Elderly patients with osteoarthritis who undergo knee or hip replacement are at high risk of having an MI in the first month following surgery, research shows.
Compared with controls those who had knee arthroplasty had a more than eight-fold increase in MI risk in the month after the surgery, reported the researchers from Boston University School of Medicine.
“Contradictory to recently published findings our study indicates that total joint arthroplasty procedures do not provide an overall protective effect on the risk of myocardial infarction,” wrote the researchers in Arthritis and Rheumatology.
The increased MI risk seen during the month after surgery declined with increasing follow-up, becoming insignificant by 6 months post surgery.
“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 concluded.
The analysis included 13,849 patients with osteoarthritis who underwent total knee arthroplasty and 6,063 who had total hip arthroplasty.
The average age of the patients was 71 and during the 4.2 years of follow-up there were 306 MIs in the knee arthroplasty group and 286 in the controls. In the hip arthroplasty and control groups there were 128 and 138, respectively.
Although the Hazard Ratio was 8.75 for having an MI within one month of surgery the confidence intervals were wide at 3.11 to 24.62.