Preventing Strokes in Patients with Atrial Fibrillation
Preventing Stroke in People With Afib: A Daily Challenge
Prevention of stroke in patients with atrial fibrillation involves the daily use of a blood thinner. Blood thinners range from aspirin to warfarin (another name for warfarin is Coumadin). Warfarin is much stronger than aspirin in preventing clot formation in the heart. However, warfarin is a difficult drug to take as it interacts with many foods, vitamins and supplements, and other drugs. It also requires frequent blood tests to adjust the dose. Newer agents have been recently approved to replace warfarin. These blood thinner agents are covered in a prior column I wrote.
Not everybody needs a strong blood thinner such as warfarin. We determine which blood thinner you may need by your stroke risk factors. These include age >65, high blood pressure, diabetes, stroke, female gender, heart failure, and peripheral vascular disease (narrowing of the arteries outside of the heart). If you have two or more of these risk factors then warfarin or one of the new warfarin substitutes is recommended. If you have less than 2 risk factors then we can use aspirin alone or with another blood thinner called Plavix. In some people with less than 2 stroke risk factors we still use warfarin for other reasons that may increase stroke.
Managing Risks of Bleeding on Blood Thinners
The use of a blood thinner is always challenging. The challenge comes from the simple problem that we want to stop clots from forming in the heart, but allow them to occur in other areas of the body to prevent bleeding. As physicians when these drugs are prescribed we also need to consider bleeding risk. Sometimes a person may have a very high risk of stroke from the risk factors described above, but they also have a risk of bleeding as great or higher than the risk of stroke if a blood thinner is used. In these patients we often cannot use the stronger blood thinners. There are consistent bleeding risk factors that we consider in making these decisions. These include advanced age, moderate to severe kidney dysfunction or kidney failure, a prior significant bleed into a body organ such a the stomach, bowel, bladder, or head, a history of cancer, alcohol abuse, abnormal liver function, or poorly controlled blood pressure.
Use of blood thinners gets more challenging when people need more than one. For example, if you have a heart attack and need a stent or bypass surgery, then use of aspirin plus Plavix or a Plavix like drug reduces risk of additional heart attacks and problems with the stent or bypass grafts. If you also have atrial fibrillation and have 2 or more risk factors for stroke, your use of aspirin or Plavix is not sufficient to prevent stroke although it is needed for other prevention needs. In these people we often use warfarin, Plavix, and aspirin or warfarin and Plavix. Unfortunately, the new agents approved to replace warfarin are not recommended if you need aspirin and Plavix or a Plavix like drug. The recommendation may change as these drugs are studied in this setting.
Kidney Function Matters
Unfortunately high blood pressure and heart disease are often associated with kidney dysfunction and atrial fibrillation. Trying to sort a way to prevent stroke without exposing a patient to a high bleeding risk is this scenario can be very challenging. Often what happens with people who have moderate-severe kidney disease, coronary artery disease, and atrial fibrillation warfarin is not used if both aspirin and Plavix are needed. This approach is used to minimize risk of severe bleeding, but is correct or justified?
A recent study published in JAMA sought to answer this question. In this study from Sweden, 24,317 patients were included that had atrial fibrillation and a hospitalization for a heart attack. The heart attack is important because this prompts the need in these patients for at least aspirin therapy. At hospital discharge 5,292 (21.8 percent) were also placed on warfarin. This low percentage found highlights physicians concerns about bleeding risk and decisions often made not to use warfarin. Amongst these study patients, 51.7 percent also had moderate-severe kidney dysfunction.
What the authors found was significant. First, patients that were treated with warfarin did not experience more bleeding events compared to those not treated with warfarin. In looking at all ranges of kidney function, there remain no increased risk of bleeding with warfarin. Next, at 1-year the risk of death, heart attack, and stroke related to a clot was lower in those patients treated with warfarin regardless of their kidney function. Breaking these data down, the authors found no significant increased risk of bleed with warfarin, but if warfarin was withheld they found an increased risk of stroke, death, and heart attack.
Being Agressive About Stroke Prevention
This study teaches a few things. First, over 75 percent of patients did not receive warfarin for a perceived risk of bleeding that may not have been fully justified. In people that experience a heart attack and also have atrial fibrillation, as physicians we need to be diligent in using warfarin if it has a potential benefit. Next, kidney function in this group of patients did not significantly increase risk of bleed or raise risk with using warfarin. This is a very important finding since kidney function is often considered heavily in determining a person’s potential bleeding risk. Finally, a conservative approach to err on not increasing risk of bleed was associated with harm. This finding prompts the need to be aggressive and upfront about stroke prevention if there is truly a potential benefit.
As always we need to exercise caution when looking at these studies, particularly until it is confirmed by other similar studies from different centers. In addition, there are often many reasons for not using warfarin that cannot be fully understood in studies designed for other purposes such as looking at post heart attack care. Some of these reasons include the fragility of a person, if they are frequently falling, if they have moderate to severe dementia, cancer, or other conditions that lower life span. In addition, many people also refuse to take warfarin for personal reasons often related to prior experiences with the medication, the need for blood draws, or the potential need to change their diet. In these patients warfarin make be recommended, but not used. Finally, people may be a good candidate for warfarin at one point in their life, but not another. As we age we often acquire additional risks for bleeding. These acquired risks over time may influence the safety of these blood thinners. The Swedish study looked primary at what happened during the 1-year period after a heart attack.
Long-term use of any blood thinner needs to involve frequent communication with your physician with an understanding that both your risk of stroke and bleed will change over time.
Video: A New Option for Preventing Stroke from Atrial Fibrillation (AFib)
Los 10 destinos de moda a los que querrás viajar en 2019
Meghan Markle and Prince Harry reportedly got a new pet dog
27 of the Cutest Wedding Cake Toppers You’ll Ever See
10 Stylish Bathing Suit Ideas for Summer 2019
Honey Heals Canker Sores
Smoking ban slashes heart attacks
How to Tell if Your BoyfriendGirlfriend Is Cheating
How to Convert DVD Movies for Samsung Galaxy Tab
How Massage Therapy Helps Relieve Osteoarthritis Pain
Blogger Camilla Coelho Makes The Perfect Couture Bride At Ralph Russo
Watch Color-Blind People See Fall Foliage For the First Time
Look 10 Years Younger With These Makeup Tricks
6 Dress Trends Taking Off on Instagram at the Moment