A Propensity Score Matched Comparison of Clinical Outcomes in Atrial Fibrillation Patients Taking Vitamin K Antagonists: Comparing the "Real-World" vs Clinical Trials

Lower-adherence direct oral anticoagulant use is associated with increased risk of thromboembolic events than warfarin

BACKGROUND

Real-world data have suggested inconsistent adherence to oral anticoagulation for thromboembolic event (TE) prevention in patients with Non valvular atrial fibrillation (NVAF), yet it remains unclear if event risk is elevated during gaps of non-adherence.

OBJECTIVE

To compare difference in outcomes between direct oral anticoagulant (DOAC) and warfarin based on adherence to the therapy in patients with NVAF.

METHODS

Using the MarketScan claims data, patients receiving prescription of warfarin or a DOAC for NVAF from January 2015 to June 2016 were included. Outcomes included hospitalization for TE (ischemic stroke or systemic embolism), hemorrhagic stroke, stroke of any kind, and major bleeding. Event rates were reported for warfarin and DOACs at a higher-adherence proportion of days covered (PDC > 80%) and lower-adherence (PDC 40-80%).

RESULTS

The cohort included 83,168 patients prescribed warfarin (51% [n = 42,639]) or DOAC (49% [n = 40,529]). Lower adherence occurred in 36% (n = 15,330) of patients prescribed warfarin and 26% (n = 10,956) prescribed DOAC. As compared to higher-adherence warfarin after multivariable adjustment, the risk of TE was highest in lower-adherence DOAC (HR 1.26; 95% CI, 1.14-1.33), and lowest in higher-adherence DOAC (HR, 0.93; 95% CI, 0.88-0.99). There was a significantly higher risk of hemorrhagic stroke and stroke of any kind in the lower-adherence groups. Major bleeding was more common with lower-adherence DOAC (HR, 1.43, 95% CI, 1.35-1.52) and lower-adherence warfarin (HR, 1.32, 95% CI, 1.26-1.39).

CONCLUSIONS

In this large real-world study, low adherence DOAC was associated with higher risk of TE events as compared to high and low adherence warfarin.

Generalisability of trials on antithrombotic treatment intensification in patients with cardiovascular disease

OBJECTIVE

Assessment of generalisability of guideline-informing trials on antithrombotic treatment intensification to real-world patients with cardiovascular disease (CVD).

METHODS

Inclusion and exclusion criteria of the Cardiovascular Outcomes for People Using Anticoagulation Strategies (COMPASS), Clopidogrel for High Atherothrombotic Risk and Ischemic Stabilization, Management and Avoidance (CHARISMA), Prevention of Cardiovascular events in Patients with Prior Heart Attack Using Ticagrelor Compared to Placebo on a Background of Aspirin-Thrombolysis in Myocardial Infarction (PEGASUS-TIMI) and Dual Antiplatelet Therapy (DAPT) study were applied to coronary artery disease (CAD) and/or peripheral artery disease (PAD) patients from Utrecht Cardiovascular Cohort-Second Manifestations of Arterial Disease (UCC-SMART) to determine real-world eligibility. Eligible and ineligible patients were compared on baseline characteristics, cardiovascular events, major bleeding and mortality.

RESULTS

Eligibility ranged from 11%-94% for CAD to 75%-90% for patients with PAD. Cardiovascular, bleeding and mortality risks were higher in COMPASS-eligible patients with CAD (rate ratios (RR) 1.98 (95% CI 1.74 to 2.26), 2.02 (95% CI 1.47 to 2.78) and 3.11 (95% CI 2.71 to 3.57), respectively) and CHARISMA-eligible patients (RR 1.51 (95% CI 1.12 to 2.06), 2.25 (95% CI 1.01 to 6.21) and 4.43 (95% CI 2.79 to 7.51), respectively), and lower in COMPASS-eligible patients with PAD (RR 0.45 (95% CI 0.36 to 0.56), 0.29 (95% CI 0.18 to 0.46) and 0.45 (95% CI 0.38 to 0.54), respectively) and DAPT-eligible patients with CAD (RR CVD 0.49 (95% CI 0.34 to 0.69) and mortality 0.67 (95% CI 0.48 to 0.94)) than ineligible patients. After adjustment for trial eligibility criteria, only higher cardiovascular and mortality risks in COMPASS-eligible patients with CAD and lower cardiovascular risks in CHARISMA-eligible and DAPT-eligible patients persisted with CAD.

CONCLUSION

A large proportion of contemporary CVD patients would be eligible for intensified antithrombotic treatment trials, with mostly similar adjusted event risks to ineligible patients. Trial-based guideline recommendations are largely applicable to real-world patients.

Healthcare outcomes assessed with observational study designs compared with those assessed in randomized trials: a meta-epidemiological study

BACKGROUND

Researchers and decision-makers often use evidence from randomised controlled trials (RCTs) to determine the efficacy or effectiveness of a treatment or intervention. Studies with observational designs are often used to measure the effectiveness of an intervention in 'real world' scenarios. Numerous study designs and their modifications (including both randomised and observational designs) are used for comparative effectiveness research in an attempt to give an unbiased estimate of whether one treatment is more effective or safer than another for a particular population. An up-to-date systematic analysis is needed to identify differences in effect estimates from RCTs and observational studies. This updated review summarises the results of methodological reviews that compared the effect estimates of observational studies with RCTs from evidence syntheses that addressed the same health research question.

