Point/Counterpoint: Dual antiplatelet therapy for vascular patients: Yes, no, or sometimes?
Introduction
As evidenced by this month’s Point/Counterpoint article by Dr. William Jordan and Dr. Joseph Mills, there is still debate as to the benefit of antiplatelet agents in patients with peripheral artery disease. Currently, dual antiplatelet agents refer to aspirin and clopidogrel, but over the last year or two, ticagrelor and vorapaxar are also being prescribed for patients with peripheral atherosclerosis. The addition of these medications will probably only add to our confusion! Why don’t you weigh in on this discussion by voting on our online poll at www.vascularspecialistonline.com?
Dr. Russell Samson is the medical editor of Vascular Specialist.
Definitely, maybe.
William D. Jordan, M.D.
First, primary prevention must be considered, as few patients with no prior intervention require dual antiplatelet therapy. It seems that we only have some scant data on the prevention of first-time events in at-risk patients when they are treated with aspirin alone.
While lipid management seems to be the most recent focus for primary prevention, single antiplatelet therapy seems appropriate for many patients who have higher risk due to atherosclerotic disease. A recent study from the University of Alabama at Birmingham found that asymptomatic carotid artery stenosis patients treated with dual antiplatelet therapy actually had higher bleed rates, higher mortality, and lower neurologic event rates, compared with those treated with aspirin alone.
While this study examined only a select group of patients treated for carotid artery disease, these vascular patients had worse outcomes when treated with aspirin and clopidogrel. Thus, caution should be considered before adding too many medical therapies.
Now, consider the short-term outlook for patients – specifically those who undergo some type of vascular intervention. The very nature of vascular intervention is disruptive to the arterial endothelium. Of course, most of the arteries that we enter have some underlying pathology; thus the intimal layer is not normal. The pathologic process is already, at least, partly underway. The concept of antiplatelet therapy is focused on limiting the platelet adhesions that might exaggerate the response to injury that creates a hyperplastic reaction within the vessels. We abhor the excessive response to injury due to the potential failure of the arterial reconstruction. Paradoxically, the same platelet inhibition can also cause excessive bleeding that may complicate the vascular repair. In the current medical climate, most of us tolerate the aggravation of diminished platelet function during open reconstruction in order to protect the target repair site and to avoid the dreaded “troponin leak” that may get classified as a myocardial infarction.
