Anticoagulants for Stroke Prevention in Atrial Fibrillation in Elderly Patients

Atrial Fibrillation as a Geriatric Syndrome: Why Are Frailty and Disability Often Confused? A Geriatric Perspective from the New Guidelines

Atrial Fibrillation can be considered a geriatric syndrome for its prevalence and incidence, its impact on patients' quality of life, and Health Systems' economy. The European Society of Cardiology 2024 guidelines introduce a recommendation for maintaining vitamin K antagonist therapy over switching to direct oral anticoagulants in clinically stable elderly patients with atrial fibrillation. This article explores the implications of this indication for the geriatric clinical context. The focus will also be devoted to the need for the stratification of older patients with atrial fibrillation, making an appropriate distinction between frailty and disability.

Current Real-World Status of Oral Anticoagulant Management in Japanese Patients

Anticoagulant therapy is a drug therapy that inhibits the formation of blood clots. Although anticoagulants are effective in preventing thromboembolism, they also carry the risk of bleeding, so they must be managed carefully, taking both efficacy and safety into account. Evidence regarding the effectiveness and safety of each anticoagulant has already accumulated through many large clinical trials and post-marketing surveillance. However, when making decisions in clinical practice, it is necessary to always take into consideration differences in patient populations between clinical trials and actual clinical practice, as well as differences in historical background. (For example, there are differences in antiplatelet drugs and coronary artery interventions that were mainly used in each era.) In this review we discuss the effectiveness and safety of currently used anticoagulants, focusing on different patient backgrounds and points to keep in mind regarding their proper use, based on the latest reports in Asian populations, especially Japanese people, over the past 1-2 years.

Cardiovascular Health of the Balearic Islands (Spain) After the COVID-19 Pandemic

Background/Objectives: The COVID-19 pandemic caused healthcare managers to reallocate resources from other areas in order to handle the outbreak. Cardiovascular usual care was especially affected during the first wave. Methods: We analyzed the short- and mid-term impact of the resource reallocation on cardiovascular health, focusing on the Balearic Islands in Spain. Data from 2019 to 2021 of the regional healthcare system and from the national and regional stats center were collected in order to analyze the variations in type of admissions, main causes of cardiovascular mortality, and the correlation between the monthly variation in those causes of mortality and total cardiovascular mortality. Results: The year 2021 showed worse results in terms of healthcare outcomes compared to the pre-pandemic period, with a population-adjusted cardiovascular mortality increase of 4.8% and heart failure and hypertension being the main drivers (6.4% and 26.45%, respectively). However, this impact was not homogeneous in both pandemic years. In 2020, the main driver for the cardiovascular mortality increase was myocardial infarction (R Pearson = 0.655/p = 0.021). On the other hand, chronic conditions such as heart failure and hypertension led to the increase in cardiovascular mortality in 2021 (R Pearson = 0.671/p = 0.017 and R Pearson = 0.619/p = 0.032, respectively). In-hospital resources for COVID-19 showed a positive correlation to cardiovascular mortality in 2021; however, it did not reach statistical significance (R Pearson = 0.41/p = 0.1). Conclusions: Mid-term cardiovascular health worsened in the Spanish Balearic Island region, with hypertension and heart failure being the main drivers, with important differences in influence between 2020 and 2021. We found a correlation between COVID-19 in-hospital resource allocation and total cardiovascular mortality.

Consequences of the Poor Anticoagulation Control of Patients with Non-Valvular Atrial Fibrillation Treated with Vitamin K Antagonists

Background: The prevention of thromboembolisms through anticoagulation and heart rate control is crucial in managing non-valvular atrial fibrillation (NVAF). This study aimed to analyze the consequences of poor anticoagulation control with vitamin K antagonists (VKAs) in Spanish patients with NVAF, focusing on thrombotic events, bleeding, mortality, healthcare resources (HRU), and costs. Methods: This observational, retrospective study used electronic medical records (BIG-PAC® database) of NVAF patients who started VKA treatment between 1 January 2016 and 31 December 2018. Patients were followed up for two years and classified by poor or adequate anticoagulation control. Demographic and clinical characteristics, treatments, incidence of cardiovascular events, mortality rates, HRU, and costs were analyzed. Results: Patients with poor control (n = 2136) had a 75% greater probability of suffering a cardiovascular event compared to patients with adequate control (n = 2351) (HR, 1.75 [95%CI: 1.43-2.14; p < 0.001]). Cardiovascular events, major bleeding, minor bleeding, systemic thromboembolism, and ischemic strokes were reduced by 32.1%, 46.2%, 29.6%, 22.2%, and 16.1%, respectively. It was estimated that adequate anticoagulant control saved EUR 455/patient with NAVF due to reduced hospitalization for cardiovascular events. Conclusions: For VKA-treated NVAF patients, poor anticoagulation control was associated with a higher number of cardiovascular events, greater consumption of HRU, and higher management costs than for patients with adequate control.

Application Value and Safety Analysis of Warfarin, Rivaroxaban, and Dabigatran Ester in Elderly Patients With Atrial Fibrillation

BACKGROUND

This study aimed to evaluate the application value and safety of Warfarin, Rivaroxaban, and Dabigatran in elderly patients with atrial fibrillation.

METHODS

A total of 180 elderly patients with atrial fibrillation admitted to our hospital were retrospectively analyzed. According to their anticoagulant treatment regimen, patients were divided into three groups: Warfarin (57 cases), Rivaroxaban (61 cases), and Dabigatran (62 cases). General demographic information was collected, and coagulation function indicators-including fibrinogen (FIB), thrombin time (PT), activated partial thrombin time (APTT), and D-dimer (D-D)-as well as liver function indexes-including total bilirubin (TbiL), alkaline phosphatase (ALP), aspartate aminotransferase (AST), and alanine transferase (ALT)-were compared before and after 4 weeks of treatment.

RESULTS

There were no significant differences in demographic characteristics such as gender, age, body mass index, or disease course among the three groups. The total effective rate in the Warfarin group (84.21%) was significantly lower than in the Rivaroxaban (98.36%) and Dabigatran (96.77%) groups (p < 0.05). However, there was no significant difference in the total effective rate between the Rivaroxaban and Dabigatran groups (p > 0.05). Additionally, no significant differences were found in the effects of the three drugs on coagulation function, liver function, or the incidence of bleeding (p = 0.052).

