Bridging of oral anticoagulation with low-molecular-weight heparin: Experience in 373 patients with renal insufficiency undergoing invasive procedures

Safety of Anticoagulation Interruption in Patients Undergoing Surgery or Invasive Procedures: A Systematic Review and Meta-analyses of Randomized Controlled Trials and Non-randomized Studies

BACKGROUND

The safety of anticoagulation interruption in patients requiring surgical or invasive procedures remains unclear. We thus performed a systematic review and meta-analyses of randomized controlled trials (RCTs) and non-randomized studies (NRS).

METHODS

MEDLINE, Embase and Central databases were searched to March 2017 without date or language restrictions. We considered RCTs and NRS comparing anticoagulation interruption with any anticoagulation (continuation or heparin bridging) in adult surgical patients taking oral anticoagulation. Data were independently extracted. The quality of the evidence was assessed following recommendations from the Cochrane collaboration (GRADE approach). Risk ratios were calculated for 30-day events: thromboembolic (TE) events, major bleeding and mortality. Additional analyses explored the effects of different anticoagulation strategies.

RESULTS

Twelve reports were included: 4 RCTs (2190 participants) and 8 NRS (18993 participants). Trials included mostly participants with atrial fibrillation. Interrupting anticoagulation did not seem to increase TE events (RR 0.65, 95% CI [0.33, 1.30]-4 studies, 2190 participants) and resulted in less bleeding (RR 0.41, 95% CI [0.22, 0.78]-3 studies, 2126 participants) compared to anticoagulation continuation or heparin bridging. The GRADE assessment was moderate. Similar results were found in non-randomized studies, but the quality of the evidence was low. Possible strategy-specific effects were identified: forgoing heparin bridging seemed beneficial, but these effects were less clear with other strategies.

CONCLUSION

Interrupting anticoagulation in patients requiring invasive procedures did not seem to result in harm and protected against major bleeding. Uncertainty remains regarding the safety of this strategy in indications other than atrial fibrillation and in moderate- to high-risk surgery.

STUDY REGISTRATION

http://www.en.anaesthesie.usz.ch/research/Pages/Study-protocols.aspx.

The HAS-BLED score predicts bleedings during bridging of chronic oral anticoagulation

Patients who receive long-term oral anticoagulant (OAC) therapy often require interruption of OAC for an elective invasive procedure. Current guidelines allow bridging therapy with either unfractionated heparin (UFH) or low-molecular-weight heparin (LMWH). Apart from the risk of embolism, bleeding is an important complication in this setting and the optimal perioperative management of such patients is still under discussion. The aims of this prospective, observational, multicentre registry of patients treated by cardiologists were: 1) to evaluate current practice of perioperative management of OAC in a large outpatient cohort, 2) to document embolic and haemorrhagic events, and 3) to identify risk factors predicting adverse events. In the years 2009 and 2010, 1,000 invasive procedures (cardiac catheterisation n=533, pacemaker implantation n = 128, surgery n = 194, other n = 145) were performed in patients with OAC. Sixty- one (6.1%) of those patients did not receive bridging therapy during interruption of OAC, 937 (93.7%) patients were treated with LMWH, two patients (0.2%) received UFH. In 22 patients (2.2%) LMWHs were given in prophylactic dose, 727 patients (72.7%) were treated with halved therapeutic (i.e. weight-adapted) LMWH doses and 188 (18.8%) received full therapeutic LMWH doses. Four thromboembolic complications were observed during 30 days of follow-up (two retinal embolisms, one stroke, one myocardial infarction; 0.4%). One major bleeding (0.1%) and 35 clinically relevant bleedings (3.5%) occurred. Rehospitalisation after bleedings was necessary in 20 patients. Independent predictors for bleedings were history of mechanical heart valve replacement (MVR) (p=0.0002) and the HAS-BLED score (<0.0001), with a cut off value ≥3 being the most predictive variable for haemorrhage (hazard ratio 11.8, 95% confidence interval 5.6–24.9, p<0.0001). A total of 527 patients with atrial fibrillation and a CHADS2 score ≤2 received halved therapeutic or full therapeutic dosages of LMWH despite a low embolic risk, whereas 49 of the patients with heart valve replacement (51%) did not receive dosages of bridging therapy as recommended in guidelines. In conclusion, in this registry of patients treated by cardiologists, 94% of patients who required interruption of OAC before invasive procedures received LMWH as a bridging therapy, of whom 73% were treated with halved therapeutic LMWH-dosages. Guideline recommendations were followed in only 31% of cases. Importantly, 69% of patients with AF were over-treated while 51% of patients with heart valve replacement were under-treated with LMWHs. A HASB-BLED score ≥3 was highly predictive of bleeding events.

