Introduction
The atrial fibrillation of the heart causing irregular and fast heart rhythm can lead to the formation of blood clots and stroke. The widely accepted medication to prevent blood clots is blood thinners. Blood thinners as per the name are not making the blood thin, but prevent the clot formation, and the blood flow is made smooth. The clots are formed due to the lumping of blood cells and block the blood flow. This is a major risk factor for stroke.
What Are Blood Thinning Agents?
Blood thinning agents also called anti-platelet drugs or anti-coagulants are medications used to prevent blood clot formation. These drugs will not break up the clots that are already formed but help to stop the clots from getting bigger. Treating blood clotting is important as the clots in the blood vessels can lead to heart attack and stroke.
There are two types of blood thinners namely anticoagulants and anti-platelets. Heparin and Warfarin are anticoagulants that slow down the process of making clots. Aspirin and Clopidogrel are antiplatelet drugs that prevent platelets from clumping and forming clots. A blood thinner is given in the following conditions.
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Certain heart diseases.
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Diseases affecting blood flow.
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Heart valve replacement.
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To prevent blood clots after surgery.
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Congenital heart defects.
The blood thinners may interact with some medicines, food, and alcohol. Always follow the instructions of the health care provider before starting the medicines. The common side effects of blood thinners include bleeding, stomach upset, nausea, and diarrhea.
How Do Blood Thinners Prevent Atrial Fibrillation Stroke?
Atrial fibrillation occurs when the electrical activity of the heart becomes fast and irregular. The small upper chambers of the heart called atria slow down the blood flow, and can cause clots in the heart. The formed blood clots can reach the brain and make a part of the brain die. This condition is called a stroke. Stroke can be very dangerous, and can affect speech, vision, movement, and balance. Severe strokes can lead to death. Anticoagulants are the medications used to prevent the stroke. They work by stopping the formation of blood clots and less likely to bleed.
Not every patient will be benefited from taking a blood thinner for atrial fibrillation stock. The doctor will calculate the risk of having a stroke with the help of a score called CHA2DS2-VASc. The higher the score higher will be the risk for stroke.
CHA2DS2-VASc - Score Calculation:
The score is calculated based on certain criteria. In men, at least two points and in women at least three points are required to benefit from a blood thinner.
Criteria That Give 2 Points Each:
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Age 75 or higher.
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History of stroke or transient ischemic attack.
Criteria That Give 1 Point Each:
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Heart failure.
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High blood pressure.
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Heart attack or prior heart or leg stent.
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Age 65 to 74.
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Female sex.
The scores are calculated to find the risk of stroke associated with atrial fibrillation and blood thinners are given. In the majority of the patients, the benefits outweigh the risks associated.
Warfarin:
Vitamin K is an essential vitamin that helps in the process of blood clotting. Warfarin works by inhibiting vitamin K and preventing blood clots. The dose can vary from person to person and a test called prothrombin time can be done to calculate the International Normalized Ratio (INR), which shows a person's ability to form a blood clot.
The dose of Warfarin can change over time and it is important to have a balanced and consistent diet while taking the anticoagulant. Increased or decreased intake of vitamin K can interfere with Warfarin. Increased intake of vitamin K can increase the INR, which directly increases the risk of bleeding. Similarly, a low INR increases the risk of blood clotting. It is important to keep the level of INR in the correct range. Periodic checking of INR is mandatory in patients taking warfarin.
Direct Oral Anticoagulants:
Oral anticoagulants work by directly blocking a protein that is essential for blood clotting. They are given in a fixed dose and frequent blood tests are not required
What Are the Benefits of Blood Thinners in Atrial Fibrillation Stroke?
A stroke occurs when the blood clots and blood flow to the brain is blocked. Blood clots can be formed in the heart, and it breaks off and travels to the brain leading to stroke. The benefits of blood thinners include
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Reduce the risk of blood clots in the heart.
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Prophylactic, it can be used as a preventive drug, in otherwise healthy individuals.
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Significantly reduce the risk of stroke.
What Are the Risks Associated With Blood Thinners?
The common risk associated is bleeding. The blood thinners stop the cascade of events that leads to blood clotting. The bleeding is usually minor, like bleeding from gums, cuts, and wounds.
Severe bleeding is rare, but if occurred can be life-threatening. Other common associated symptoms are
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Vomiting blood.
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Bloody, dark stools due to bleeding in the stomach.
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Sudden headache or injury due to bleeding inside the head.
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Nosebleeds.
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Bleeding into a joint.
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Blood in the urine.
- In patients with liver or kidney damage, the risk of bleeding is higher.
- Alcohol also increases the risk of bleeding. The consumption of alcohol should be lowered to not more than eight alcoholic drinks per week. Ibuprofen and other non-steroidal anti-inflammatory drugs (NSAIDS) should be avoided to reduce the risk of bleeding.
- Anticoagulants reduce the risk of blood clots in the heart but can increase the risk of bleeding in the brain.
What Are the Newly Available Blood Thinners?
The Food and Drug Administration (FDA) has approved four new blood thinners in recent years. The drugs are Dabigatran, Rivaroxaban, Apixiban and Edoxaban. The newer drugs have advantages over Warfarin and make it more acceptable.
Warfarin has interactions with certain medications, and food, making it less effective and more chances for bleeding. The patient needs to be monitored regularly with Warfarin blood tests. The newer drugs have very less interaction with other drugs and do not require any blood monitoring. Newer drugs have a lower risk of bleeding in the brain. These drugs act quickly and do not need to wait for a few days to have their effect.
Conclusion
Blood thinning agents can be used prophylactically to prevent stroke in patients with atrial fibrillation. The medications are better prescribed by the doctor and need monitoring. In patients with a previous history of stroke or cardiovascular diseases, further episodes of stroke are prevented. Bleeding is the complication associated, but the benefits are more than the risks associated.
