Systemic Embolism Research Articles

Treatment of gastric varices with cyanoacrylate complicated by systemic embolization

Acute gastric variceal bleeding is a life-threatening condition that could be effectively treated with endoscopic cyanoacrylate injection diluted with lipiodol. The mixture acts as a tissue adhesive that polymerizes when in contact with blood in a gastric varix. This work reports a patient that presented to the emergency department with upper gastrointestinal bleeding due to acute variceal bleeding, who developed systemic embolization following cyanoacrylate injection therapy. This complication culminated in cerebral, splenic and renal infarctions with a fatal outcome. Systemic embolization is a very rare, but the most severe complication associated with endoscopic cyanoacrylate injection and should be considered in patients undergoing this treatment.

Efficacy and outcomes of antiplatelet therapy versus oral anticoagulants in patients undergoing transcatheter aortic valve replacement: a systematic review and meta-analysis.

Recent guidelines suggest that antiplatelet therapy (APT) is the standard of care in the absence of long-term oral anticoagulation (OAC) indications in patients post-transcatheter aortic valve replacement (TAVR). The superiority of one method over the other remains controversial. Several databases, including MEDLINE, Google Scholar, and EMBASE, were electronically searched. The primary endpoint was the all-cause mortality (ACM) rate. Secondary endpoints included cardiovascular death, myocardial infarction (MI), stroke/TIA, haemorrhagic stroke, bleeding events, systemic embolism, and valve thrombosis in post-TAVR patients receiving APT and oral anticoagulants (OACs). Forest plots were generated using Review Manager version 5.4, with a p value less than 0.05 indicating statistical significance. Subgroup analysis was performed to explore potential sources of heterogeneity. Twelve studies were selected. No significant differences were observed in APT and OAC group for ACM [risk ratio (RR): 0.67; 95% CI:0.45-1.01; P=0.05], cardiovascular death [RR:0.91; 95% CI:0.73-1.14; P=0.42], MI [RR:1.69; 95% CI:0.43-6.72; P=0.46], Stroke/TIA [RR:0.79; 95% CI:0.58-1.06; P=0.12], ischaemic stroke [RR:0.83; 95% CI:0.50-1.37; P=0.47], haemorrhagic stroke [RR:1.08; 95% CI: 0.23-5.15; P=0.92], major bleeding [RR:0.79; 95% CI:0.51-1.21; P=0.28], minor bleeding [RR:1.09; 95% CI: 0.80-1.47; P=0.58], life-threatening bleeding [RR:0.85; 95% CI:0.55-1.30; P=0.45], any bleeding [RR:0.98; 95% CI:0.83-1.15; P=0.78], and systemic embolism [RR:0.87; 95% CI:0.44-1.70; P=0.68]. The risk of valve thrombosis was higher in patients receiving APT than in those receiving OAC [RR:2.61; 95% CI:1.56-4.36; P =0.0002]. Although the risk of valve thrombosis increased in patients receiving APT, the risk of other endpoints was comparable between the two groups.

Left Atrial Appendage Closure in Patients With a Mechanical Mitral Valve Prosthesis: A Multicentre Italian Pilot Study

BackgroundIn patients with atrial fibrillation (AF) on vitamin K antagonist (VKA) therapy and therapeutic international normalized ratio (INR) range, the incidence of cardiac thromboembolism is not negligible, and the subgroup of patients who have a mechanical prosthetic mitral valve (PMV) has the highest risk. We aimed to assess the long-term effects of left atrial appendage closure (LAAC) in AF patients with a mechanical PMV who experienced a failure of VKA therapy. MethodsIn this retrospective, multicentre study, patients underwent LAAC because of thrombotic events including transient ischemic attack and/or stroke, systemic embolism, and evidence of left atrial appendage thrombosis and/or sludge, despite VKA therapy, were enrolled. Patients with a mechanical PMV were included and compared with those affected by nonvalvular AF. The primary endpoint was the composite of all-cause death, major cardiovascular events, and major bleedings at follow-up. The feasibility and safety of LAAC also were assessed. ResultsA total of 55 patients (42% female; mean age, 70 ± 9 years), including 12 with a mechanical PMV, were enrolled. The most-frequent indication to LAAC (71%) was LAA thrombosis or sludge. Procedural success was achieved in 96% of overall cases, and in 100% of patients with a PMV. In 35 patients, a cerebral protection device was used. During a median follow-up of 6.1 ± 4.3 years, 4 patients with a PMV, and 20 patients without a PMV, reported adverse events (hazard ratio 0.73 [95% confidence interval 0.25-2.16, P = 0.564]). ConclusionsLAAC seems to be a valuable alternative in patients with AF who have a mechanical PMV, with failure of VKA therapy. This off-label, real-world clinical practice indication deserves validation in further studies.

