January 18th, 2012
Cangrelor and Alaska’s “Bridge to Nowhere”
The Gravina Island Bridge (also known as The Bridge to Nowhere) was a proposed bridge to replace the ferry that currently connects Ketchikan, Alaska (population, 14,000) to the Ketchikan International Airport on Gravina Island (population, 50) at a projected cost of $398 million. The bridge was to have been nearly as long as the Golden Gate Bridge and taller than the Brooklyn Bridge.
A study published yesterday, entitled “Bridging Antiplatelet Therapy With Cangrelor in Patients Undergoing Cardiac Surgery,” showed that in patients who discontinue thienopyridine therapy before cardiac surgery, the use of cangrelor compared with placebo resulted in a higher rate of maintenance of platelet inhibition, as assessed with the VerifyNow P2Y12 platelet assay. (See also our CardioExchange news coverage here.)
Cangrelor, an intravenously administered P2Y12 receptor antagonist with a rapid offset effect (half life, 3-6 minutes), was used to “bridge” patients to surgery after irreversible platelet P2Y12 inhibitors (i.e., clopidogrel or prasugrel) were discontinued. Cangrelor infusion was initiated a median of 29 hours (IQR, 11-38) after thienopyridines were discontinued and was administered for up to 7 days until shortly (1-6 hours) before surgical incision. Cangrelor was associated with a numerical increase in minor, but not major, bleeding before CABG, and with no increase in CABG-related bleeding events.
What’s the connection?
It is the rare person who flies from Ketchikan…or experiences a serious ischemic event after cessation of clopidogrel 5 days before CABG. As a result, the benefits of the Alaskan bridge — and of bridging antiplatelet therapy with cangrelor — are unlikely to justify its cost. Both the bridge to Gravina Island and the VerifyNow platelet assay are models in search of rationales. Certainly, we can build (or perform) it, but does it have a meaningful impact?
In your patients referred for CABG, do you need to give “bridging antiplatelet therapy?”
If so, when and how often?
Would you support the approval of cangrelor for “bridging therapy”?