OBJECTIVES

To assess and compare synthesised effect estimates by study type, contrasting RCTs with observational studies. To explore factors that might explain differences in synthesised effect estimates from RCTs versus observational studies (e.g. heterogeneity, type of observational study design, type of intervention, and use of propensity score adjustment). To identify gaps in the existing research comparing effect estimates across different study types.

SEARCH METHODS

We searched MEDLINE, the Cochrane Database of Systematic Reviews, Web of Science databases, and Epistemonikos to May 2022. We checked references, conducted citation searches, and contacted review authors to identify additional reviews.

SELECTION CRITERIA

We included systematic methodological reviews that compared quantitative effect estimates measuring the efficacy or effectiveness of interventions tested in RCTs versus in observational studies. The included reviews compared RCTs to observational studies (including retrospective and prospective cohort, case-control and cross-sectional designs). Reviews were not eligible if they compared RCTs with studies that had used some form of concurrent allocation.

DATA COLLECTION AND ANALYSIS

Using results from observational studies as the reference group, we examined the relative summary effect estimates (risk ratios (RRs), odds ratios (ORs), hazard ratios (HRs), mean differences (MDs), and standardised mean differences (SMDs)) to evaluate whether there was a relatively larger or smaller effect in the ratio of odds ratios (ROR) or ratio of risk ratios (RRR), ratio of hazard ratios (RHR), and difference in (standardised) mean differences (D(S)MD). If an included review did not provide an estimate comparing results from RCTs with observational studies, we generated one by pooling the estimates for observational studies and RCTs, respectively. Across all reviews, we synthesised these ratios to produce a pooled ratio of ratios comparing effect estimates from RCTs with those from observational studies. In overviews of reviews, we estimated the ROR or RRR for each overview using observational studies as the reference category. We appraised the risk of bias in the included reviews (using nine criteria in total). To receive an overall low risk of bias rating, an included review needed: explicit criteria for study selection, a complete sample of studies, and to have controlled for study methodological differences and study heterogeneity. We assessed reviews/overviews not meeting these four criteria as having an overall high risk of bias. We assessed the certainty of the evidence, consisting of multiple evidence syntheses, with the GRADE approach.

MAIN RESULTS

We included 39 systematic reviews and eight overviews of reviews, for a total of 47. Thirty-four of these contributed data to our primary analysis. Based on the available data, we found that the reviews/overviews included 2869 RCTs involving 3,882,115 participants, and 3924 observational studies with 19,499,970 participants. We rated 11 reviews/overviews as having an overall low risk of bias, and 36 as having an unclear or high risk of bias. Our main concerns with the included reviews/overviews were that some did not assess the quality of their included studies, and some failed to account appropriately for differences between study designs - for example, they conducted aggregate analyses of all observational studies rather than separate analyses of cohort and case-control studies. When pooling RORs and RRRs, the ratio of ratios indicated no difference or a very small difference between the effect estimates from RCTs versus from observational studies (ratio of ratios 1.08, 95% confidence interval (CI) 1.01 to 1.15). We rated the certainty of the evidence as low. Twenty-three of 34 reviews reported effect estimates of RCTs and observational studies that were on average in agreement. In a number of subgroup analyses, small differences in the effect estimates were detected: - pharmaceutical interventions only (ratio of ratios 1.12, 95% CI 1.04 to 1.21); - RCTs and observational studies with substantial or high heterogeneity; that is, I2 ≥ 50% (ratio of ratios 1.11, 95% CI 1.04 to 1.18); - no use (ratio of ratios 1.07, 95% CI 1.03 to 1.11) or unclear use (ratio of ratios 1.13, 95% CI 1.03 to 1.25) of propensity score adjustment in observational studies; and - observational studies without further specification of the study design (ratio of ratios 1.06, 95% CI 0.96 to 1.18). We detected no clear difference in other subgroup analyses.

AUTHORS' CONCLUSIONS

We found no difference or a very small difference between effect estimates from RCTs and observational studies. These findings are largely consistent with findings from recently published research. Factors other than study design need to be considered when exploring reasons for a lack of agreement between results of RCTs and observational studies, such as differences in the population, intervention, comparator, and outcomes investigated in the respective studies. Our results underscore that it is important for review authors to consider not only study design, but the level of heterogeneity in meta-analyses of RCTs or observational studies. A better understanding is needed of how these factors might yield estimates reflective of true effectiveness.

A propensity score matched comparison of blood pressure lowering in essential hypertension patients treated with antihypertensive Chinese herbal Medicine: comparing the real-world registry data vs. randomized controlled trial

BACKGROUND

Randomized controlled trials have demonstrated that Songling Xuemaikang capsule (SXC) is effective in blood pressure (BP) lowering for essential hypertension. However, the effectiveness of SXC in real-world clinical practice remains unknown. We aimed to investigate whether the BP-lowering effectiveness of SXC in the real-world practice setting is comparable to the efficacy of the intervention in a randomized controlled trial.

METHODS

We included 1325 patients treated with SXC monotherapy from a real-world registry and 300 from the SXC-BP trial. A propensity score matching (PSM) approach was used to select participants from the two cohorts. The primary outcome was a change in the office of BP from baseline to 8 weeks.

