Depressed Inflammatory Response to Repeated Angioplasty in Unstable Angina Patients with an In-Stent Restenosis

BACKGROUND: Inflammation plays a key role in the pathogenesis of an in-stent restenosis because it promotes neointimal proliferation. This study was performed to determine responses of the C-reactive protein (CRP) in unstable angina patients with an in-stent restenosis undergoing repeated percutaneous transluminal coronary angioplasty (re-PTCA).

METHODS: The study subjects (unstable angina) were classified into 2 groups:Group A (n=30, 15 men, mean age 62 years) had a re-PTCA for an in-stent restenosis lesion and Group B (n=60, 33 men, mean age 63 years) underwent a stent implantation for a de novo lesion.

RESULTS: The baseline CRP levels in group A were significantly lower than in group B, as well as 6 and 24 hours after intervention. Twenty four hours after intervention, the CRP levels increased (>4 mg/L) in 3 out of 30 patients (10%) of group A but increased in 32 out of 60 patients (53%) in group B (p<0.001). The differences in the CRP levels between the baseline and 24 hours after intervention were significantly lower in group A than in group B (0.8 and 2.15 mg/L, respectively, p<0.001). In group B, the serum CRP levels 24 hours after intervention were significantly higher than the baseline levels (p<0.05), but not in group A.

CONCLUSION: The CRP expression level is significantly lower in unstable angina patients undergoing a re-PTCA for an in-stent restenosis than those undergoing a stent implantation for a de novo lesion.