Ezetimibe enhances and stabilizes anticoagulant effect of warfarin

Effect of NPC1L1 polymorphism on warfarin stable dose in Chinese patients under heart valve replacement surgery

Warfarin is the most often anticoagulant choice for preventable thromboembolism. Notably, vitamin K plays a vital role in the process of warfarin's anticoagulant effect. Therefore, we presume NPC1L1, a key transporter of vitamin K (VK) intestinal absorption, may modulate the anticoagulant effect of warfarin. Studies have shown that NPC1L1(-762T>C, rs2073548) and p53 (P72R, rs1042522) variations are implicated in influencing NPC1L1 expression. This study aimed to assess the association between these two variants and warfarin stable dose (WSD). A two-stage extreme phenotype design was used to explore the influence of these two variants (rs2073548, rs1042522) on WSD variance in 655 Chinese patients undergoing heart valve replacement surgery. NPC1L1 rs2073548, p53 rs1042522, VKORC1 rs9923231 and CYP2C9*1/*3 polymorphisms were genotyped by polymerase chain reaction-restriction fragment polymorphism (PCR-RFLP) or Sanger sequencing, respectively. WSD was identified when target monitoring international normalized ratio (INR) value at 2.0-3.0. In the discovery phase, NPC1L1 rs2073548 A allele carriers occupied a significantly higher rate in the low dose group (P = .019). However, in the validation group, warfarin dosage in patients with the rs2073548 AA, AG and GG genotypes were 2.91 ± 0.97 mg/day, 3.02 ± 1.00 mg/day and 3.00 ± 1.06 mg/day, respectively. Multiple linear regression analysis results suggested that CYP2C9*3 and VKORC1 rs9923231, but not NPC1L1 rs2073548, were independent predictors of WSD in Chinese heart valve replacement (HVR) surgical patients.

Differential effect of statin use on coagulation markers: an active comparative analysis in the NEO study

Background

Statins are a potential treatment for venous thromboembolism (VTE) prophylaxis complementary to conventional anticoagulants without associated bleeding complications. This study aimed to compare pro-thrombotic activities of different classes of lipid-lowering drugs in an active comparator design and determine whether there is a relation between statin versus fibrate/niacin use and pro-coagulant factor outcomes.

Methods

This is a cross-sectional analysis of participants from the Netherlands Epidemiology of Obesity study using any class of lipid-lowering drugs, including any types of statins, niacin, and fibrates. We performed linear regression analyses to determine fibrinogen, factor (F) VIII, FIX, and FXI activity in statins versus fibrate/niacin users and adjusted for age, sex, tobacco smoking, body mass index (BMI), hypertension, diabetes, and prevalent cardiovascular disease.

Results

Among 1043 participants, the mean age was 58.4 ± 5.2 years, 61% were men, and the mean BMI was 31.3 ± 4.5 kg/m². Clinical characteristics were balanced between statin and fibrate/niacin users. Statin users had lower mean FXI (18.3 IU/dL, 95% confidence interval (CI) 9.4 to 27.3) levels compared to fibrate/niacin users. The level of FVIII (15.8 IU/dL, 95% CI − 0.003 to 31.6), and FIX (11.3 IU/dL, 95% CI − 0.4 to 23.2) were lower in statin users than fibrate/niacin users with marginal statistical significance.

Conclusion

Current statin use was associated with lower plasma levels of FXI than fibrate/niacin use. The effects on coagulation factors may, in part, explain the benefit of statin therapy rendered in primary and secondary prevention of VTE.

Drug-drug interaction between warfarin and statins: A Danish cohort study

Initiation of statin treatment is suggested to increase the international normalised ratio (INR) among warfarin users. However, available data is limited and conflicting. We conducted a register-based cohort study to evaluate the drug-drug interaction between warfarin and statins. By linking data on INR measurements and filled prescriptions, we identified warfarin users 2000-2015 initiating simvastatin (n = 1363), atorvastatin (n = 165) or rosuvastatin (n = 23). Simvastatin initiation led to an increase in mean INR from 2.40 to 2.71, with INRs peaking after 4 weeks, corresponding to a mean change of 0.32 (95%CI 0.25-0.38). High-dose and low-dose simvastatin led to comparable changes (mean change 0.33 vs 0.29). Initiation of atorvastatin and rosuvastatin lead to INR increases of 0.27 (95%CI 0.12-0.42) and 0.30 (95%CI -0.09-0.69). In conclusion, initiation of simvastatin, atorvastatin or rosuvastatin among warfarin users led to a minor increase in INR. The magnitude of this change is for most patients likely of limited clinical relevance.