RESULTS

After PSM, there were 552 patients for the comparative analysis. Clinically meaningful BP reductions were observed both in the real world and in the RCT cohorts after 8-week SXC treatment. The 8-week systolic/diastolic BP was 129.50/81.33 mm Hg vs. 134.97/84.14 mm Hg in the real-world population and the RCT population, respectively. The changes in systolic BP (15.82 ± 10.71 vs. 10.48 ± 10.24; P < .001), and diastolic BP (10.01 ± 7.73 vs. 7.75 ± 8.14; P = .001) from baseline to 8 weeks were significantly greater in the real-world population.

CONCLUSION

The current comparison demonstrated that SXC monotherapy is at least as effective in real-world settings as within the randomized controlled trial for BP lowering in patients with grade 1 hypertension.

Long term follow up of direct oral anticoagulants and warfarin therapy on stroke, with all-cause mortality as a competing risk, in people with atrial fibrillation: Sentinel network database study

Background

We investigated differences in risk of stroke, with all-cause mortality as a competing risk, in people newly diagnosed with atrial fibrillation (AF) who were commenced on either direct oral anticoagulants (DOACs) or warfarin treatment.

Methods and results

We conducted a retrospective cohort study of the Oxford Royal College of General Practitioners (RCGP) Research and Surveillance Centre (RSC) database (a network of 500 English general practices). We compared long term exposure to DOAC (n = 5,168) and warfarin (n = 7,451) in new cases of AF not previously treated with oral anticoagulants. Analyses included: survival analysis, estimating cause specific hazard ratios (CSHR), Fine-Gray analysis for factors affecting cumulative incidence of events occurring over time and a cumulative risk regression with time varying effects.We found no difference in CSHR between stroke 1.08 (0.72–1.63, p = 0.69) and all-cause mortality 0.93 (0.81–1.08, p = 0.37), or between the anticoagulant groups. Fine-Gray analysis produced similar results 1.07 (0.71–1.6 p = 0.75) for stroke and 0.93 (0.8–1.07, p = 0.3) mortality. The cumulative risk of mortality with DOAC was significantly elevated in early follow-up (67 days), with cumulative risk decreasing until 1,537 days and all-cause mortality risk significantly decreased coefficient estimate:: -0.23 (-0.38–0.01, p = 0.001); which persisted over seven years of follow-up.

Conclusions

In this large, contemporary, real world primary care study with longer follow-up, we found no overall difference in the hazard of stroke between warfarin and DOAC treatment for AF. However, there was a significant time-varying effect between anti-coagulant regimen on all-cause mortality, with DOACs showing better survival. This is a key methodological observation for future follow-up studies, and reassuring for patients and health care professionals for longer duration of therapy

Factors affecting physician decision-making regarding antiplatelet therapy in minor ischemic stroke

Purpose

To identify the most important factors affecting physician decision-making regarding antiplatelet therapy.

Methods

We retrospectively gathered data from minor ischemic stroke patients with NIHSS scores ≤ 5 within 72 h of onset from 2010 to 2018. The population was divided into four groups by initial antiplatelet therapy: aspirin monotherapy (AM), dual antiplatelet therapy with aspirin and a loading dose of clopidogrel (clopidogrel loading dose of 300 mg on the first day; DAPT-ALC), dual antiplatelet therapy with aspirin and no loading dose of clopidogrel (clopidogrel 75 mg daily, no loading dose; DAPT-AUC), and clopidogrel monotherapy (CM).

Results

In total, 1,377 patients were included in the analysis (excluding patients who accepted thrombolytic drugs, participated in other clinical trials, or had not used antiplatelet drugs). The mean ± S.D. age was 62.0 ± 12.7 years; 973 (70.7%) patients were male. The four groups were AM (n = 541, 39.3%), DAPT-ALC (n = 474, 34.4%), DAPT- AUC (n = 301, 21.9%), and CM (n = 61, 4.4%). Patients receiving antiplatelet monotherapy were older than those receiving dual antiplatelet therapy (63.7–65.7 vs. 59.6–61.4 years), and the median initial systolic blood pressure level was higher in the DAPT-ALC group than in the other groups (all P < 0.05). Patients under 75 years old with an admission SBP lower than 180 mmHg, a history of AM, coronary heart disease, no history of intracerebral hemorrhage, stroke onset occurring after guideline recommendations were updated (the year of 2015), onset-to-arrival time within 24 h, and initial NIHSS score ≤ 3 were more likely to take DAPT-ALC than AM. Compared with DAPT-ALC, DAPT-AUC was associated with an initial SBP level lower than 180 mmHg, a history of smoking, hypertension, no history of ICH, previous treatment with antihypertensives, and onset year after the recommendations were updated.

Conclusions

Many factors affect doctors' decisions regarding antiplatelet therapy, especially guidelines, age, admission SBP level, and hypertensive disease.

Relationship between temporal rhythm-based classification of atrial fibrillation and stroke: real-world vs. clinical trial

Background

The risk of stroke according to clinical classification of atrial fibrillation (AF) remains poorly defined. Here, we assessed the impact of AF type on stroke risk in vitamin K antagonist-treated patients with AF in ‘real-world’ and ‘clinical trial’ cohorts.