CONCLUSION

Warfarin, Rivaroxaban, and Dabigatran can effectively prevent thrombosis in elderly patients with atrial fibrillation, with Rivaroxaban and Dabigatran showing superior effectiveness. All three drugs demonstrated similar low rates of bleeding events and had no significant impact on coagulation and liver function.

Comparison between non-vitamin K oral antagonist versus warfarin in atrial fibrillation with and without valvular heart disease: a systematic review and meta-analysis

BACKGROUND

Atrial fibrillation (AF) poses a significant stroke risk in heart disease patients. This systematic review aims to evaluate the efficacy and safety of non-vitamin K oral antagonists (NOACs) versus vitamin K antagonists (VKAs) in AF patients with and without any valvular heart disease (VHD/N-VHD).

METHODS

A systematic search was conducted on PubMed, Scopus, and Google Scholar up to March 3, 2022. Efficacy and safety parameters were analyzed.

RESULTS

A total of 85,423 subjects from 10 studies were included in this meta-analysis. NOACs and VKAs showed similar effects on ischemic stroke in AF patients with VHD/N-VHD (RR 0.97; 95% CI 0.72-1.30; p = 0.83) and also on systemic embolic events (RR 1.02; 95% CI 0.83-1.25; p = 0.86). Similar effects were seen in VHD and N-VHD subgroups. Both treatments had similar effects on myocardial infarction in AF patients with VHD/N-VHD (RR 0.79; 95% CI 0.49-1.26; p = 0.32), VHD (RR 0.78; 95% CI 0.59-1.02; p = 0.07), and N-VHD subgroups (RR 0.82; 95% CI 0.30-2.21; p = 0.69). NOACs reduced the risk of intracranial bleeding in AF VHD/N-VHD (RR 0.64; 95% CI 0.54-0.77; p < 0.0001), VHD (RR 0.59; 95% CI 0.42-0.82; p = 0.002), and N-VHD subgroups (RR 0.70; 95% CI 0.57-0.85; p = 0.0003). Additionally, NOACs reduced the risk of gastrointestinal bleeding in AF VHD/N-VHD (RR 0.80; 95% CI 0.66-0.96; p = 0.02), specifically in the VHD subgroup (RR 0.69; 95% CI 0.54-0.89; p = 0.004). Moreover, NOACs were associated with a decreased risk for minor and non-fatal bleeding in AF patients with VHD/N-VHD (RR 0.86; 95% CI 0.75-0.99; p = 0.04).

CONCLUSION

NOACs are effective and safe for ischemic stroke, systemic embolic events, myocardial infarction, intracranial bleeding, and gastrointestinal bleeding in AF patients with VHD/N-VHD.

The effect of antiplatelet therapy and oral anticoagulants on the accuracy of faecal immunochemical testing

INTRODUCTION

Faecal immunochemical testing (FIT) has been adopted to identify patients requiring further investigations on the colorectal cancer (CRC) referral pathway. We aimed to investigate the effect of antiplatelet and anticoagulant drugs on the accuracy of FIT results.

METHODS

This observational study categorised patients with suspected CRC symptoms, who completed both FIT and colonic investigations, into two groups (control and exposed) based on their use of antiplatelet and anticoagulant drugs. Two-by-two tables and receiver operating characteristic (ROC) curve analysis were used to determine accuracy.

RESULTS

A total of 928 patients were divided into a control (n=683) and an exposed group (n=245). A nonsignificant higher proportion of patients tested positive in the exposed group (24.1% vs 18.4%, p=0.063). For detection of CRC, improved sensitivity of 87% vs 81.2%, specificity of 84.8% vs 79.9% and negative predictive value of 99.2% vs 98.3% was calculated in the control vs exposed groups, respectively. The positive predictive value was comparable between the two groups (21.4% vs 22% in the control and exposed groups, respectively). In ROC analysis, there was no difference between the groups (AUC 90% vs 87%, p=0.56). The use of antiplatelet and anticoagulant drugs did not increase the risk of positive FIT results on multivariate logistic regression analysis.

CONCLUSIONS

FIT accuracy for CRC detection remained unaffected despite more patients testing positive in the exposed group. FIT should be considered a supplementary tool for triage. Antiplatelet and anticoagulant drugs do not need to be discontinued before collection of FIT.

AF-React study: Prevalence of thrombotic events in patients with atrial fibrillation receiving NOACs - real-world data analysis from northern Portugal primary healthcare

Introduction

Anticoagulation is recommended for stroke prevention in patients with atrial fibrillation (AF). The guidelines suggest non-vitamin K antagonist anticoagulants (NOACs) as the primary therapy for anticoagulation in AF. Several patient-related factors increase the risk of thrombotic events: elderly individuals, a previous history of stroke, and chronic kidney disease. This study aims to determine the association between NOACs and other patient variables in AF and the occurrence of thrombotic events.

Methods

The database included all adults with the code K78 (ICPC-2 code for AF) who received clinical care in Northern Portugal's Primary Health Care between January 2016 and December 2018 and were dispensed the same NOAC at the pharmacy.

Results

The results indicate that 10.2% of AF patients on NOAC anticoagulation experienced a stroke. Furthermore, patients treated with apixaban and dabigatran had higher odds of experiencing a stroke compared to those treated with rivaroxaban. Among patients with the same age, gender, and CHA2DS2Vasc Score, apixaban was significantly associated with a higher likelihood of thrombotic events than rivaroxaban.

Discussion

These results have not been previously reported in studies with real-world data; therefore, a more detailed analysis should be conducted to enhance the validity of these findings.

Does prescribing apixaban or rivaroxaban versus warfarin for patients diagnosed with atrial fibrillation save health system costs? A multivalued treatment effects analysis

BACKGROUND

Non-valvular atrial fibrillation (AF) is a common heart arrhythmia in the elderly population. AF patients are at high-risk of ischemic strokes, but oral anticoagulant (OAC) therapy reduces such risks. Warfarin had been the standard OAC for AF patients, however its effectiveness is highly variable and dependent on close monitoring of the anticoagulant response. Newer OACs such as rivaroxaban and apixaban address these drawbacks but are more costly. It is uncertain which OAC therapy for AF is cost-saving from the healthcare system perspective.

