First of their kind: Canadian guidelines specific to antiplatelet therapy

The Canadian Cardiovascular Society (CCS) has issued guidelines, the first of their kind anywhere, specific to the use to antiplatelet therapy, including their use in multiple settings, such as primary and secondary prevention, as well as following PCI, CABG surgery, and in patients with peripheral arterial disease and diabetes.

The evidence-based document is intended for practical use and is designed to help healthcare professionals manage individuals who have or are at risk of developing vascular disease.

"We felt that although guidelines exist for the management of other cardiovascular risk factors, including hypertension, lipids, and diabetes, among others, in Canada there is really nothing to provide guidance to Canadian physicians on the use of antiplatelet therapy," Dr Alan Bell (University of Toronto, ON), the cochair of the antiplatelet-therapy guideline committee "And it's really quite a confusing topic, with a number of drugs currently available on the market and new drugs approaching the market, so we felt it was important to provide guidance on the optimal use of these medications."

The new guidelines make recommendations on one of the more debated issues in interventional cardiology—namely, just how long an individual needs to take dual antiplatelet therapy. Following PCI with a bare-metal stent, the guideline committee recommends indefinite aspirin therapy, 75 to 162 mg daily, and clopidogrel 75 mg daily for at least one month and up to 12 months, in the absence of excessive bleeding risks. All patients who receive a drug-eluting stent should be prescribed clopidogrel 75 mg for 12 months in addition to indefinite aspirin therapy. Continuation of dual antiplatelet therapy beyond 12 months remains an option in acute coronary syndrome patients.

"In terms of coronary disease, we tried to define the duration of dual antiplatelet therapy post-acute coronary syndrome, with or without intervention," said Bell. "I think where we have stepped forward is stating clearly that dual antiplatelet therapy with aspirin plus a P2Y12 inhibitor is appropriate to continue beyond one year in patients with a high thrombotic risk and low risk of bleeding. I think it provides license to physicians who would like to do that but who previously haven't seen guidelines suggesting it."

The new antiplatelet drug prasugrel is also given consideration, with the 10-mg daily dose recommended in addition to aspirin in patients with acute coronary syndrome who undergo stent implantation and who have an increased risk of stent thrombosis. The drug is to be avoided in certain patients, specifically in the elderly, lighter patients, those with an increased bleeding risk, and those with a history of stroke.