Methods

Post-hoc analysis of patient-level data from the Murcia AF Project and AMADEUS trial. Clinical classification of AF was based on contemporary recommendations from international guidelines. Study endpoint was the incidence rate of ischaemic stroke. Stroke risk was determined using CHA₂DS₂-VASc score and CARS. A modified CHA₂DS₂-VAS‘c’ score that applied one additional point for a ‘c’ criterion of continuous AF (i.e. non-paroxysmal AF) was calculated.

Results

We included 5,917 patients: 1,361 (23.0%) real-world and 4,556 (77.0%) clinical trial. Baseline demographics were balanced in the real-world cohort but clinical trial participants with non-pAF (vs. pAF) were older, male-predominant and had more comorbidities. Crude stroke rates were comparable between the groups in real-world patients (IRR 0.72 [95% CI,0.37-1.28], p = 0.259) though clinical trial participants with non-pAF had a significantly higher crude rate of stroke events (IRR 4.66 [95%,CI,2.41-9.48], p < 0.001). Using multivariable analysis, AF type was not independently associated with stroke risk in the real-world (adjusted HR 1.41 [95% CI,0.80-2.50], p = 0.239) and clinical trial (adjusted HR 1.16 [95% CI,0.62-2.20], p = 0.646) cohorts, after accounting for other risk factors. There was no significant improvement in the CHA₂DS₂-VAS‘c’ compared to CHA₂DS₂-VASc score in either cohorts (p > 0.05).

Conclusions

Overall, our results support the need for anticoagulation based on thromboembolic risk profile rather than AF type.

Supplementary Information

The online version contains supplementary material available at 10.1007/s11239-022-02638-0.

Adherence is an optimal factor for maximizing the effective and safe use of oral anticoagulants in patients with atrial fibrillation

Few studies assessed the association between major adverse cardiovascular events and adherence to warfarin and direct oral anticoagulants (DOACs) in patients with atrial fibrillation (AF). Therefore, we aimed to evaluate the effects of adherence to oral anticoagulants (OACs) in patients with AF using claims data (July 2014–April 2019). Using the initial 3-month medication possession rate (MPR), patients were categorized into adherent (MPR ≥ 0.8) or non-adherent (MPR < 0.8) groups. Propensity score matching of non-adherent group to adherent group was conducted for warfarin (1:1) and DOAC (1:3), respectively. Incidence of ischemic stroke, myocardial infarction (MI), intracranial hemorrhage, and all-cause death was assessed in the matched cohort (67,147 patients). The hazard ratio (HR) for adherence to OAC was estimated using the Cox proportional hazard model with adjusting covariate including age and sex. The risk for ischemic stroke, MI, and all-cause death was lower in the DOAC adherent group than in the DOAC non-adherent group (HR: 0.78; 95% confidence intervals: 0.73–0.84; 0.75, 0.60–0.94; 0.54, 0.51–0.57, respectively). Adherence to OAC was not associated with the risk of intracranial hemorrhage (1.01, 0.85–1.20). Commitment programs to improve adherence in patients with AF could maximize drug effectiveness and safety.

Can a Single Measurement of Apixaban Levels Identify Patients at Risk of Overexposure? A Prospective Cohort Study

Background Patients with atrial fibrillation (AF) are frequently treated with apixaban 2.5-mg twice daily (BID) off-label, presumably to reduce the bleeding risk. However, this approach has the potential to increase the risk of ischemic stroke. If a single measurement could reliably identify patients with high drug levels, the increased stroke risk may be mitigated by confining off-label dose reduction to such patients.

Objectives This study aimed to determine whether a single high apixaban level is predictive of a similarly high level when the test is repeated in 2 months.

Methods In this prospective cohort study of clinic patients receiving apixaban 5-mg BID for AF or venous thromboembolism, peak and trough apixaban levels were measured using the STA-Liquid anti-Xa assay at baseline and 2 months. We calculated the proportions of patients with levels that remained in the upper quintile.

Results Of 100 enrolled patients, 82 came for a second visit, 55 of whom were treated with apixaban 5-mg BID. Seven (63.6%, 95% confidence interval [CI]: 35.4–84.8%) and nine (81.8%, 95% CI: 52.3–94.9%) of 11 patients with a baseline trough and peak level in the upper quintile, respectively, had a subsequent level that remained within this range. Only one (9.1%, 95% CI: 1.6–37.7%) patient had a subsequent level that fell just lower than the median.

Conclusion The trough and peak levels of apixaban in patients who have a high level on a single occasion, usually remain high when the assay is repeated in 2 months. Accordingly, the finding of a high apixaban level in patients deemed to be at high risk of bleeding, allows physicians contemplating off-label use of the 2.5-mg BID dose to limit its use to selected patients who are less likely to be exposed to an increased risk of thrombosis.

