New Blood Thinner Fails to Help Heart Valve Patients
Dabigatran increases risk of complications for patients with mechanical heart valves compared to standard therapy, study finds.
For patients with severe heart valve disease, mechanical valve replacement is often the best treatment option. Man-made valves are long-lasting and usually don’t need to be replaced, unlike biological valves that usually last 10–15 years. The only downside is that mechanical valves require patients to take blood thinners for the rest of their lives to help prevent clots from forming on the valve. Warfarin (Coumadin) is the go-to therapy for patients with mechanical heart valves but has its limitations, and researchers are constantly trying to identify better treatment options. But they haven’t had much luck testing a new blood thinner called dabigatran on heart valve patients, according to a study recently published in the New England Journal of Medicine.
Results of this study, the RE-ALIGN (Randomized, Phase II Study to Evaluate the Safety and Pharmacokinetics of Oral Dabigatran Etexilate in Patients after Heart Valve Replacement) trial, were presented at the European Society of Cardiology meeting in Amsterdam. The study was designed to compare dabigatran—a drug typically used to treat atrial fibrillation—with warfarin, the standard therapy to prevent blood clots in patients with mechanical heart valves. The hope was that dabigatran might be just as, if not more, safe and effective in preventing blood clots in heart valve patients as warfarin.
Unfortunately, the study was cut short when researchers found that patients taking dabigatran had significantly greater risk of complications (stroke and bleeding) compared to patients taking the standard therapy. Experts are disappointed with these findings, especially since they may discourage future research of similar therapies in patients with mechanical heart valves. It’s possible that tweaking certain qualities of this study, such as the type of patient and dose of the drug, could render different results. But the Food and Drug Administration and European Medicines Agency have already recommended against the use of dabigatran in patients with mechanical heart valves and prescribing dabigatran for this use is prohibited. So for the time being, warfarin remains the standard therapy for patients with mechanical heart valves, and experts continue to search for new therapies that could serve as a safe and effective alternative.
Questions for You to Consider
- What is heart valve disease?
- Heart valve disease, also referred to as valvular heart disease, occurs when any of the heart’s four valves fail to work properly. Heart valve disease happens when the heart’s valves can’t open far enough to let blood through (stenosis) or can’t close enough to prevent blood from flowing back into the heart (regurgitation).
- What is the difference between biological and man-made valves?
- When faulty heart valves can’t be repaired, they are often replaced with either biological or man-made valves. Biological valves are made from pig, cow or human heart tissue and are specially treated to prevent the body from rejecting the valve. Mechanical valves, on the other hand, are made from man-made materials and patients with mechanical valves need to take blood thinners for the rest of their lives to prevent clots from forming on the valve. Mechanical valves last longer and usually don’t require replacement, while biological valves usually last no longer than 15 years. Which type of valve is right for each patient depends on individual characteristics, such as age, health and personal preference.