Oral Anticoagulants in the Oldest Old with Recent Stroke and Atrial Fibrillation

Time to benefit and harm of direct oral anticoagulants in device-detected atrial fibrillation: A pooled analysis of the NOAH-AFNET 6 and ARTESiA trials

BACKGROUND

Direct oral anticoagulants (DOACs) reduce stroke risk in patients with device-detected atrial fibrillation (DD-AFib) but increase major bleeding risk. The time to benefit (TTB) and time to harm (TTH) are not well quantified.

OBJECTIVE

The purpose of this study was to determine TTB and TTH in DOAC-treated patients with DD-AFib.

METHODS

Studies were identified from PubMed searching until November 2023. The primary efficacy outcome was the time to the first stroke event, and the primary safety outcome was the time to the first major bleeding event. Pooled hazard ratio (HR) and its confidence interval (CI) were calculated through reconstructed patient-level data and study-level data. Weibull model and Markov chain Monte Carlo simulation were applied to determine time to specific absolute risk change thresholds.

RESULTS

Two trials involving DOACs-NOAH-AFNET 6 (Non-vitamin K antagonist Oral anticoagulants in patients with Atrial High rate episodes) and ARTESiA (Apixaban for the Reduction of Thrombo-Embolism in Patients With Device-Detected Sub-Clinical Atrial Fibrillation)-were identified, which randomized 6548 adults with a mean age of >75 years and a median atrial high-rate episode duration ranging from 1.5 to 2.8 hours. DOACs decreased the risk of stroke (HR 0.67; 95% CI 0.50-0.90) but increased the risk of major bleeding (HR 1.57; 95% CI 1.21-2.04). A TTB of 2.67 years was needed to prevent 1 stroke per 100 DOAC-treated patients, while a TTH of 1.67 years was needed to observe 1 major bleeding.

CONCLUSION

In elderly patients with low durations of DD-AFib, DOACs result in a delayed and restricted stroke-preventive benefit while posing an early-onset bleeding risk. Our findings offer new insights into the risk-benefit profile and provide clinicians an additional dimension to facilitate shared decision-making discussions with patients.

Optimal use of antithrombotic agents in recent small subcortical strokes accompanied by atrial fibrillation

BACKGROUND

This study aimed to evaluate the efficacy and safety of anticoagulants (AC) and antiplatelets (APT) in patients with recent small subcortical infarctions (RSSI) and atrial fibrillation (AF).

METHODS

We utilized a prospective multicenter stroke registry database to identify patients with RSSI with a concurrent diagnosis of AF. Propensity score matching analysis was used to balance baseline differences among the AC-only, APT-only, and their combination groups. The main outcomes of interest were time to occurrence of minor and major bleeding, stroke recurrence, and all-cause mortality. Adjusted hazard ratios (aHRs) and 95% confidence intervals (CIs) for each outcome were calculated using the multivariable Cox proportional hazard regression analysis.

RESULTS

Of the 404 eligible patients, 28.2% received APT only, 53.0% received AC only, and 18.9% received a combination of both. Notable differences were observed between these groups in terms of the 1-year stroke recurrence (APT, 32.5%; AC, 5.6%; APT + AC, 9.2%) and all-cause mortality (APT, 21.9%; AC, 6.1%; APT + AC, 14.5%), whereas the rates of bleeding events were comparable. The multivariable analysis indicated a significant association of AC alone with reduced risks of severe bleeding, stroke recurrence, and all-cause mortality compared with APT alone (aHR 0.64, 95% CI 0.41-0.98; aHR 0.11, 95% CI 0.06-0.22; aHR 0.22, 95% CI 0.11-0.44, respectively). The combination group showed a reduced risk of stroke recurrence compared to APT alone (aHR 0.19, 95% CI 0.08-0.46). These findings remained consistent with the propensity score-matched analysis.

CONCLUSION

AC showed better clinical outcomes than APT in patients with RSSI and AF. Additionally, combination therapy with AC and APT was associated with a lower risk of stroke recurrence than APT alone.

Reversal and resumption of anticoagulants in patients with anticoagulant-associated intracerebral hemorrhage

The use of anticoagulants has become more frequent due to the progressive aging population and increased thromboembolic events. Consequently, the proportion of anticoagulant-associated intracerebral hemorrhage (AAICH) in stroke patients is gradually increasing. Compared with intracerebral hemorrhage (ICH) patients without coagulopathy, patients with AAICH may have larger hematomas, worse prognoses, and higher mortality. Given the need for anticoagulant reversal and resumption, the management of AAICH differs from that of conventional medical or surgical treatments for ICH, and it is more specific. Understanding the pharmacology of anticoagulants and identifying agents that can reverse their effects in the early stages are crucial for treating life-threatening AAICH. When patients transition beyond the acute phase and their vital signs stabilize, it is important to consider resuming anticoagulants at the right time to prevent the occurrence of further thromboembolism. However, the timing and strategy for reversing and resuming anticoagulants are still in a dilemma. Herein, we summarize the important clinical studies, reviews, and related guidelines published in the past few years that focus on the reversal and resumption of anticoagulants in AAICH patients to help implement decisive diagnosis and treatment strategies in the clinical setting.

