Breadth of complications of long-term oral anticoagulant care

Machine learning approach for prediction of outcomes in anticoagulated patients with atrial fibrillation

BACKGROUND

The accuracy of available prediction tools for clinical outcomes in patients with atrial fibrillation (AF) remains modest. Machine Learning (ML) has been used to predict outcomes in the AF population, but not in a population entirely on anticoagulant therapy.

METHODS AND AIMS

Different supervised ML models were applied to predict all-cause death, cardiovascular (CV) death, major bleeding and stroke in anticoagulated patients with AF, processing data from the multicenter START-2 Register.

RESULTS

11078 AF patients (male n = 6029, 54.3%) were enrolled with a median follow-up period of 1.5 years [IQR 1.0-2.6]. Patients on Vitamin K Antagonists (VKA) were 5135 (46.4%) and 5943 (53.6%) were on Direct Oral Anticoagulants (DOAC). Using Multi-Gate Mixture of Experts, a cross-validated AUC of 0.779 ± 0.016 and 0.745 ± 0.022 were obtained, respectively, for the prediction of all-cause death and CV-death in the overall population. The best ML model outperformed CHA2DSVA2SC and HAS-BLED for all-cause death prediction (p < 0.001 for both). When compared to HAS-BLED, Gradient Boosting improved major bleeding prediction in DOACs patients (0.711 vs. 0.586, p < 0.001). A very low number of events during follow-up (52) resulted in a suboptimal ischemic stroke prediction (best AUC of 0.606 ± 0.117 in overall population). Body mass index, age, renal function, platelet count and hemoglobin levels resulted the most important variables for ML prediction.

CONCLUSIONS

In AF patients, ML models showed good discriminative ability to predict all-cause death, regardless of the type of anticoagulation strategy, and major bleeding on DOAC therapy, outperforming CHA2DS2VASC and the HAS-BLED scores for risk prediction in these populations.

Long-Term Efficacy and Safety of Direct Oral Anticoagulants at Reduced Doses in the Secondary Prevention of Venous Thromboembolism and Post-Thrombotic Syndrome

Background: Anticoagulation for venous thromboembolism (VTE) is required for at least three to six months; however, it is advisable to extend the duration in certain cases, in which case a reduced dose of Direct Oral Anticoagulants (DOACs) may be an option. Our objective was to investigate the efficacy and safety of reduced-dose DOACs in extended anticoagulation treatment compared to full doses. Methods and Results: This retrospective single-centre study included 185 patients treated with DOACs for at least 6 months who were divided into two groups: (1) the Full Dose (FD) group (n = 113) and (2) the Reduced Dose (RD) group (n = 72), which included patients treated with Apixaban at 2.5 mg bis in die (BID) and Rivaroxaban at 10 mg once daily (OD). Post-thrombotic syndrome (PTS) and its progression were evaluated. During an overall follow-up of 48.32 ± 29.49 months, no VTE occurred, and no patients experienced major bleeding; clinically relevant non-major bleeding occurred in three patients in each group (2.7% vs. 4.2% in FD vs. RD, respectively, p = 0.57). From baseline to follow-up, the prevalence of PTS was not significantly decreased in either group (FD: 54.9% vs. 51.3%, p = 0.29; RD 51.4% vs. 44.4%, p = 0.12); conversely, the Villalta score values were significantly decreased at the last follow-up (FD: 5.51 ± 4.18 vs. 5.51 ± 4.18, p < 0.001; RD 5.49 ± 4.06 vs. 5.11 ± 3.73, p = 0.006). Conclusion: In this real-world retrospective registry, very long-term extended anticoagulant therapy with DOACs at full or reduced doses showed comparable efficacy, safety, and impact on PTS progression. Larger studies are needed.

