Patients who undergo total hip and total knee arthroplasty are at a heightened risk for heart attacks in the 2 weeks following their surgeries, according to a study published online in the Archives of Internal Medicine this week.

Researchers at Utrecht University in the Netherlands reviewed the cases of more than 95,000 patients in Danish databases who had elective joint replacement surgeries between 1998 and 2007

They found that, among patients 60 years and up, the hip patients were 25.5 times more likely and the knee patients nearly 31 times more likely to suffer a cardiac incident in the immediate post-op period than those who didn't undergo surgery. This risk was seen regardless of age, sex, socioeconomic and medication differences, although those with a history of heart disease were at particular risk. After 2 weeks, the potential for cardiac complications declined, though hip patients still saw elevated risks for 6 weeks after surgery.

The study's authors are not conclusively sure how or why joint replacement surgery burdens the heart. Given the stresses of the post-op period, however, the authors of an accompanying commentary urge that physicians not only review patients' risk factors, but work to reduce them.

David Bernard