Perioperative Treatment with Rivaroxaban and Dabigatran on Changes of Coagulation and Platelet Activation Biomarkers following Left Atrial Appendage Closure.

Insufficient data exist regarding the investigation of the impact of novel oral anticoagulants (NOACs) on coagulation activation biomarkers in the context of left atrial appendage closure (LAAC) and device-related thrombosis (DRT). The study was designed to investigate the changes and presence of coagulation activation biomarkers between different antithrombotic strategies following LAAC. A total of 120 nonvalvular atrial fibrillation patients intolerant of long-term anticoagulants, who underwent successful WATCHMAN closure implantation, were enrolled (rivaroxaban, n = 82; dabigatran, n = 38). Blood samples were obtained from left atrium (LA) and left atrial appendage (LAA) during the operation and fasting blood samples on the same day of LAAC and 45 days after discharge. The biochemical indicators, thrombin-antithrombin complex (TAT), soluble P-selectin (sP-selectin), von Willebrand factor (vWF), and CD40 ligand (CD40L), were measured by enzyme-linked immunosorbent assay. The primary endpoints of this study were the efficacy and safety characteristics of different antithrombotic strategies, including DRT incidence, stroke or transient ischemic attack, systemic embolism, and clinical major and nonmajor bleeding complications during the follow-up of 180 days. The results revealed that TAT, vWF, sP-selectin, and CD40L levels in vein were significantly reduced by 2.4% (p = 0.043), 5.0% (p < 0.001), 8.7% (p < 0.001), and 2.5% (p = 0.043) from their baseline levels after rivaroxaban treatment. Conversely, no significant changes were detected in the dabigatran group. Furthermore, the plasma levels of platelet activation biomarkers (CD40L and sP-selectin) in both LA and LAA groups were significantly lower after anticoagulation with rivaroxaban, as compared to dabigatran treatment (CD40L: 554.62 ± 155.54 vs. 445.02 ± 130.04 for LA p = 0.0013, 578.51 ± 156.28 vs. 480.13 ± 164.37 for LAA p = 0.0052; sP-selectin: 2849.07 ± 846.69 vs. 2225.54 ± 799.96 for LA p = 0.0105, 2915.52 ± 1402.40 vs. 2203.41 ± 1061.67 for LAA p = 0.0022). Notably, the present study suggests that rivaroxaban may be more effective in the prevention of DRT for patients undergoing LAAC.

Elevated factor XI is associated with recurrent left ventricular thrombus of unknown origin.

Elevated factor XI (FXI) has been shown to predispose to thromboembolism. We investigated whether it is associated with left ventricular thrombus (LVT) formation, its recurrence and subsequent thromboembolic events. In 54 patients with prior LVT of unknown origin, who stopped anticoagulation and 54 controls, we determined FXI, along with plasma clot permeability (Ks), fibrinolysis time (CLT), endogenous thrombin potential (ETP), von Willebrand factor (vWF) and fibrinolysis proteins. During follow-up, the primary endpoint involving the recurrence of LVT a symptomatic ischemic stroke or systemic embolism was recorded. Elevated (>120%) FXI levels were more often observed in LVT patients when compared to the control group (14 [25.9%] vs. 6 [11.1%], p = .048) in association with the presence of active FXI. FXI correlated with age (r = .406, p = .002), Ks (r = -.542, p < .001) and CLT (r = .406, p = .002), also after adjustment for age, but not with ETP, vWF or fibrinolysis proteins. During follow-up of 77.6 ± 18.5 months the primary endpoint occurred in 17 (31.5%) LVT patients, including 11 (20.4%) recurrent LVT, and in 4 (7.4%) controls (annual incidence rate 4.9% vs. 1.1%, respectively; p = .002). On multivariate logistic regression analysis, elevated FXI was independently associated with the primary endpoint (OR 1.18; 95% CI 1.09-1.28). Elevated FXI in association with a prothrombotic state characterizes patients with prior LVT of unknown origin and predisposes to its recurrence and/or ischemic stroke during follow-up. It might be speculated that the measurement of FXI helps identify patients who could benefit from prolonged anticoagulation and FXI inhibitors in the future.