METHODS

We followed a cohort of patients in Ontario, Canada, aged ≥ 66 who were newly diagnosed with AF and prescribed OACs between 2012 and 2017. We used a two-stage estimation procedure. First, we account for the patient selection into OACs using a multinomial logit regression model and estimated propensity scores. Second, we used an inverse probability weighted regression adjustment approach to determine cost-saving OAC options. We also examined component-specific costs (i.e., drug, hospitalization, emergency department and physician) to understand the drivers of cost-saving OACs.

RESULTS

We found that compared to warfarin, rivaroxaban and apixaban treatments were cost-saving options, with per-patient 1-year healthcare cost savings at $2436 and $1764, respectively. These savings were driven by cost-savings in hospitalization, emergency department visits, and physician visits, outweighing higher drug costs. These results were robust to alternative model specifications and estimation procedures.

CONCLUSIONS

Treating AF patients with rivaroxaban and apixaban than warfarin reduces healthcare costs. OAC reimbursement policies for AF patients should consider rivaroxaban or apixaban over warfarin as the first-line treatment.

Influence of the COVID-19 pandemic on patients receiving oral anticoagulants for the treatment of non-valvular atrial fibrillation

Background

Frequent monitoring of patients declined during the COVID-19 pandemic, harming patients with chronic diseases who critically needed correct monitoring. We evaluated the impact of the COVID-19 pandemic in patients with non-valvular atrial fibrillation (NVAF) receiving treatment with vitamin K antagonists (VKA) or non-vitamin K antagonist oral anticoagulants (NOAC) in clinical practice in Spain.

Methods

This observational, retrospective study analyzed prevalent patients treated with NOAC/VKA on 14/03/2019 (pre-COVID-19 period) and 14/03/2020 (COVID-19 period), who were followed up to 12 months. The study also considered incident patients who started treatment with NOAC/VKA between 15/03/2019 and 13/03/2020 (pre-COVID-19 period) and from 15/03/2020 to 13/03/2021 (COVID-19 period). Demographic characteristics, comorbidities, effectiveness, treatment patterns, and healthcare resource utilization were considered.

Results

Prevalent patients amounted to 12,336 and 13,342 patients, whereas 1,612 and 1,602 incident patients were included in the pre-COVID-19 and COVID-19 periods, respectively. Prevalent patients treated with VKA had more strokes, thromboembolism, and major bleeding compared to those receiving NOAC, particularly during the COVID-19 period. NOAC patients had a 12 % lower risk of death than those on treatment with VKA (Hazard ratio = 0.88 [95 % CI: 0.81 - 0.95], p = 0.033). In addition, VKA patients were less persistent after 12 months than NOAC patients (pre-COVID-19 period: 52.1 % vs. 78.9 %, p < 0.001; COVID-19 period: 49.2 % vs. 80.3 %, p < 0.001), and required more healthcare visits and hospitalizations than those on treatment with NOAC.

Conclusion

Compared to VKA, NOAC seems to have reduced the incidence of severe events and the use of healthcare resources for NVAF, particularly during the pandemic.

Risk of both intracranial hemorrhage and ischemic stroke in elderly individuals with nonvalvular atrial fibrillation taking direct oral anticoagulants compared with warfarin: Analysis of the ANAFIE registry

BACKGROUND AND AIMS

Elderly patients with nonvalvular atrial fibrillation (NVAF) might have a higher risk of intracerebral hemorrhage. To investigate this, we compared the incidence of intracranial hemorrhage (ICH) and its subtypes, as well as ischemic stroke, in patients taking direct oral anticoagulants (DOACs) compared with warfarin in a real-world setting. We also determined the baseline characteristics associated with both ICH and ischemic stroke.

METHODS

Patients aged ⩾ 75 years with documented NVAF enrolled in the prospective, multicenter, observational All Nippon Atrial Fibrillation in the Elderly Registry between October 2016 and January 2018 were evaluated. The co-primary endpoints were the incidence of ischemic stroke and ICH. Secondary endpoints included subtypes of ICH.

RESULTS

Of 32,275 patients (13,793 women; median age, 81.0 years) analyzed, 21,585 (66.9%) were taking DOACs and 8233 (25.5%) were taking warfarin. During the median 1.88-year follow-up, 743 patients (1.24/100 person-years) developed ischemic stroke and 453 (0.75/100 person-years) developed ICH (intracerebral hemorrhage, 189; subarachnoid hemorrhage, 72; subdural/epidural hemorrhage, 190; unknown subtype, 2). The incidence of ischemic stroke (adjusted hazard ratio (aHR) 0.82, 95% confidence interval (CI) 0.70-0.97), ICH (aHR 0.68, 95% CI 0.55-0.83), and subdural/epidural hemorrhage (aHR 0.53, 95% CI 0.39-0.72) was lower in DOAC users versus warfarin users. The incidence of fatal ICH and fatal subarachnoid hemorrhage was also lower in DOAC users versus warfarin users. Several baseline characteristics other than anticoagulants were also associated with the incidence of the endpoints. Of these, history of cerebrovascular disease (aHR 2.39, 95% CI 2.05-2.78), persistent NVAF, (aHR 1.90, 95% CI 1.53-2.36), and long-standing persistent/permanent NVAF (aHR 1.92, 95% CI 1.60-2.30) was strongly associated with ischemic stroke; severe hepatic disease (aHR 2.67, 95% CI 1.46-4.88) was strongly associated with overall ICH; and history of fall within 1 year was strongly associated with both overall ICH (aHR 2.29, 95% CI 1.76-2.97) and subdural/epidural hemorrhage (aHR 2.90, 95% CI 1.99-4.23).

CONCLUSION

Patients aged ⩾ 75 years with NVAF taking DOACs had lower risks of ischemic stroke, ICH, and subdural/epidural hemorrhage than those taking warfarin. Fall was strongly associated with the risks of intracranial and subdural/epidural hemorrhage.

DATA ACCESS STATEMENT

The individual de-identified participant data and study protocol will be shared for up to 36 months after the publication of the article. Access criteria for data sharing (including requests) will be decided on by a committee led by Daiichi Sankyo. To gain access, those requesting data access will need to sign a data access agreement. Requests should be directed to yamt-tky@umin.ac.jp.

Predictive value of bleeding risk scores in elderly patients with atrial fibrillation and oral anticoagulation

BACKGROUND

The predictive value of bleeding risk scores for atrial fibrillation in older patients is not as well known. The goal of this study was to evaluate the predictive value of HASBLED, ORBIT and ATRIA for major bleeding (MB) and intracranial hemorrhage (ICH) in patients ≥ 75 years with atrial fibrillation and oral anticoagulation (OAC).

