Lead thrombus under standard-dose edoxaban in a patient with normal to high creatinine clearance and protein S deficiency

Edoxaban Improved End-QRS Notches and Early Repolarizations

Cardiac computed tomography (CT) images sometimes show a donut-like oval structure on the antero-superior wall of the left atrium (LA). What is a donut? Left atrium diverticula (LADs) are common, but there are many unknown features of LADs. The direct effects of pulmonary vein thrombi (PVTs) on the heart are poorly understood. Herein, we report a case report in which we describe the different effects of edoxaban on LA thrombi, the LAD, coronary artery collaterals, early repolarizations, and end-QRS notches using cardiac CT and transesophageal echocardiography (TEE). First, we showed that there was a LAD on the anterior wall of the LA where the LA thrombi from the right lower pulmonary vein (RLPV) thrombi were connected. To our knowledge, this is the first report to reveal LAD's annular transformation and the beneficial effect of edoxaban on the end-QRS notch.

Impact of baseline renal function on the efficacy and safety of different Anticoagulants in Atrial Fibrillation Patients - A cohort study

Background

Vitamin K antagonists and different direct oral anticoagulants (DOACs) have different renal clearance rates. However, the impact of different stages of chronic renal impairment on the efficacy and safety of warfarin, dabigatran, rivaroxaban, apixaban, and edoxaban in atrial fibrillation (AF) patients remains unclear.

Methods

This study enrolled AF patients from the Chang Gung Research Database. The study endpoints included thromboembolic events, major/fatal bleeding, gastrointestinal (GI) bleeding and intracranial hemorrhage (ICH). The risks of time to study endpoints between groups were compared using a Cox proportional hazards regression model with adjustment.

Results

This study enrolled 3525 patients with moderate renal impairment (30 ≤ creatinine clearance (CrCl) < 60 mL/min), 2846 patients with mild renal impairment (60 ≤ CrCl < 90 mL/min) and 1153 patients with CrCl ≥ 90 mL/min. Over the 3.3 ± 0.9 years follow-up period, the cumulative thromboembolic events rates and the cumulative event rates of major/fatal bleeding and ICH did not differ among the warfarin and different DOAC groups at different stages of chronic renal impairment. The annual incidences of thromboembolic events, major/fatal bleeding, GI bleeding, and ICH were similar among the warfarin and different DOAC groups at different stages of renal impairment.

Conclusion

There did not appear to be major differences in bleeding or thromboembolic risk compared to warfarin in AF patients across a range of degree of renal failure when appropriate dose reductions of the DOACs are made.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12959-022-00423-w.

Inherited Thrombophilia in the Era of Direct Oral Anticoagulants

Severe inherited thrombophilia includes rare deficiencies of natural anticoagulants (antithrombin and proteins C and S) and homozygous or combined factor V Leiden and FII G20210A variants. They are associated with a high thrombosis risk and can impact the duration of anticoagulation therapy for patients with a venous thromboembolism (VTE) event. Therefore, it is important to diagnose thrombophilia and to use adapted anticoagulant therapy. The widespread use of direct anticoagulants (DOACs) for VTE has raised new issues concerning inherited thrombophilia. Concerning inherited thrombophilia diagnosis, DOACs are directed toward either FIIa or FXa and can therefore interfere with coagulation assays. This paper reports DOAC interference in several thrombophilia tests, including the assessment of antithrombin, protein S, and protein C activities. Antithrombin activity and clot-based assays used for proteins C and S can be overestimated, with a risk of missing a deficiency. The use of a device to remove DOACs should be considered to minimize the risk of false-negative results. The place of DOACs in the treatment of VTE in thrombophilia patients is also discussed. Available data are encouraging, but given the variability in thrombosis risk within natural anticoagulant deficiencies, evidence in patients with well-characterized thrombophilia would be useful.

A thrombophilia family with protein S deficiency due to protein translation disorders caused by a Leu607Ser heterozygous mutation in PROS1

BACKGROUND

Protein S deficiency (PSD) is an autosomal dominant hereditary disease. In 1984, familial PSD was reported to be prone to recurrent thrombosis. Follow-up studies have shown that heterozygous protein S (PROS1) mutations increase the risk of thrombosis. More than 300 PROS1 mutations have been identified; among them, only a small number of mutations have been reported its possible mechanism to reduce plasma protein S (PS) levels. However, whether PROS1 mutations affect protein structure and why it can induce PSD remains unknown.

METHODS

The clinical phenotypes of the members of a family with thrombosis were collected. Their PS activity was measured using the coagulation method, whereas their protein C and antithrombin III activities were measured using methods such as the chromogenic substrate method. The proband and her parents were screened for the responsible mutation using second-generation whole exon sequencing, and the members of the family were verified for suspected mutations using Sanger sequencing. Mutant and wild type plasmids were constructed and transfected into HEK293T cells to detect the mRNA and protein expression of PROS1.

RESULTS

In this family, the proband with venous thrombosis of both lower extremities, the proband's mother with pulmonary embolism and venous thrombosis of both lower extremities, and the proband's younger brother had significantly lower PS activity and carried a PROS1 c. 1820 T > C:p.Leu607Ser heterozygous mutation (NM_000313.3). However, no such mutations were found in family members with normal PS activity. The PS expression in the cell lysate and supernatant of the Leu607Ser mutant cells decreased, while mRNA expression increased. Immunofluorescence localization showed that there was no significant difference in protein localization before and after mutation.

CONCLUSIONS

The analysis of family phenotype, gene association, and cell function tests suggest that the PROS1 Leu607Ser heterozygous mutation may be a pathogenic mutation. Serine substitution causes structural instability of the entire protein. These data indicate that impaired PS translation and synthesis or possible secretion impairment is the main pathogenesis of this family with hereditary PSD and thrombophilia.