Epicardial left atrial appendage clipping versus direct oral anticoagulant to reduce stroke risk in non-paroxysmal atrial fibrillation (LAA-CLIP): rationale, design and study protocol for a multicentre randomised controlled trial

IntroductionThe prevalence of atrial fibrillation (AF) is increasing globally, and stroke prevention is the key to reduce the morbidity and mortality related to AF. Currently, direct oral anticoagulants (DOACs) are...

Systolic blood pressure visit-to-visit variability and outcomes in Asian patients with atrial fibrillation.

We aimed to assess the association between SBP-VVV and outcomes in Asian patients with atrial fibrillation (AF). AF patients in the COOL-AF registry with SBP measured at baseline, and at least two other visits were studied. We defined SBP-VVV using the standard deviation (SD) of average SBP. Patients were categorized according to the quartiles of SBP SD. The associations between SBP-VVV and outcomes were assessed in the adjusted Cox model. We studied 3172 patients (mean age 67.7 years; 41.8% female), with the prevalence of hypertension being 69%. Warfarin was used in 69% of patients, whereas 7% received non-vitamin K antagonist oral anticoagulants. The minimum and maximum SD of average SBP in the study population was 0.58 and 56.38 mmHg respectively. The cutoff of SD of average SBP for each quartile in our study were 9.09, 12.15, and 16.21 mmHg. The rates of all-cause mortality, ischemic stroke or systemic embolization (SSE), major bleeding, and intracranial hemorrhage (ICH) were 3.10, 1.42, 2.09, and 0.64 per 100 person-years, respectively. Compared with the first quartile, patients in the fourth quartile had a significantly higher risk of mortality (adjusted HR 1.60, 95%CI 1.13-2.25), bleeding (aHR 1.92, 95%CI 1.25-2.96) and ICH (aHR 3.51, 95%CI 1.40-8.76). The risk of SSE was not significantly different among the quartiles. SBP-VVV had a significant impact on the long-term outcomes of Asian patients with AF, particularly mortality and bleeding. Adequate SBP control and maintaining SBP stability over time may improve outcomes for AF patients.

Comparative effectiveness of factor Xa non-vitamin K antagonist oral anticoagulants versus phenprocoumon in patients with non-valvular atrial fibrillation

BackgroundNon-vitamin K antagonist oral anticoagulants (NOACs) have largely supplanted vitamin K antagonists (VKAs) for oral anticoagulation in non-valvular atrial fibrillation (NVAF). However, data on the real-world effectiveness of NOACs vs. phenprocoumon, a VKA widely used in Germany, are limited. The RELOADED study aimed to compare effectiveness of factor Xa NOACs and phenprocoumon in NVAF in clinical practice. MethodsPatients who started on a factor Xa NOAC or phenprocoumon for NVAF during the study period were enrolled from the Institute for Applied Healthcare Research Berlin. Patients were followed from first prescription until the end of exposure or available data. Primary outcomes were analyzed by Cox proportional hazard regression models and included ischemic stroke and systemic embolism for effectiveness, and intracranial hemorrhage (ICH) for safety. Subgroups of interest were patients with diabetes and patients with renal impairment. ResultsThe total study population was 64,920; 36.3% of patients initiated phenprocoumon, 34.4% initiated rivaroxaban, 25.0% apixaban, and 4.4% edoxaban. Treatment with phenprocoumon is associated with a similar risk of ischemic stroke/systemic embolism as treatment with rivaroxaban or apixaban; while rivaroxaban (adjusted hazard ratio [HR] 0.57, 95% confidence interval [CI] 0.43–0.75) and apixaban (adjusted HR 0.43, 95% CI 0.31–0.6) were associated with a lower risk of ICH compared to phenprocoumon in NVAF patients. The use of rivaroxaban and apixaban was associated with a lower risk of developing kidney failure in patients with diabetes or renal impairment in comparison to those treated with phenprocoumon. ConclusionThe factor Xa NOACs rivaroxaban and apixaban demonstrated similar effectiveness and lower rates of ICH compared with phenprocoumon in this study.

