Atrial fibrillation, often called AFib, is the most common type of irregular heartbeat, especially among older adults. In this condition, the heart beats in a fast and uneven way, which can cause blood to pool inside the heart.
When blood does not flow smoothly, it can form clots. These clots can travel to the brain and cause a stroke, which can be life-threatening or lead to long-term disability. Because of this risk, many people with AFib must take medicines that thin the blood and control heart rate to prevent serious complications.
A new study published in JAMA has found that one commonly used heart medication may increase the risk of severe bleeding when taken together with certain blood thinners. The findings are especially important for older adults, who are more likely to have AFib and often take several medications at the same time.
Doctors usually prescribe blood-thinning drugs such as apixaban or rivaroxaban to prevent clots in people with AFib. These medicines reduce the blood’s ability to clot, lowering the chance of stroke.
However, because they thin the blood, they can also increase the risk of bleeding. For this reason, doctors must carefully choose which additional heart medicines to use alongside them.
To help control heart rate in AFib, patients are often given drugs such as diltiazem or metoprolol. Both medications slow the heart and help it beat more regularly, but they work in different ways. Researchers wanted to know whether one of these drugs might be safer than the other when combined with blood thinners.
The study was led by Dr. Eli Zimmerman of Northwestern University and examined health records of adults aged 65 and older who were covered by Medicare. The researchers tracked patients who began treatment between 2012 and 2020. All participants were taking either apixaban or rivaroxaban along with either diltiazem or metoprolol.
The results showed a clear difference. Patients who took diltiazem were about 20 percent more likely to be hospitalized or die because of serious bleeding compared to those who took metoprolol. This suggests that the combination of diltiazem with certain blood thinners may increase the danger of bleeding complications.
Interestingly, when researchers looked at other outcomes such as strokes or new blood clots, they did not find major differences between the two groups. This means the increased risk was mainly related to bleeding rather than the effectiveness of stroke prevention.
Scientists believe the higher risk may be due to how the drugs interact inside the body. Each person’s body processes medications differently, and some combinations can cause drug levels to build up in the bloodstream.
When blood thinners become too strong, the risk of dangerous bleeding rises. Genetic differences between individuals may also play a role in how medications are handled.
The study highlights the growing importance of personalized medicine, where treatments are tailored to each person’s unique biology and health conditions.
Older adults often take multiple medications for different health problems, which increases the chance of harmful interactions. Doctors may need to monitor patients more closely and adjust treatment plans to reduce risks.
The findings also remind patients not to change or stop their medications without medical advice. Blood thinners and heart medicines are essential for preventing strokes and controlling heart rhythm, but they must be used carefully. Anyone with concerns should talk with their doctor about the safest options for their situation.
Researchers hope future studies will explore whether monitoring drug levels in the blood or using genetic testing could help identify patients at higher risk. Such approaches could make treatment safer and more effective for people living with atrial fibrillation.
This study provides an important warning that even widely used medications can carry hidden risks when combined. By continuing to study these interactions, doctors can better protect patients and improve care for people with heart conditions.
If you care about heart health, please read studies about how eating eggs can help reduce heart disease risk, and herbal supplements could harm your heart rhythm.
For more health information, please see recent studies about how drinking milk affects risks of heart disease and cancer, and results showing strawberries could help prevent Alzheimer’s disease.
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