Abstract / Summary
Background: Rheumatoid arthritis (RA) is recognized as a cardiovascular risk-enhancing condition. Whether a normal myocardial perfusion imaging (MPI) study confers similar prognostic reassurance in RA as in non-RA patients remains unclear. Methods: We retrospectively analyzed 282 patients with RA and 282 matched controls without autoimmune disease who underwent SPECT or PET MPI. Matching included age, sex, cardiovascular comorbidities, and stress modality. The primary outcome (MACE) was a composite of cardiovascular-specific mortality, myocardial infarction, late revascularization, or heart failure hospitalization. Multivariable Cox regression and interaction testing between RA and ischemia were performed. Results: Over a median follow-up of 4.0 years, 95 MACE occurred. Rates of reversible perfusion defects were similar between groups, although coronary artery calcification (CAC) was more prevalent in RA than controls (67% vs. 56%, p = 0.048). Despite comparable ischemia burden, RA was independently associated with increased MACE (adjusted HR 1.91, 95%CI 1.24–2.95, p = 0.003). RA patients without ischemia had worse outcomes than controls without ischemia (HR 2.16, 95%CI 1.27–3.68, p = 0.005), whereas outcomes were similar among patients with ischemia irrespective of RA status. Among patients with detectable CAC, RA was associated with higher risk (HR 1.97, 95%CI 1.07–3.62; p = 0.029), and the association between RA and MACE remained significant after additional adjustment for CAC. Conclusions: In patients referred for stress MPI, RA confers excess cardiovascular risk independent of inducible ischemia and CAC. A normal MPI does not identify a low-risk RA subgroup, supporting aggressive preventive strategies even when perfusion imaging is normal.