Simple scores to predict 1-year mortality in atrial fibrillation.

Traditional scores as CHADS2 and CHA2DS2-Vasc are suitable for predicting stroke and systemic embolism in patients with atrial fibrillation (AF) and have shown to be also associated with mortality. Other more complex scores have been recommended for survival prediction. The purpose of our analysis was to test the performance of different clinical scores in predicting 1-year mortality in AF patients. CHADS2 and CHA2DS2-Vasc scores were calculated for AF patients of the BLITZ-AF register and compared to R2-CHADS2, R2-CHA2DS2-Vasc and CHA2DS2VASc-RAF scores in predicting 1-year survival. Scores including renal function were calculated both with glomerular filtration rate (GFR) and creatinine clearance. One-year vital status (1960 alive and 199 dead) was available in 2159 patients. Receiver-operating characteristic curves displayed an association of each score to all-cause mortality, with R2(ClCrea)-CHADS2 being the best [area under the curve (AUC) 0.734]. Differences among the AUCs of the eight scores were not so evident, and a significant difference was found only between R2(ClCrea)-CHADS2 and CHADS2, CHA2DS2VASc, (ClCrea)-CHA2DS2-VASC-RAF.All the scores showed a similar performance for cardiovascular (CV) mortality, with CHA2DS2VASc-RAF being the best (AUC 0.757), with a significant difference with respect to CHADS2, CHA2DS2VASc, and (ClCrea)CHA2DS2Vasc-RAF. More complex scores, even if with better statistical performance, do not show a clinically relevant higher capability to discriminate alive or dead patients at 12 months. The classical and well known CHA2DS2VASc score, which is routinely used all around the world, has a high sensitivity in predicting all-cause mortality (AUC 0.695; Sensit. 80.4%) and CV mortality (AUC 0.691; Sensit. 80.0%). http://links.lww.com/JCM/A632.

Cardiac imaging correlates and predictors of stroke in patients with atrial fibrillation: a meta-analysis.

New nonclinical parameters are needed to improve the current stroke risk stratification schemes for patients with atrial fibrillation. This study aimed to summarize data on potential cardiac imaging correlates and predictors of stroke or systemic embolism in patients with atrial fibrillation. MEDLINE, EMBASE, and Web of Science were searched to identify all published studies providing relevant data through 16 November 2022. Random effects meta-analysis method was used to pool estimates. We included 64 studies reporting data from a pooled population of 56 639 patients. Left atrial spontaneous echo-contrast [adjusted odds ratio (aOR) 3.32, 95% confidence interval (CI) 1.98-5.49], nonchicken wing left atrial appendage (LAA) morphology (aOR 2.15, 95% CI 1.11-4.18), left atrial enlargement (aOR 2.12, 95% CI 1.45-3.08), and higher LAA orifice diameter (aOR 1.56, 95% CI 1.18-2.05) were highly associated with stroke. Other parameters associated with stroke included higher left atrial sphericity (aOR 1.14, 95% CI 1.01-1.29), higher left atrial volume (aOR 1.03, 95% CI 1.01-1.04), higher left atrial volume index (aOR 1.014, 95% CI 1.004-1.023), lower left atrial reservoir strain [adjusted hazard ratio (aHR) 0.86, 95% CI 0.76-0.98], higher left ventricular mass index (aOR 1.010, 95% CI 1.005-1.015) and E / e' ratio (aOR 1.12, 95% CI 1.07-1.16). There was no association between LAA volume (aOR 1.37, 95% CI 0.85-2.21) and stroke. These cardiac imaging parameters identified as potential predictors of thromboembolism may improve the accuracy of stroke risk stratification schemes in patients with atrial fibrillation. Further studies should evaluate the performance of holistic risk scores including clinical factors, biomarkers, and cardiac imaging.