Comparative safety review of antithrombotic treatment options for patients with atrial fibrillation undergoing percutaneous coronary intervention

INTRODUCTION

Balancing antithrombotic therapy for atrial fibrillation (AF) patients undergoing percutaneous coronary intervention (PCI) remains a clinical challenge due to coexisting thrombogenic risks. This review emphasizes the delicate balance required to prevent ischemic events while minimizing bleeding complications, particularly in the context of risk assessment.

AREAS COVERED

This review spans from 2010 to October 2023, exploring the complexities of antithrombotic management for AF patients undergoing PCI. It stresses the need for personalized treatment decisions to optimize antithrombotic therapies effectively.

EXPERT OPINION

The evolving evidence supports double antithrombotic therapy (DAT) over triple antithrombotic therapy (TAT) for these patients, showcasing a more favorable safety profile without compromising efficacy. Non-vitamin K antagonist oral anticoagulant (NOAC)-based DAT strategies exhibit superiority in reducing major bleeding events while effectively preventing ischemic events. Recommendations from the 2023 European Society of Cardiology (ESC) Guidelines advocate for NOAC-based DAT post-PCI, endorsing safer antithrombotic profiles.Challenges persist for specific patient categories requiring both oral anticoagulants and antiplatelets, necessitating personalized approaches. Future advances in intravascular imaging and novel coronary stent technologies offer promising avenues to optimize outcomes and influence antithrombotic strategies in AF-PCI patients.

Factor XI/XIa Inhibitors: A New Approach to Anticoagulation

For more than 60 years, anticoagulation drugs have served as a mainstay in preserving and improving the cardiovascular health of patients across the globe. Functioning to reduce a patient's ability to produce blood clots, prescription rates for anticoagulants have been steadily rising year-over-year both in the United States and abroad. Despite decades of clinical usage, modern-day anticoagulants have been shown to predispose an individual to pathological bleeding. Even in seemingly benign instances of bleeding, patients on anticoagulation therapy might require intensive and expensive medical procedures or monitoring. Understanding the clinical implications of pathological bleeding, research and development of future anticoagulants seeking to minimize these effects. One emerging category of anticoagulant drugs are Factor XI/XIa (FXI) inhibitors. Targeting the coagulation cascade, clinical trials of Factor XIa inhibitors have shown promising results in preventing blood clot formation without increasing the instances of spontaneous and/or pathological bleeding events. While still in phase II and III clinical trials, and potentially years away from being implemented as standard of care, these novel drugs might have the potential to improve the safety and quality of life of patients taking anticoagulants. In this review, we discuss a brief history of anticoagulation therapy, followed by an analysis of the potential risks, benefits, and implications of Factor XI/XIa inhibitors across elements of patient care.

Hybrid Paraclavicular Decompression for Venous Thoracic Outlet Syndrome with Primary Endovascular Reconstruction

BACKGROUND

Venous thoracic outlet syndrome (vTOS) is characterized by severe stenosis and potential thrombosis of the axillary-subclavian vein (effort thrombosis) with significant effects on patient mobility, quality of life, and risks associated with possible anticoagulation. Treatment goals are aimed at symptomatic improvement and freedom from recurrent thrombosis. To date, there exist no clear protocols or recommendations on surgical approach that result in optimal outcomes. We highlight our institution's experience with a systematized, paraclavicular approach with intraoperative balloon angioplasty only, if needed.

METHODS

This was a retrospective case series identifying 33 patients that underwent thoracic outlet decompression for vTOS from 2014 to 2021 via paraclavicular approach at Trinity Health Ann Arbor. Demographics, presenting symptoms, perioperative details, and follow-up details describing symptomatic improvement and imaging surveillance were obtained.

