Patients who undergo knee or hip replacement surgery have a higher risk of suffering a heart attack within the first month after the procedure, according to a new study.

Researchers at the Boston University School of Medicine (BUSM) discovered that the heart attack risks for people who had total knee replacement were more than eight times higher during the first 30 days after the surgery compared to those who did not undergo the procedure.

Meanwhile, individuals who had hip replacement were found to be four times more likely to experience a heart attack during the first month following the surgery.

Despite these findings, the researchers noted that patients should not be deterred from undergoing knee or hip replacement surgery, citing that both procedures did not increase heart attack risk over the entirety of the study's follow-up period. They said that the heart attack risks for patients observed in the study eventually dissipated over time.

The risks of developing blood clots in lungs and veins, however, also increased in the first month after knee or hip replacement and lasted for years following the procedure.

Yuqing Zhang, medicine and epidemiology professor at BUSM and lead author of the study, said that contrary to earlier findings, their research suggests that total joint replacement surgeries do not provide patients with protection against heart attack risks.

Zhang added that the latest findings point to the possibility that heart attack risk following knee or hip replacement could have been underestimated.

Cardiology professor Dr. Gregg Fonarow of the University of California, Los Angeles (UCLA) said that the elevated risk of heart attack during and after different surgical procedures is well documented.

A previous study involving osteoarthritis patients compared individuals who had knee or hip replacement surgery to those who did not undergo any of the procedures. Based on background information featured in the study, it had suggested that people who opted for surgery experience lower heart attack risks.

Fonarow said that the data on heart attacks during the first 30 days following surgery were not included in the previous study, skewing its results.

Zhang said that measures may have to be taken in order to lessen heart attack risks following surgery.

In their research, Zhang and his colleagues gathered data on close to 14,000 people over 50 years old with osteoarthritis who underwent total knee replacement. The team then compared these individuals with a similar number of patients who did not have the procedure.

The researchers also gathered data on over 6,000 individuals over 50 years old with osteoarthritis who underwent total hip replacement surgery and compared them with a similar number of patients who did not undergo the surgery.

The findings of the Boston University School of Medicine study are featured in the journal Arthritis & Rheumatology.

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