Greater vigilance in monitoring for these outcomes and their modifiable risk factors is recommended.
Patients with systemic lupus erythematosus are more likely to have myocardial infarctions and ischemic strokes, especially during the first 12 months after diagnosis, than persons from the general population who do not have the disease.
Researchers evaluated information from persons with incident cases of systemic lupus erythematosus who were identified from population-based administrative data that represented residents in British Columbia, Canada, in a study published online May 9 in Arthritis Care & Research.
Led by J. Antonio AviÃ±a-Zubieta, MD, PhD, University of British Columbia, the investigators assessed incidence rates of myocardial infarctions, ischemic stroke, and cardiovascular disease (a combination of myocardial infarction and stroke) between cases and matched controls.
“We found that the risks of MI, stroke, and CVD in SLE patients are substantially higher when compared to non-SLE controls, with a greater than 2-fold increase of risk in all 3 outcomes,” wrote AviÃ±a-Zubieta and colleagues. “Overall, the elevated risk was 6-fold during the first year after SLE diagnosis and remained significantly high even after 5 years.”
Although the link between systemic lupus erythematosus and cardiovascular disease is well-established, very few studies have used population-based data to evaluate this relationship.
This was a matched cohort study of patients with systemic lupus erythematosus (n=4863) and persons without the disease who were randomly selected from the general population in British Columbia (n=49,316). Cases and controls were matched on age, sex, and calendar year for entering the study. British Columbia has a population of about 4.5 million persons and has universal health care coverage. Population-based administrative data with linkable data files for all province-funded outpatient medical visits have been available since 1990.
The study team’s definition of a systemic lupus erythematosus case was as follows: (1) persons aged ≥ 18 years; (2) 1 International Classification of Diseases, Ninth Revision, Clinical Modification (ICD-9-CM) code for systemic lupus erythematosus by a rheumatologist or from a hospital (710.0 or ICD-10 M32.1, M32.8, and M32.9) or 2 ICD-9-CM codes for systemic lupus erythematosus (710.0) at least 2 months apart within 2 years by a non-rheumatologist physician; and (3) absence of a prior systemic lupus erythematosus diagnosis between January 1990 and December 1995.
In general, persons in the systemic lupus erythematosus group had higher use of glucocorticoids and COX-2 inhibitors, had higher Charlson comorbidity indices, and used more health care resources during the previous 12 months, compared with those without systemic lupus erythematosus.
The incidence rates of myocardial infarction, stroke, and cardiovascular disease were 6.4, 4.4, and 9.9 events per 1000 person-years, respectively, in the 4863 patients with systemic lupus erythematosus, compared with 2.8, 2.3, and 4.7 events per 1000 person-years in persons who did not have systemic lupus erythematosus.
The highest relative risk for myocardial infarction was in persons with systemic lupus erythematosus aged 45 to 59 years (hazard ratio, 4.26 [95% CI, 3.02–6.01]); the highest relative risk for stroke was in persons ≥ 45 years with systemic lupus erythematosus (hazard ratio, 5.38 [95% CI, 2.1–13.70]).
During the first year after a diagnosis of systemic lupus erythematosus, hazard ratios were the most pronounced with age-, sex-, and entry time–matched HRs of 5.63 (95% CI, 4.02–7.87), 6.47 (95% CI, 4.42–9.47), and 6.28 (95% CI, 4.83–8.17), respectively.
“Based on our findings, there is significant value in routine evaluation for modifiable CVD risk factors in SLE patients by clinicians,” noted AviÃ±a-Zubieta and study team. “CVD should remain on the differential for any SLE patients presenting with chest pain or stroke-like symptoms, and patients should be taught to identify potential symptoms, especially early in the disease course.”
This research was supported by the Canadian Arthritis Network, the Arthritis Society of Canada/the British Columbia Lupus Society, and the Canadian Institutes of Health Research.
AviÃ±a-Zubieta, J. A., To, F., Vostretsova, K., et al. “Risk of Myocardial Infarction and Stroke in Newly Diagnosed Systemic Lupus Erythematosus: A General Population-Based Study.” Arthritis Care Res (Hoboken). Published online May 9, 2017. DOI:10.1002/acr.23018