Patients with systemic lupus erythematosus (SLE) who undergo noncardiac surgery face an increased risk of postoperative major adverse cardiac events (MACE), according to a study published in ACR Open Rheumatology.
"The increased risk of MACE is likely driven by increased Revised Cardiac Risk Index (RCRI) scores because, after adjustment for RCRI score, the odds ratio decreased and was no longer statistically different from that of controls," Sebastian Bruera, MD, of the Baylor College of Medicine and colleagues said in the study. "This is consistent with the hypothesis that patients with SLE have increased underlying comorbidities that further increase the risk of MACE."
Bruera and colleagues conducted a retrospective cohort study of patients with SLE aged at least 18 years who had undergone noncardiac surgeries and had 2 or more administrative claims for SLE. The patients also had insurance coverage between 2 years before and 1 month after surgery, and prescription claims for antimalarials, corticosteroids, biologics, and/or immunosuppressants for at least a 90-day supply within 2 years before the first SLE code.
The study also looked at two control cohorts without SLE. One of the control groups included patients with diabetes, while the other group had patients without diabetes. In addition, the study looked at the use of preoperative cardiac testing. Overall, the study included 4,750 patients with SLE, 496,381 patients with diabetes, and 1,484,986 patients without diabetes.
The study's primary outcome was MACE, which was defined as myocardial infarction, ischemic stroke, or death from any cause, within 1 month of surgery. The secondary outcome was MACE within 3 months of surgery.
The odds ratio for MACE in patients with SLE versus the non-diabetes control group was 1.51 (95% CI, 1.09-2.08) and decreased after adjusting for RCRI score (OR = 0.97; 95% CI, 0.7-1.36). There was no significant difference observed in the incidence of MACE between patients with SLE and diabetes (0.82 vs 1.04; P = .16). In addition, high-risk patients with SLE, defined as an RCRI score of 3 or higher, were less likely to receive preoperative cardiac testing than the non-diabetes control group (42.7% vs 35.1%; P < .05).
Bruera and colleagues noted that the risk of MACE in patients with SLE was close to 1% at 1 month and 1.5% at 3 months, respectively, and that when compared with matched non-diabetic controls, patients with SLE had a 49% increase in MACE at 1 month (0.82% vs 0.55%) and 83% increase at 3 months (1.45% vs 0.79%).
"Although, as a whole, our SLE cohort had more cardiac testing than the general cohort, use remained low (because most patients did not undergo testing), even for those 45 years and older," Bruera and colleagues said in the study. "Concerningly, high-risk patients with SLE with an RCRI score of 3 or higher underwent less preoperative cardiac testing within two months than non-diabetic controls, suggesting that there may be a lack of awareness of the heightened cardiovascular risk in this population."
One challenge identified in the study was that while rheumatologists could be more aware of cardiovascular risk in this patient population, it is unknown how often patients with SLE see their rheumatologists before surgery and whether testing would be recommended. In addition, patients with SLE may undergo more unexpected or emergent operations before testing can be done.
Bruera and colleagues suggested additional studies to evaluate the impact of perioperative risk stratification and management to reduce MACE in this patient population.
Disclosures: Authors declared financial ties to drugmakers. See full study for details.
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