METHODS

A retrospective unicenter study including patients ≥ 75 years with atrial fibrillation (AF) and OAC. A total of 7613 patients ≥ 75 years with AF and OAC included between 2014 and 2018 (registry: NCT04364516). We analyzed the discriminative value of HASBLED, ATRIA and ORBIT scores for bleeding endpoints (major bleeding as primary endpoint and intracerebral hemorrhage as secondary). Cox regression was used to predict major bleeding with each scale and also for searching other variables potentially predictor of major bleeding. Model discrimination was assessed using Harrell's C-statistic. Calibration was assessed with goodness-of-fit test proposed by Gronnesby and Borgan.

RESULTS

During a mean follow up of 4.0 years (IQR: 2.4-5.7 years), 729 patients developed MB (2.61 per 100 patients/year) and 243 patients developed ICH (0.85 per 100 patients/year). Three scores showed a low discrimination for major bleeding, being ORBIT the best (HASBLED C statistic = 0.557; ATRIA C statistic = 0.568; ORBIT C statistic = 0.595) and also a low discrimination for ICH (HASBLED C statistic = 0.509; ATRIA C statistic = 0.522; ORBIT C statistic = 0.526). Among the variables that are part of the scores and other baseline characteristics, after multivariable adjustment only sex (male), dementia, prior admission for bleeding, anemia and liver disease were found as a predictors of MB.

CONCLUSIONS

In older patients under oral anticoagulation with atrial fibrillation, the risk scores HASBLED, ATRIA and ORBIT showed a weak discrimination for major bleeding and intracranial hemorrhage. Therefore, other better alternatives should be evaluated for this purpose.

[Anticoagulation in older patients]

Prescribing oral anticoagulation in older patients for e.g. stroke prophylaxis has proven to be beneficial, but some special risks have to be considered. Renal function may be substantial impaired and dose reduction in at least some of the substances is recommended. Therefore, a closer monitoring of renal function is essential. Further as bleeding risk also increases with age usual scoring lists do less help this therapeutic dilemma than in younger patients. Adequate blood pressure control is essential in preventing intracerebral hemorrhage. Fall risk has to be assessed to initiate early compensation for this risk. Only high and unimprovable fall incidence may outweigh the benefits of oral anticoagulation therapy (>1 hospital admission per month due to a fall incident). Comprehensive geriatric assessment is crucial for early detection of specific adherence problems in older patients and is also helpful for discussion of individual deprescribing options in an end of live situation.

Plasma Drug Values of DOACs in Patients Presenting with Gastrointestinal Bleeding: A Prospective Observational Study

Background and Objectives: Anticoagulants are a well-known risk factor for gastrointestinal bleeding (GIB). In recent years, direct oral anticoagulants (DOACs) have taken a leading role in the treatment and prevention of thromboembolic incidents. The aim of this study was to investigate the prevalence of DOAC-treated patients with GIB whose plasma drug concentrations exceeded the cut-off values reported in the literature and to evaluate their clinical characteristics. Materials and Methods: Patients who were admitted to the Intensive Care Unit in the period 2/2020-3/2022 due to GIB were prospectively included in the study and classified into three groups according to the prescribed type of DOAC (apixaban, rivaroxaban, and dabigatran). For all participants, it was determined if the measured plasma drug levels exceeded the maximum serum concentration (Cmax) or trough serum concentration (Ctrough) obtained from the available data. A comparison of clinical parameters between the patients with and without excess drug values was performed. Results: There were 90 patients (54.4% men) included in the study, of whom 27 were treated with dabigatran, 24 with apixaban, and 39 with rivaroxaban. According to Cmax, there were 34 (37.8%), and according to Ctrough, there were 28 (31.1%) patients with excess plasma drug values. A statistically significant difference regarding excess plasma drug values was demonstrated between DOACs according to both Cmax (p = 0.048) and Ctrough (p < 0.001), with the highest rate in the group treated with dabigatran (55.6% for Cmax and 59.3% for Ctrough). Multivariate logistic regression showed that age (OR 1.177, p = 0.049) is a significant positive and glomerular filtration rate (OR 0.909, p = 0.016) is a negative predictive factor for excess plasma drug values. A total of six (6.7%) patients had fatal outcomes. Conclusions: Plasma drug concentrations exceed cut-off values reported in the literature in more than one-third of patients with GIB taking DOAC, with the highest rate in the dabigatran group. Clinicians should be more judicious when prescribing dabigatran to the elderly and patients with renal failure. In these patients, dose adjustment, plasma drug monitoring, or substitution with other, more appropriate DOACs should be considered.

Contemporary trends and barriers to oral anticoagulation therapy in Non-valvular atrial fibrillation during DOAC predominant era

There is a need to reassess contemporary oral anticoagulation (OAC) trends and barriers against guideline directed therapy in the United States. Most previous studies were performed before major guideline changes recommended direct oral anticoagulant (DOAC) use over warfarin or have otherwise lacked patient level data. Data on overuse of OAC in low-risk group is also limited. To address these knowledge gaps, we performed a nationwide analysis to analyze current trends. This is a retrospective cohort study assessing non-valvular AF identified using a large United States de-identified administrative claims database, including commercial and Medicare Advantage enrollees. Prescription fills were assessed within a 90-day follow-up from the patient's index AF encounter between January 1, 2016, and December 31, 2020. Among the 339,197 AF patients, 4.4%, 8.0%, and 87.6% were in the low-, moderate-, and high-risk groups (according to CHA₂DS₂-VASc score). An over (29.6%) and under (52.2%) utilization of OAC was reported in low- and high-risk AF patients. A considerably high frequency for warfarin use was also noted among high-risk group patients taking OAC (33.1%). The results suggest that anticoagulation use for stroke prevention in the United States is still comparable to the pre-DOAC era studies. About half of newly diagnosed high-risk non-valvular AF patients remain unprotected against stroke risk. Several predictors of OAC and DOAC use were also identified. Our findings may identify a population at risk of complications due to under- or over-treatment and highlight the need for future quality improvement efforts.

