Operations to replace a knee or a hip appear to increase heart attack risk in the short term and the risk of blood clots in the long term, according to a new study.
The heart attack risk falls again over time, but blood clot risk is still elevated years later, the researchers found.Within a month after the operations, there were 35 heart attacks among knee replacement patients, compared to four in the control group. In that same period, there were 13 heart attacks in the hip replacement group vs three in the control group.
Heart attack risk was highest in that first month following surgery and declined again over time, the authors reported in Arthritis & Rheumatology. By three years after the operations, heart attack rates had evened out for the surgery groups and the control groups.
A previous study had suggested that joint replacement may actually decrease heart risk in the long run and help protect the cardiovascular system.
In that earlier study, the researchers analyzed not just heart attacks but also strokes and coronary revascularization, and they took arthritis severity into account.