An emerging report reveals that older hip implant and knee replacement patients face increased heart attack risks following surgery. The risk for acute myocardial infarction (AMI) was seen in the first two weeks after these surgical procedures.
Total hip replacement (THR) and total knee replacement (TKR) are used to treat patients with moderate to severe osteoarthritis. In fact, some 1.8 million procedures are performed each year, worldwide, according to the study background published Online First by the Archives of Internal Medicine, a Journal of the American Medical Association (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 commented.
For their study, the team used Danish national registries that enrolled patients who underwent either procedure from January 1998 through December 2007, as well as 286,165 people as matched controls. The average age for THR patients was just under 72 years and just more than 67 years for TKR patients.
The risk for AMI at six weeks was 51 percent in total hip replacement patients and 21 percent in total knew replacement patients, according to the study. “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 concluded.
In a commentary, Arthur W. Wallace, M.D., Ph.D., of the University of California, San Francisco explained that the time before, during, and following surgery are particularly stressful to the patient. It is during these phases that physicians should more deeply assess risk factures to reduce these risks. “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.”
Specifically, said Dr. Wallace, physicians should be looking at heart risks, saying, “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,” said Dr. Wallace, the team “clearly reinforce the importance and significance of the cardiac risk and the need to prevent perioperative cardiac morbidity and mortality.”