Converting patients from warfarin to non-vitamin K antagonist oral anticoagulants

BACKGROUND

Non-vitamin K antagonist oral anticoagulants (NOACs) are favorable in stroke prevention for geriatric patients with nonvalvular atrial fibrillation versus warfarin. These anticoagulants do not require international normalized ratio (INR) monitoring and have lower food/drug interactions. In addition, NOACs have risk reduction in bleeding and all-cause mortality compared with warfarin.

LOCAL PROBLEM

At a geriatric primary care practice, two registered nurses manage 88 patients on warfarin for INR monitoring. Nurse practitioners (NPs) provide oversight for warfarin titration after abnormal results. The goal of this quality-improvement project was to decrease the time spent monitoring patients on warfarin.

METHODS

Primary care providers and cardiologists of patients on warfarin were contacted to gain approval of transition to a NOAC. The NP reviewed patients' renal function and the indication for anticoagulation and then created a list of eligible patients for transition.

INTERVENTIONS

Patients eligible for transition to NOACs were contacted for their consent. The transition process included stopping warfarin, ordering apixaban, ordering INR level, educating about starting apixaban, and coordinating appropriate follow-up.

RESULTS

Of 88 patients on warfarin, 21 were eligible for conversion from warfarin to apixaban. Of these 21 patients, 66% ( n = 14) consented to the conversion. Of those who were not converted to apixaban, five declined due to cost and two were lost to follow-up.

CONCLUSION

There was a reduction in nurses' monthly monitoring of patients on warfarin by 22%. Transition to NOAC was not only beneficial for patient safety and efficacy but also reduced nursing clinical time for anticoagulation encounters.

Medical record data-enabled machine learning can enhance prediction of left atrial appendage thrombosis in nonvalvular atrial fibrillation

BACKGROUND

As a major complication of non-valvular atrial fibrillation (NVAF), left atrial appendage (LAA) thrombosis is associated with cerebral ischemic strokes, as well as high morbidity. Due to insufficient incorporation of risk factors, most current scoring methods are limited to the analysis of relationships between clinical characteristics and LAA thrombosis rather than detecting potential risk. Therefore, this study proposes a clinical data-driven machine learning method to predict LAA thrombosis of NVAF.

METHODS

Patients with NVAF from January 2014 to June 2022 were enrolled from Southwest Hospital. We selected 40 variables for analysis, including demographic data, medical history records, laboratory results, and the structure of LAA. Three machine learning algorithms were adopted to construct classifiers for the prediction of LAA thrombosis risk. The most important variables related to LAA thrombosis and their influences were recognized by SHapley Addictive exPlanations method. In addition, we compared our model with CHADS2 and CHADS2-VASc scoring methods.

RESULTS

A total of 713 participants were recruited, including 127 patients with LAA thrombosis and 586 patients with no obvious thrombosis. The consensus models based on Random Forest and eXtreme Gradient Boosting LAA thrombosis prediction (RXTP) achieved the best accuracy of 0.865, significantly outperforming CHADS2 score and CHA2DS2-VASc score (0.757 and 0.754, respectively). The SHAP results showed that B-type natriuretic peptide, left atrial appendage width, C-reactive protein, Fibrinogen and estimated glomerular filtration rate are closely related to the risk of LAA thrombosis in nonvalvular atrial fibrillation.

CONCLUSIONS

The RXTP-NVAF model is the most effective model with the greatest ROC value and recall rate. The summarized risk factors obtained from SHAP enable the optimization of the treatment strategy, thereby preventing thromboembolism events and the occurrence of cardiogenic ischemic stroke.

Changing trends and factors influencing anticoagulant use in patients with acute ischemic stroke and NVAF at discharge in the NOACs era

OBJECTIVES

We sought to explore the trends and influencing factors of the use of anticoagulants in patients with acute ischemic stroke and non-valvular atrial fibrillation (NVAF) at discharge in the era of novel oral anticoagulants (NOACs).

METHODS

We recruited consecutive inpatients with acute ischemic stroke and NVAF in a registered study (NCT04080830) from January 2016 to December 2021. The relevant data of patients were collected. We compared the proportions of anticoagulant treatment at discharge before and after NOACs entered China's medical insurance system. The proportion of each antithrombotic status as well as anticoagulant agents at discharge in every year were calculated, and the trends during the study period were analyzed. The relevant factors affecting anticoagulant use at discharge were further analyzed.

RESULTS

The proportion of anticoagulation at discharge increased significantly after NOACs entered China's medical insurance system in 2018 versus before (χ² = 42.828, P < 0.001). There were statistically significant differences in antithrombotic status (χ² = 69.954, P < 0.001) and in the proportion of different anticoagulant drugs (χ² = 63.049, P<0.001) by year. Anticoagulant therapy (χ² = 1.55, P = 0.671) and NOACs (χ² = .178, P = 0.243) increased over 2016-2018 but was relatively stable during 2018-2021. Multivariate logistic regression analysis showed that age ≥75 years, coexisting cerebral artery stenosis, massive cerebral infarction and hemorrhagic transformation were independent risk factors affecting anticoagulants use (all P < 0.05).

CONCLUSION

NOACs have indeed improved anticoagulants use in patients with acute ischemic stroke and NVAF at discharge. However, some specific factors affect anticoagulation therapy use at discharge and hinder further improvement even in the NOACs era.

Optimal stroke preventive strategy for patients aged 80 years or older with atrial fibrillation: a systematic review with traditional and network meta-analysis

BACKGROUND

An optimal antithrombotic strategy for patients aged 80 years or older with atrial fibrillation (AF) remains elusive.

OBJECTIVE

Using a systematic review with traditional and network meta-analysis, we investigated outcomes in AF patients ≥80 years treated with different antithrombotic strategies.

METHODS

We searched eligible randomised controlled trials (RCTs) and observational studies from MEDLINE, EMBASE, Cochrane Library and Web of Science databases from inception to 16 December 2021. Research comparing treatment outcomes of novel oral anticoagulants (NOACs), aspirin, vitamin K antagonists (VKAs) or no oral anticoagulant/placebo therapy in patients ≥80 years with AF were included. Outcomes were stroke or systemic embolism (SSE), major bleeding, all-cause mortality, intracranial bleeding (ICH) and gastrointestinal bleeding. Traditional and network meta-analyses were performed. Net clinical benefit integrating SSE and major bleeding was calculated.

