asa/plavix resistance

[jer_sd]

Hey everyone here is a question that is comming up in my practice:

Should we screen all PVD patients for asa/plavix resistance? My isue is if they are resistant then I would need to change anticoagulation management either increasing the dose or possibly placing them on coumadin.

Is anyone screening for resistance and how often does it happen? Is it cost effective practice for patients who have had peripheral vascular intervention?

My isue is I do not want to become a coumadin clinic, and I hate placing 70+ year-old patients on coumadin. I do not have the resources or time to properly educate new counmadin patients. If it will only be an occasinal patient I can manage the scheduale. Optimal anticoagulation will maintain the status of PVD interventions such as stents and may increase quality of life issues so it is probably worth it.

Any input?

Jeremy

[augigi, CNS]

It is difficult to give a concise answer, because even the literature cannot agree on these issues. The good news with regard to your question is that even those that agree ASA/clopidogrel resistance is a problem mostly tend to think that this is dose-dependent. So you should not need coumadin to overcome the problem.

The bad news is that assessing resistance is very difficult. There are multiple platelet function tests/assays, none of which is really "gold standard" apart from platelet aggregometry and mapping.

So the answer I would give is: if it is critical - as in stent patients - I would be using TEG, or some other point of care test for platelet inhibition, and then adjust dose of ASA or plavix appropriately.