Secular Trends in Outcomes and Impact of Novel Oral Anticoagulants in Atrial Fibrillation-Related Acute Ischemic Stroke

BACKGROUND

Novel oral anticoagulants (NOACs) are currently recommended for the secondary prevention of stroke in patients with acute ischemic stroke (AIS) accompanied by atrial fibrillation (AF). However, the impact of NOACs on clinical outcomes in real-world practice remains ambiguous. This study analyzes the trend of clinical events in patients with AF-related AIS and determines how much the introduction of NOACs has mediated this trend.

METHODS

We identified patients with AIS and AF between January 2011 and December 2019 using a multicenter stroke registry. Annual rates of NOAC prescriptions and clinical events within 1 year were evaluated. The primary outcome was a composite of recurrent stroke, myocardial infarction, and all-cause mortality. To assess the mediation effect of NOACs on the relationship between the calendar year and these outcomes, we used natural effect models and conducted exposure-mediator, exposure-outcome, and mediator-outcome analyses using multivariable regression models or accelerated failure time models, adjusting for potential confounders.

RESULTS

Among the 12 977 patients with AF-related AIS, 12 500 (average age: 74.4 years; 51.3% male) were analyzed after excluding cases of valvular AF. Between 2011 and 2019, there was a significant decrease in the 1-year incidence of the primary composite outcome from 28.3% to 21.7%, while the NOAC prescription rate increased from 0% to 75.6%. A 1-year increase in the calendar year was independently associated with delayed occurrence of the primary outcome (adjusted time ratio, 1.10 [95% CI, 1.07-1.14]) and increased NOAC prescription (adjusted odds ratio, 2.20 [95% CI, 2.14-2.27]). Increased NOAC prescription was associated with delayed occurrence of the primary outcome (adjusted time ratio, 3.82 [95% CI, 3.17 to 4.61]). Upon controlling for NOAC prescription (mediator), the calendar year no longer influenced the primary outcome (adjusted time ratio, 0.97 [95% CI, 0.94-1.00]). This suggests that NOAC prescription mediates the association between the calendar year and the primary outcome.

CONCLUSIONS

Our study highlights a temporal reduction in major clinical events or death in Korean patients with AF-related AIS, mediated by increased NOAC prescription, emphasizing NOAC use in this population.

Atrial Fibrillation Detected before or after Stroke: Role of Anticoagulation

BACKGROUND

Atrial fibrillation (AF) known before ischemic stroke (KAF) has been postulated to be an independent category with a recurrence risk higher than that of AF detected after stroke (AFDAS). However, it is unknown whether this risk difference is confounded by pre-existing anticoagulation, which is most common in KAF and also indicates a high ischemic stroke recurrence risk.

METHODS

Individual patient data analysis from 5 prospective cohorts of anticoagulated patients following AF-associated ischemic stroke. We compared the primary (ischemic stroke recurrence) and secondary outcome (all-cause death) among patients with AFDAS versus KAF and among anticoagulation-naïve versus previously anticoagulated patients using multivariable Cox, Fine-Gray models, and goodness-of-fit statistics to investigate the relative independent prognostic importance of AF-category and pre-existing anticoagulation.

RESULTS

Of 4,357 patients, 1,889 (43%) had AFDAS and 2,468 (57%) had KAF, while 3,105 (71%) were anticoagulation-naïve before stroke and 1,252 (29%) were previously anticoagulated. During 6,071 patient-years of follow-up, we observed 244 recurrent strokes and 661 deaths. Only pre-existing anticoagulation (but not KAF) was independently associated with a higher hazard for stroke recurrence in both Cox and Fine-Gray models. Models incorporating pre-existing anticoagulation showed better fit than those with AF category; adding AF-category did not result in better model fit. Neither pre-existing anticoagulation nor KAF were independently associated with death.

CONCLUSION

Our findings challenge the notion that KAF and AFDAS are clinically relevant and distinct prognostic entities. Instead of attributing an independently high stroke recurrence risk to KAF, future research should focus on the causes of stroke despite anticoagulation to develop improved preventive treatments. ANN NEUROL 2023;94:43-54.

