Joint Replacement Patients at High Post-Op MI Risk
According to a new study, older patients undergoing knee or hip replacement find themselves at greater risk for myocardial infarction (MI) in the first month after surgery.
A team led by researchers from the Boston University School of Medicine analyzed 13,849 patients with osteoarthritis who underwent total knee arthroplasty and 6,063 patients who had total hip arthroplasty between the years 2000 and 2012, as well as equal numbers of propensity score-matched controls. The mean age for study participants was 71, and more than half of the patients were women. The mean duration of osteoarthritis was 4 years, and the mean body mass index (BMI) was 28 kg/m2. Over the course of a follow-up period of 4.2 years, there were 306 MIs in the knee arthroplasty group, and 286 among their controls. There were 128 myocardial infarctions in the hip arthroplasty groups and 138 in the control groups.
________________________________________________________________________________________________________________________________________________________________________
RELATED CONTENT
Total Hip Replacement: What Will You Tell Your Patient
Total Knee Replacement in the Very Elderly
________________________________________________________________________________________________________________________________________________________________________
In comparison to controls that did not have total joint replacement surgery, those who underwent knee arthroplasty saw an eight-fold increase in their MI risk in the month after surgery. Among those who had total hip replacement surgery, the risk was raised by more than 4 times.
While pointing out that the limitations of the study included a dependence on administrative data for diagnoses and the potential for unmeasured confounders, the authors note that “our general population-based study indicates that total knee arthroplasty and total hip arthroplasty are associated with a substantially increased risk of myocardial infarction during the immediate postoperative period among osteoarthritis patients.”
In addition, while it remains unclear whether perioperative factors such as aspirin discontinuation and anticoagulation prophylaxis also contribute to MI risk among joint replacement surgery patients, the findings suggest that “the immediate postoperative risk of myocardial infarction following total joint arthroplasty may have been previously underappreciated, and further measures to prevent this serious event may need to be considered,” the authors added.
—Mark McGraw
Reference
Lu N, Misra D, et al. Total joint arthroplasty and the risk of myocardial infarction - a general population, propensity score-matched cohort study. Arthritis Rheum. 2015.