Infection Risk Not Increased by Use of Antirheumatic Drugs Prior to Surgery in Patients with Rheumatoid Arthritis

Released: 18-Oct-2013 2:25 PM EDT
Embargo expired: 26-Oct-2013 4:30 PM EDT
Source Newsroom: American College of Rheumatology (ACR)
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Citations American College of Rheumatology Annual Meeting

Newswise — SAN DIEGO — Patients with rheumatoid arthritis may not need to halt use of their antirheumatic drugs prior to surgery due to fears of increased infection risk, according to research presented this week at the American College of Rheumatology Annual Meeting in San Diego.

Rheumatoid arthritis is a chronic disease that causes pain, stiffness, swelling, and limitation in the motion and function of multiple joints. Though joints are the principal body parts affected by RA, inflammation can develop in other organs as well. An estimated 1.3 million Americans have RA, and the disease typically affects women twice as often as men.

Researchers based at the Michael E. DeBakey Veterans Affairs Medical Center and the Baylor College of Medicine in Houston, Tex., gathered data on perioperative use of disease-modifying antirheumatic drugs, such as methotrexate, and the subsequent rate of postoperative infections from RA patients treated in the VA Medical Center over a 10-year period from 2000 to 2009. While there was little evidence to support temporary stopping of DMARDs or biologic agents in RA patients prior to surgery, the common reasoning had been that the drugs may increase patients’ infection risk due to their suppression of the immune system to control inflammation in autoimmune diseases like RA.

The researchers’ aim was to examine postoperative infection rates in a sample of RA patients in order to determine if use of the immunosuppressant drugs prior to surgery had any effect on their infection risks 30 days after their procedures, says Bernard Ng, MD; associate professor of medicine and chief of rheumatology; VA Puget Sound HCS; and an investigator in the study.

“Our ability to make evidence-based recommendations on whether immunosuppressive drugs for treatment of RA should be stopped before an elective surgery is limited based on current literature on this topic,” explains Dr. Ng. “We often receive consults from our surgery colleagues for this issue, and apart from certain orthopedic surgeries and the use of methotrexate, we don’t really have much to say when other surgeries and DMARDs are involved.”

Using VA administrative patient databases, the researchers looked at 6,548 RA patients who had been using only one DMARD or biologic agent in the perioperative period. Those patients using multiple agents were excluded to simplify the results. The researchers then compared the rate of wound infections within 30 days of surgery for these patients with the amount of time prior to surgery that their medication had been stopped. Wound infections, according to the modified 1992 U.S. Centers for Disease Control and Prevention criteria for postoperative infection, were recorded and analyzed by themselves and together with other infections like pneumonia, urinary tract infections and sepsis. Other factors that might also affect infection rates, such as co-existing diseases, diabetes mellitus, smoking or chronic steroid use, were also factored in by the researchers.

Results showed that RA patients who did not stop their use of a DMARD or biologic agent prior to surgery did not have a significantly higher risk of postoperative infection compared to patients who did stop their drugs. Conversely, those patients who stopped using their DMARD or biologic agent after surgery did have an increased incidence of both postoperative wound infections and general infections. Drug treatments likely were halted because the patients developed postoperative infections, the study authors concluded.

“Our results suggest that the likelihood of postoperative infections between those who discontinued RA medications before surgery and those who continued did not differ significantly. Thereby, suggesting that it may not be necessary for RA patients to discontinue these medications prior to elective surgeries. Indeed, continuing these medications may reduce the risk of RA flares that may result from stopping them,” says Dr. Ng.

Dr. Ng goes on to say, “This is a preliminary database study with several limitations. For example, the analyses done involved only single DMARD and biologic use, and the types of surgeries were not categorized. Further studies analyzing various combinations of DMARD and biologics, and specific types of surgeries will be useful in helping us develop deeper knowledge in this area.”
Patients should talk to their rheumatologists to determine their best course of treatment.

