Blood Thinners After Heart Valve Surgery

How Your Medication May Change After Surgery On Your Heart

Doctor explaining model to patient in examination room

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A blood thinner is almost always prescribed if you have a heart valve replacement done with an artificial (man-made) valve. You will probably be on a blood thinner, also known as an anticoagulant, for the rest of your life. As great as artificial valves are, they still aren’t the same as the one you were born with, and that has the potential to cause problems.

Why Blood Thinner Are Given After Valve Replacement

There are two reasons that blood thinners are prescribed after surgery. First, your blood may have a tendency to “stick” to the artificial valve, which can cause clots to form in your blood. While the artificial valve is not sticky, blood may cling to it in a way that does not occur with a natural heart valve.

Secondly, an artificial valve can create “turbulence” in the blood flowing through your heart, meaning that the blood doesn’t flow quite as smoothly as it does with a natural valve. This turbulence creates an opportunity for blood clots to form. If clots form, they can then travel to other parts of your body, causing strokes, deep vein thrombosis (DVT), or other major problems.

To prevent serious complications that can result from a blood clot, blood thinners are prescribed. You will bleed more easily while on these drugs, and you may also find that you bruise more easily, but you will clot more slowly. This slower clotting time reduces the risk of a blood clot in your body.

Blood Thinners After Valve Replacement Surgery

During your hospital stay, you may be given an injectable blood thinner, such as heparin or Lovenox. Most patients are given a prescription blood thinner in a pill form when they go home, but during a hospital stay the injectable form is most common, and IV medication is used in certain circumstances.

Life With Blood Thinners After Valve Replacement Surgery

Monitoring will be done in the months after your surgery to ensure you are taking the right dosage of anticoagulant. The dosage may be adjusted based on the results of your clotting time to make sure your blood is not too “thin” or not “thin” enough. You may be asked to make some dietary changes, as the effectiveness of some blood thinners can be altered by your food choices.

Please be aware that you should tell your doctors, whether it is a medical doctor or a dentist, that you’ve had a valve surgery and you are taking a blood thinner. You should inform your dentist when you schedule your appointment, as you may need to take prophylactic antibiotics before your visit. This is also true before surgery in general.

This will also be important information to share before minor procedures, such as a colonoscopy, and before any changes are made in your medications. Major changes in your diet, such as starting a new weight loss regimen on New Years Day, can cause changes in how thin your blood is and should be discussed with your doctor—particularly if the amount of vegetables you will be eating will be dramatically changed and you are on Coumadin (Warfarin).

A Word From Verywell

A blood thinner can be a bit of a nuisance, particularly if it requires frequent monitoring, but the hassle is far better than the alternative: a heart attack or stroke. New blood thinners are now available that require less monitoring, and these may be right for you, or you may be better off with an older medication with a different risk profile.

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Article Sources

Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial policy to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
  1. Types of Replacement Heart Valves. American Heart Association. May 2016.

  2. What are Blood Clots?. American Academy of Family Physicians. January 2019.

  3. Highlights of Prescribing Information: Lovenox. US Food & Drug Administration.

  4. Blood Thinners and Dental Care. The American Academy of Oral Medicine. May 2015.

  5. Highlights of Prescribing Information: Coumadin. US Food & Drug Administration.

Additional Reading

  • Valve Repair or Replacement. The Texas Heart Institute at St. Luke’s Episcopal Hospital