Managing older people with atrial fibrillation and preventing stroke: a review of anticoagulation approaches

INTRODUCTION

Oral anticoagulants (OACs) are the cornerstone of stroke prevention in atrial fibrillation (AF), but prescribing decisions in older people are complicated. Clinicians must assess the net clinical benefit of OAC in the context of multiple chronic conditions, polypharmacy, frailty and life expectancy. The under-representation of high-risk, older adult sub-populations in clinical trials presents the challenge of choosing the right OAC, where a 'one-size-fits-all' approach cannot be taken.

AREAS COVERED

This review discusses OAC approaches for stroke prevention in older people with AF and presents a prescribing aid to support clinicians' decision-making. High-risk older adults with multiple chronic conditions, specifically chronic kidney disease, dementia/cognitive impairment, previous stroke/transient ischemic attack or intracranial hemorrhage, polypharmacy, frailty, low body weight, high falls risk, and those aged ≥75 years are considered.

EXPERT OPINION

Non-vitamin K antagonist OACs are the preferred first-line OAC in older adults with AF, including high-risk subpopulations, after individual assessment of stroke and bleeding risk, except those with mechanical heart valves and moderate-to-severe mitral stenosis. Head-to-head comparisons of NOACs are not available, therefore the choice of drug (and dose) should be based on an individual's risk (stroke and bleeding) and incorporate their treatment preferences. Treatment decisions must be person-centered and principles of shared decision-making applied.

Direct Oral Anticoagulants versus Vitamin K Antagonists in Individuals Aged 80 Years and Older: An Overview in 2021

Two main types of oral anticoagulants are available in France: vitamin K antagonists (VKA) and, more recently, direct oral anticoagulants (DOAC). The benefit−risk profile appears to be favorable for DOAC, which is as effective as VKA but safer (fewer cases of severe and cerebral bleeding). In a study in 2017, we observed that older adults did not seem to receive the same modalities of oral anticoagulants as younger individuals for various reasons. To assess anticoagulation prescribing practices over time, we repeated this cross-sectional study by comparing very old individuals taking DOAC to those taking VKA. Ambulatory individuals aged 80 years and older were included. They were affiliated with the Mutualité Sociale Agricole of Burgundy and were refunded for a medical prescription of oral anticoagulation in March 2021. The demographic characteristics, registered chronic diseases (RCD), number and types of prescribed drugs, and mortality of the DOAC group and the VKA group were compared. A total of 4275 subjects were included in the study: 67.44% (2883) received DOAC and 32.56% (1392) received VKA. The two groups were similar in age. In the DOAC group, there were more women (54.98% vs. 46.98%) (p < 0.001), fewer RCD (91.47% vs. 93.68%) (p = 0.014), and lower rates of venous thromboembolism (2.53% vs. 6.75%) (p < 0.001), severe heart failure (56.50% vs. 68.03%) (p < 0.001), and severe kidney diseases (1.38% vs. 3.59%) (p < 0.001), but there were more subjects with Alzheimer’s disease (7.49% vs. 4.31%) (p = 0.001). Individuals in the DOAC group had fewer prescriptions of furosemide (48.53% vs. 55.75%) (p < 0.001) and fibrates (2.32% vs. 3.88%) (p = 0.044). They also had more prescriptions of proton pump inhibitors (43.95% vs. 39.44%) (p = 0.006) and antirheumatics (1.60% vs. 0.65%) (p = 0.009) than those in the VKA group. There was no difference in mortality. This study revealed that prescribing practices for DOAC have changed over time.

Once versus twice daily direct oral anticoagulants in patients with recent stroke and atrial fibrillation

BACKGROUND

Data on the safety and effectiveness of once-daily (QD) versus twice-daily (BID) direct oral anticoagulants (DOAC) in comparison to vitamin K antagonists (VKA) and to one another in patients with atrial fibrillation (AF) and recent stroke are scarce.

PATIENTS AND METHODS

Based on prospectively obtained data from the observational registry Novel-Oral-Anticoagulants-in-Ischemic-Stroke-Patients(NOACISP)-LONGTERM (NCT03826927) from Basel, Switzerland, we compared the occurrence of the primary outcome - the composite of recurrent ischemic stroke, major bleeding, and all-cause death - among consecutive AF patients treated with either VKA, QD DOAC, or BID DOAC following a recent stroke using Cox proportional hazards regression including adjustment for potential confounders.

RESULTS

We analyzed 956 patients (median age 80 years, 46% female), of whom 128 received VKA (13.4%), 264 QD DOAC (27.6%), and 564 BID DOAC (59%). Over a total follow-up of 1596 patient-years, both QD DOAC and BID DOAC showed a lower hazard for the composite outcome compared to VKA (adjusted HR [95% CI] 0.69 [0.48, 1.01] and 0.66 [0.47, 0.91], respectively). Upon direct comparison, the hazard for the composite outcome did not differ between patients treated with QD versus BID DOAC (adjusted HR [95% CI] 0.94 [0.70, 1.26]). Secondary analyses focusing on the individual components of the composite outcome revealed no clear differences in the risk-benefit profile of QD versus BID DOAC.

