(RxWiki News) Surgery to replace a damaged hip or knee can put an end to the pain of osteoarthritis. But, like any surgery, there are risks involved.
Patients who have undergone total hip replacement or total knee replacement surgery may have a higher risk of heart attack, compared to those who have not undergone surgery.
"Know your heart risks before going into surgery."
Some studies have suggested that the risk of heart attack may be higher shortly after hip and knee replacement surgeries, said Arief Lalmohamed, PharmD, of Utrecht University in the Netherlands, and colleagues in their recent study.
Yet, the risk of heart attack in surgery patients has not been compared against patients who have not been through surgery, they said.
Dr. Lalmohamed and colleagues set out to study the timing of heart attack in patients undergoing total hip replacement or total knee replacement surgery.
In the first two weeks after totally hip replacement surgery, there was a 25-fold increased increased of heart attack, compared to those who did not undergo surgery.
The risk of heart attack remained for about two to six weeks after surgery. After six weeks, the risk returned to the same level as it was when the study began.
There was a 31-fold increased risk of heart attack in the first two weeks after total knee replacement surgery. However, after two weeks, the risk of heart attack for surgery patients was similar to that of non-surgery patients.
The absolute risk of heart attack within six weeks was 0.51 percent in hip replacement patients and 0.21 percent in knee replacement patients.
The risk of heart attack after surgery was greatest in patients 80 years of age and older.
The researchers also "were able to show a sharp decrease in risk of a new [heart attack] when the previous [heart attack] had occurred more than 1 year before surgery."
This finding suggests that patients should reconsider joint replacement surgery if they have had a heart attack within the last year.
According to the authors, the risk of heart attack should be assessed in the first six weeks after hip replacement surgery and the first two weeks after knee replacement surgery.
For their study, the researchers studied more than 95,000 Danish people who had undergone total hip replacement or total knee replacement surgery.
Dr. Lalmohamed and co-authors Corinne Klop, PharmD; Anthonius de Boer, MD, PhD; Hubertus Leufkens, PhD; Tjeerd P. van Staa, MD, PhD; and Frank de Vries, PharmD, PhD, are employed by the Division of Pharmacoepidemiology and Clinical Pharmacology at the Utrecht Institute for Pharmaceutical Sciences, which has received unrestricted funding from GlaxoSmithKline, Top Institute Pharma, the Dutch Medicines Evaluation Board and the Dutch Ministry of Health.
The research received support from the Netherlands Organization for Scientific Research.
The study was published in July in the Archives of Internal Medicine.