A team of Boston-based researchers has found that osteoarthritis patients who have total knee or hip joint replacement surgery, known as arthroplasty, face a significantly increased risk of heart attack.

The findings, published in the Arthritis & Rheumatology, suggests post-surgical blood clots in the veins and lungs may be a culprit.

"While evidence shows that joint replacement surgery improves pain, function, and quality of life for the osteoarthritis patient, the impact of cardiovascular health has not been confirmed," explained lead researcher Yuqing Zhang, a professor of medicine and epidemiology at Boston University School of Medicine. "Our study examines if joint replacement surgery reduces risk of serious cardiovascular events among osteoarthritis patients."

The study included 13,849 patients who underwent total knee replacement surgery between 2000 and 2012, and 13,849 others who did not have surgery. The findings indicated that 306 patients in the arthroplasty group and 286 in the non-surgical group had subsequent heart attacks.

Risk of heart attack was significantly higher during the first post-operative month in those who had knee replacement surgery compared to those in the non-surgical group, and gradually declined over time.

"Our findings provide the first general population-based evidence that osteoarthritis patients who have total knee or total hip replacement surgery are at increased risk of heart attack in the immediate postoperative period," said Zhang. "The long-term risk of heart attack was insignificant, but risk of blood clots in the lung remained for years after surgery to replace a hip or knee damaged by osteoarthritis."

Osteoarthritis is the most common form of arthritis, affecting 27 million Americans over the age of 25. As the joint cartilage and bone deteriorates, knee or hip replacement surgery may be the only option to relieve pain and stiffness, and restore mobility.

Past studies estimate that 1.8 million arthroplasty procedures are performed each year worldwide.