Clinical Importance of Drug-Drug Interaction Between Warfarin and Prednisolone and Its Potential Mechanism in Relation to the Niemann-Pick C1-Like 1-Mediated Pathway

BACKGROUND

Warfarin is an anticoagulant drug used to prevent thromboembolic disorders, but its pharmacological effect is affected by co-administered drugs. Therefore, careful management of warfarin-related drug-drug interactions (DDIs) is necessary for its safety and effectiveness. Recently, intestinal vitamin K1absorption through the Niemann-Pick C1-like 1 (NPC1L1)-mediated pathway was found to affect the pharmacological effect of warfarin. This study aimed to identify high-frequency warfarin-related DDIs in a clinical setting and elucidate their mechanism(s) in terms of changes in NPC1L1 expression and/or activity.

METHODS AND RESULTS

Prednisolone was the most frequently suspected drug in retrospective surveys of medical records of patients who experienced warfarin-related DDIs. Prednisolone significantly increased the international normalized ratio of prothrombin time (PT-INR) values in warfarin-treated patients. To demonstrate the involvement of NPC1L1 in warfarin-prednisolone DDI, we conducted an in vitro vitamin K1uptake assay using NPC1L1-overexpressing cells and found that prednisolone inhibited NPC1L1-mediated vitamin K1uptake. Additionally, we found that prednisolone downregulates NPC1L1 in a glucocorticoid receptor α-dependent manner.

CONCLUSIONS

Co-administration of warfarin and prednisolone frequently enhanced the anticoagulant effect of warfarin in a clinical setting. Prednisolone-mediated suppression of NPC1L1 expression and activity could be the mechanism of DDI between warfarin and prednisolone. To manage warfarin therapy, the potential of concomitant drugs to change its anticoagulant effect through NPC1L1-related mechanisms merits consideration.

Associations between Lifestyle-Related Diseases and Transporters Involved in Intestinal Absorption and Biliary Excretion of Cholesterol

Westernization of dietary habits leads to an increase in lipid intake and is thought to be responsible for an increase in patients with dyslipidemia. It is a well-known fact that the impaired cholesterol homeostasis is closely related to the development of various lifestyle-related diseases such as fatty liver, diabetes, and gallstone as well as dyslipidemia leading to atherosclerosis and cardiovascular diseases such as heart attack and stroke. Therefore, appropriate management of cholesterol levels in the body is considered important in prevention and treatments of these lifestyle-related diseases and in addition, molecular mechanisms controlling plasma (and/or hepatic) cholesterol levels have been intensively studied. Due to its hydrophobicity, cholesterol was long believed to pass through cell membranes by passive diffusion. However, recent studies have identified a number of plasma membrane transporters that are responsible for the cellular uptake or efflux of cholesterol and involved in developments of lifestyle-related diseases. In this review, we focus on Niemann-Pick C1 Like 1 (NPC1L1) and a heterodimer of ATP-binding cassette transporter G5 and G8 (ABCG5/G8), both of which are responsible for intestinal cholesterol absorption and biliary cholesterol secretion, and discuss the relationship between these cholesterol transporters and lifestyle-related diseases. In addition, we also discuss the related uncertainties that need to be explored in future studies.

Temporal trends of time in therapeutic range and incidence of cardiovascular events in patients with non-valvular atrial fibrillation

BACKGROUND

Optimal time in therapeutic range (TTR) of vitamin K antagonists (VKAs) is crucial for cardiovascular events (CVEs) prevention in non-valvular atrial fibrillation (NVAF). The relationship between temporal changes of TTR and the incidence of CVEs has been poorly investigated. We investigated 1) temporal trends of TTR in a long-term follow-up of NVAF patients; 2) the incidence of CVEs according to changes of TTR.

