Antidotes for reversal of direct oral anticoagulants

Is General Anesthesia for Peripheral Vascular Surgery Correlated with Impaired Outcome in Patients with Cardiac Comorbidity? A Closer Look into the Nationwide Danish Cohort

OBJECTIVE

General anesthesia (GA) may impair outcome after vascular surgery. The use of anticoagulant medication is often used in patients with cardiac comorbidity. Regional anesthesia (RA) requires planning of discontinuation before neuraxial blockade(s) in this subgroup. This study aimed to describe the effect of anesthesia choice on outcome after vascular surgery in patients with known cardiac comorbidity.

DESIGN

Retrospective cohort study.

SETTING

Danish hospitals.

PARTICIPANTS

6302 patients with known cardiac comorbidity, defined as ischemic heart disease, valve disease, pulmonary vascular disease, heart failure, and cardiac arrhythmias, undergoing lower extremity vascular surgery between 2005 and 2017.

INTERVENTIONS

GA versus RA.

MEASUREMENTS AND MAIN RESULTS

Data were extracted from national registries. GA was defined as anesthesia with mechanical ventilation. Multivariable regression models were used to describe the incidence of postoperative complications as well as 30-day mortality, hypothesizing that better outcomes would be seen after RA. The rate of RA decreased from 48% in 2005 to 20% in 2017. The number of patients with 1 or more complications was 9.7% vs 6.2% (p < 0.001), and 30-day mortality was 6.0% vs 3.4% (p < 0.001) after GA. After adjusting for baseline differences, the odds ratio (OR) was significantly lower for medical complications (cardiac, pulmonary, renal, new dialysis, intensive care unit and other medical complications; OR, 0.97; 95% confidence interval [CI], 0.95-0.98) and 30-day mortality (OR 0.98; 95% CI, 0.97-0.99) after RA.

CONCLUSIONS

RA may be associated with a better outcome than GA after lower extremity vascular surgery in patients with a cardiac comorbidity. Prioritizing RA, despite the inconvenience of discontinuing anticoagulants, may be recommended.

Andexanet alfa therapy showed No increased rate of thromboembolic events in spontaneous intracranial hemorrhage patients: A multicenter electronic health record study

•Intracranial hemorrhage accounts for two out of every three major intracranial hemorrhages.•Systemic anticoagulation is routinely prescribed for prevention of cerebrovascular accidents.•The FDA approved Andexanet alfa to treat life-threatening bleeding.•Andexanet alfa relationship to outcomes requires further investigation.

Emergent external ventricular drain placement in patients with factor Xa inhibitor-associated intracerebral hemorrhage after reversal with andexanet alfa

BACKGROUND

Andexanet alfa (AA), a factor Xa-inhibitor (FXi) reversal agent, is given as a bolus followed by a 2-hour infusion. This long administration time can delay EVD placement in intracerebral hemorrhage (ICH) patients. We sought to evaluate the safety of EVD placement immediately post-AA bolus compared to post-AA infusion.

METHODS

We conducted a retrospective study that included adult patients admitted with FXi-associated ICH who received AA and underwent EVD placement The primary outcome was the occurrence of a new hemorrhage (tract, extra-axial, or intraventricular hemorrhage). Secondary outcomes included mortality, intensive care unit and hospital length of stay, and discharge modified Rankin Score. The primary safety outcome was documented thrombotic events.

RESULTS

Twelve patients with FXi related ICH were included (EVD placement post-AA bolus, N = 8; EVD placement post-AA infusion, N = 4). Each arm included one patient with bilateral EVD placed. There was no difference in the incidence of new hemorrhages, with one post-AA bolus patient had small, focal, nonoperative extra-axial hemorrhage. Morbidity and mortality were higher in post-AA infusion patients (mRS, post-AA bolus, 4 [4-6] vs. post-AA infusion 6 [5,6], p = 0.24 and post-AA bolus, 3 (37.5 %) vs. post-AA infusion, 3 (75 %), p = 0.54, respectively). One patient in the post-AA bolus group had thrombotic event. There was no difference in hospital LOS (post-AA bolus, 19 days [12-26] vs. post-AA infusion, 14 days [9-22], p = 0.55) and ICU LOS (post-AA bolus, 10 days [6-13] vs. post-AA infusion, 11 days [5-21], p = 0.86).

CONCLUSION

We report no differences in the incidence of tract hemorrhage, extra-axial hemorrhage, or intraventricular hemorrhage post-AA bolus versus post-AA infusion. Larger prospective studies to validate these results are warranted.

Pharmacology of Heparin and Related Drugs: An Update

Heparin has been used extensively as an antithrombotic and anticoagulant for close to 100 years. This anticoagulant activity is attributed mainly to the pentasaccharide sequence, which potentiates the inhibitory action of antithrombin, a major inhibitor of the coagulation cascade. More recently it has been elucidated that heparin exhibits anti-inflammatory effect via interference of the formation of neutrophil extracellular traps and this may also contribute to heparin's antithrombotic activity. This illustrates that heparin interacts with a broad range of biomolecules, exerting both anticoagulant and nonanticoagulant actions. Since our previous review, there has been an increased interest in these nonanticoagulant effects of heparin, with the beneficial role in patients infected with SARS2-coronavirus a highly topical example. This article provides an update on our previous review with more recent developments and observations made for these novel uses of heparin and an overview of the development status of heparin-based drugs. SIGNIFICANCE STATEMENT: This state-of-the-art review covers recent developments in the use of heparin and heparin-like materials as anticoagulant, now including immunothrombosis observations, and as nonanticoagulant including a role in the treatment of SARS-coronavirus and inflammatory conditions.

