Tuesday, April 05, 2016

Perioperative anticoagulant bridging in atrial fibrillation patients for procedures

Here are some findings from a recent study in Circulation:

Methods and Results—The ORBIT-AF registry is a prospective, observational registry study of US outpatients with AF. We recorded incident temporary interruptions of OAC for a procedure, including use and type of bridging therapy. Outcomes included multivariable-adjusted rates of myocardial infarction (MI), stroke or systemic embolism (SSE), major bleeding, cause-specific hospitalization, and death within 30 days...

Bleeding events were more common in bridged patients than non-bridged (5.0% vs. 1.3%, adjusted OR 3.84, p less than 0.0001). Incidence of MI, SSE, major bleeding, hospitalization, or death within 30 days was also significantly more common in patients receiving bridging (13% vs. 6.3%, adjusted OR 1.94, p=0.0001).

Conclusions—Bridging anticoagulation is used in one-quarter of anticoagulation interruptions and is associated with higher risk for bleeding and adverse events. These data do not support the use of routine bridging and additional data are needed to identify best practices around anticoagulation interruptions.

In their discussion the authors felt that patients in this study tended to be bridged more often than guidelines call for. Not all patients need bridging and the guidelines recommend deciding based on the level of risk. From my earlier post on the ACCP guidelines the bridging recommendations can be summarized as follows:

Bridging indications: whether in patients with mechanical heart valves, atrial fibrillation or VTE as the warfarin indication the decision to bridge or not depends on risk assessment. Yes for high, no for low, and individualized decision making for moderate. How is that risk determined? For mechanical heart valve prostheses mitral position, tilting disc or caged ball, or cerebrovascular event in the past 6 months constitute high; bileaflet aortic position with a fib, prior cerebrovascular event, HT, DM, CHF or age over 75 constitute moderate; aortic bileaflet absent the above constitutes low. For a fib, CHADS 2 of 5 or above, cerebrovascular event within 3 months or rheumatic disease constitute high; CHADS 2 of 3 or 4 constitutes moderate; CHADS 2 of 2 or less with no cerebrovascular history constitutes low. For VTE event within 3 months or severe thrombophilia (meaning protein C, S, or antithrombin deficiency or APLS) constitute high risk; non-severe thrombophilia, history of multiple VTEs, event within 12 months or active cancer constitute moderate; event greater then 12 months out absent the above constitutes low.

According to commentary in the ACP Hospitalist Weekly bridging should not be the default strategy but rather be selectively applied and based on the guidelines.

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