Balancing Between Blood Clots and Bleeding

Clopidogrel without aspirin may lead to less bleeding during anticoagulant therapy

/ Author:  / Reviewed by: Chris Galloway, M.D.

(RxWiki News) Aspirin is often used with prescription medicine to prevent blood clots after some medical procedures. But new evidence suggests dropping the aspirin to prevent bleeding.

Some patients have to take medication on a long-term basis to prevent blood from clotting. If these patients have medical procedures to improve blood flow, they are faced with a delicate balancing act between preventing blood clots and preventing bleeding.

After non-surgical artery procedures, current medical guidelines recommend adding two additional anti-blood clotting medications, clopidogrel (brand name Plavix) and aspirin. A  dangerous side effect of these medications is bleeding.

A recent study found that the addition of clopidogrel medication alone (without aspirin) was linked to less bleeding and blood clots after patients had non-surgical artery procedures. Adding aspirin increased bleeding and clotting.

"Ask your doctor about medications to prevent blood clots."

Willem Dewilde, MD, of Department of Cardiology, Twee Steden Hospital, Netherlands, and colleagues set out to examine bleeding episodes and thrombotic (blood clotting) events within the year after patients underwent percutaneous coronary intervention.

Anticoagulants (sold under brand name Coumadin) prevent the clotting of blood and are usually taken on a long-term basis. Patients on anticoagulant medication can also have reduced blood flow to the heart that may require additional interventions.

Percutaneous coronary intervention is a non-surgical treatment to open blocked or narrowed coronary (heart) arteries. The treatment is done using a catheter inserted into the artery. The tip of the catheter has a device, such as a stent (small tube), that can be deployed to help widen the blocked or narrowed artery.

Current medical guidelines recommend giving clopidogrel (anti-platelet) medication and aspirin to patients after the artery procedure to prevent bleeding and clotting.

The study led by Dr. Dewilde included 563 study patients that had a stent non-surgically inserted into an artery. Researchers measured the number of bleeding episodes within one year of receiving the stent. Bleeding episodes were defined as any bleeding that required medical treatment.

The patients were divided into different medication groups. The double-therapy group consisted of 279 patients who continued taking their anticoagulant medication in addition to clopidogrel. The triple-therapy group included 284 patients who also continued taking anticoagulants in addition to clopidogrel plus aspirin.

The average age was 70.3 years in the double-therapy group and 69.5 in the triple-therapy group.

Results showed the following bleeding complications:

Bleeding episode

  • 19.4 percent of the double-therapy group
  • 44.4 percent of the triple-therapy group

Multiple bleeding events

  • 2.2 percent of double-therapy group
  • 12 percent of the triple-therapy group

Blood transfusion received

  • 3.9 percent of the double-therapy group
  • 9.5 percent of the triple-therapy group

Reported deaths

  • 11.1 percent of the double-therapy group
  • 17.6 percent of the triple-therapy group

Results indicated that clopidogrel without aspirin led to a significant reduction in bleeding and no increase in blood clots. Researchers noted that more studies are needed before changing the current treatment guidelines.

There were some limitations to the study. It was an open-label study, which means both the doctor and the patient knew what medication the patient was taking. Due to limited financial resources, a placebo (fake pill) was not used as a comparison to aspirin.

Furthermore, doctors treating patients did not always use "modern measures" to prevent bleeding. Only 25 to 27 percent of patients received radial artery access and 34 to 39 percent received proton pump inhibitors. Researchers noted that overall bleeding rates were higher than expected.

This study, titled "Use of clopidogrel with or without aspirin in patients taking oral anticoagulant therapy and undergoing percutaneous coronary intervention: an open-label, randomized, controlled trial," was published in The Lancet. Dr. Dewilde and colleagues disclosed no conflicts of interest.

Reviewed by: 
Review Date: 
February 26, 2013
Last Updated:
March 1, 2013