The impact of antithrombotic therapy on surgical delay and 2-year mortality in older patients with hip fracture: a prospective observational study

PURPOSE

To analyze the associations of oral anticoagulant and antiplatelet treatments in older patients requiring surgical treatment for hip fracture with mortality, length of stay, waiting time to surgery and postsurgical immediate complications.

METHODS

A prospective observational study, including surgically treated hip fracture patients aged 65 years and older. We analyzed admission status variables, and time to surgery, length of stay and immediate surgical and medical complications. We recorded a 2-year survival follow-up.

RESULTS

Of the 237 patients studied, 32.5% received antiplatelet treatment and 17.7% received oral anticoagulant treatment. The overall 2-year mortality was 29.1%. The 2-year mortality rate reached the 33.8% for antiplatelet-treated patients (n.s.) and 45.2% for oral anticoagulated patients (p = 0.011). The length of stay increased significantly associated with the oral anticoagulant or high-dose antiplatelet treatment (p < 0.001). The same happened for the time to surgery (p < 0.001), but no delay was observed for patients with low-dose antiplatelet treatment. Oral anticoagulated and antiplatelet-treated patients had a higher Charlson comorbidity index (p = 0.004, p = 0.019) and ASA score (p = 0.006, p = 0.011). Those treatments were also associated with a higher rate of some immediate postsurgical medical complications. We found a relationship between low hemoglobin at admission and high-dose antiplatelet treatment (p = 0.044).

CONCLUSIONS

Hip fracture patients following previous oral anticoagulant treatment have a higher 2-year mortality rate. The oral anticoagulant or high-dose antiplatelet treatments are significantly associated with an increase in the length of stay, related to time to surgery, but we could not demonstrate an effect on early mortality.

Innovative Three-Step Microwave-Promoted Synthesis of N-Propargyltetrahydroquinoline and 1,2,3-Triazole Derivatives as a Potential Factor Xa (FXa) Inhibitors: Drug Design, Synthesis, and Biological Evaluation

The coagulation cascade is the process of the conversion of soluble fibrinogen to insoluble fibrin that terminates in production of a clot. Factor Xa (FXa) is a serine protease involved in the blood coagulation cascade. Moreover, FXa plays a vital role in the enzymatic sequence which ends with the thrombus production. Thrombosis is a common causal pathology for three widespread cardiovascular syndromes: acute coronary syndrome (ACS), venous thromboembolism (VTE), and strokes. In this research a series of N-propargyltetrahydroquinoline and 1,2,3-triazole derivatives as a potential factor Xa (FXa) inhibitor were designed, synthesized, and evaluated for their FXa inhibitor activity, cytotoxicity activity and coagulation parameters. Rational design for the desired novel molecules was performed through protein-ligand complexes selection and ligand clustering. The microwave-assisted synthetic strategy of selected compounds was carried out by using Ullmann-Goldberg, N-propargylation, Mannich addition, Friedel-Crafts, and 1,3-dipolar cycloaddition type reactions under microwave irradiation. The microwave methodology proved to be an efficient way to obtain all novel compounds in high yields (73–93%). Furthermore, a thermochemical analysis, optimization and reactivity indexes such as electronic chemical potential (µ), chemical hardness (η), and electrophilicity (ω) were performed to understand the relationship between the structure and the energetic behavior of all the series. Then, in vitro analysis showed that compounds 27, 29–31, and 34 exhibited inhibitory activity against FXa and the corresponding half maximal inhibitory concentration (IC₅₀) values were calculated. Next, a cell viability assay in HEK293 and HepG2 cell lines, and coagulation parameters (anti FXa, Prothrombin time (PT), activated Partial Thromboplastin Time (aPTT)) of the most active novel molecules were performed to determine the corresponding cytotoxicity and possible action on clotting pathways. The obtained results suggest that compounds 27 and 29 inhibited FXa targeting through coagulation factors in the intrinsic and extrinsic pathways. However, compound 34 may target coagulation FXa mainly by the extrinsic and common pathway. Interestingly, the most active compounds in relation to the inhibition activity against FXa and coagulation parameters did not show toxicity at the performed coagulation assay concentrations. Finally, docking studies confirmed the preferential binding mode of N-propargyltetrahydroquinoline and 1,2,3-triazole derivatives inside the active site of FXa.

Role of direct oral anticoagulants in patients with kidney disease

The anticoagulation field is experiencing a renaissance that began with regulatory approval of the direct thrombin inhibitor dabigatran, a direct oral anticoagulant (DOAC), in 2010. The DOAC medication class has rapidly evolved to include the additional approval of 4 direct factor Xa inhibitors. Commensurately, DOAC use has increased and collectively account for the majority of new anticoagulant prescriptions. Despite exclusion of patients with moderate-to-severe kidney disease from most pivotal DOAC trials, DOACs are increasingly used in this setting. An advantage of DOACs is similar or improved antithrombotic efficacy with less bleeding risk when compared with traditional agents. Several post hoc analyses, retrospective studies, claims data studies, and meta-analyses suggest that these benefits extend to patients with kidney disease. However, the lack of randomized controlled trial data in specific kidney disease settings, with their unique pathophysiology, should be a call to action for the kidney community to systematically study these agents, especially because early data suggest that DOACs may pose less risk of anticoagulant-related nephropathy than do vitamin K antagonists. Most DOACs are renally cleared and are significantly protein bound in circulation; thus, the pharmacokinetics of these drugs are influenced by reduced renal function and proteinuria. DOACs are susceptible to altered metabolism by P-glycoprotein inhibitors and inducers, including drugs commonly used for the management of kidney disease comorbidities. We summarize the currently available literature on DOAC use in kidney disease and illustrate knowledge gaps that represent important opportunities for prospective investigation.