Systemic markers of inflammation increase after percutaneous coronary intervention (PCI). The rise in inflammatory markers after PCI is frequently attributed to the inflammatory stimulus associated with coronary artery injury during balloon inflation and coronary stent implantation. The aim of this study was the determine whether diagnostic coronary angiography performed in patients with stable angina triggers a systemic inflammatory response.

We prospectively studied patients with chronic stable angina undergoing either coronary angiography (n = 13) or coronary angiography followed by PCI (n = 13). Peripheral blood samples were obtained before and 24 hours, 48 hours, and 4 weeks after the procedure and analyzed for C-reactive protein (CRP), interleukin-6 (IL-6), and tumor necrosis factor-⍺ (TNF-⍺). Patients with periprocedural myocardial necrosis were excluded.

There was a significant increase in CRP levels at 24 and 48 hours in both the coronary angiography (P <.05) and PCI (P <.01) groups. IL-6 levels peaked at 24 hours in both the coronary angiography (median, 2.5–9.5 pg/mL; P = .01) and PCI (median, 3.0–8.2 pg/mL; P <.005) groups. At 4 weeks, both CRP and IL-6 returned to baseline levels. TNF-⍺ levels were unchanged with either coronary angiography or PCI. The magnitude of the rise of CRP and IL-6 levels was not significantly different between the groups. There was a fair correlation between baseline and peak postprocedural levels of CRP (r = 0.67, P = .008) and IL-6 (r = 0.48, P = .016).

Uncomplicated diagnostic coronary angiography triggers a systemic inflammatory response in patients with stable angina. The contribution of coronary angiography should be considered in interpreting the significance of the systemic inflammatory response observed after PCI.