Warning for Joint Replacement Patients With Atrial Fibrillation
A-fib may trigger complications during or after surgery and lengthen hospital stays.
A new hip or knee may be just what you need – but if you’re considering joint replacement and you have atrial fibrillation (A-fib), you may have an increased risk of complications, according to a study published in The Journal of Bone & Joint Surgery in 2013. People with rheumatoid arthritis (RA) are up to 60 percent more likely than people without RA to develop A-fib, either due to the disease itself or the medications, such as corticosteroids, used to treat it. Additionally, the chances of anyone developing A-fib increase greatly with age.
“The study found that A-fib patients had a longer length of stay [in the hospital], an increased cost of medical care and higher complication rates,” said senior study author Alvin C. Ong, MD, assistant professor of orthopaedic surgery at the Rothman Institute at Thomas Jefferson University Hospital in Philadelphia. The complication rates were about 27 percent higher in patients who had A-fib compared with those who didn’t. The complications included infections around the new joint, the need for blood transfusions and later readmission to the hospital.
In A-fib, faulty electrical signals cause the upper chambers of the heart (the atria) to “fibrillate,” or contract irregularly and, usually, too fast. As a result, blood isn’t pumped effectively to the heart’s lower chambers and out through the body. Blood thinners (also called anti-coagulants) such as warfarin (Coumadin) are used to prevent blood clots that can result from the pooling of blood in the heart – and it’s these blood thinners that make joint replacement surgery more risky.
Lead study author Vinay K. Aggarwal, MD, an orthopaedic surgeon at NYU Langone Medical Center noted, “Given that elderly patients very frequently have chronic A-fib and also very frequently undergo total joint arthroplasty [repair or replacement], it made sense to examine the two distinct variables together.”
The study reported that The patients with A-fib had a longer pre-operative hospital stay (1.7 days versus 0.2 days), a longer postoperative stay (4.6 days vs. 3.2 days) and were significantly more likely to develop a joint infection and need a blood transfusion. They were also four times more likely to be unexpectedly readmitted to the hospital after their release.
The study results were not what Tad M. Mabry, MD, assistant professor of orthopaedics at Mayo Clinic in Rochester, Minn., who specializes in primary and revision hip and knee replacement, would have expected.
He noted several limitations of the study as it was presented. One problem may be how well the A-fib patients were matched with the controls. Patients in the study were matched in terms of factors such as age, gender, body weight and which side of the body was being operated on.
“I’m not sure the A-fib group and the control group were actually the same group of people – that the only thing that was different was A-fib,” says Dr. Mabry. “There are some other things that may be different between the groups that they did not talk about. For example, we don’t know if there was a difference in the two groups in terms of patients who had a history of heart attack or coronary artery disease, or a difference in patients that have diabetes or rheumatoid arthritis.”
He said if the group that had A-fib also had a higher rate of coronary artery disease, for example, that would increase the risk of them needing a blood transfusion and having postoperative readmission. Another question Dr. Mabry had with the study is, why A-fib patients were getting transfusions at a much higher rate even though hemoglobin levels – an indicator of anemia, which reflects increased bleeding – were not significantly different between the two groups. “Usually one of the main features that tells you that you’re going to give somebody a blood transfusion is how low their hemoglobin gets,” he says. “Despite the fact that the two groups’ hemoglobin levels were relatively similar, they were transfusing patients that had A-fib at a much higher rate. They don’t talk about why they were giving those patients blood.”
So what should an A-fib patient about to undergo joint replacement surgery do? “Before a patient who’s taking a blood thinner has elective surgery, they should always consult with a medical expert regarding their risk of clotting,” Dr. Mabry says. “A plan can be developed that finds the best balance of avoiding an undue risk of clotting, and an unnecessarily high bleeding risk.”