C-reactive protein (CRP) levels increased more than sixfold above baseline when measured 48 hours after elective percutaneous transluminal coronary angioplasty (PTCA) in patients without underlying inflammatory conditions and did not change significantly in controls undergoing coronary angiography. Only 3 of the 42 PTCA patients had clinical restenosis and underwent target vessel revascularization during the 6-month follow-up, but 2 of the 3 had very high CRP levels 48 hours after the procedure.