Risk for death after coronary revascularization doubled in patients with SLE vs. diabetes
ATLANTA — Patients on Medicaid with systemic lupus erythematosus who underwent coronary revascularization procedures had 1.7 times higher 30-day mortality rates than those with diabetes who underwent the same procedures, according to a presenter here.
“In previous work, our group studied Medicaid patients and showed that despite having a lower prevalence of traditional cardiovascular disease risk factors, lupus patients have a similar risk of myocardial infarction compared to diabetes,” Medha Barbhaiya, MD, a rheumatologist and clinical researcher at the Hospital for Special Surgery, said during a press conference. “We also previously showed that lupus patients in Medicaid had an 18% risk of undergoing coronary revascularization procedures compared to diabetics.”
She added, “For us, understanding the magnitude of the risk of death in patients after coronary revascularization procedures was very important to be able to hopefully manage our patients better moving forward.”
The risks for myocardial infarction are similar among patients with SLE and those with diabetes, but those with SLE on Medicaid had significantly higher rates of coronary artery bypass grafting and percutaneous coronary intervention, according to researchers. Little is known about mortality after these procedures in patients with SLE compared with the general population and those with diabetes. Based on this, Barbhaiya and colleagues assessed 30-day mortality rates following revascularization procedures between the three groups.
The researchers used data from Medicaid Analytic eXtract, which contained billing claims from 2007 to 2010 in 29 of the most populated states. They identified adults aged between 18 and 65 years with SLE or diabetes and those without either, deemed the general population.
Post-procedure 30-day mortality rates and mortality rate ratios were calculated per 1,000 person-years among patients in each cohort undergoing first coronary artery bypass grafting or percutaneous coronary intervention, and compared with the general population and diabetes population separately. Odds ratios and 95% CIs for 30-day mortality after procedures were also calculated in the SLE vs. diabetes groups using logistic regression models, adjusting for age, sex, race/ethnicity and Charlson index.
Barbhaiya and colleagues identified 608 coronary revascularization procedures among 40,212 patients with SLE; 1,185 procedures among 80,424 patients with diabetes; and 628 procedures among 160,848 patients in the general population.
The SLE group had the youngest patients at the time of their procedure and the highest proportion of black patients.
Thirty-day post-revascularization mortality rate per 1,000 person years was highest among patients in the SLE group (351.35; 95% CI, 221.36-557.67) compared with the diabetes group (mortality rate ratio: 1.67; 95% CI, 1.25-2.21) and general population (mortality rate ratio: 1.85; 95% CI, 1.31-2.63).
Multivariable adjustment demonstrated the odds of death were doubled in the SLE group compared with the diabetes group within 30 days of revascularization (OR = 2.13; 95% CI, 1.09-4.13). The trend was similar — though not significant — for SLE vs. the general population (OR = 1.93; 95% CI, 0.85-4.42).
“To our knowledge, this is the first study looking at post-coronary revascularization outcomes and deaths in lupus patients and quantifying the risk of this compared to another chronic disease cohort like diabetes,” Barbhaiya said. “Although our findings were based on a small number of deaths in the post-procedural 30-day period, we did find that lupus patients had 2.4 times the odds of 30-day mortality post-coronary revascularization compared to diabetes.”
She noted, “I think, in particular, while our results suggest there may be an increased risk for death in lupus patients compared to diabetes, it may be due — and this needs further investigation — to severity of the lupus.”
Barbhaiya said other factors should be accounted for in any future studies, including health care utilization, complexity of the procedures performed, reason for the procedure, severity of lupus and severity of cardiovascular disease. – by Stacey L. Adams
Barbhaiya M, et al. Abstract #897. Presented at ACR/ARP Annual Meeting, Nov. 8-13, 2019; Atlanta.
Disclosure: Barbhaiya reports no relevant financial disclosures. Please see the abstract for all other authors’ relevant financial disclosures.