A new study finds that cancer patients treated with bisphosphonate drugs such as Aredia or Zometa to reduce or delay bone complications from cancer may be at higher risk for the irregular heartbeat known as atrial fibrillation and for a related event, stroke. In atrial fibrillation, the upper chambers of the heart beat chaotically, causing blood to pool and increasing the potential of clots, stroke, heart failure and death. However, the bump up in risk with bisphosphonates was “relatively modest,” said Dr. James Goodwin, director of UTMB’s Sealy Center on Aging and senior author of a paper appearing online Oct. 12 in the Journal of Clinical Oncology. “The final message is that it still is a relatively modest increase [in risk],” Goodwin stated. “While it’s a serious toxicity, you have to think about the people these drugs are used in. Many of these people who are getting these drugs are not going to live that long and the drug is having a dramatic effect. There’s no doubt that for most people for whom this drug is given for cancer there’s an enormous benefit.” But because atrial fibrillation can lead to stroke, this latest information might come in useful to “heighten awareness for oncologists that this is a real thing … [which] could lead to an earlier recognition of risk and prevent stroke,” Goodwin said. The news also appears in Reuters Health.