RESULTS

Fifty-three studies were identified for analysis. In the meta-analysis of RCTs, risk of SSE (risk ratio [RR]: 0.82; 95% confidence interval [CI]: 0.73-0.99) and ICH (RR: 0.38; 95% CI: 0.28-0.52) was significantly reduced when NOACs were compared with VKAs. Network meta-analysis of RCTs demonstrated that edoxaban (P-score: 0.8976) and apixaban (P-score: 0.8528) outperformed other antithrombotic therapies by showing a lower major bleeding risk and better net clinical benefit. Both traditional and network meta-analyses from RCTs combining with observational studies showed consistent results.

CONCLUSIONS

In patients aged 80 years or older with AF, NOACs have better outcomes than VKAs regarding efficacy and safety profiles. Edoxaban and apixaban may be preferred treatment options since they are safer than other antithrombotic strategies.

Functional outcome prediction of ischemic stroke patients with atrial fibrillation accepting post-acute care training

Background

Ischemic stroke poses a major threat to human health and represents the third leading cause of death worldwide and in Taiwan. Post-acute care (PAC) training has been reported to be beneficial for post-index stroke events. However, knowledge is still lacking on the outcome of stroke events with cardiac origin. The focus of the current study is to investigate the effectiveness of PAC in this subgroup of patients as well as identify key baseline pointers that are capable of early prediction of patients' physical recovery. In addition, the authors hypothesize that the routinely arranged non-invasive carotid duplex that evaluates the characteristics of the carotid lumen could play a significant role in providing an early outcome prediction.

Methods

For the current research, 142 ischemic stroke patients with underlying cardiac arrhythmia (atrial fibrillation) were retrospectively recruited. The patients' basic demographics, neuroimaging, carotid duplex, and basic biochemistry datasets were accurately documented. The pre and post-admission National Institutes of Health Stroke Scale (NIHSS) (6-month follow-ups), Barthel Index, and mRS score (12-month follow-ups) were also recorded. All statistical analyses were performed using R for Windows (version 3.6.3). Barthel Index, NIHSS, and mRS scores obtained before and after hospitalization were compared to determine the patients' outcomes and were classified as improved or unimproved. A multivariate logistic analysis was designed and applied to assess the significance of risk factors and to obtain the odds ratios (ORs). The receiver operating characteristic (ROC) curve and the Youden Index was used to find the important cut-off point information, and the area under the curve (AUC) was calculated to provide accuracy.

Results

The average age of the 142 ischemic stroke patients enrolled in the current study was about 66 years, of which 88 patients were male and 54, female. Many of them had other comorbidities: 86 patients had mixed hyperlipidemia (60.56%), 115 had hypertension (80.99%), and 49 suffered from diabetes mellitus (34.51%). The mRS showed an improvement in the condition of only 40 patients (28.175%), whereas the Barthel Index showed improvement in 71 patients (50%), and 68 patients (47.89%) showed recovery on the NIHSS. The Barthel Index and NIHSS were selected because they already had an almost equal number of samples among the improved and unimproved groups (50%), rather than mRS, which had a lower number (28.17%) of improved cases. While conducting the EuroQol-5 Dimension (EQ-5D) assessment, anxiety/depression stood out as the most prominent issue, affecting 44 patients (30.99%). Self-care was another factor that was involved in the ongoing improvement of 36 patients (25.35%). Multivariate logistic analysis of both NIHSS and Barthel Index showed improvement with a contralateral plaque index statistical significance (P&lt;0.05), whereas NIHSS showed a relevant significance in anxiety/depression and Barthel Index registered usual activity in the data analysis (P&lt;0.05). ROC curve and Youden index analysis showed similar results in both NIHSS and Barthel Index of contralateral plaque index of 4.5, this being the cutoff point value for this group of patients.

Conclusion

In the current study, nearly half of the enrolled patients showed favorable functional recovery. The outcome assessments seem to correlate well with NIHSS and Barthel Index scores, rather than mRS. The anxiety/depression and usual activities domains of the EQ-5D results are associated with and have a great impact after the patients undertake the PAC rehabilitative strategy. Moreover, the variables obtained through carotid duplex and plaque index might also play a significant role in determining the patient's functional outcome.

CACHET-CADB: A Contextualized Ambulatory Electrocardiography Arrhythmia Dataset

ECG is a non-invasive tool for arrhythmia detection. In recent years, wearable ECG-based ambulatory arrhythmia monitoring has gained increasing attention. However, arrhythmia detection algorithms trained on existing public arrhythmia databases show higher FPR when applied to such ambulatory ECG recordings. It is primarily because the existing public databases are relatively clean as they are recorded using clinical-grade ECG devices in controlled clinical environments. They may not represent the signal quality and artifacts present in ambulatory patient-operated ECG. To help build and evaluate arrhythmia detection algorithms that can work on wearable ECG from free-living conditions, we present the design and development of the CACHET-CADB, a multi-site contextualized ECG database from free-living conditions. The CACHET-CADB is subpart of the REAFEL study, which aims at reaching the frail elderly patient to optimize the diagnosis of atrial fibrillation. In contrast to the existing databases, along with the ECG, CACHET-CADB also provides the continuous recording of patients' contextual data such as activities, body positions, movement accelerations, symptoms, stress level, and sleep quality. These contextual data can aid in improving the machine/deep learning-based automated arrhythmia detection algorithms on patient-operated wearable ECG. Currently, CACHET-CADB has 259 days of contextualized ECG recordings from 24 patients and 1,602 manually annotated 10 s heart-rhythm samples. The length of the ECG records in the CACHET-CADB varies from 24 h to 3 weeks. The patient's ambulatory context information (activities, movement acceleration, body position, etc.) is extracted for every 10 s interval cumulatively. From the analysis, nearly 11% of the ECG data in the database is found to be noisy. A software toolkit for the use of the CACHET-CADB is also provided.

Impact of direct oral anticoagulant use on mortality in very old patients with non-valvular atrial fibrillation

BACKGROUND

the efficacy and safety of direct oral anticoagulants (DOACs) compared with that of warfarin in very old patients with non-valvular atrial fibrillation (NVAF) have been reported in terms of thromboembolisms and bleeding. However, the association of DOAC use and mortality in such patients remains unclear.

OBJECTIVES

this study aimed to investigate the incidence of mortality, as well as thromboembolisms and major bleeding, in very old patients with NVAF using DOACs as compared with warfarin.