Prediction of Residual Stroke Risk in Anticoagulated Patients with Atrial Fibrillation: mCARS

Our ability to evaluate residual stroke risk despite anticoagulation in atrial fibrillation (AF) is currently lacking. The Calculator of Absolute Stroke Risk (CARS) has been proposed to predict 1-year absolute stroke risk in non-anticoagulated patients. We aimed to determine whether a modified CARS (mCARS) may be used to assess the residual stroke risk in anticoagulated AF patients from ‘real-world’ and ‘clinical trial’ cohorts. We studied patient-level data of anticoagulated AF patients from the real-world Murcia AF Project and AMADEUS clinical trial. Individual mCARS were estimated for each patient. None of the patients were treated with non-vitamin K antagonist oral anticoagulants. The predicted residual stroke risk was compared to actual stroke risk. 3503 patients were included (2205 [62.9%] clinical trial and 1298 [37.1%] real-world). There was wide variation of CARS for each category of CHA₂DS₂-VASc score in both cohorts. Average predicted residual stroke risk by mCARS (1.8 ± 1.8%) was identical to actual stroke risk (1.8% [95% CI, 1.3–2.4]) in the clinical trial, and broadly similar in the real-world (2.1 ± 1.9% vs. 2.4% [95% CI, 1.6–3.4]). AUCs of mCARS for prediction of stroke events in the clinical trial and real-world were 0.678 (95% CI, 0.598–0.758) and 0.712 [95% CI, 0.618–0.805], respectively. mCARS was able to refine stroke risk estimation for each point of the CHA₂DS₂-VASc score in both cohorts. Personalised residual 1-year absolute stroke risk in anticoagulated AF patients may be estimated using mCARS, thereby allowing an assessment of the absolute risk reduction of treatment and facilitating a patient-centred approach in the management of AF. Such identification of patients with high residual stroke risk could help target more aggressive interventions and follow-up.

Number needed to treat for net effect of anticoagulation in atrial fibrillation: Real-world vs. clinical-trial evidence

AIMS

The net benefit of oral anticoagulants (OACs) in atrial fibrillation (AF) is poorly understood. We aimed to determine the NNT for net effect (NNT_net ) using calculator of absolute stroke risk (CARS) in anticoagulated patients with AF in real-world and clinical trial cohorts.

METHODS

Post-hoc analysis of patient-level data from the real-world Murcia AF Project and AMADEUS clinical trial. Baseline risk of stroke was determined using CARS. The risk of stroke and major bleeding events with OAC were determined using the number of respective events at 1-year. NNT_net was calculated as a reciprocal of the net effect of absolute risk reduction with OAC (NNT_net  = 1/(absolute risk reduction of stroke[ARR_stroke ] - absolute risk increase of major bleeding[ARI_bleeding ])).

RESULTS

In total, 3511 patients were included (1306 [37.2%] real-world patients and 2205 [62.8%] clinical trial participants). The absolute 1-year stroke risk was similar across both cohorts. In the real-world cohort, OAC was associated with a 4.0% ARR_stroke , 25 NNT_benefit , 1.0% ARI_bleeding , 100 NNT_harm and 34 NNT_net . In the clinical trial cohort, OAC was associated with a 3.8% ARR_stroke , 27 NNT_benefit , 1.6% ARI_bleeding , 63 NNT_harm and 46 NNT_net . In both cohorts, the NNT_net was significantly lower in patients with an excess stroke risk of ≥2% by CARS.

CONCLUSION

Overall, the NNT_net approach in AF incorporates information regarding baseline risk of stroke and major bleeding, and relative effects of OAC with the potential to include multiple additional outcomes and weighting of events based on their perceived effects by individual patients.

Cost-Effectiveness Analysis of Direct Oral Anticoagulants Vs. Vitamin K Antagonists in the Elderly With Atrial Fibrillation: Insights From the Evidence in a Real-World Setting

Background: In the clinical setting, the economic benefits of direct oral anticoagulants (DOACs) in elderly patients with atrial fibrillation (AF) remain unclear. This study aimed to estimate and compare the cost-effectiveness of DOACs (dabigatran, rivaroxaban, apixaban, and edoxaban) and vitamin K antagonists (VKAs; warfarin) in preventing stroke among AF patients aged >75 years in real-world practice. Methods: A Markov model with a 10-year span was constructed to estimate the long-term clinical and economic outcomes among AF patients aged >75 years treated with DOACs and warfarin. The study was populated with a hypothetical cohort of 10,000 AF patients aged >75 years. Probabilities of clinical outcomes were obtained from the pooled observational studies (OSs), comparing DOACs (dabigatran, rivaroxaban, apixaban, and edoxaban) with VKAs. Other model inputs, including the utilities and the costs, were all estimated from public sources and the published literature. The costs, quality-adjusted life-years (QAYLs), and incremental cost-effectiveness ratios (ICER) were estimated for each treatment strategy. Subgroup analyses of individual DOACs and the scenario analysis were performed. Uncertainty was evaluated by deterministic sensitivity analysis and probabilistic sensitivity analysis (PSA). Results: Compared to warfarin, DOACs were associated with a gain of 0.36 QALY at an additional cost of $15,234.65, resulting in an ICER of $42,318.47 per QALY. Sensitivity analysis revealed that the ICER was sensitive to the cost of DOACs. Direct oral anticoagulants also shifted from dominating to dominated status When their annual costs of DOACs were over $3,802.84 or the risk ratio of death compared to warfarin was over 1.077%/year. Probabilistic sensitivity analysis (PSA) suggested that DOACs had a 53.83 and 90.7% probability of being cost-effective when the willingness-to-pay threshold was set at $50,000 and $100,000, respectively. Among all the four individual DOACs, edoxaban treatment was revealed as the preferred treatment strategy for the AF patients aged over 75 years by yielding the most significant health gain with the relatively low total cost. Conclusions: Despite the high risk for major bleeding in elderly patients with AF, DOACs are more cost-effective treatment options than warfarin in real-world practice. Edoxaban was the preferred treatment strategy among four kinds of DOACs for AF patients aged over 75 years. Furthermore, beyond their safety profiles, the treatment benefits of DOACs assumed greater relevance and importance in older adults.

