Optimal oral anticoagulant therapy in Chinese patients with mechanical heart valves

Anticoagulation decision-making before non-cardiac surgery in patients with mechanical heart valve: A retrospective study

Objective

To clarify the timing of warfarin discontinuation at different ranges of INR. Improve anticoagulation management in non-cardiac surgical patients with MHV.

Design

This is a single-center retrospective observational study.

Setting

and participants This study used data from the Hospital Information System, and the Surgery and Anesthesia Information System of the Second Affiliated Hospital of Army Military Medical University. Participants included 121 adult patients with MHV who underwent non-cardiac surgery from 2012 to 2021.

Results

Overall, 121 patients with MHV (15 aortic valve only, 56 mitral valve only, and 50 with multiple valves) underwent non-cardiac surgery. When the duration of warfarin discontinuation was ≤ 3 days, 3-5 days, and≥5 days, the INR was 1.45, 1.15, and 1.09, respectively. Bleeding between INR ≤1.2 and INR >1.2 groups was not statistically significant using Student's t-test (95% CI -0.57, 0.14 P = 0.24). Multivariate regression analysis revealed that Intraoperative bleeding volume correlated with preoperative albumin levels (OR = 0.68，95% CI 0.49, 0.89).

Conclusions

When need preoperative INR is less than 1.5 in patients with MHV undergoing non-cardiac surgery, preoperative warfarin discontinuation for 3 days is sufficient. If INR less than 1.2, preoperative warfarin discontinuation for 3-5 days is appropriate. And in patients with MHV underwent abdominal surgery, intraoperative bleeding is not significant reduced by lower INR after preoperative warfarin discontinuation. Furthermore, the effect of albumin levels on coagulation function cannot be ignored in patients with MHV.

Strengths and limitations

This study was derived from real-world clinical data. It's a retrospectively study to describe the INR changed according to the duration of warfarin discontinuation in patients with MHV and compared intraoperation of bleeding volume between INR>1.2 and INR ≤ 1.2after warfarin discontinuation. To clarify the timing of warfarin discontinuation at different ranges of INR. Improve anticoagulation management in non-cardiac surgical patients with MHV, while providing clinicians with a reference for preoperative warfarin adjustment. This study does have a few limitations. The number of cases is small because patients undergoing repeat noncardiac surgery after heart valve surgery are a special case population. And the patients were not followed up after non-cardiac surgery. The impact of changes in INR on postoperative complications could not be assessed in patients with MHV.

Safety and efficacy of using portable coagulation monitor for INR examination after left-sided mechanical prosthetic valve replacement

BACKGROUND

Time in therapeutic range (TTR) is an index to assess the effectiveness of anticoagulation and is important to predict the risk of bleeding and thrombosis in patients taking warfarin. In recent years, the portable coagulation monitor, a point-of-care testing device for patients to perform self-management international normalized ratio (INR) examination, has provided an opportunity to improve the quality of oral warfarin treatment. In this study, we applied TTR to evaluate the safety and efficacy of the portable coagulation monitor for patients with oral anticoagulant warfarin after left-sided mechanical prosthetic valve (MPV) replacement.

METHODS

It is a single-centre cohort study. From September 2019 to June 2021, a total of 243 patients who returned to our institution for outpatient clinic revisit at 3 months after left-sided MPV replacement, met the inclusion criteria and agreed to be followed up were included. Self-management group used portable coagulation monitor for INR examination, and patients in the conventional group had their INR monitored in routine outpatient visits. Clinical data of the patients would be recorded for the next 12 months, and results were compared between the two groups to assess the effect of the coagulation monitor on TTR and complications related to bleeding and thrombosis in patients with left-sided MPV replacement.

RESULTS

A total of 212 individuals provided complete and validated INR data spanning of 1 year. Those who applied the portable coagulation monitor had higher TTR values and larger number of tests for INR. No significant differences were seen between the two groups in postoperative bleeding and thromboembolic complications, but portable coagulation monitor showed a trend toward fewer bleeding events.

CONCLUSION

Portable devices for coagulation monitoring are safe and can achieve a higher TTR. Patients who use the portable coagulation monitor for home INR self-management can achieve a safe and effective warfarin therapy.

Combining portable coagulometers with the Internet: A new model of warfarin anticoagulation in patients following mechanical heart valve replacement

Heart valve replacement, as a safe and effective treatment for severe valvular heart disease, can significantly improve hemodynamics in patients. However, such patients then require lifelong anticoagulant therapy. Warfarin, a cheap and highly effective vitamin K antagonist, remains the major anticoagulant recommended for lifelong use following mechanical heart valve replacement. However, the effect of warfarin anticoagulant therapy is complicated by physiological differences among patients and non-compliance with treatment at different degrees. Effective management of warfarin therapy after heart valve replacement is currently an important issue. Portable coagulometers and the emergence of the Internet have provided new opportunities for long-term management of anticoagulation therapy, but the safety and affordability of this approach remain to be fully evaluated. This paper reviews recent progress on the use of portable coagulometers and the Internet in the management of warfarin anticoagulation therapy following mechanical heart valve replacement, which offers opportunities for reducing complications during postoperative anticoagulation and for facilitating patient compliance during follow-up.

