Monitoring the roles of prothrombin activation fragment 1 and 2 (F1 + 2) in patients with atrial fibrillation receiving rivaroxaban and apixaban.

Factor Xa (FXa) inhibitors are recommended for use in fixed doses without laboratory monitoring. However, prior studies reported the importance of establishing biomarkers representing anticoagulation intensity related to bleeding or thrombotic events. To test the hypothesis that prothrombin activation fragment 1 and 2 (F1 + 2), a non-specific marker of thrombin generation, could be altered during FXa inhibitor treatment in patients with atrial fibrillation. We conducted the study in two different clinical settings. First, the interrelations among biomarkers representing coagulation/fibrinolysis were investigated in 80 patients in an outpatient clinic. Second, these biomarkers were evaluated in 75 patients who underwent radiofrequency catheter ablation. Plasma concentration of FXa inhibitors was evaluated using an anti-FXa chromogenic assay (C-Xa). In the outpatient study, only F1 + 2 exhibited a significant and negative association with C-Xa (rS = - 0.315, p = 0.026), and 37% of the variance could be explained by C-Xa levels. F1 + 2 levels above the reference range (> 229 pmol/L) could be considered as a cut-off to identify poor patient compliance or under-dosing. In the peri-ablation study, increased F1 + 2 levels were associated with decline of C-Xa levels after periprocedural discontinuation of FXa inhibitors, which was greater in the rivaroxaban group than in the apixaban group. F1 + 2 showed modest and inverse association with plasma concentration of rivaroxaban and apixaban in patients with atrial fibrillation. Larger study to test the hypothesis that continued thrombin generation despite anticoagulation is associated with a heightened risk of clinical events is required.

Nutri-pharmacogenomics of warfarin anticoagulation therapy: VKORC1 genotype-dependent influence of dietary vitamin K intake.

Warfarin is the most widely prescribed oral anticoagulant, but large interindividual variations exist in the dose required to achieve comparable therapeutic effects. Several clinical and genetic variables have been identified that influence warfarin dosing. However, interactions between genotype and nutrition remain uncertain in terms of dietary vitamin K intake. To investigate genotype-nutrient interactions in warfarin anticoagulation therapy, 202 consecutive outpatients (M/F = 142/60, mean age, 69 years) undergoing treatment with warfarin were enrolled. Prevalent single nucleotide polymorphisms in VKORC1 and CYP2C9 were genotyped, and dietary vitamin K intake during the week preceding the blood sampling was quantitatively estimated by a dietitian-assisted questionnaire. Patients were classified according to low, medium, or high vitamin K intake. The mean daily warfarin dose in subjects with a VKORC1-1639 A/A genotype was significantly smaller than that with a -1639A/G genotype (2.74 vs. 3.91 mg/day, respectively, p < 0.0001). Dose requirements did not differ between subjects with a CYP2C9 *1/*3 genotype versus a CYP2C9 *1/*1 genotype. In subjects with a variant VKORC1-1639 G allele, the mean daily warfarin dose was significantly attenuated by low vitamin K intake compared with medium and high intake after adjustment for covariates (3.4 vs. 5.0 vs. 4.0 mg/day, respectively, p = 0.028). No such genotype effects were observed in homozygous patients for the VKORC1-1639 A allele. The results of the present study suggest that the capacity of dietary vitamin K intake to influence warfarin dose requirements during anticoagulation therapy is VKORC1 genotype-dependent, at least in part.

Thrombotic Microangiopathy after a 15-year Treatment with Interferon Beta-1b in a Patient with Multiple Sclerosis: A Case Report and Review of Literature.

A 54-year-old woman with multiple sclerosis treated with interferon-ß (IFN-ß)-1b for 15 years presented with sustained hypertension (240/124 mmHg) and retinal bleeding. She had proteinuria, anemia, thrombocytopenia, elevated serum creatinine levels, and haptoglobin depletion. Intravenous nicardipine stabilized her blood pressure, but her renal function and platelet count deteriorated. The initial disintegrin-like metalloprotease with thrombospondin type 1 motifs 13 (ADAMTS13) activity was 28% of normal without its inhibitor. The subsequent peripheral appearance of schistocytes suggested thrombotic microangiopathy (TMA). After IFN-ß-1b cessation, the platelet count increased, and the blood pressure stabilized. The ADAMTS13 activity normalized, although the creatinine level did not. TMA may develop after the long-term use of IFN-ß without adverse events.

A Case of Myopericarditis After the Second Dose of mRNA COVID-19 Vaccine in a Patient With a History of Myopericarditis.