METHODS

we conducted a single-centre historical cohort study of consecutive patients with NVAF aged ≥80 years who used oral anticoagulants. We compared the 5-year outcomes (all-cause mortality, thromboembolism, major bleeding and intracranial haemorrhage) between the DOAC and Warfarin groups.

RESULTS

of 1,676 patients with atrial fibrillation aged 80 years and over, 1,208 with NVAF were included. Propensity score matching provided 461 patients in each group, and the risk of all-cause mortality, thromboembolisms, major bleeding and intracranial haemorrhages was significantly lower in the DOAC group than Warfarin group (hazard ratio [95% confidence interval] for DOAC use, 0.68 [0.54-0.87], 0.31 [0.19-0.53], 0.56 [0.36-0.88], 0.23 [0.10-0.56], log-rank P = 0.002, P < 0.001, P = 0.010, P < 0.001). The mortality rate within 1 year after major bleeding was significantly lower in the DOAC group than Warfarin group (14% versus 38%, P = 0.03), however, that after a thromboembolism was similar between the two groups (33% versus 35%).

CONCLUSION

patients with NVAF aged ≥80 years and using DOACs had a lower mortality than those using warfarin.

Direct Oral Anticoagulants Versus Warfarin in Patients With Atrial Fibrillation: Patient-Level Network Meta-Analyses of Randomized Clinical Trials With Interaction Testing by Age and Sex

BACKGROUND

Direct oral anticoagulants (DOACs) are preferred over warfarin for stroke prevention in atrial fibrillation. Meta-analyses using individual patient data offer substantial advantages over study-level data.

METHODS

We used individual patient data from the COMBINE AF (A Collaboration Between Multiple Institutions to Better Investigate Non-Vitamin K Antagonist Oral Anticoagulant Use in Atrial Fibrillation) database, which includes all patients randomized in the 4 pivotal trials of DOACs versus warfarin in atrial fibrillation (RE-LY [Randomized Evaluation of Long-Term Anticoagulation Therapy], ROCKET AF [Rivaroxaban Once Daily Oral Direct Factor Xa Inhibition Compared With Vitamin K Antagonism for Prevention of Stroke and Embolism Trial in Atrial Fibrillation], ARISTOTLE [Apixaban for Reduction in Stroke and Other Thromboembolic Events in Atrial Fibrillation], and ENGAGE AF-TIMI 48 [Effective Anticoagulation With Factor Xa Next Generation in Atrial Fibrillation-Thrombolysis in Myocardial Infarction 48]), to perform network meta-analyses using a stratified Cox model with random effects comparing standard-dose DOAC, lower-dose DOAC, and warfarin. Hazard ratios (HRs [95% CIs]) were calculated for efficacy and safety outcomes. Covariate-by-treatment interaction was estimated for categorical covariates and for age as a continuous covariate, stratified by sex.

RESULTS

A total of 71 683 patients were included (29 362 on standard-dose DOAC, 13 049 on lower-dose DOAC, and 29 272 on warfarin). Compared with warfarin, standard-dose DOACs were associated with a significantly lower hazard of stroke or systemic embolism (883/29 312 [3.01%] versus 1080/29 229 [3.69%]; HR, 0.81 [95% CI, 0.74-0.89]), death (2276/29 312 [7.76%] versus 2460/29 229 [8.42%]; HR, 0.92 [95% CI, 0.87-0.97]), and intracranial bleeding (184/29 270 [0.63%] versus 409/29 187 [1.40%]; HR, 0.45 [95% CI, 0.37-0.56]), but no statistically different hazard of major bleeding (1479/29 270 [5.05%] versus 1733/29 187 [5.94%]; HR, 0.86 [95% CI, 0.74-1.01]), whereas lower-dose DOACs were associated with no statistically different hazard of stroke or systemic embolism (531/13 049 [3.96%] versus 1080/29 229 [3.69%]; HR, 1.06 [95% CI, 0.95-1.19]) but a lower hazard of intracranial bleeding (55/12 985 [0.42%] versus 409/29 187 [1.40%]; HR, 0.28 [95% CI, 0.21-0.37]), death (1082/13 049 [8.29%] versus 2460/29 229 [8.42%]; HR, 0.90 [95% CI, 0.83-0.97]), and major bleeding (564/12 985 [4.34%] versus 1733/29 187 [5.94%]; HR, 0.63 [95% CI, 0.45-0.88]). Treatment effects for standard- and lower-dose DOACs versus warfarin were consistent across age and sex for stroke or systemic embolism and death, whereas standard-dose DOACs were favored in patients with no history of vitamin K antagonist use (P=0.01) and lower creatinine clearance (P=0.09). For major bleeding, standard-dose DOACs were favored in patients with lower body weight (P=0.02). In the continuous covariate analysis, younger patients derived greater benefits from standard-dose (interaction P=0.02) and lower-dose DOACs (interaction P=0.01) versus warfarin.

CONCLUSIONS

Compared with warfarin, DOACs have more favorable efficacy and safety profiles among patients with atrial fibrillation.

Added value of systemic inflammation markers in predicting pulmonary infection in stroke patients: A retrospective study by machine learning analysis

Exploring candidate markers to predict the clinical outcomes of pulmonary infection in stroke patients have a high unmet need. This study aimed to develop machine learning (ML)-based predictive models for pulmonary infection.Between January 2008 and April 2021, a retrospective analysis of 1397 stroke patients who had CT angiography from skull to diaphragm (including CT of the chest) within 24 hours of symptom onset. A total of 21 variables were included, and the prediction model of pulmonary infection was established by multiple ML-based algorithms. Risk factors for pulmonary infection were determined by the feature selection method. Area under the curve (AUC) and decision curve analysis were used to determine the model with the best resolution and to assess the net clinical benefits associated with the use of predictive models, respectively.A total of 889 cases were included in this study as a training group, while 508 cases were as a validation group. The feature selection indicated the top 6 predictors were procalcitonin, C-reactive protein, soluble interleukin-2 receptor, consciousness disorder, dysphagia, and invasive procedure. The AUCs of the 5 models ranged from 0.78 to 0.87 in the training cohort. When the ML-based models were applied to the validation set, the results also remained reconcilable, and the AUC was between 0.891 and 0.804. The decision curve analysis also showed performed better than positive line and negative line, indicating the favorable predictive performance and clinical values of the models.By incorporating clinical characteristics and systemic inflammation markers, it is feasible to develop ML-based models for the presence and consequences of signs of pulmonary infection in stroke patients, and the use of the model may be greatly beneficial to clinicians in risk stratification and management decisions.