Outcomes in VKA-treated patients with atrial fibrillation and chronic kidney disease: Clinical trials vs 'real-world'

BACKGROUND

Our objectives were to evaluate the risk of adverse events in a 'real-world' vs 'clinical trial' cohort of atrial fibrillation (AF) patients with chronic kidney disease (CKD).

METHODS

We studied patient-level data for vitamin K antagonist-treated AF patients with a creatinine clearance <60 mL/min from the Murcia AF Project and AMADEUS trial. The study end-points were ischaemic stroke, major bleeding, all-cause mortality, myocardial infarction and intracranial haemorrhage.

RESULTS

This study included 1,108 AF patients with CKD. The annual rate of the composite study outcome of ischaemic stroke, major bleeding and all-cause mortality was higher in the real-world (13.4%) vs AMADEUS (6.6%) cohort with an IRR of 2.04 (95% CI,1.34-3.09), P < .001. Individual annual rates of major bleeding, all-cause mortality and non-cardiovascular mortality were significantly greater in the real-world cohort. Similar findings were demonstrated even after multivariable adjustment, with the composite outcome HR of 2.85 (95% CI,1.74-4.66), P < .001. In a propensity score matched cohort, this risk remained significantly higher in the real-world cohort (IRR 2.95 [95% CI,1.03-10.28], P = .027), as did the risk of major bleeding and all-cause mortality.

CONCLUSION

Vitamin K antagonist-treated AF patients with CKD are exposed to significant annual rates of major adverse events including all-cause mortality. This risk may be under-appreciated in the idealised environment of randomised controlled trials.

Apixaban for Stroke Prevention in Atrial Fibrillation: Why are Event Rates Higher in Clinical Practice than in Randomized Trials?—A Systematic Review

Background Recent reports suggest an important contribution from frequent off-label use of apixaban 2.5 mg twice daily to the higher rates of thromboembolic events observed in observational studies (OSs) relative to in randomized controlled trials (RCTs), and consequently, advocate against such use in all patients.

Objectives To examine factors contributing to the higher thromboembolic event rates, we estimated the prevalence of off-label use in contemporary practice, and compared patient characteristics and rates of stroke/systemic embolism, major bleeding, and mortality by apixaban dose and by study design in a systematic review and meta-analysis.

Results and Discussion We identified 18 OSs and 2 RCTs that included 155,228 and 11,928 patients, respectively. Patients in OSs more often received apixaban 2.5 mg twice daily (31.3% vs. 5.1%), were older (mean age 73.8 vs. 69.8 years), and had higher CHA2DS2-VASc scores (mean 3.6 vs. 2.9) versus those in RCTs. We observed a consistent pattern of higher rates of thromboembolic events, bleeding, and mortality in patients treated with 2.5 versus 5 mg twice daily apixaban in both OSs and RCTs.

Conclusion The higher risk profiles of patients in OSs versus RCTs, and higher rates of both bleeding and mortality not attributable to thromboembolism in patients treated with apixaban 2.5 versus 5 mg twice daily suggest that differences in patient characteristics are additional important contributors to the higher than expected thromboembolic event rates in clinical practice.

Treatment strategies for patients with atrial fibrillation and anticoagulant-associated intracranial hemorrhage: an overview of the pharmacotherapy

INTRODUCTION

Oral anticoagulants (OAC) reduce stroke/systemic embolism and mortality risks in atrial fibrillation (AF). However, there is an inherent bleeding risk with OAC, where intracranial hemorrhage (ICH) is the most feared, disabling, and lethal complication of this therapy. Therefore, the optimal management of OAC-associated ICH is not well defined despite multiple suggested strategies.

AREAS COVERED

In this review, the authors describe the severity and risk factors for OAC-associated ICH and the associated implications for using DOACs in AF patients. We also provide an overview of the management of OAC-associated ICH and treatment reversal strategies, including specific and nonspecific reversal agents as well as a comprehensive summary of the evidence about the resumption of DOAC and the optimal timing.

EXPERT OPINION

In the setting of an ICH, supportive care/measures are needed, and reversal of anticoagulation with specific agents (including administration of vitamin K, prothrombin complex concentrates, idarucizumab and andexanet alfa) should be considered. Most patients will likely benefit from restarting anticoagulation after an ICH and permanently withdrawn of OAC is associated with worse clinical outcomes. Although the timing of OAC resumption is still under debate, reintroduction after 4-8 weeks of the bleeding event may be possible, after a multidisciplinary approach to decision-making.

