Monday, April 13, 2009

Nuisance bleeding prompts patients to drop clopidogrel

Medical Tribune March 2009 P18
David Brill

“Nuisance bleeding” is a common and under-recognized cause of clopidogrel cessation following drug-eluting stent implantation, according to a recent study.

Some eleven percent of patients who experienced nuisance bleeds stopped taking the drug, increasing their long-term risk of potentially fatal stent thrombosis, US investigators reported.

The American Journal of Cardiology study is the first to quantify the impact of superficial bleeding on clopidogrel compliance, the authors claim, noting that previous research has tended to focus on major and internal bleeding events. Nuisance bleeding included bleeds from minor cuts, easy bruising, ecchymosis and petechia. [2008 Dec 15;102(12):1614-7]

Dr. Ron Waksman, the study’s lead author, said that he was “alarmed” by the findings and called for better education of patients about the potential complications of prolonged antiplatelet therapy.

“Patients should be aware that they are going to experience this bleeding and that they should still adhere to the clopidogrel. We have to explain to them that having stent thrombosis could be life-threatening whereas nuisance bleeding is just a nuisance,” he said.

“This is one of the taxes that you pay if you get a drug-eluting stent. It’s something that is not usually captured in clinical trials so we don’t tend to care much about it but for patients it is a real issue,” he added.

Waksman and his colleagues followed up 2,360 patients who underwent successful sirolimus-eluting stent implantation at Washington Hospital Center (WHC), a tertiary referral hospital in the US, and were subsequently recommended for a minimum of 6 months of dual antiplatelet therapy.

After 36 months of clinical follow-up, 32.4 percent of patients had experienced some form of bleeding – 85.7 percent of which fell into the nuisance category. Of those who had nuisance bleeds, 11.1 percent stopped taking clopidogrel and 5 percent stopped taking aspirin.

Around 70 percent of those who experienced nuisance bleeds did so on a daily basis, according to Waksman, who is associate director of the division of cardiology at the WHC. He noted that the aspirin dosage can be reduced for those who continue to experience inconvenient bleeding but stressed that clopidogrel should be maintained for at least a year.

Future research is directed at better understanding the mechanisms by which these drugs affect platelet inhibition, said Waksman, adding that this will help us to learn why some patients experience bleeding while others do not.

“It can go both ways: those who don’t bleed at all may be still at risk for stent thrombosis and may need a higher dose, while those who have nuisance bleeding may be too sensitive to the drug and could do well with half the dose,” he said.

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