DISCUSSION AND CONCLUSION

The overall benefit of DOAC over VKA seems to apply to both QD and BID DOAC in AF patients with a recent stroke, without clear evidence that one DOAC dosing regimen is more advantageous than the other.

Oral anticoagulants and outcomes in adults ≥80 years with atrial fibrillation: A global federated health network analysis

BACKGROUND

The objective of this study was to determine associations between use of oral anticoagulation (OAC) and stroke and bleeding-related outcomes for older people ≥80 years with atrial fibrillation (AF), and to determine trends over time in prescribing of OAC for this population.

METHODS

A retrospective cohort study was conducted. People aged ≥80 years with AF receiving (1) no OAC; (2) warfarin; or (3) a non-vitamin-K antagonist oral anticoagulant (NOAC) between 2011 and 2019 were included. Propensity score matching was used to balance cohorts (no OAC, warfarin or a NOAC) on characteristics including age, sex, ethnicity, and co-morbidities. Cox proportional hazard models were used to derive hazard ratios (HRs) and 95% confidence intervals (CIs).

RESULTS

The proportion of people aged ≥80 years receiving any OAC increased from 32.4% (n = 27,647) in 2011 to 43.6% (n = 110,412) in 2019. After propensity score matching, n = 169,067 individuals were included in the cohorts receiving no OAC or a NOAC. Compared to no OAC, participants receiving a NOAC had a lower risk of incident dementia (hazHR 0.68, 95% CI 0.65-0.71), all-cause mortality (HR 0.49, 95% CI 0.48-0.50), first-time ischaemic stroke (HR 0.87, 95% CI 0.83-0.91), and a higher risk of major bleeding (HR 1.08, 95% CI 1.05-1.11). Compared to participants receiving warfarin, participants receiving a NOAC had a lower risk of dementia (HR 0.90, 95% CI: 0.86-0.93), all-cause mortality (HR 0.74, 95% CI: 0.72-0.76), ischaemic stroke (HR 0.86, 95% CI: 0.82-0.90) and major bleeding (HR 0.88, 95% CI: 0.85-0.90). Similar results were observed when only including people with additional bleeding risk factors.

CONCLUSIONS

The proportion of people aged ≥80 years receiving OAC has increased since the introduction of NOACs, but remains low. Use of a NOAC was associated with improved outcomes compared to warfarin, and compared to no OAC, except for a small but statistically significant higher risk of major bleeding.

Switching from warfarin to direct-acting oral anticoagulants: it is time to move forward!

Oral vitamin K antagonists (VKAs), warfarin, have been in routine clinical use for almost 70 years for various cardiovascular conditions. Direct-Acting Oral Anticoagulants (DOACs) have emerged as competitive alternatives for VKAs to prevent stroke in patients with non-valvular atrial fibrillation (AF) and have become the preferred choice in several clinical indications for anticoagulation. Recent guidelines have limited the use of DOACs to patients with non-valvular AF to reduce the risk of cardioembolic complications and to treat venous thromboembolism (VTE). Although emerging evidence is suggestive of its high efficacy, there was a lack of data to support DOACs safety profile in patients with mechanical valve prosthesis, intracardiac thrombi, or other conditions such as cardiac device implantation or catheter ablation. Therefore, several clinical trials have been conducted to assess the beneficial effects of using DOACs, instead of VKAs, for various non-guideline-approved indications. This review aimed to discuss the current guideline-approved indications for DOACs, advantages, and limitations of DOACs use in various clinical indications highlighting the potential emerging indications and remaining challenges for DOACs use. Several considerations are in favour of switching from warfarin to DOACs including superior efficacy, better adverse effect profile, fewer drug-drug interactions, and they do not require frequent international normalized ratio (INR) monitoring. Large randomized controlled trials are required to determine the safety and efficacy of their use in various clinical indications.

Net clinical benefit of anticoagulant therapy from a neurologist's perspective: A review

In this article the concept of "net clinical benefit" (NCB) is considered in the context of stroke, the role of direct oral anticoagulants in secondary prevention of cardioembolic stroke and NCB from their prescription. Practical aspects of NCB evaluation from the neurologist's point of view are presented, taking into account such factors as stroke duration and severity, features of neurological deficit (severity of residual limitations, dysphagia, motor disorders and risk of falls), neuroimaging characteristics of stroke (focal size and hemorrhagic transformation) and concomitant neurological diseases (epilepsy and dementia). In all these situations, the use of oral anticoagulants has a significant clinical benefit, which justifies the inadmissibility of refusal to prescribe them.