Vaccination is important for the prevention of coronavirus-induced disease 2019 (COVID-19) caused by SARS-CoV-2 (severe acute respiratory syndrome coronavirus 2) and to protect persons with a high risk for complications. There have been reports of myopericarditis following COVID-19 vaccination, especially in adolescent males and young adults. Breakthrough infections, such as the Delta or Omicron variant of SARS-CoV-2, have raised great concern about the necessity for repeated doses of the vaccine. A case of myopericarditis after the second dose of COVID-19 mRNA-1273 (Moderna) vaccine in a 23-year-old man with a prior episode of viral myopericarditis is presented. He received the second dose of the COVID-19 mRNA vaccine, after which he developed persistent midsternal chest pain and he was subsequently transferred to our emergency department. An echocardiogram showed a trivial inferior pericardial effusion with diffuse left ventricular systolic dysfunction. He was treated with colchicine from the first day of hospitalization with a diagnosis of myopericarditis. His chest pain had resolved by the third day, and left ventricular wall motion was dramatically improved by the seventh day of hospitalization. A strong response to the second vaccination in the present case suggests that the prior history of myopericarditis is evidence of strong congenital or acquired immunological features in this individual. Individuals with such a strong immune response may be more likely to develop myopericarditis after mRNA vaccination. Immunization against COVID-19 is currently recommended from a risk-benefit standpoint. We advised the patient to avoid additional COVID-19 mRNA vaccines because of this episode. The risk of COVID-19 weighed against myopericarditis associated with the mRNA vaccination should be considered on a case-by-case basis. This case may help us better understand the mechanism of myopericarditis following COVID-19 mRNA vaccination.

The circulating furin-cleaved/mature PCSK9 ratio has a potential prognostic significance in statin-naïve patients with acute ST elevation myocardial infarction.

Background and aims: Proprotein convertase subtilisin/kexin type 9 (PCSK9) circulates as mature and furin-cleaved forms, but their biological functions are uncertain. We investigated whether their levels associate with prognosis in patients with acute ST elevation myocardial infarction (STEMI). Methods: We enrolled 160 statin-naïve patients with acute STEMI and followed for 3 years. PCSK9 subtype levels were determined by an enzyme-linked immunosorbent assay before and at five timepoints up to 48 h after emergent coronary intervention. The occurrence of coronary and cardiac events was compared between subjects stratified by the PCSK9 level. Results: One hundred and twenty-six patients completed 3 years of follow-up. In the acute phase, both PCSK9 subtype levels decreased, and thereafter increased from 6 to 48 h (mature: from 198 ± 67 to 334 ± 116 ng/mL, furin-cleaved: from 20 ± 7 to 39 ± 16 ng/mL, both p < 0.01). Major cardiac events occurred in 46 patients. The furin-cleaved/mature PCSK9 ratio at 48 h after coronary intervention predicted the likelihood of experiencing of events; patients in the third tertile had lower event-free survival than those in the first and second tetiles in Kaplan-Meier analysis (p = 0.004). Multivariate Cox regression analysis revealed that this ratio had a greater impact (HR: 1.92; 95% CI: 1.06-3.45, p = 0.03) on events than other known atherosclerosis risk factors. Conclusions: The furin-cleaved/mature PCSK9 ratio was associated with 3-year cardiovascular events in statin-naïve patients with acute STEMI, suggesting a potential link between furin cleavage process of PCSK9 and its effect on prognosis. (249 words).

A case of cardiac resynchronization therapy in a patient with coronary sinus ostial atresia and persistent left superior vena cava.

Coronary sinus ostial atresia is rare and usually not clinically relevant, but it should be noted in cases of cardiac resynchronization therapy. A rare case of successful left ventricular lead implantation for cardiac resynchronization therapy via the left superior vena cava in a patient with coronary sinus ostial atresia is reported. The persistent left superior vena cava associated with these cases tends to be smaller than usual in its diameter and difficult to identify, since the direction of venous drainage is reversed. Therefore, in the present case, it was useful to use a small-diameter, soft inner catheter as a guiding catheter to perform selective imaging and avoid vascular injury. In addition, it appeared to be important to plan the surgical strategy using prior imaging information, since it would be difficult to obtain the backup needed for lead insertion. 〈: Learning objective: Cardiac resynchronization therapy via the left superior vena cava with coronary sinus ostial atresia is generally possible without problems if prior imaging information is available, such as three-dimensional computed tomography and the venous phase of coronary angiography. It is important to determine whether there is a persistent left superior vena cava before the procedure. Thromboprophylaxis remains controversial in this situation.〉.