What is the risk of postoperative bleeding if anticoagulation is started? Any decision about the benefits of anticoagulation must be weighed against the risks, most notably the risk of serious or life-threatening bleeding. This risk may be heightened in the immediate perioperative period. Discussions should always take place with our surgical colleagues about type of surgery, intraoperative complications, and postoperative risk of bleeding.
Anticoagulation, if indicated, should not be started until postoperative bleeding risk is deemed appropriately low. That said, the 2015 BRIDGE trial (looking at the benefits and risks of “bridging” patients before surgery) provides some peripheral but meaningful information about postoperative bleeding risk. In this study, patients with preexisting AF who underwent low-bleeding-risk surgery and were bridged on day one after surgery with therapeutic doses of unfractionated or low-molecular-weight heparin had a significantly higher risk of postoperative bleeding compared to non-bridged patients, with a number needed to harm of 50.15 It may be reasonable—and likely safer—to wait a couple days to start anticoagulation for patients with POAF.
What is the expert’s opinion? We asked one of our cardiac electrophysiologists what her approach is to this situation. In general, if a patient has a low stroke risk and is in AF for fewer than 24 hours, it is reasonable to defer anticoagulation and follow as an outpatient. Regardless of risk, if AF is sustained for more than 24 hours, we recommend at least four weeks of anticoagulation and close outpatient follow-up, which should include a period of ambulatory monitoring to determine the need for continued anticoagulation. We also recommend considering what comprises the patient’s stroke risk.
For example, if the CHA2DS2-VASc score is 2 but the points come from being a female with coronary artery disease, we would consider forgoing anticoagulation but arranging for an outpatient cardiac monitor with cardiology follow-up. If the patient has a history of stroke or TIA, we recommend continuing anticoagulation indefinitely.
Back to the Case
Given our patient’s episode of POAF lasted fewer than 24 hours, it would be reasonable to hold off starting anticoagulation, but he should be followed as an outpatient with ambulatory monitoring at a minimum, monitoring for recurrence. If he were to develop recurrent AF, then he would warrant anticoagulation based on an annual stroke risk of 3.2% as determined by a CHA2DS2-VASc score of 3.
Bottom Line
Our strategy is as follows: If a patient has a low stroke risk (i.e., CHA2DS2-VASc score <2) and is in AF for fewer than 24 hours, anticoagulation is not started, but outpatient follow-up is arranged to monitor symptoms. Regardless of stroke risk, if a patient is in AF for more than 24 hours, we initiate and continue anticoagulation for a minimum of four weeks and arrange outpatient follow-up with a period of ambulatory monitoring to determine need for continued anticoagulation. If a patient has a high stroke risk (CHA2DS2-VASc >2) or if their risk factors include a history of stroke or TIA, anticoagulation is started and continued indefinitely. Risk-benefit discussion is held with the patient, especially with regard to bleeding risk, prior to anticoagulation initiation. If the individual patient’s situation presents further nuance, we ask for the assistance of our cardiology or cardiac electrophysiology colleagues.
Final Thought
None of the mentioned studies investigated or included newer oral anticoagulants. Risk-benefit ratios may change (potentially considerably) with these agents. Further study is needed. We expect, in due time, studies will look at the question of POAF in regard to newer anticoagulant agents, and perhaps then our decision making will change. TH