Management of patients on long-term oral anticoagulant therapy undergoing elective surgery: survey of the clinical practice in the Italian anticoagulation clinics

Bridging therapy for oral anticoagulation increases the risk for bleeding-related complications in total joint arthroplasty

Background

Patients scheduled for elective surgery with a high risk of thromboembolism require anticoagulation bridging therapy perioperatively. The purpose of this study was to assess the risk of thromboembolic events and bleeding-related complications after total hip and knee arthroplasty in patients requiring bridging therapy for anticoagulants.

Methods

A retrospective cohort study of all patients with primary total hip or total knee replacement in a 4-year period was performed. Outcome measures were blood loss, thromboembolic and bleeding-related complications and hospital stay.

Results

Bridged patients had more blood loss and higher complication rates than the control group. Most complications were bleeding-related, and there were no thromboembolic events. Seven of the 14 (50 %) total hip patients bridged with unfractioned heparin required reoperation (three patients with ischial neuropraxia due to hematoma). There were two bleeding-related deaths in total hip patients bridged with low-molecular-weight heparin. Mean hospital stay was significantly longer in unfractioned heparin bridging.

Conclusion

In this study, there was a significant increase in bleeding-related complications in total joint replacement with bridging therapy compared to prophylaxis. This risk was highest in patients with total hip arthroplasty. There were no thromboembolic events in bridged patients.

Striking a balance between the risks and benefits of anticoagulation bridge therapy in patients with atrial fibrillation: clinical updates and remaining controversies

Long-term anticoagulation with a vitamin K antagonist (VKA) or the new agent dabigatran is recommended to decrease stroke risk in patients with atrial fibrillation. When patients with atrial fibrillation undergo initiation or interruption of VKA therapy, or experience an isolated subtherapeutic international normalized ratio (INR), bridge therapy with a parenteral anticoagulant may be considered. To describe the literature for anticoagulation bridge therapy in patients with atrial fibrillation, we conducted a MEDLINE search (1966-February 2011) of the English-language literature to identify related studies. Ongoing clinical trials were identified through a search of the ClinicalTrials.gov registry. Major national and international guidelines were gathered and evaluated. Additional literature was obtained through review of relevant references of the identified articles. Bridging is not supported by guidelines or clinical trials for patients starting VKA therapy for atrial fibrillation. A subtherapeutic INR value during long-term VKA therapy may be associated with increased thromboembolic events, but the benefit of bridging has not been demonstrated. When VKA therapy is interrupted for procedures, retrospective and cohort data suggest that the decision to bridge should be based on a patient's thromboembolic and bleeding risks associated with the procedure. Typically, it is recommended to use bridge therapy in patients with atrial fibrillation at high risk for thromboembolism, but the benefit of bridging is less clear in patients at low risk. Not all procedures necessitate anticoagulation interruption. Recent trials suggest that VKAs can be continued when patients are undergoing cardiac device procedures and some types of radiofrequency ablation. Several clinical trials are ongoing that will provide more definitive guidance for perioperative anticoagulation management of patients with atrial fibrillation. Patients taking dabigatran are unlikely to require bridge therapy because of a predictable anticoagulant effect and rapid onset of action. However, evidence for optimal perioperative management of dabigatran is needed.

Standardized low-molecular-weight heparin bridging regimen in outpatients on oral anticoagulants undergoing invasive procedure or surgery: an inception cohort management study

BACKGROUND

Bridging therapy with low-molecular-weight heparin is usually recommended in patients who must stop oral anticoagulants before surgical or invasive procedures. To date, there is no universally accepted bridging regimen tailored to the patient's thromboembolic risk. This prospective inception cohort management study was designed to assess the efficacy and safety of an individualized bridging protocol applied to outpatients.

METHODS AND RESULTS

Oral anticoagulants were stopped 5 days before the procedure. Low-molecular-weight heparin was started 3 to 4 days before surgery and continued for 6 days after surgery at 70 anti-factor Xa U/kg twice daily in high-thromboembolic-risk patients and prophylactic once-daily doses in moderate- to low-risk patients. Oral anticoagulation was resumed the day after the procedure with a boost dose of 50% for 2 days and maintenance doses afterward. The patients were followed up for 30 days. Of the 1262 patients included in the study (only 15% had mechanical valves), 295 (23.4%) were high-thromboembolic-risk patients and 967 (76.6%) were moderate- to low-risk patients. In the intention-to-treat analysis, there were 5 thromboembolic events (0.4%; 95% confidence interval, 0.1 to 0.9), all in high-thromboembolic-risk patients. There were 15 major (1.2%; 95% confidence interval, 0.7 to 2.0) and 53 minor (4.2%; 95% confidence interval, 3.2 to 5.5) bleeding episodes. Major bleeding was associated with twice-daily low-molecular-weight heparin administration (high-risk patients) but not with the bleeding risk of the procedure.

CONCLUSIONS

This management bridging protocol, tailored to patients' thromboembolic risk, appears to be feasible, effective, and safe for many patients, but safety in patients with mechanical prosthetic valves has not been conclusively established.

Perioperative bridging therapy with unfractionated heparin or low-molecular-weight heparin in patients with mechanical prosthetic heart valves on long-term oral anticoagulants (from the REGIMEN Registry)

Patients with mechanical prosthetic heart valves require long-term oral anticoagulant therapy (OAT). During the temporary interruption of OAT, bridging anticoagulant therapy with unfractionated heparin (UFH) or low-molecular-weight heparin (LMWH) is recommended. This prespecified subgroup analysis from REGIMEN-a large, prospective, multicenter registry-compared UFH (n = 73) and LMWH (n = 172) as bridging anticoagulation in patients with mechanical heart valves on long-term OAT. Patient demographics and co-morbidities were generally similar between groups. There were more bileaflet valves in the LMWH group (67.4% vs 43.8%, p = 0.0005), but no differences in valve positions between groups. The LMWH group was less likely to undergo major surgery (33.7% vs 58.9%, p = 0.0002) and cardiothoracic surgery (7.6% vs 19.2%, p = 0.008), and to receive intraprocedural anticoagulants or thrombolytics (4.1% vs 13.7%, p = 0.007). Major adverse event rates (5.5% vs 10.3%, p = 0.23) and major bleeds (4.2% vs 8.8%, p = 0.17) were similar in the LMWH and UFH groups, respectively; 1 arterial thromboembolic event occurred in each group. More LMWH-bridged patients were treated as outpatients or discharged from the hospital in <24 hours (68.6% vs 6.8%, p <0.0001). Multivariate logistic analysis found no significant differences in major bleeds and major composite adverse events when adjusting for cardiothoracic or major surgery between groups. In conclusion, for patients with mechanical prosthetic heart valves on long-term OAT, mostly outpatient-based LMWH bridging therapy appears to be feasible for selected procedures, is as safe as UFH, and is associated with a low arterial thromboembolic rate.