Protamine is of course routinely used for want of anything better, but I wouldn't characterize it as satisfactory… I've seen in one article a figure of 2.6% for major adverse events from protamine in cardiac surgery.
Only a portion of cardiac procedures require heparin reversal; hence, your 2.6% figure should be multiplied by another fraction to produce a meaningful gauge of the medical need for an improved heparin-reversal agent.
There’s no doubt that using protamine to reverse the effects of heparin is far from ideal. But within the realm of unmet medical needs, I would characterize this need as a minor one at best.
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