Hospitalizations for coronary artery disease among patients with systemic lupus erythematosus

Objective. Although patients with systemic lupus erythematosus (SLE) have an increased risk of coronary artery disease (CAD) compared with persons without SLE, the burden of CAD among SLE patients is unknown. This study was undertaken to estimate this burden. Methods. We used the Nationwide Inpatient Sample of the Healthcare Cost and Utilization Project to estimate the number of hospitalizations for CAD among patients with SLE in the US in 1998. CAD diagnoses included acute myocardial infarction (MI), unstable angina, cardiac catheterization, percutaneous transluminal coronary angioplasty, or coronary artery bypass grafting as the primary reason for hospitalization. We compared these estimates with the frequency of hospitalization for other reasons. Results. There were an estimated 98,217 hospitalizations among patients with SLE in 1998. Of these, 11,947 (12%) were among men, 43,674 (44%) were among women <50 years of age, and 42,596 (43%) were among women greater than or equal to50 years of age. There were 4,951 hospitalizations for CAD, with 1,763 of these for acute MI. In women <50 years old, there were an estimated 311 hospitalizations for MI. Hospitalizations for CAD were less common than hospitalizations for SLE itself or for infections, and in young women, were less common than hospitalizations for complications of chronic renal failure. Conclusion. CAD is an important comorbid condition in patients with SLE, hut is not as common a reason for hospitalization as SLE itself, infections, and, in some patient subgroups, chronic renal failure.