Abstract: Aim To observe the changes of serum C-reactive protein (CRP) in patient s with unstable angina after percutaneous transluminal coronary angioplasty (PTCA) and to invetstig ate the relationship between the peak values of CRP and clinical restenosis.Methods A prospective case study was undertaken in 47 patients who underwent successful PTCA (PTCA group) for unstable angina and another 25 patients as control who underwent coronary angiog raphy.Levels of CRP were measured by RIA at baseline, 48 hours and one week after PTCA.All of PTCA group were followed clinically for 9 months.An exercise testing or a thallium perfusion scan (TPS) was performed within nine months post-PTCA and CAG was repeated in the part of abnormal patient s.Results At nine-month follow-up, clinical restenosis developed in 44% of 25 patients with high serum levels (>30 mg·L^-1) of CRP, and in 9.1% of 22 patient s with normal CRP levels(P<0.01).Conclusion Serum CRP 48 hours after PTCA is a marker of ninemonth clinical performance.

Key words: percutaneous transluminal coronary angioplasty, C-reactive protein, restenosis, unstable angina