A new study published in the May issue of Journal of Bone and Mineral Research (JBMR) found that use of bisphosphonates – bone-building drugs – appear to significantly lower the risk of heart attacks in rheumatoid arthritis (RA) patients.

People with RA (as well as other forms of inflammatory arthritis, such as psoriatic arthritis and ankylosing spondylitis) have an increased risk of cardiovascular events, including heart attack, as a result of chronic inflammation. Many also take bisphosphonates to counteract bone loss caused by the disease and by corticosteroids – powerful anti-inflammatories sometimes used to control symptoms.

This combination of high incidence for both cardiac events and bisphosphonate use is one reason the researchers say they decided to use a group of RA patients to test their hypothesis that bisphosphonates lower the risk of death not just by reducing fractures, but also by protecting the heart. An earlier study found that people who take bisphosphonates live an average of five years longer compared to those who don’t; the longer lifespan is only partially explained by a reduction in fractures.

“[The findings] supported our hypotheses that bisphosphonates may have a protective effect,” says study co-author Cathleen S. Colon-Emeric, MD, associate professor of medicine at Duke University School of Medicine in Durham, N.C.

Dr. Colon-Emeric and her colleagues reviewed data from 19,281 RA patients in the National Data Bank for Rheumatic Diseases, who completed at least, two self-reported questionnaires sent out at six-month intervals. Among this group, approximately 5,800 had ever used bisphosphonates (the vast majority of the medication was taken orally; the most common drug was alendronate (Fosamax). The researchers confirmed all reported heart attacks  – also called myocardial infarction (MI) – with physician or hospital medical records.

Three models were set up to analyze the findings: the first looked only at the patients who had ever taken bisphosphonates and compared their heart attack risk on and off the drugs; the second compared patients who had taken bisphosphonates at some point with patients who had never taken them; and the third looked at patients who had had multiple heart attacks and compared the risk in patients who had taken bisphosphonates to those who had not. This was done to ensure the findings were more than just a fluke.

“Depending on how we analyzed the data, there was somewhere between a 30 to 50 percent decreased risk of a heart attack … after accounting for diabetes and other risk factors we worry about,” Dr. Colon-Emeric explains. 

The researchers also found that those with the lowest risk of heart attack were also taking – in addition to bisphosphonates – vitamin D and calcium supplements. (Recent studies have linked calcium supplements to an increased risk of heart attack.)