The long-term efficacy and safety of combining ablation and left atrial appendage closure: A systematic review and meta-analysis

BACKGROUND

Combined ablation and left atrial appendage closure (LAAC) is an alternative for atrial fibrillation patients with a high risk of stroke. However, the long-term outcomes of this combined procedure remain elusive.

METHODS

PubMed, Embase, Cochrane Library, and Web of Science were systematically searched from the establishment of databases to 1 January 2021. Studies on the long-term (defined as a mean follow-up of approximately 12 months or longer) efficacy and safety outcomes of combined ablation and LAAC were included.

RESULTS

A total of 16 studies comprising 1428 patients were enrolled. The pooled long-term freedom rate from atrial arrhythmia was 0.66 (95% confidence interval [CI]: 0.59-0.71), long-term successful rate sealing of LAAC was 1.00 (95% CI: 1.00-1.00), and ischemic stroke/transient ischemic attack/systemic embolism during follow-up was 0.01 (95% CI: 0.00-0.02). Meanwhile, of the periprocedural adverse events, phrenic nerve palsy, intracoronary air embolus, device embolization, and periprocedural death had a rate of 0.00 (95% CI: 0.00-0.00), procedure-related bleeding events of 0.03 (95% CI: 0.02-0.04), and pericardial effusion requiring or not requiring intervention of 0.00 (95% CI: 0.00-0.01). Moreover, for the long-term adverse events, device dislocation, intracranial bleeding, pericardial effusion requiring or not requiring intervention, and all-cause mortality had a rate of 0.00 (95% CI: 0.00-0.00), device embolization of 0.01 (95% CI: 0.00-0.01), and other bleeding events of 0.01 (95% CI: 0.00-0.03).

CONCLUSION

This meta-analysis suggests that the combined atrial ablation and LAAC is an effective and safe strategy with long-term benefits.

Anticoagulants for stroke prevention in heart failure with reduced ejection fraction

Impaired left-ventricular ejection-fraction (LV-EF) is a known risk factor for ischemic stroke and systemic embolism in patients with heart failure (HF) even in the absence of atrial fibrillation. While stroke risk is inversely correlated with LV-EF in HF patients with sinus rhythm, strategies using anticoagulation with Vitamin-K antagonists (VKA) were futile as the increase in major bleedings outweighed the potential benefit in stroke reduction. Non-Vitamin K oral anticoagulants (NOACs) proved to be an effective and in general safer approach for stroke prevention in patients with atrial fibrillation and may also have a favourable risk–benefit profile in HF patients. In HF patients with sinus rhythm, the COMPASS trial suggested a potential benefit for rivaroxaban, whereas the more dedicated COMMANDER-HF trial remained neutral on overall ischemic benefit owed to a higher mortality which was not influenced by anticoagulation. More recent data from subgroups in the COMMANDER-HF trial, however, suggest that there might be a benefit of rivaroxaban regarding stroke prevention under certain circumstances. In this article, we review the existing evidence for NOACs in HF patients with atrial fibrillation, elaborate the rationale for stroke prevention in HF patients with sinus rhythm, summarise the available data from anticoagulation trials in HF with sinus rhythm, and describe the patient who might eventually profit from an individualised strategy aiming to reduce stroke risk.

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.

Pharmacokinetic-Pharmacodynamic Analysis' Role in Design of Phase ⅠClinical Trials of Anticoagulant Agents: A Systematic Review

INTRODUCTION

There remains an unmet need for better anticoagulants. The phase I clinical trial is of great significance in the development of anticoagulants, and the design is special. This system review aims to provide insights for the design of future phase I clinical trials of anticoagulants.

AREAS COVERED

We searched the database PubMed and ClinicalTrail.gov website, to collate the phase I clinical trial of anticoagulants in healthy people. The study protocol, inclusion-exclusion criteria, safety, and pharmacodynamic indexes were reviewed.

EXPERT OPINION

New anticoagulants under development focused on inhibiting one or more than one serine proteases within the coagulation cascade. Agents targeting intrinsic factors are in the pipeline of the drug development. The enrollment eligibility criteria have more restrictions on laboratory tests, medical history, or medication history related to bleeding and coagulation; more precautions were taken to assess and minimize the risk of hemorrhagic events. Pharmacodynamics markers were evaluated as a surrogate marker of anticoagulation potency to guide further dose selection in drug's development. In future, the positive control study can be applied in phase I studies of new anticoagulants with appropriate pharmacodynamics markers, which can provide more favorable information on making 'go/no' decision in drug development.

Anti-thrombotic strategies in patients with atrial fibrillation undergoing PCI

Triple anti-thrombotic therapy combining oral anticoagulation and dual anti-platelet therapy following percutaneous coronary intervention in patients with atrial fibrillation was considered as standard and recommended by guidelines. While bleeding risk is considerable with that approach, data for efficacy are scare. Several trials assessed the possibility of reducing anti-thrombotic treatment by mainly shortening the exposure to acetylsalicylic acid. Dropping one of the anti-platelet components might increase the risk of stent thrombosis, myocardial infarction or stroke. Despite that fear, the recent trials' primary endpoint was major and/or clinically-relevant non-major bleeding. We review data on major bleedings, intracranial bleedings and major adverse cardiovascular events from the published reports. We demonstrate that Non-Vitamin K oral anticoagulant (NOAC)-based strategies compared to VKA-based triple therapies significantly reduce the risk for TIMI-major bleedings by 39% and for intracranial bleedings by 66%, while they did not increase the risk for overall ischemic or embolic events. However, recent meta-analyses indicate an increased risk for stent thrombosis with less intense anti-thrombotic therapy. While the overall incidence rate for stent thrombosis is rather low, relative increases by about 30-60% are reported, but they did not translate into adverse clinical net-benefit ratios. This review highlights that using certain NOAC regimens proven effective for stroke prevention in AF can reduce the rate of bleeding without increasing ischemic or embolic events. Furthermore, additive ASA in triple anti-thrombotic regimens should be limited to 1 month and individual weighing of ischemic versus bleeding risk during the first 30 days seems to be reasonable.