27, 000 Patient Study: Heart Attack Risk Initially High, Then Drops After TJR

Does hip or knee arthroplasty increase a patient’s risk of a later heart attack? Replies to that question have been all over the map in the past decade. Now a study published in Arthritis & Rheumatology, a journal of the American College of Rheumatology (ACR), indicates that the long-term risk of experiencing a heart attack after large joint surgery does not persist. However the study indicated that the risk for venous thromboembolism—blood clots in veins and lungs—remained for years after the procedure.

Osteoarthritis affects about 27 million Americans over the age of 25, according to the ACR. Other studies estimate that 1.8 million arthroplasty procedures are performed each year, worldwide, and that number will probably increase as the population ages.

The lead study author was Yuqing Zhang, D.Sc. Professor of Medicine and Epidemiology at Boston University School of Medicine in Boston, Massachusetts. He said, “While evidence shows that joint replacement surgery improves pain, function, and quality of life for the osteoarthritis patient, the impact on cardiovascular health has not been confirmed. 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 and 13, 849 matched controls who did not have surgery. Patients were 50 years of age or older and had been diagnosed with knee or hip osteoarthritis between January 2000 and December 2012.

The researchers found that 306 patients in the arthroplasty group and 286 in the non-surgical group developed myocardial infarction during the follow-up period. Risk of heart attack was significantly higher during the first postoperative month in those who had knee replacement surgery compared to those in the non-surgical group. However, this risk gradually declined over time.

Venous thromboembolism was a significant risk during the first month and continued over time for those having total knee or total hip arthroplasty.

“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, ” concludes 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.”