[Periprocedual management of vitamin K antagonist's with low molecular weight heparins during invasive procedures--Consensus of experts]

Interruption of an ongoing therapy with vitamin K antagonists (VKAs) is necessary in almost all patients undergoing major surgery. The purpose of the following expert recommendations is to provide easy to use guidance for the periprocedural management of patients on VKAs based on current evidence from the literature. Management of anticoagulation during the time of interruption of VKAs is based on balancing the thromboembolic (TE) risk of underlying conditions against the bleeding risk of the surgical procedure. VKAs should be stopped 3–7days prior to surgery. Low molecular weight heparin (LMWH) is used to cover (“bridge”) the progressive pre-operative loss of anticoagulation and the slow post-operative onset of anticoagulant activity of VKAs. Patients with high risk of TE should receive a therapeutic dose of LMWH, patients with a moderate risk of TE should receive half of this dose. Patients with a low risk of TE do not need bridging therapy with LMWH. In case of an uneventful postoperative course, patients with a therapeutic pre-operative dose should be treated post-operatively with the same dose, starting on day 4 in case of major surgery and on day 2 in case of minor procedures. Patients with a half-therapeutic preoperative dose should be treated post-operatively with the same dose, starting on day 3 in case of major surgery and on day 1 in case of minor procedures. Therapy with VKAs should be re-instituted on the second post-operative day based on the preoperative dosage. Procedure-related post-operative thromboprophylaxis should be given irrespective of these recommendations on days without “bridging” anticoagulation.

Anticoagulant and antithrombotic drugs in pregnancy: what are the anesthetic implications for labor and cesarean delivery?

Neuraxial anesthetic techniques are commonly used during the peripartum period to provide effective pain relief for labor and anesthesia during cesarean delivery. Major neurologic complications are rare after neuraxial anesthesia; however, spinal hematoma is associated with catastrophic neurologic outcomes (including lower-limb paralysis). Anticoagulant and antithrombotic drugs can increase the risk of spinal hematoma after neuraxial anesthesia, and better understanding of the pharmacokinetics and pharmacodynamics of anticoagulants has led to greater appreciation for withholding anticoagulation before and after neuraxial anesthesia. A number of national anesthetic societies have produced guidelines for performing neuraxial anesthesia in patients receiving anticoagulation. However, there is limited information about anesthetic implications of anticoagulation during the peripartum period. This article will review the risks of spinal hematoma after neuraxial anesthesia in pregnant patients; current guidelines for neuraxial anesthesia for anticoagulated patients; and relevant pharmacological data of specific anticoagulant and antithrombotic drugs in pregnancy.

Update on perioperative bridging in patients on chronic oral anticoagulation

Oral anticoagulation (OAC) with vitamin K antagonists is commonly used for long-term prevention or treatment of arterial or venous thromboembolism. In the USA alone, approximately 250,000 patients will require temporary interruption of OAC annually. Managing anticoagulation in those patients on chronic OAC who require invasive procedures continues to be a major clinical dilemma. This article summarizes the existing evidence in light of the recommendations of the American College of Chest Physicians. Management of anticoagulation in the perioperative period will continue to be an important clinical challenge and an evolving area of research. If new oral anticoagulants are successful in replacing warfarin, the entire perioperative anticoagulation scene will change.