Study Indicates Increased Risk of Heart Attack and Blood Clots after Knee or Hip ReplacementSep 3, 2015
New research from a team based in Boston shows that osteoarthritis patients who have total knee or hip joint replacement surgery (arthroplasty) face an increased risk of heart attack (myocardial infarction) in the early post-operative period.
Researchers from Boston University Medical School and Massachusetts General Hospital published the study this week in Arthritis & Rheumatology, a journal of the American College of Rheumatology (ACR). While the risk of heart attack did not persist long term, the risk for venous thromboembolism—blood clot in veins and lungs—remained years after the procedure, News-Medical.net reports.
The ACR says osteoarthritis is the most common form of arthritis.Osteoarthritis affects 27 million Americans over the age of 25. As the joint cartilage and bone deteriorate, the patient may find that knee or hip replacement is the only option to relieve pain and stiffness, and restore mobility. About 1.8 million arthroplasty procedures are performed each year worldwide, News-Medical.net reports, and that number is likely to increase as the population ages.
The study's lead author, Yuqing Zhang, D.Sc., Professor of Medicine and Epidemiology at Boston University School of Medicine in Boston, Massachusetts, 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."
The study examined whether joint replacement surgery reduces the risk of serious cardiovascular events among osteoarthritis patients. The researchers examined nearly 28,000 patients: 13,849 patients who underwent total knee replacement surgery and 13,849 matched controls who did not have surgery. All of the patients were 50 or older and were diagnosed with knee or hip osteoarthritis between January 2000 and December 2012.
Three hundred six patients in the arthroplasty group and 286 in the non-surgical group developed myocardial infarction during the follow-up period, with a greater risk of risk of heart attack during the first postoperative month in those who had knee replacement surgery compared to those in the non-surgical group. The risk gradually declined over time, News-Medical reports. Venous thromboembolism was a significant risk during the first month and continued over time in patients who had total knee or total hip arthroplasty.
These 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," the researchers write in conclusion. The long-term risk of heart attack was "insignificant," but the risk of blood clots in the lung continued for years after knee or hip replacement surgery.