In subclinical AF, apixaban reduced stroke or systemic embolism but increased major bleeding vs. aspirin at 3.5 y.

Healey JS, Lopes RD, Granger CB, et al; ARTESIA Investigators. Apixaban for stroke prevention in subclinical atrial fibrillation. N Engl J Med. 2024;390:107-117. 37952132.

Association Between Atrial Fibrillation Symptoms and Clinical Outcomes: A Prospective Multicenter Registry Study

The presence of symptoms plays an important role in determining whether to focus on rhythm control or rate control when treating atrial fibrillation (AF). Previous comparative studies on the clinical outcomes of symptomatic and asymptomatic AF have yielded inconsistent results, and a link between AF symptoms and left atrial (LA) remodeling is not established. Patients selected from the COmparison study of Drugs for symptom control and complication prEvention of AF (CODE-AF) registry, which is a prospective, multicenter study consisting of patients with non-valvular AF, were grouped into 2 groups: symptomatic and asymptomatic. The primary outcome was a composite of the following cardiovascular outcomes: all-cause death, ischemic stroke, transient ischemic attack, systemic embolism, myocardial infarction, and heart failure hospitalization. Of 10,210 patients with AF, 4,327 (42%) had symptomatic AF. The asymptomatic group had an older mean age, more men, and more patients with hypertension and diabetes mellitus than the symptomatic group. The asymptomatic group had a larger left atrium (LA) diameter (43.6 vs 42.2 mm, p <0.001) than the symptomatic group. During a median follow-up of 32.9 (29.5 to 36.4) months, the asymptomatic and symptomatic groups showed similar incidences of the primary outcome (1.44 vs 1.45 per 100 person-years; log-rank, p = 0.8). In conclusion, the absence of AF symptoms is associated with increased LA. However, symptomatic and asymptomatic patients with AF have a similar risk of cardiovascular outcomes. This suggests that beneficial treatment for AF may be considered regardless of whether patients have symptomatic or asymptomatic AF.

Factor Xa inhibitors versus warfarin in severely obese patients with venous thromboembolism or atrial fibrillation

Objectives: Clinical data for the safety and efficacy of Factor Xa (FXa) inhibitors in severely obese patients is limited. Additional information is needed to assess the risks and benefits of using FXa inhibitors in this patient population. Materials and Methods: A single-center and retrospective chart review was conducted in severely obese patients (body mass index [BMI] &gt;40 kg/m2 or weight &gt;120 kg), who received rivaroxaban, apixaban or warfarin for venous thromboembolism (VTE) treatment or prevention of stroke and systemic embolism in non-valvular atrial fibrillation (AF). The primary endpoint was treatment failure, defined as recurrent VTE in VTE treatment or stroke, transient ischemic attack or systemic embolism in AF within one year of anticoagulation initiation. Secondary endpoints included a composite of major bleeding rates and clinically relevant non-major bleeding (CRNMB) rates. Results: Seventy-three patients were included in the final analysis consisting of 43 patients in the FXa inhibitor arm (apixaban [n = 33] and rivaroxaban [n = 10]) and 30 patients in the warfarin arm. The rate of treatment failure was similar between the FXa inhibitor and warfarin groups (4.7% vs. 6.7%; P = 0.814). Although not statistically significant, major bleeding and CRNMB occurred less frequently in patients receiving FXa inhibitors compared to warfarin (9.3% vs. 23.3%; P = 0.182). Subgroup analysis in patients with BMI &gt;50 kg/m2 or weight &gt;150 kg demonstrated similar efficacy and safety outcomes. The use of non-recommended dosing was more common in the apixaban group compared to the rivaroxaban group. Conclusion: FXa inhibitors (apixaban and rivaroxaban) appear to have similar efficacy and safety compared to warfarin in severely obese patients. Larger prospective studies are needed to confirm these results.

