Dr. Colon-Emeric discloses she and several of her co-researchers have a financial conflict of interest in this research, although several outside experts say this study is sound, but preliminary.

This emerging benefit – if confirmed – may help neutralize fears over the use of bisphosphonates due to certain relatively rare – but highly publicized – side effects: atypical femur fracture and osteonecrosis of the jaw. To reduce the risk – and because there is still no consensus on how long bisphosphonates should be taken – doctors may take their patients off the medication after two to five years, depending on the patient’s risk factors. Linda A. Russell, MD, a rheumatologist and director of perioperative services at New York’s Hospital for Special Surgery, says this added benefit could be a reason to continue treatment longer.

“It’s just a wonderful side benefit if you can treat their osteoporosis and reduce their heart attack risk,” Dr. Russell says.

Chad Deal, MD, rheumatologist and head of the Center for Osteoporosis and Metabolic Bone Disease at the Cleveland Clinic in Ohio, is cautious about the findings. While “it’s a slam dunk association” now, he predicts that “there will be conflicting studies” in the future.

The study also has limitations including the fact that it is a “post-hoc analysis” as opposed to a prospective study. In other words, the information was analyzed retrospectively, for an outcome that was not specified when the patient information was collected.

And there may be unmeasured confounders, or factors that were not accounted for, and selection bias, meaning patients who took bisphosphonates were somehow different from those who didn’t. For example, Dr. Colon-Emeric points out there are many different reasons patients take bisphosphonates and these are patients being followed by doctors, so they generally take care of themselves, which could explain the decrease in heart attacks.

Additionally, the study was limited to RA patients and may not apply to the general population.

The next step is a randomized control trial, or a meta-analysis, to look at the data and see if the same benefit is found, says Dr. Colon-Emeric. The findings also have to be replicated among the general population. Until then, she says that people already taking bisphosphonates for osteoporosis “can be reassured that it doesn’t have a negative effect on their cardiovascular events and may protect them.”

Dr. Deal agrees. He says that when discussing medication with patients, “You have to convince patients that the benefits outweigh the risks, so it’s nice to have something positive in the literature.”