METHODS

Prospective observational study including 1341 NVAF outpatients (mean age 73.5 years, 42.5% male) starting VKAs. Patients were divided into 4 groups: Group 0: Optimal TTR, consistently ≥70% (n = 241); Group 1: Temporally worsening TTR, from above to below 70% (n = 263); Group 2: Temporally improving TTR, from below to above 70% (n = 270); Group 3: Suboptimal TTR, consistently <70% (n = 567).

RESULTS

In a mean follow-up of 37.7 months (4214.2 patient-years), 108 CVEs occurred (2.6%/year). Survival analysis showed a graded increased risk of CVEs in relation to temporal changes in TTR, with the worst outcomes in Groups 1 and 3 (log-rank test p = 0.013). Multivariable Cox proportional hazards regression analysis showed that Group 1 vs. 0 (HR: 2.096; 95%CI 1.061-4.139, p = 0.033), Group 3 vs. 0 (HR: 2.292; 95%CI 1.205-4.361, p = 0.011), CHA₂DS₂VASc score (HR:1.316; 95%CI 1.153-1.501, p < 0.001) and PPIs (HR:0.453; 95%CI 0.285-0.721, p = 0.001) were independently associated with CVEs.

CONCLUSION

A decrease of TTR <70% over time is observed in almost 20% of NVAF patients. Patients with worsening TTR temporally (ie. from initially above 70% to below 70%) have similar risk of CVEs of patients with consistently suboptimal anticoagulation.

Transporters for the Intestinal Absorption of Cholesterol, Vitamin E, and Vitamin K

Humans cannot synthesize fat-soluble vitamins such as vitamin E and vitamin K. For this reason, they must be obtained from the diet via intestinal absorption. As the deficiency or excess of these vitamins has been reported to cause several types of diseases and disorders in humans, the intestinal absorption of these nutrients must be properly regulated to ensure good health. However, the mechanism of their intestinal absorption remains poorly understood. Recent studies on cholesterol using genome-edited mice, genome-wide association approaches, gene mutation analyses, and the development of cholesterol absorption inhibitors have revealed that several membrane proteins play crucial roles in the intestinal absorption of cholesterol. Surprisingly, detailed analyses of these cholesterol transporters have revealed that they can also transport vitamin E and vitamin K, providing clues to uncover the molecular mechanisms underlying the intestinal absorption of these fat-soluble vitamins. In this review, we focus on the membrane proteins (Niemann-Pick C1 like 1, scavenger receptor class B type I, cluster of differentiation 36, and ATP-binding cassette transporter A1) that are (potentially) involved in the intestinal absorption of cholesterol, vitamin E, and vitamin K and discuss their physiological and pharmacological importance. We also discuss the related uncertainties that need to be explored in future studies.

Effects of ezetimibe and anticoagulant combined therapy on progressing stroke: a randomized, placebo-controlled study

Despite the high prevalence of progressing stroke in patients with acute stroke, preventative treatments are still the unmet needs for those patients. The aim of this study was to evaluate, prospectively, the efficacy and safety of ezetimibe in the prevention of acute progressing stroke and thereby the improvement of patient outcome. A total of 423 patients (267 men and 156 women with a mean age of 65.2 years) were randomly assigned to receive ezetimibe (10 mg daily oral administration, n = 209) or placebo (n = 214) for 14 consecutive days. Analytical procedures performed at baseline (i.e., day 1) and 14 days after the treatments were completed. These included a real-time three-dimensional ultrasound (RT-3DU) examination for carotid plaque volume, clinical laboratory analyses of serum levels of IL-6 and MMP-9, as well as lipid parameters and liver dysfunction marker ALT and TBIL. Ezetimibe significantly reduced the average NIHSS score after 14 days of treatment and attenuated the stroke progression rate, which was associated with reduction in carotid plaque volume and attenuation of serum levels of IL-6, MMP-9, and LDL, without inducing liver dysfunction. Ezetimibe treatment may be a beneficial and effective strategy for preventing progressing stroke.