How the Hemostasis Laboratory Can Help Clinicians to Manage Patients on Oral Anticoagulants.

Oral anticoagulants are widely used to treat or prevent cardiovascular diseases in millions of patients worldwide. They are the drugs of choice for stroke prevention and systemic embolism in patients with non-valvular atrial fibrillation and prosthetic heart valves, as well as for treatment/prevention of venous thromboembolism. Oral anticoagulants include vitamin K antagonists (VKAs) and direct oral anticoagulants (DOACs). The hemostasis laboratory plays a crucial role in the management of treated patients, spanning from dose adjustment based on laboratory testing that applies to VKAs to the measurement of drug concentrations in special situations that apply to DOACs. This article aims to overview how the hemostasis laboratory can help clinicians manage patients on oral anticoagulants. Special interest is devoted to the international normalized ratio, used to manage patients on VKAs and to the measurement of DOAC concentrations, for which the role of the laboratory is still not very well defined, and most interferences of DOACs with some of the most common hemostatic parameters are not widely appreciated.

Long-Term Efficacy Analysis of Surgical Resection of 70 Primary Right Heart Tumors

Introduction: The aim of the study was to investigate the clinical characteristics, surgical treatment, and long-term efficacy of primary right heart tumors. Methods: This study is retrospective analysis of the clinical data of 70 patients with primary right heart tumors admitted to our department between 1980 and 2022 (observation group) and 70 patients with left heart tumors during the same period (control group). The surgical treatment was performed under cardiopulmonary bypass after differential diagnosis by echocardiography, cardiac CTA, and PET-CT before the surgery. The perioperative characteristics, recurrence rate, and long-term survival rates of right heart tumor versus left heart tumor were compared. Results: The most common pathological types of right heart tumors were myxoma (60%), lipoma (8.57%), and papillary elastofibroma (7.14%). During the perioperative period, there were 1 case of systemic embolism in the observation group, compared with 6 in the control group (p = 0.026), 13 cases of malignant tumor in the observation group versus 1 in the control group (p = 0.01). During the follow-up period, there were 15 cases of tumor recurrence and 17 cases of death in the observation group versus 4 (p = 0.002) and 7 in the control group (p = 0.006), comparatively. Conclusion: Compared with left heart tumors, primary right heart tumors had a higher incidence of malignant tumors and a lower risk of systemic embolism during perioperative period. During the follow-up period, primary right heart tumors had a higher rate of tumor recurrence and a lower long-term survival rate.

Prophylactic Anticoagulation to Prevent Left Ventricular Thrombus Following Acute Myocardial Infarction: A Systematic Review and Meta-Analysis

Clinical practice guidelines from the American Heart Association recommend consideration of prophylactic anticoagulation to prevent left ventricular thrombus (LVT) formation in anterior ST-elevation myocardial infarction (STEMI) patients. These guidelines were given a low certainty of evidence (Class IIb, Level C), relying primarily on case studies and expert consensus to inform practice. Our objective was to compare the safety and efficacy of prophylactic anticoagulation, in addition to dual antiplatelet therapy (DAPT), in the current era of timely primary percutaneous coronary intervention (pPCI). EMBASE, MEDLINE and Cochrane Library were systematically searched from January 2012 through June 2022. A total of 7,378 publications were screened, and 5 publications were eventually included in this review: 1 randomized control trial and 4 retrospective studies involving 1,461 patients. Data were pooled using a fixed effects model and reported as odds ratios (OR) with 95% confidence intervals (CI). The primary outcome of interest was the rate of LVT formation, and the secondary outcomes were the rate of major bleeding and systemic embolism. Pooled analysis showed a significantly lower rate of LVT formation (OR: 0.28 [95% CI: 0.11–0.73; p < 0.01]) and significantly higher rates of bleeding (OR: 2.85 [95% CI: 1.13–7.24; p= 0.03]) in the triple therapy (TT) group compared to DAPT. No significant difference was observed in the rate of systemic embolism between the groups (OR: 0.37 [95% CI: 0.12–1.13; p = 0.08]). In this meta-analysis, there is no conclusive evidence to either support or oppose the use of TT for LVT prevention in anterior STEMI patients treated with pPCI. Appropriately powered randomized controlled trials are warranted to further evaluate the benefits of LVT prevention against the risks of major bleeding in this population.

