A new study published in JAMA has raised concerns about a possible risk linked to common treatments for atrial fibrillation (AFib), a condition that causes an irregular and often rapid heartbeat. The research suggests that some patients may face a higher chance of serious bleeding when certain blood pressure medications are combined with blood thinners.
AFib affects millions of people and is known to increase the risk of blood clots and strokes. To lower these risks, many patients are prescribed blood thinners (also called anticoagulants), which prevent clots from forming.
They may also take medications to help slow down their heart rate. But using multiple medications at once can be tricky, especially in older adults, as drug interactions may lead to unexpected side effects.
This new study focused on more than 65,000 patients aged 65 and older who were enrolled in Medicare between 2012 and 2020. All participants had started taking a blood thinner—either apixaban or rivaroxaban—and were also using a heart rate control medication, either diltiazem or metoprolol.
The results showed that those who took diltiazem were 20% more likely to be hospitalized or die due to bleeding compared to those who were treated with other medications like metoprolol.
Interestingly, both groups had similar rates of stroke and clot-related problems, meaning the blood thinners worked just as well in preventing clots regardless of the heart rate drug used.
So why was there a higher bleeding risk in patients taking diltiazem?
According to Dr. Eli Zimmerman, a neurologist and one of the study’s authors, part of the answer may lie in how medications are broken down in the body. Not everyone metabolizes drugs the same way. Genetic differences and interactions between medications can affect how strong a drug’s effects are—and how likely it is to cause harm.
Diltiazem may affect how blood thinners are processed, possibly making them more powerful and increasing the risk of excessive bleeding. Older adults, who are already more vulnerable to side effects, may be especially at risk.
This study doesn’t suggest that everyone should stop taking diltiazem. Instead, it emphasizes the need for personalized care—finding the right balance between managing heart rate and reducing side effects. One possible step forward is to closely monitor drug levels in the blood.
This would help doctors better understand how each patient is responding and allow them to adjust medication doses as needed.
The findings are a reminder that even commonly used medications can have unexpected risks, especially when combined. It’s important for both doctors and patients to be aware of these potential issues and to work together to find the safest treatment plan.
Beyond medication, lifestyle choices also play a big role in heart health. For example, drinking too much coffee can raise blood pressure, especially in people who already have hypertension.
On the other hand, healthy habits like eating more plant-based foods or following early time-restricted eating (where meals are eaten earlier in the day) have been linked to better blood pressure control.
In summary, this new research points to the importance of weighing both the benefits and risks when treating atrial fibrillation—especially in older adults. It highlights the need for tailored treatment plans and continued monitoring to ensure that patients receive the safest and most effective care possible.
If you care about heart health, please read studies about how eating eggs can help reduce heart disease risk, and Vitamin K2 could help reduce heart disease risk.
For more information about heart health, please see recent studies about how to remove plaques that cause heart attacks, and results showing a new way to prevent heart attacks, strokes.
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