Objective: To identify clinical and biochemical parameters that have good predictive value for identifying giant cell (temporal) arteritis (GCA) patients who are at high or low risk of developing cranial ischemic events.

Methods: In this multicenter study, records of patients at 3 university hospitals in Barcelona were reviewed retrospectively. Two hundred consecutive patients with biopsy-proven GCA were studied.

Results: Thirty-two patients developed irreversible cranial ischemic complications. The duration of clinical symptoms before diagnosis was similar in patients with and those without ischemic events. Patients with ischemic complications less frequently had fever (18.8% versus 56.9%) and weight loss (21.9% versus 62%) and more frequently had amaurosis fugax (32.3% versus 6%) and transient diplopia (15.6% versus 3.6%). Patients with ischemic events had lower erythrocyte sedimentation rates (ESR) (82.7 mm/hour versus 104.4 mm/hour) and higher concentrations of hemoglobin (12.2 gm/dl versus 10.9 gm/dl) and albumin (37.4 gm/liter versus 32.7 gm/liter). Clinical inflammatory status and biologic inflammatory status were defined empirically (clinical: fever and weight loss; biologic: ESR > or =85 mm/hour and hemoglobin < 11.0 gm/dl). Patients not showing a clinical and biologic inflammatory response were at high risk of developing ischemic events (odds ratio [OR] 5, 95% confidence interval [95% CI] 2.05-12.2). The risk was greatly reduced among patients with either a clinical (OR 0.177, 95% CI 0.052-0.605) or a biologic (OR 0.226, 95% CI 0.076-0.675) inflammatory reaction. No patient with both a clinical and a biologic response developed ischemic events.

Conclusion: The presence of a strong acute-phase response defines a subgroup of patients at very low risk of developing cranial ischemic complications. Our findings provide a rationale for testing less aggressive treatment schedules in these individuals. Conversely, a low inflammatory response and the presence of transient cranial ischemic events provide a high risk of developing irreversible ischemic complications and require a prompt therapeutic intervention.