Optimizing warfarin dosing for patients with atrial fibrillation using machine learning

While novel oral anticoagulants are increasingly used to reduce risk of stroke in patients with atrial fibrillation, vitamin K antagonists such as warfarin continue to be used extensively for stroke prevention across the world. While effective in reducing the risk of strokes, the complex pharmacodynamics of warfarin make it difficult to use clinically, with many patients experiencing under- and/or over- anticoagulation. In this study we employed a novel implementation of deep reinforcement learning to provide clinical decision support to optimize time in therapeutic International Normalized Ratio (INR) range. We used a novel semi-Markov decision process formulation of the Batch-Constrained deep Q-learning algorithm to develop a reinforcement learning model to dynamically recommend optimal warfarin dosing to achieve INR of 2.0–3.0 for patients with atrial fibrillation. The model was developed using data from 22,502 patients in the warfarin treated groups of the pivotal randomized clinical trials of edoxaban (ENGAGE AF-TIMI 48), apixaban (ARISTOTLE) and rivaroxaban (ROCKET AF). The model was externally validated on data from 5730 warfarin-treated patients in a fourth trial of dabigatran (RE-LY) using multilevel regression models to estimate the relationship between center-level algorithm consistent dosing, time in therapeutic INR range (TTR), and a composite clinical outcome of stroke, systemic embolism or major hemorrhage. External validation showed a positive association between center-level algorithm-consistent dosing and TTR (R2 = 0.56). Each 10% increase in algorithm-consistent dosing at the center level independently predicted a 6.78% improvement in TTR (95% CI 6.29, 7.28; p < 0.001) and a 11% decrease in the composite clinical outcome (HR 0.89; 95% CI 0.81, 1.00; p = 0.015). These results were comparable to those of a rules-based clinical algorithm used for benchmarking, for which each 10% increase in algorithm-consistent dosing independently predicted a 6.10% increase in TTR (95% CI 5.67, 6.54, p < 0.001) and a 10% decrease in the composite outcome (HR 0.90; 95% CI 0.83, 0.98, p = 0.018). Our findings suggest that a deep reinforcement learning algorithm can optimize time in therapeutic range for patients taking warfarin. A digital clinical decision support system to promote algorithm-consistent warfarin dosing could optimize time in therapeutic range and improve clinical outcomes in atrial fibrillation globally.

Optimal antithrombotic strategy in patients with atrial fibrillation beyond 1 year after drug-eluting stent implantation: Design and rationale of the randomized ADAPT AF-DES trial

BackgroundBoth anticoagulation and antiplatelet therapies are recommended after percutaneous coronary intervention (PCI) in patients with atrial fibrillation (AF). Although contemporary guidelines recommend discontinuation of antiplatelet therapy 1 year after drug-eluting stent (DES) implantation due to excessive bleeding risk, supporting randomized trials are still lacking. MethodsThe ADAPT AF-DES trial is a multicenter, prospective, open-label, randomized, non-inferiority trial, enrolling 960 patients with AF with a CHA2DS2-VASc score > 1, who underwent PCI with DES implantation at least 12 months before enrollment. Eligible patients are randomly assigned to receive either non-vitamin K antagonist oral anticoagulant (NOAC) monotherapy or NOAC plus clopidogrel combination therapy. The primary outcome is net adverse clinical event (NACE) at 1 year after randomization, defined as a composite of all-cause death, myocardial infarction, stent thrombosis, stroke, systemic embolism, and major or clinically relevant non-major bleeding, as defined by the International Society on Thrombosis and Hemostasis criteria. We hypothesize that NOAC monotherapy would be non-inferior to NOAC plus clopidogrel combination therapy for NACE in patients with AF beyond 12 months after DES implantation. ConclusionsThe ADAPT AF-DES trial will evaluate the efficacy and safety of NOAC monotherapy versus NOAC plus clopidogrel combination therapy in patients with AF beyond 12 months after PCI with DES implantation. The ADAPT AF-DES trial will provide robust evidence for an optimal antithrombotic strategy in patients with AF after DES implantation. Clinical trial registrationhttps://www.clinicaltrials.gov. Unique identifier: NCT04250116.

