The 9th edition of the ACCP Antithrombotic guidelines (CHEST 2012) states the following:
For patients with stable therapeutic INRs presenting with a single subtherapeutic INR value, we suggest against routinely administering bridging with heparin (Grade 2C).
It should be noted that this is not specific to MHVs, does not speak to repeatedly subtherapeutic INR, and does not speak specifically to high-risk indications. One could extrapolate from current recommendations about bridging for intentional interruptions, but this does not add much clarity to the issue if the guidelines and available literature are taken in context. First, the annualized stroke risk associated with MHVs has been estimated at 2-4% so one can assume a daily risk of no more than 0.01% - quite low. While some societies still encourage periprocedural bridging for certain patients with MHVs, it should be clear that all available literature would suggest net HARM from bridging in all patient populations represented in studies to date. Across the board, the data demonstrates no significant reduction in the risk of thromboembolic events, with significant increase in the risk of major bleeding. Clear data on the risk and benefit of bridging in the highest risk population (including the highest risk patients with MHVs) are lacking, but the net harm from other populations seems so clear that the likelihood of any population exhibiting net benefit is low. As such, bridging for a single subtherapeutic INR should likely be avoided in most cases. For the highest risk patients and/or those with multiple subtherapeutic INRs, the above should be taken
- CHEST 2012; 141(2)(Suppl):7S–47S.
- Circulation. 2017;135:e1159–e1195.
- European Heart Journal (2017) 38, 2739–2791.
- J Am Coll Cardiol 2000; 86:1097–101.