Murcia atrial fibrillation project II: protocol for a prospective observational study in patients with atrial fibrillation

INTRODUCTION

Atrial fibrillation (AF) is characterised by a high stroke risk. Vitamin K antagonists (VKAs) are the most commonly used oral anticoagulants (OACs) in Spain, but their efficacy and safety depend on the time in therapeutic range of International Normalized Ratio (INR) 2.0-3.0 over 65%-70%. Unfortunately, the difficulties of maintaining an optimal level of anticoagulation and the complications of VKAs (particularly haemorrhagic ones), frequently lead to cessation of this therapy, which has been associated with higher risk of adverse events (AEs), including ischaemic stroke. Our aims are as follows: (1) to evaluate the quality of oral anticoagulation with VKAs, the prevalence of poor quality of anticoagulation, and to identify factors predisposing to poor quality anticoagulation; and (2) to identify patients who will stop OAC and to investigate what factors influence the decision of OAC withdrawal.

METHODS AND ANALYSIS

Prospective observational cohort study including outpatients newly diagnosed with AF and naïve for OACs from July 2016 to June 2018 in an anticoagulation clinic. Patients with prosthetic heart valves, rheumatic mitral valves or valvular AF will be excluded. Follow-up will extend for up to 3 years. During this period, the INR results and changes in the anticoagulant therapy will be recorded, as well as all AEs, or any other information that would be relevant to the proper conduct of research.

ETHICS AND DISSEMINATION

All patients were informed about the nature and purpose of the study, and the protocol was approved by the Ethics Committee of Hospital General Universitario Morales Meseguer (reference: EST:20/16). This is an observational study focusing on 'real life' practice and therefore all treatments and follow-up will be performed in accordance to the routine clinical practice with no specific interventions or visits. The results of our study will be disseminated by presentations at national and international meetings, and publications in peer-reviewed journals.

Use of rivaroxaban in patients attending a hematology unit in clinical practice

Aim: To determine drug persistence and rates of events among patients treated with rivaroxaban in a hematology unit. Methods: Retrospective study of patients that started treatment with rivaroxaban, in the hematology unit of a tertiary hospital. Results: A total of 161 patients were included, of whom 83.9% had atrial fibrillation and 11.2% venous thromboembolism, and 76.4% of patients were taking rivaroxaban 20 mg, 22.4% 15 mg and 1.2% 10 mg. After a follow-up of 1.8 ± 1.1 years, only four patients (2.5%) discontinued treatment. Rates of thromboembolic events, major bleeding/clinically relevant nonmajor bleeding and intracranial hemorrhage were 1.1, 2.8, 0.3 events per 100 patient-years, respectively. Conclusion: In patients attended in a hematology unit, medication persistence was high, and the incidence of outcomes low.

Integrated Care Management of Patients With Atrial Fibrillation and Risk of Cardiovascular Events: The ABC (Atrial fibrillation Better Care) Pathway in the ATHERO-AF Study Cohort

OBJECTIVE

To investigate the impact on cardiovascular events (CVEs) in a real-world population of patients with atrial fibrillation (AF) by implementing the Atrial fibrillation Better Care (ABC: A, Avoid stroke with anticoagulation; B, better symptom management; C, Cardiovascular and comorbidity risk management) pathway.

PATIENTS AND METHODS

This prospective single-center cohort study included 907 consecutive patients with nonvalvular AF on vitamin K antagonists from February 2008 to December 2016. The A, B, and C groups were defined as follows: "A" by a Time in Therapeutic Range ≥65%; "B" by a European Heart Rhythm Association (EHRA) symptom scale I-II, and "C" as optimized cardiovascular comorbidity management. Primary end point was a composite outcome of CVEs.

RESULTS

During a median follow-up of 36.9 months (interquartile range [IQR] 20.0-57.5; 3022 patient-years), 118 CVEs occurred (3.9% per year; 95% confidence interval [CI], 3.2-4.7). Symptomatic patients (EHRA III-IV) had a higher risk of CVEs compared with those in EHRA I (hazard ratio [HR], 2.73, 95% CI, 1.61-4.63, P<.001). Optimally managed patients in the ABC group (n=198) had a lower risk of CVEs (1.8 [95% CI, 0.9-3.0] vs 4.5% [95% CI, 3.7-5.5] per year, P=.001) compared with those presenting with at least 1 suboptimal ABC factor (HR, 0.40, 95% CI, 0.22-0.74, P=.003). This association was evident using multivariate Cox proportional regression analysis (HR, 0.44, 95% CI, 0.24-0.80, P=.007).

CONCLUSION

Integrated care management according to the ABC pathway resulted in a significantly lower rate of CVEs, suggesting a clear benefit of a holistic approach to optimize the management of patients with AF.

TRIAL REGISTRATION

clinicaltrials.gov Identifier: NCT01882114.

Direct oral anticoagulation and mortality in moderate to high-risk atrial fibrillation

OBJECTIVE

Although direct oral anticoagulants (DOAC) are the recommended antithrombotic therapy for patients with non-valvular atrial fibrillation (NVAF), anticoagulation in patients with NVAF is still inadequate. The effect of withholding DOAC therapy on patient survival is unknown. Therefore, our objective was to compare all-cause mortality rates between DOAC-treated patients with NVAF and similar patients receiving no anticoagulation.

