Hip or Knee Replacement Increases Risk for Heart Attacks Among Seniors
Worst problems for those 80 and over, very little risk for those under 60
July 24, 2012 - Total hip replacement (THR) and total knee replacement (TKR) surgeries were associated with increased
risk of acute myocardial infarction (AMI, heart attack) in the first two weeks after the surgical procedures, according to a new study. The
average age in the study for THR was less than 72 and for TKR it was just over 67.
THR and TKR are effective for treating patients with moderate to severe osteoarthritis. These surgical procedures are
commonly performed, with an estimated 1.8 million procedures performed annually worldwide, according to the study background published Online
First by Archives of Internal Medicine, a JAMA Network publication.
This study demonstrated an increased risk of AMI during the first two weeks after THR (25-fold) and TKR (31-fold)
surgery compared with matched controls. The risk of AMI sharply decreased after this period, although it remained significantly elevated in
the first six weeks for THR patients.
The association was strongest in patients 80 years or older, whereas we could not detect a significantly increased risk
in patients younger than 60 years, Arief Lalmohamed, Pharm.D., of Utrecht University, the Netherlands, and colleagues comment.
Researchers utilized Danish national registries for their study that enrolled patients who underwent THR or TKR
(n=95,227) from January 1998 through December 2007 and 286,165 individuals as matched controls. The mean (average) age for THR patients was
just less than 72 years and for TKR patients it was just more than 67 years.
The absolute six-week risk of AMI was 0.51 percent in THR patients and 0.21 percent in TKR patients, according to the
Furthermore, a previous AMI in the six months before surgery increased the risk of new AMI during the first six weeks
after THR and TKR (4-fold increase) surgery but did not modify the relationship between THR or TKR and AMI, the authors conclude.
The Division of Pharmacoepidemiology and Clinical Pharmacology, Utrecht Institute for Pharmaceutical Sciences has
received unrestricted funding for pharmacoepidemiologic research from GlaxoSmithKline, the private-public-funded Top Institute Pharma, the
Dutch Medicines Evaluation Board and the Dutch Ministry of Health. This study was supported by a grant from the Netherlands Organization for
Commentary: Important for Physicians to Recognize, Reduce
In a commentary, Arthur W. Wallace, M.D., Ph.D., of the University of California, San Francisco, writes: The
perioperative period is stressful to patients The present study once again confirms that the perioperative period increases cardiac risk.
Physicians must go further than establishing risk factors; physicians must actively work to reduce perioperative risk.
It is important for physicians caring for patients in the perioperative period to recognize the potential for cardiac
morbidity and mortality and then appropriately use the armamentarium of medical therapies we now have to reduce cardiac risk, prevent
perioperative MIs (myocardial infarction, heart attack), and prevent cardiac deaths, Wallace continues.
In their present study, Lalmohamed et al clearly reinforce the importance and significance of the cardiac risk and the
need to prevent perioperative cardiac morbidity and mortality, Wallace concludes.
This work has been supported by the Northern California Institute for Research and Education and the Veterans Affairs
Medical Center, San Francisco.
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