Patient-centered Research into Outcomes Stroke Patients prefer and Effectiveness Research.

Warfarin Study

Atrial fibrillation (also called A-Fib) is a common type of abnormal heart rhythm characterized by rapid and irregular beating. More than 2.7 million Americans have atrial fibrillation.1 Atrial
fibrillation increases the risk of stroke. It is associated with approximately 15% of all strokes.2-4 Using blood thinners like warfarin (also known by the brand name Coumadin) are one way to prevent strokes in patients with atrial fibrillation.
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OVERALL: Took Warfarin (Coumadin)

13% fewer MACE events*
48 more home-time days** over 2 years after stroke

Slightly higher but not significant differences in risk of bleeding into the brain (hemorrhagic stroke, 1.4% [warfarin] vs. 1.1% [no warfarin])

The PROSPER study used data from Get-with-the-Guidelines-Stroke and Medicare claims to examine 2-year outcomes among U.S. ischemic stroke patients who were 65 and older.

*Major Adverse Cardiovascular Events (MACE) = death, stroke, or cardiovascular readmission

**Home-time = days alive and out of the hospital or a skilled nursing facility

AGE: Took Warfarin

AGE: 65–80 years

5% fewer MACE events*
41 more home-time days over 2 years after stroke**

AGE: > 80 years

20% fewer MACE events*
59 more home-time days over 2 years after stroke**

The PROSPER study used data from Get-with-the-Guidelines-Stroke and Medicare claims to examine 2-year outcomes among U.S. ischemic stroke patients who were 65 and older.

*Major Adverse Cardiovascular Events (MACE) = death, stroke, or cardiovascular readmission

**Home-time = days alive and out of the hospital or a skilled nursing facility

GENDER: Took Warfarin

GENDER: Female

16% fewer MACE events*
53 more home-time days** over 2 years after stroke

GENDER: Male

7% fewer MACE events*
38 more home-time days** over 2 years after stroke

The PROSPER study used data from Get-with-the-Guidelines-Stroke and Medicare claims to examine 2-year outcomes among U.S. ischemic stroke patients who were 65 and older.*Major Adverse Cardiovascular Events (MACE) = death, stroke, or cardiovascular readmission

**Home-time = days alive and out of the hospital or a skilled nursing facility

SEVERITY OF STROKE: Took Warfarin

Mild Stroke (NIHSS☨ = 0-5)

12% fewer MACE events*
57 more home-time days** over 2 years after stroke

Moderate Stroke (NIHSS☨ = 6-14)

8% fewer MACE events *
26 more home-time days** over 2 years after stroke

Severe Stroke (NIHSS☨>= 15)

22% fewer MACE events *
56 more home-time days** over 2 years after stroke

The PROSPER study used data from Get-with-the-Guidelines-Stroke and Medicare claims to examine 2-year outcomes among U.S. ischemic stroke patients who were 65 and older.

*Major Adverse Cardiovascular Events (MACE) = death, stroke, or cardiovascular readmission

**Home-time = days alive and out of the hospital or a skilled nursing facility

☨National Institutes of Health Stroke Scale (NIHSS) is a measure of stroke severity ranging from 0-42, with a higher score indicating more severe stroke.
 

MEDICAL HISTORY: Took Warfarin

Coronary Artery Disease

9% fewer MACE events*
51 more home-time days** over 2 years after stroke

No Coronary Artery Disease

17% fewer MACE events*
49 more home-time days** 2 years after stroke

Had Previous Stroke or Transient Ischemic Attack (TIA)

15% fewer MACE events*
33 more home-time days** 2 years after stroke

No Previous Stroke or Transient Ischemic Attack (TIA)

12% fewer MACE events*
51 more home-time days** 2 years after stroke

The PROSPER study used data from Get-with-the-Guidelines-Stroke and Medicare claims to examine 2-year outcomes among U.S. ischemic stroke patients who were 65 and older.*Major Adverse Cardiovascular Events (MACE) = death, stroke, or cardiovascular readmission

**Home-time = days alive and out of the hospital or a skilled nursing facility

 

 

What is Warfarin (Coumadin)?

Warfarin (Coumadin) is a type of blood thinner. It is used to prevent blood clots from forming or growing. These blood clots can possibly lead to medical problems, such as stroke, heart attack, deep vein thrombosis (blood clots in the legs), or pulmonary embolism (blood clots in the lungs).

Why is Warfarin Therapy recommended after stroke?