METHODS

We performed a retrospective cohort study analysing Clalit Health Services' extensive electronic database, regarding all newly diagnosed, anticoagulant-naïve patients with NVAF who were eligible for DOAC therapy from 1 January 2011 to 31 December 2016. Patients who received DOAC therapy were matched by propensity scoring to patients receiving no anticoagulation. The primary outcome was all-cause mortality. Final patient follow-up date was 15 May 2017.

RESULTS

18 901 eligible patients were identified. 8298 received treatment with a DOAC and 10 603 received no anticoagulation therapy. Of those, 5657 patients who received DOAC therapy were matched with 5657 patients who did not receive any anticoagulant. Death occurred in 715 patients in the DOAC-treated group (7.6% per year) and in 2075 patients in the non-anticoagulated patient group (11.1% per year). DOAC therapy was associated with significantly lower risk for all-cause mortality (HR=0.69, 95% CI 0.63 to 0.75, p<0.001). The benefit of DOAC therapy was demonstrated across all subgroups analysed.

CONCLUSIONS

In this cohort of newly diagnosed patients with NVAF, DOAC therapy was associated with a significantly lower risk of death compared with no oral anticoagulation. Our findings provide further evidence for the importance of providing DOAC anticoagulation in patients with NVAF.

Predicting Thromboembolic and Bleeding Event Risk in Patients with Non-Valvular Atrial Fibrillation: A Systematic Review

BACKGROUND

 Atrial fibrillation (AF) is a common cardiac arrhythmia that increases the risk of stroke. Medical therapy for decreasing stroke risk involves anticoagulation, which may increase bleeding risk for certain patients. In determining the optimal therapy for stroke prevention for patients with AF, clinicians use tools with various clinical, imaging and patient characteristics to weigh stroke risk against therapy-associated bleeding risk.

AIM

 This article reviews published literature and summarizes available risk stratification tools for stroke and bleeding prediction in patients with AF.

METHODS

 We searched for English-language studies in PubMed, Embase and the Cochrane Database of Systematic Reviews published between 1 January 2000 and 14 February 2018. Two reviewers screened citations for studies that examined tools for predicting thromboembolic and bleeding risks in patients with AF. Data regarding study design, patient characteristics, interventions, outcomes, quality, and applicability were extracted.

RESULTS

 Sixty-one studies were relevant to predicting thromboembolic risk and 38 to predicting bleeding risk. Data suggest that CHADS₂, CHA₂DS₂-VASc and the age, biomarkers, and clinical history (ABC) risk scores have the best evidence for predicting thromboembolic risk (moderate strength of evidence for limited prediction ability of each score) and that HAS-BLED has the best evidence for predicting bleeding risk (moderate strength of evidence).

LIMITATIONS

 Studies were heterogeneous in methodology and populations of interest, setting, interventions and outcomes analysed.

CONCLUSION

 CHADS₂, CHA₂DS₂-VASc and ABC scores have the best prediction for stroke events, and HAS-BLED provides the best prediction for bleeding risk. Future studies should define the role of imaging tools and biomarkers in enhancing the accuracy of risk prediction tools.

PRIMARY FUNDING SOURCE

 Patient-Centered Outcomes Research Institute (PROSPERO #CRD42017069999).

Pharmaceutical Care Increases Time in Therapeutic Range of Patients With Poor Quality of Anticoagulation With Warfarin

Thromboembolic events are associated with high mortality and morbidity indexes. In this context, warfarin is the most widely prescribed oral anticoagulant agent for preventing and treating these events. This medication has a narrow therapeutic range and, consequently, patients usually have difficulty in achieving and maintaining stable target therapeutics. Some studies on the literature about oral anticoagulant management showed that pharmacists could improve the efficiency of anticoagulant therapy. However, the majority of these studies included general patients retrospectively. The aim of this study was to prospectively evaluate a pharmacist’s warfarin management in patients with poor quality of anticoagulation therapy (Time in the Therapeutic Range- TTR < 50%). We included 268 patients with atrial fibrillation (AF) and without stable dose of warfarin (TTR < 50%, based on the last three values of International Normalized Ratio-INR). We followed them up for 12 weeks, INR values were evaluated and, when necessary, the dose adjustments were performed. During the first four visits, patient’s INR was measured every 7 days. Then, if INR was within the target therapeutic range (INR: 2–3), the patient was asked to return in 30 days. However, if INR was out the therapeutic target, the patient was asked to return in 7 days. Adherence evaluation was measured through questionnaires and by counting the pills taken. Comparison between basal TTR (which was calculated based on the three last INR values before prospective phase) and TTR of 4 weeks (calculated by considering the INR tests from visits 0 to 4, in the prospective phase of the study) and basal TTR and TTR of 12 weeks (calculated based on the INR tests from visits 0 to 12, in the prospective phase of the study) revealed significant statistical differences (0.144 ± 0.010 vs. 0.382 ± 0.016; and 0.144 ± 0.010 vs. 0.543 ± 0.014, p < 0.001, respectively). We also observed that the mean TTR of 1 year before (retrospective phase) was lower than TTR value after 12 weeks of pharmacist-driven treatment (prospective phase) (0.320 ± 0.015; 0.540 ± 0.015, p < 0.001). In conclusion, pharmaceutical care was able to improve TTR values in patients with AF and poor quality of anticoagulation with warfarin.