The American College of Rheumatology is an international professional medical society that represents more than 9,000 rheumatologists and rheumatology health professionals around the world. Its mission is to advance rheumatology. The ACR/ARHP Annual Meeting is the premier meeting in rheumatology. For more information about the meeting, visit http://www.acrannualmeeting.org/ or join the conversation on Twitter by using the official hashtag: #ACR13

Editor’s Notes: Dr. Zaki will present this research during the ACR Annual Meeting at the San Diego Convention Center at 3:45 PM on Sunday, October 27 in Room 30 E. Dr. Ng will be available for media questions and briefing at 8:30 AM on Monday, October 28 in the on-site press conference room, 27 AB.

Abstract Number: 807

Perioperative Use Of Anti-Rheumatic Agents Does Not Increase Early Postoperative Infection Risks: A Veteran Affairs’ Administrative Database Study
Zaki AbouZahr, Baylor College of Medicine, Houston, TX, Andrew Spiegelman, Michael E DeBakey Veteran Affairs Medical Center, Houston, TX, Maria Cantu, Baylor College Of Medicine, Houston, TX and Bernard Ng, Michael E. DeBakey VA Medical Center, Houston, TX

Background/Purpose: Evidences for perioperative management of disease modifying anti-rheumatic drugs (DMARDs) and biologic agents (BA) are sparse, and limited mainly to methotrexate & specific surgeries (orthopedics). Such data may not be generalizable to other surgeries or DMARDs/BA. The use of administrative database is difficult here due to lack of validated methods to predict stopping of DMARDs/BA before surgery. Using novel techniques to predict stopping of DMARDs/BA, we used data from Veterans Affairs (VA) to compare infection risks of RA patients who stopped versus continued DMARDs/BA perioperatively over a 10-year period from 2000-2009.

Methods: We identified 6548 RA patients in VA administrative databases using validated algorithms & included only those on 1 DMARD or BA in the perioperative period. Those on multiple DMARDs/BA were excluded to simplify result interpretation.
We predicted drug stoppages by calculating x = medication stop date closest to the surgery - next start date. y = surgery date-stop date was used to determine if the drug was stopped before or after surgery. To validate this method, two investigators independently reviewed clinic notes from the Houston VA facility for actual start or stop dates before or after surgery. A third investigator reviewed and resolved conflicting chart review results. ROC analyses were performed to obtain optimal x and y values to distinguish if DMARDs/BA were stopped and if it occurred before or after surgery.
The primary endpoints were wound infections within 30 days of surgery, according to the modified 1992 US Centers for Disease Control and Prevention criteria for postoperative infection, and other infections including pneumonia, UTI and sepsis. Propensity scores were used to match factors that may influence infection rates such as comorbidity scores, chronic steroid use, smoking, diabetes mellitus, etc.

Results:In the validation part of the study, ROC analyses found that x≥33 days best predicted stoppage of DMARD/BA (AUC=0.954) and y≥-11 best predicted that DMARD/BA was stopped before surgery (AUC=0.846).
Risk of post-op general infection or wound infection in RA patients who stopped DMARDs/BA before surgery were not significantly different compared with those who did not stop these agents. Those who stopped BA after surgery had significantly higher odds of post-op wound (OR 13.7, p=0.014) and post-op general infections (OR 9.2, p=0.005) compared to those who did not stop BA. Similarly stopping DMARDs after surgery was associated with increased risk of post op wound infection (OR 3.08, p=0.000) and post op general infection (OR 1.68, p=0.024) compared with not stopping treatment. Treatment was stopped postoperatively likely because of post-operative infection.

Conclusion: Using our novel technique of identifying DMARDs/BA discontinuation, we showed that there was no significant difference in post-op infection risk whether stopping anti-rheumatic treatment preoperatively or not. Our results grouped all types of surgeries and different DMARDs/BA. Further analyses looking at different types of surgeries and individual DMARDs/BA will be helpful to evaluate possible differences in infection risks between individual DMARDs/BA in different types of surgeries.

Disclosures: Z. AbouZahr, None. A. Spiegelman, None. M. Cantu, None.


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