RESULTS

The average age of our patients was 37 years with the most common presenting symptoms of pain and swelling (91%). The average time from diagnosis to thrombolysis for effort thrombosis was 4 days, with an average time to operative intervention of 46 days. All patients underwent a paraclavicular approach with full first rib resection, anterior and middle scalenectomy, subclavian vein venolysis, and intraoperative venogram. Of these, 20 (61%) underwent endovascular balloon angioplasty, 1 required balloon with stent placement, 13 (39%) required no additional intervention, and no patients required surgical reconstruction of the subclavian-axillary vein. Duplex imaging was used to evaluate recurrence in 26 patients at an average of 6 months postop. Of these, 23 demonstrated complete patency (89%), 1 demonstrated chronic nonocclusive thrombus, and 2 demonstrated chronic occlusive thrombus. Almost all our patients (97%) had moderate or significant improvement of their symptoms. None of our patients required a subsequent operation for recurrence of symptomatic thrombosis. The mode length of anticoagulation use postoperatively was 3 months, with an average use of 4.5 months.

CONCLUSIONS

A systematized surgical approach of paraclavicular decompression for venous thoracic outlet syndrome with primary endovascular balloon angioplasty carries minimal morbidity with excellent functional results and symptomatic relief.

Comparison of outcomes for fixed and weight-based four-factor prothrombin complex concentrate dosing regimens

OBJECTIVES

Although fixed dose regimens using four-factor prothrombin complex concentrate (4F-PCC) are more widely accepted, using a 'one size fits all' approach remains an area of uncertainty. The primary objective of this study was to compare percentages of haemostasis between fixed dose and weight-based dose 4F-PCC regimens for multiple bleed types and anticoagulants. Secondary objectives compared differences in the time to administration and in-hospital mortality.

METHODS

This retrospective, cohort study took place at a community hospital and included patients ≥18 years of age receiving 4F-PCC for major bleeding while on either warfarin or a factor-Xa inhibitor between January 2015 and December 2022. Patients received either fixed dose (treatment) or weight-based dose (comparison). Patients who had been treated for a non-urgent procedure, with unknown haemorrhage source, not on anticoagulation, coagulopathic from hepatic failure, had received dabigatran or were allergic to heparin were excluded. Fisher's exact test and logistic regression were used to analyse primary and secondary outcomes.

RESULTS

94 patients met the inclusion criteria; 38 patients were assigned to the treatment group and 56 to the comparator group. There was no statistical evidence of a difference in the achievement of haemostasis between groups (45% vs 46%, p=0.872). The fixed dose patients received the dose on average 13 min faster than weight-based (32 min vs 46 min, p=0.031). There was no difference in mortality (29% vs 29%, p=0.968).

CONCLUSION

Fixed 4F-PCC regimens may achieve similar outcomes and a faster time to administration compared with weight-based regimens.

Unprovoked Venous Thromboembolism: The Search for the Cause

Venous thromboembolism (VTE) is a common vascular disorder encompassing deep vein thrombosis (DVT) and pulmonary embolism (PE). There is no data on global estimates of VTE prevalence and incidence. Most patients with unprovoked VTE require secondary thromboprophylaxis upon the completion of the primary treatment phase if they have no high bleeding risk. Risk prediction models can help identify patients at low VTE recurrence risk who may discontinue anticoagulation upon the completion of the primary treatment phase.

Mortality and morbidity following initiation of anticoagulant or antiplatelet treatment for blunt cerebrovascular injury

OBJECTIVE

Cerebrovascular accidents (CVA) are potential sequelae of blunt cerebrovascular injuries (BCVI). To minimize their risk, medical therapy is used commonly. It is unclear if anticoagulant or antiplatelet medications are superior for decreasing CVA risk. It is also unclear as to which confer fewer undesirable side effects specifically in patients with BCVI. The aim of this study was to compare outcomes between nonsurgical patients with BCVI with hospital admission records who were treated with anticoagulant medications and those who were treated with antiplatelet medications.