Efficacy and safety of low intensity vitamin K antagonists in Western and East-Asian patients with left-sided mechanical heart valves

The optimal INR target in patients with mechanical heart valves is unclear. Higher INR targets are often used in Western compared with East Asian countries. The objective of this systematic review and meta-analysis was to summarize the evidence for the efficacy and safety of lower versus higher INR targets in Western and East Asian left-sided mechanical heart valve patients. We searched Western databases including Cochrane CENTRAL, Medline, and Embase as well as Chinese databases including SinoMed, CNKI, and Wanfang Data in addition to grey literature for Randomized Controlled Trials (RCTs) and observational studies. We pooled risk ratios (RRs) using random-effects model. Low and high INR targets were defined by the individual studies. We identified nine RCTs, including six Western (n = 5496) and three East Asian (n = 209) trials, and 17 observational studies, including two Western (n = 3199) and 15 East Asian (n = 5485) studies. In the RCTs, lower compared with higher targets were associated with similar rates of thromboembolism (2.4 vs. 2.3%; RR: 1.14, 95% CI 0.82, 1.60, I² = 0%) and lower rates of both total bleeding (21.9 vs. 40.9%, RR: 0.46, 95% CI 0.28, 0.78, I² = 88%) and major bleeding. RCT data showed no statistical heterogeneity by region. These effects were consistent in the observational data. We downgraded the quality of evidence due to serious risk of bias and imprecision. In patients with left-sided contemporary mechanical heart valves, low quality evidence suggests lower INR targets are associated with similar rates of thromboembolism and moderate quality evidence suggests lower rates of bleeding.

Effect of rifampicin on anticoagulation of warfarin: A case report

BACKGROUND

The drug interaction between warfarin and rifampicin is widely known, but there are still some difficulties in managing the combination of the two drugs.

CASE SUMMARY

A patient with brucellosis received strict monitoring from a Chinese pharmacist team during combination of warfarin and rifampicin. The dose of warfarin was increased to 350% in 3 mo before reaching the lower international normalized ratio treatment window. No obvious adverse reaction occurred during the drug-adjustment period. This is the first case report of long-term combined use of rifampicin and warfarin in patients with brucellosis and valve replacement in China based on the Chinese lower warfarin dose and international normalized ratio range.

CONCLUSION

Anticoagulation for valve replacement in Chinese patients differs from that in other races. Establishment of a pharmacist clinic provides vital assistance in warfarin dose adjustment.

Anticoagulation Resumption in a Patient With Mechanical Heart Valves, Antithrombin Deficiency, and Hemorrhagic Transformation Following Thrombectomy After Ischemic Stroke

Anticoagulation is essential for patients undergoing mechanical heart valve replacement; however, the timing to reinitiate the anticoagulant could be a dilemma that imposes increased risk for bleeding events in patients suffering from the life-threatening hemorrhagic transformation (HT) after ischemic stroke. Such a situation was presented in this case report. A 71-year-old woman was transferred directly to the Neurocritical Care Unit because of a HT that occurred following the mechanical thrombectomy for ischemic stroke. Since she had a history of prosthetic metallic valve replacement, how the anticoagulating therapy could balance the hemorrhagic and thrombotic risks was carefully evaluated. On day 6 after the onset of hemorrhage transformation, the laboratory results of coagulation and fibrinolysis strongly suggested thrombosis as well as antithrombin deficiency. The short-acting and titratable anticoagulant argatroban was immediately initiated at low dose, and thrombosis was temporarily terminated. On day 3 of anticoagulation resumption, argatroban was discontinued for one dose when the prothrombin time and activated partial thromboplastin time significantly prolonged after argatroban infusion. Aortic valve thrombosis was detected the next day. The anticoagulation was then strengthened by dose adjustment to keep mitral valve intact, to stabilize the aortic valve thrombosis, and to decrease the aortic flow rate. The intravenous argatroban was transited to oral warfarin before the patient was discharged. This study is the first report of administering argatroban and titrating to its appropriate dose in the patient with valve thrombosis, antithrombin deficiency, and HT after mechanical thrombectomy for acute ischemic stroke. Notably, the fluctuations argatroban brings to the coagulation test results might not be interpreted as increased bleeding risk. This case also suggested that the reported timing (day 6 to day 14 after hemorrhage) of anticoagulant resumption in primary intracerebral hemorrhage with mechanical valves might be late for some patients with HT.

Anticoagulation and antiplatelet therapy in patients with prosthetic heart valves

BACKGROUND

The choice of antithrombotic therapy, anticoagulants or antiplatelets, after prosthetic heart valve replacement or repair, remains a disputed topic in the literature. Antithrombotic therapies are used after heart valve intervention to reduce the rates of thromboembolic events, therefore improving patient outcomes. Different interventions may require different therapeutic regimens to achieve the most efficacious clinical outcome for patients.

METHODS AND DISCUSSION

This review aims to summarize and critique the available literature concerning therapeutic agents used for bioprosthetic and mechanical valves as well as for valve repair, so as to assist clinicians and researchers in making decisions with regard to their patients and research endeavors.