offer better value relative to NOACs. The results of this analysis should be considered when formulating policy and practice guidelines for stroke prevention in AF.

Choosing the right drug to fit the patient when selecting oral anticoagulation for stroke prevention in atrial fibrillation

Atrial fibrillation (AF) is the most common cardiac arrhythmia worldwide and is a growing health problem that is associated with a significantly increased risk of stroke and thromboembolism. Oral anticoagulant (OAC) therapy reduces the risk of stroke and all-cause mortality in patients with AF. OAC therapy is commonly given as a well-controlled vitamin K antagonist (VKA; e.g. warfarin) and can reduce the risk of stroke in AF patients by almost two-thirds. However, the widespread use of VKAs has been hampered by the unpredictable pharmacokinetic and pharmacodynamic properties of the drugs and justifiable concerns about the consequent risk of haemorrhage. The non-VKA OACs (NOACs) have revolutionized thromboprophylaxis in AF by providing therapeutic options with predictable pharmacodynamic and pharmacokinetic properties that are as efficacious as warfarin in the prevention of stroke and thromboembolism but are more convenient to use. In this review, we provide a patient-centred framework to assist clinicians in recommending the right OAC therapy to fit the individual patient with AF, including methods for stratifying the risk of stroke and haemorrhage and the chances of achieving tight control of VKA anticoagulation, and we discuss the properties of the NOACs that favour their use in particular patient cohorts.