METHODS

We performed a 5-year (2016-2020) analysis of the Nationwide Readmission Database. We identified all adult trauma patients who were diagnosed with BCVI and treated with either anticoagulant or antiplatelet agents. Patients who were diagnosed with index admission CVA, intracranial injury, hypercoagulable states, atrial fibrillation, and or moderate to severe liver disease were excluded. Those who underwent vascular procedures (open and/or endovascular approaches) and or neurosurgical treatment were also excluded. Propensity score matching (1:2 ratio) was performed to control for demographics, injury parameters, and comorbidities. Index admission and 6-month readmission outcomes were examined.

RESULTS

We identified 2133 patients with BCVI who were treated with medical therapy; 1091 patients remained after applying the exclusion criteria. A matched cohort of 461 patients (anticoagulant, 159; antiplatelet, 302) was obtained. The median patient age was 72 years (interquartile range [IQR], 56-82 years), 46.2% of patients were female, falls were the mechanism of injury in 57.2% of cases, and the median New Injury Severity Scale score was 21 (IQR, 9-34). Index outcomes with respect to (1) anticoagulant treatments followed by (2) antiplatelet treatments and (3) P values are as follows: mortality (1.3%, 2.6%, 0.51), median length of stay (6 days, 5 days; P < .001), and median total charge (109,736 USD, 80,280 USD, 0.12). The 6-month readmission outcomes are as follows: readmission (25.8%, 16.2%, <0.05), mortality (4.4%, 4.6%, 0.91), ischemic CVA (4.9%, 4.1%, P = not significant [NS]), gastrointestinal hemorrhage (4.9%, 10.2%, 0.45), hemorrhagic CVA (0%, 0.41%, P = NS), and blood loss anemia (19.5%, 12.2%, P = NS).

CONCLUSIONS

Anticoagulants are associated with a significantly increased readmission rate within 6 months. Neither medical therapy is superior to one another in the reduction of the following: index mortality, 6-month mortality, and 6-month readmission with CVA. Notably, antiplatelet agents seem to be associated with increased hemorrhagic CVA and gastrointestinal hemorrhage on readmission, although neither association is statistically significant. Still, these associations underscore the need for further prospective studies of large sample sizes to investigate the optimal medical therapy for nonsurgical patients with BCVI with hospital admission records.

Risk and Management of Bleeding Complications with Direct Oral Anticoagulants in Patients with Atrial Fibrillation and Venous Thromboembolism: a Narrative Review

Atrial fibrillation (AF) and venous thromboembolism (VTE) are highly prevalent conditions with a significant healthcare burden, and represent the main indications for anticoagulation. Direct oral anticoagulants (DOACs) are the first choice treatment of AF/VTE, and have become the most prescribed class of anticoagulants globally, overtaking vitamin K antagonists (VKAs). Compared to VKAs, DOACs have a similar or better efficacy/safety profile, with reduced risk of intracerebral hemorrhage (ICH), while the risk of major bleeding and other bleeding harms may vary depending on the type of DOAC. We have critically reviewed available evidence from randomized controlled trials and observational studies regarding the risk of bleeding complications of DOACs compared to VKAs in patients with AF and VTE. Special patient populations (e.g., elderly, extreme body weights, chronic kidney disease) have specifically been addressed. Management of bleeding complications and possible resumption of anticoagulation, in particular after ICH and gastrointestinal bleeding, are also discussed. Finally, some suggestions are provided to choose the optimal DOAC to minimize adverse events according to individual patient characteristics and bleeding risk.

Deep Venous Thrombosis and Pulmonary Embolism Secondary to Mild Traumatic Injury in an Elderly Male With No Additional Risk Factors

Venous thromboembolism (VTE) is a significant cardiovascular disease with a relatively high incidence rate, presenting a significant clinical burden. Its effective diagnosis and treatment are critical to the proper management of patients with the condition. Though there are several risk factors associated with VTE, advanced age itself presents as particularly significant, with age-related risk alone leading to high incidences of VTE in elderly patients even in the absence of other risk factors or relevant medical history. We present such a case of an elderly male patient with limited risk factors beyond advanced age who nonetheless presented with symptoms of deep-vein thrombosis (DVT) following a mild traumatic injury, and upon further inspection, was found to have a pulmonary embolism (PE). Proper precautions taken in assessing potential PE upon initial discovery of DVT and post-diagnostic management were critical in this patient's outcome.

