Single Photon Emission Computed Tomography Dual Isotope Myocardial Perfusion Imaging in Women with Systemic Lupus Erythematosus. II. Predictive Factors for Perfusion Abnormalities

IAN N. BRUCE, DAFNA D. GLADMAN, DOMINIQUE IBAÑEZ, and MURRAY B. UROWITZ

ABSTRACT.

Objective. We have reported that 40% of patients with systemic lupus erythematosus (SLE) had abnormal myocardial perfusion studies. Here we investigated risk factors for abnormal myocardial perfusion in a cohort of women with SLE without history of coronary artery disease.

Methods. Consecutive women with SLE followed at a large lupus clinic underwent single photon emission computed tomography dual isotope myocardial perfusion imaging (DIMPI) following pharmacological stress using dipyridamole. At the time of study each patient had a clinical and laboratory assessment performed by a standard protocol. We compared traditional risk factors as well as disease and therapy related factors in those with and without perfusion abnormalities.

Results. A total of 129 patients were studied. The mean ± SD age was 44.8 ± 10.9 yrs, and mean SLE Disease Activity Index was 4.2 ± 5.1. Forty-nine (38%) patients had an abnormality of myocardial perfusion. Factors associated with an abnormal DIMPI included current hypertension (OR 2.11, p = 0.05), elevated cholesterol ever (OR 2.51, p < 0.05), and total cholesterol:high density lipoprotein-cholesterol ratio (OR 1.96 for each increase of 1.0, p < 0.008).

Conclusion. Myocardial perfusion abnormalities are common in women with SLE without known coronary artery disease (CAD), suggesting a high burden of subclinical CAD. Several metabolic and therapy related factors appear to be associated with the process of atherogenesis in SLE. These results suggest that SLE should be considered a predisposing factor for atherosclerosis. (J Rheumatol 2003;30:288-91)

Key Indexing Terms:

LUPUS
PREDICTIVE FACTORS
MYOCARDIAL PERFUSION IMAGING

---

From the University of Toronto Lupus Clinic, Centre for Prognosis Studies in the Rheumatic Diseases, and Division of Cardiology, University Health Network, Toronto Western Hospital, Toronto, Ontario, Canada.

Supported by a grant from The Arthritis Society. Dr. Bruce was Geoffrey Carr Lupus Fellow of The Ontario Lupus Association and received the Richard Havelock Charles Scholarship, Queen's University, Belfast, UK.

I.N. Bruce, MD, MRCP(UK), Geoffrey Carr Ontario Lupus Association Lupus Fellow, University of Toronto Lupus Clinic, Centre for Prognosis Studies in the Rheumatic Diseases; D.D. Gladman, MD, FRCPC, Professor of Medicine, Deputy Director, Centre for Prognosis Studies in the Rheumatic Diseases; D. Ibañez, MSc, Biostatistician, Centre for Prognosis Studies in the Rheumatic Diseases; M.B. Urowitz, MD, FRCPC, Professor of Medicine, Director, Centre for Prognosis Studies in the Rheumatic Diseases.

Address reprint requests to Dr. M.B. Urowitz, Centre for Prognosis Studies in the Rheumatic Diseases, 1-318 Main Pavilion, Toronto Western Hospital, 399 Bathurst Street, Toronto, Ontario, Canada M5T 2S8. E-mail: m.urowitz@utoronto.ca

Submitted December 11, 2001; revision accepted August 7, 2002.

---