Multiple clinical trials have demonstrated that warfarin (Coumadin) can considerably lower the risk of stroke in people with atrial fibrillation. Physician experts from the American Heart Association and American Stroke Association recommend warfarin for prevention of stroke in high-risk patients with atrial fibrillation, as well as prevention of recurrent stroke in patients who have already had a stroke.

What are the Risks/Side effects?

Although it helps to prevent medical problems like a stroke or a heart attack, taking warfarin (Coumadin) can be complicated. People who take warfarin need to have their blood drawn on a regular basis to make sure that the dose that they are taking is both safe and effective. If the dose is too low, it is not sufficient to prevent stroke. If the dose is too high, patients may experience bleeding side effects. People who take warfarin also need to be aware that certain food, such as green leafy vegetables, alcohol, and drugs (other medications prescribed by a doctor, over-the-counter medicines, herbal medicines, and vitamins) can change how well warfarin works in the body.

Within the past 5 years, new blood thinners have been developed and approved by the FDA for stroke prevention in patients with atrial fibrillation. These new medications include dabigatran (Pradaxa), rivaroxaban (Xarelto), apixaban (Eliquis), and edoxaban (Savaysa). Talk to your doctor about the benefits and risks of any blood thinner so that you can make the right medication decision together.

Why look at real world experience data?

The positives and negatives of warfarin (Coumadin) are well understood because it has been studied in clinical trials.5-8 Unfortunately, these clinical trials that studied how well warfarin prevented stroke seldom enrolled patients while in the hospital for a stroke. Patients in clinical trials are highly screened, so they are usually younger and healthier than patients who typically would use the medication in the real world. Community-based studies, like PROSPER, help us to understand how warfarin may help different groups of patients that may not have been studied in clinical trials. These studies also allow us to study other things that are important to patients, like days alive and out of the hospital, which may not have been studied in clinical trials.

For more information, please talk to your doctor or visit: A Patient’s Guide to Taking Warfarin American Heart Association website

The PROSPER Warfarin study is designed to evaluate the risks and benefits of warfarin (Coumadin) therapy in older ischemic stroke patients (age≥65 years) with atrial fibrillation in the real world.

REFERENCES

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2. Goldstein LB, Bushnell CD, Adams RJ, Appel LJ, Braun LT, Chaturvedi S, Creager MA, Culebras A, Eckel RH, Hart RG, Hinchey JA, Howard VJ, Jauch EC, Levine SR, Meschia JF, Moore WS, Nixon JV and Pearson TA. Guidelines for the Primary Prevention of Stroke. Stroke. 2011;42:517-584.

3. Kernan WN, Ovbiagele B, Black HR, Bravata DM, Chimowitz MI, Ezekowitz MD, Fang MC, Fisher M, Furie KL, Heck DV, Johnston SC, Kasner SE, Kittner SJ, Mitchell PH, Rich MW, Richardson D, Schwamm LH, Wilson JA, American Heart Association Stroke Council CoC, Stroke Nursing CoCC and Council on Peripheral Vascular D. Guidelines for the prevention of stroke in patients with stroke and transient ischemic attack: a guideline for healthcare professionals from the American Heart Association/American Stroke Association. Stroke. 2014;45:2160-236.

4. Wolf PA, Abbott RD and Kannel WB. Atrial fibrillation as an independent risk factor for stroke: the Framingham Study. Stroke. 1991;22:983-988.

5. Ezekowitz MD, Bridgers SL, James KE, Carliner NH, Colling CL, Gornick CC, Krause-Steinrauf H, Kurtzke JF, Nazarian SM, Radford MJ, Rickles FR, Shabetai R and Deykin D. Warfarin in the Prevention of Stroke Associated with Nonrheumatic Atrial Fibrillation. New England Journal of Medicine. 1992;327:1406-1412.

6. The effect of low-dose warfarin on the risk of stroke in patients with nonrheumatic atrial fibrillation. The Boston Area Anticoagulation Trial for Atrial Fibrillation Investigators. The New England journal of medicine. 1990;323:1505-11.

7. Adjusted-dose warfarin versus low-intensity, fixed-dose warfarin plus aspirin for high-risk patients with atrial fibrillation: Stroke Prevention in Atrial Fibrillation III randomised clinical trial. Lancet.
1996;348:633-8.

8. Petersen P, Boysen G, Godtfredsen J, Andersen ED and Andersen B. Placebo-controlled, randomised trial of warfarin and aspirin for prevention of thromboembolic complications in chronic atrial fibrillation. The Copenhagen AFASAK study. Lancet. 1989;1:175-9.