Second consensus document on diagnosis and management of acute deep vein thrombosis: updated document elaborated by the ESC Working Group on aorta and peripheral vascular diseases and the ESC Working Group on pulmonary circulation and right ventricular function

This consensus document is proposed to clinicians to provide the whole spectrum of deep vein thrombosis management as an update to the 2017 consensus document. New data guiding clinicians in indicating extended anticoagulation, management of patients with cancer, and prevention and management of post-thrombotic syndrome are presented. More data on benefit and safety of non-vitamin K antagonists oral anticoagulants are highlighted, along with the arrival of new antidotes for severe bleeding management.

Diagnostic accuracy of D-Dimer testing for recurrent venous thromboembolism: A systematic review with meta-analysis.: VTE recurrence and D-dimer

OBJECTIVE

Venous thromboembolism (VTE) recurrence is a major concern after a first symptomatic episode, potentially impacting survival and healthcare needs in community, hospital and rehabilitation settings. We evaluated the association of D-Dimer positivity after oral anticoagulant therapy (OAT) discontinuation with VTE recurrence.

METHODS

PubMed, Web of Science, Scopus and EMBASE databases were systematically searched. Differences were expressed as Odds Ratio (OR) with 95% confidence intervals (95%CI). Pooled sensitivity, specificity, positive (PLR) and negative likelihood ratio (NLR), and summary ROC (sROC) curve were calculated.

RESULTS

Twenty-six articles on 10,725 VTE patients showed that the absolute risk of recurrence was 16.1% (95%CI: 13.2%-19.5%) among 4,049 patients with a positive D-Dimer and 7.4% (95%CI: 6.0%-9.0%) in 6,676 controls (OR: 2.1, 95%CI: 1.7-2.8, P<0.001), with an attributable risk of 54.0%. sROC curve of the association between positive D-Dimer and recurrence showed a diagnostic AUC of 63.8 (95%CI: 60.3-67.4), with a pooled sensitivity of 54.3% (95%CI: 51.3%-57.3%), specificity of 64.2% (95%CI: 63.2-65.1), PLR of 1.53 (95%CI: 1.37-1.72), and NLR of 0.71 (95%CI: 0.60-0.84). Subgroup and meta-regression analyses suggested that a positive D-Dimer may have a higher discriminatory ability for patients with provoked events, confirmed by better pooled diagnostic indexes for recurrence and a diagnostic AUC of 70.6 (95%CI: 63.8-77.4). Regression models showed that the rate of OAT resumption after the evidence of D-Dimer positivity was inversely associated with VTE recurrence (Z-score: -3.91, P<0.001).

CONCLUSIONS

D-Dimer positivity after OAT may identify VTE patients at higher risk of recurrence, with a better diagnostic accuracy for provoked events.

An unusual vermiform giant arachnoid granulation

Arachnoid granulations are outpouchings of arachnoid membrane which extend into the dural sinuses or calvarium, surrounded by a capsule of dense connective tissue. Within dural sinuses, these appear as well-defined, nodular, rounded, or ovoid structures of focal localization. However, it is important to be aware of their variability in presentation in order to correctly identify them and distinguish them from other dural sinus pathology, especially a misdiagnosis of venous sinus thrombosis with risks of unnecessary anticoagulation, intravascular thrombolysis/thrombectomy, or invasive intracranial pressure monitoring. Here we demonstrate a case of a previously unreported giant intrasinus arachnoid granulation of an unusual vermiform morphology, unduly elongated up to 6 cm in length, involving a significant segment of the superior sagittal sinus. The proof of this diagnosis was the radiologic appearance on multiple modalities and an unchanged appearance over the long-term.