Comparative Safety and Effectiveness of Reduced Doses of Direct Acting Oral Anticoagulants for Stroke Prevention in Atrial Fibrillation

This Nordic observational cohort study aims to assess the effectiveness and safety of reduced-dose direct-acting oral anticoagulants (DOACs) dabigatran, rivaroxaban, and apixaban compared to standard warfarin for stroke prevention in nonvalvular atrial fibrillation. The study, utilizing nationwide administrative databases from Denmark, Sweden, Norway, and Finland, spanned from January 1, 2011 to December 31, 2018 (2017 for Sweden). The cohort included 26,883 patients initiating reduced-dose DOACs and 108,014 comparable warfarin patients. Effectiveness was measured by the composite endpoint of ischemic stroke and systemic embolism, while safety was assessed through intracranial hemorrhage. The meta-analysis across countries revealed similar or lower incidences of ischemic stroke and systemic embolism in patients on reduced-dose DOACs compared to standard warfarin (rivaroxaban: HR 0.93, dabigatran: HR 0.88, apixaban: HR 0.79). Incidences within warfarin groups ranged from 2.16 to 3.71 per 100 person-years, comparable to DOAC recipients. Intracranial hemorrhage rates were generally low, ranging from 0.16 to 1.85 per 100 person-years. In comparison with warfarin patients, meta-analyses yielded HRs for rivaroxaban (1.41), dabigatran (0.35), and apixaban (0.72). In this study, atrial fibrillation patients initiating reduced-dose rivaroxaban and dabigatran exhibited incidences of ischemic stroke and systemic embolism similar to warfarin, and for apixaban, even lower. Rates of intracranial hemorrhage were comparable to or lower for patients on DOACs compared to warfarin.

The ABC-Stroke Risk Score and Effects of Atrial Fibrillation Screening on Stroke Prevention: Results From the Randomized LOOP Study.

The ABC-stroke score is a risk scheme for prediction of stroke or systemic embolism (SE) in atrial fibrillation (AF). This study sought to examine whether the score could be useful in predicting stroke in AF-naïve individuals and risk stratifying for AF screening. The LOOP (Atrial Fibrillation Detected by Continuous ECG Monitoring Using Implantable Loop Recorder to Prevent Stroke in High-Risk Individuals) study randomized 6004 AF-naïve individuals aged 70 to 90 years with stroke risk factors to either screening with an implantable loop recorder and anticoagulation upon detection of new-onset AF episodes ≥6 minutes, or usual care. A total of 5781 participants had available ABC-stroke score at baseline and were included in this secondary analysis: 4170 (72.1%) with an estimated stroke/SE risk ≤1%/year versus 1611 (27.9%) with an estimated stroke/SE risk >1%/year. Having an annual ABC-stroke risk >1% was associated with stroke/SE, stroke/SE/cardiovascular death, and all-cause death (hazard ratio, 1.82 [95% CI, 1.44-2.21], 2.17 [95% CI, 1.80-2.62], and 2.19 [95% CI, 1.87-2.56], respectively). For screening with implantable loop recorder versus usual care, no significant reduction in these study outcomes was obtained in any ABC-stroke risk groups (P>0.0500 for all), with no signal toward interaction (Pinteraction>0.2500 for all). Similar findings were yielded when assessing theABC-stroke score as a continuous variable. In an elderly, AF-naïve population with additional stroke risk factors, a higher ABC-stroke score could identify individuals with increased stroke risk. However, this risk score may not be useful in pinpointing those more likely to benefit from AF screening and subsequent preventive treatment. These findings should be considered as hypothesis generating and warrant further study. URL: https://www.clinicaltrials.gov; unique identifier: NCT02036450.