Comparing clinical outcomes of vitamin K antagonists vs non-vitamin K antagonists in anticoagulant therapy for mesenteric venous thrombosis.

OBJECTIVE: Non-vitamin K antagonist oral anticoagulants have shown similar efficacy and lower bleeding rates than vitamin K antagonists for venous thromboembolism. However, this has not been proven in mesenteric vein thrombosis. This study aimed to compare the clinical outcomes of vitamin K antagonists and non-vitamin K antagonist oral anticoagulants. METHODS: Between January 2014 and July 2022, mesenteric vein thrombosis was diagnosed on computed tomography in 225 patients in a tertiary hospital. Among them, a total of 44 patients who underwent long-term anticoagulation therapy over 3 months were enrolled in this study. Patients were divided into two groups based on the anticoagulant used: vitamin K antagonists (Group 1, n = 21) and non-vitamin K antagonist oral anticoagulants (Group 2, n = 23). The efficacy outcomes were symptom recurrence and thrombus resolution on follow-up computed tomography, and the safety outcome was bleeding complications. RESULTS: The median age of the patients was 56 years (range, 46-68 years), and 52% were men. The most common risk factors were unprovoked intra-abdominal infections (30%). The median duration of anticoagulation therapy was 13 months (20 months in Group 1 vs 6 months in Group 2; P = .076). Of the 44 patients, 17 (39%) received the standard treatment. The median follow-up period was longer in Group 1 than in Group 2 (57 vs 28 months; P = .048). No recurrence of mesenteric vein thrombosis-related symptoms were observed in either group. The median duration of follow-up computed tomography was 31 months (42 months in Group 1 vs 18 months in Group 2; P = .064). Computed tomography revealed complete thrombus resolution, partial resolution, and no changes in 71%, 19%, and 10%, respectively (P = .075). Regarding bleeding complications, varix bleeding and melena developed in two patients in Group 2, and anticoagulation treatment thereafter ceased. CONCLUSIONS: Despite the short follow-up duration in the non-vitamin K antagonist oral anticoagulants group, there was no clinically significant difference in the thrombus resolution rate or bleeding complications when compared with the vitamin K antagonists group. Although research on the long-term effects of non-vitamin K antagonist oral anticoagulants in patients is limited, non-vitamin K antagonist oral anticoagulants can be considered an alternative to conventional treatments.

Optimum tacrolimus trough levels for enhanced graft survival and safety in kidney transplantation: a retrospective multicenter real-world evidence study.

BACKGROUND: The current study aimed to determine the optimal tacrolimus trough levels for balancing graft survival and patient safety following kidney transplantation. MATERIALS AND METHODS: We conducted a retrospective cohort study involving 11,868 kidney transplant recipients from five medical centers. The association between tacrolimus exposures (periodic mean trough level, coefficient of variability, time in therapeutic range) and composite allograft outcome (de novo donor specific antibody, biopsy-proven rejection, kidney dysfunction, and graft failure), as well as safety outcomes (severe infection, cardiovascular events, malignancy, and mortality) were assessed. Data were sourced from Clinical Data Warehouses and analyzed using advanced statistical methods, including Cox marginal structural models with inverse probability treatment weighting. RESULTS: Tacrolimus levels of 5.0-7.9 ng/mL and 5.0-6.9 ng/mL during the 2-12 month and 12-72 month post-transplantation periods, respectively, were associated with reduced risks of composite allograft outcomes. During the first post-transplant year, the adjusted hazard ratios (aHR) for composite allograft outcomes were: 0.69 (95% CI 0.55-0.85, P<0.001) for 5.0-5.9 ng/mL; 0.81 (95% CI 0.67-0.98, P=0.033) for 6.0-6.9 ng/mL; and 0.73 (95% CI 0.60-0.89, P=0.002) for 7.0-7.9 ng/mL (compared to levels ≥8.0 ng/mL). For the 6-year composite outcomes, aHRs were 0.68 (95% CI 0.53-0.87, P=0.002) for 5.0-5.9 ng/mL and 0.65 (95% CI 0.50-0.85, P=0.001) for 6.0-6.9 ng/mL. These optimal ranges showed reduced rates of severe infection (6 y), malignancy (6 y), and mortality (1 y). CONCLUSION: This multicenter study provides robust evidence for optimal tacrolimus trough levels during the periods 2-12 and 12-72 months following kidney transplantation.