Re-angioplasty of in-stent restenosis versus balloon restenoses--a matched pair comparison.

Background: Despite different biological mechanisms involved in the restenotic process of in-stent restenosis and restenosis after balloon angioplasty alone, the occurrence of a second restenosis has been reported in the same range. There are no data available comparing the outcome after re-angioplasty of such lesions. We analyzed in a matched pair comparison the clinical outcome and angiographic long-term result of patients with balloon angioplasty of a first in-stent restenosis versus patients with balloon re-angioplasty of a first balloon restenosis.

Methods: Both groups consisted of 74 lesions matched by treated vessel, lesion location differentiated in proximal and non-proximal, and angiographic appearance of coronary artery disease differentiated in singular stenosis, diffuse or mixed pattern. Clinical follow-up was 100%. Angiographic follow-up was 78.4% after median 174 days.

Results: Angiographic restenosis rate in matched pairs of patients (n=46/74) was significantly higher in the balloon restenosis group (41.3%, n=19/46) compared to the in-stent restenosis group (21.7%, n=10/46, p<0.042). There was no death or myocardial infarction. After clinical follow-up, target lesion revascularization rate was significantly lower in the in-stent restenosis group compared to the balloon restenosis group (12.1%, n=9/74 versus 27.0%, n=20/74; difference between groups 14.9%, 95% confidence interval 2.0-27.3%, p<0.023). Multivariate logistic regression analysis revealed as predictors for a second restenosis unstable angina pectoris, non-proximal lesion, restenosis after balloon angioplasty and the occurrence of the first restenosis within 90 days after initial intervention.

Conclusion: Clinical and angiographic outcome after balloon angioplasty of a first in-stent restenosis was significantly better compared with balloon re-angioplasty of a first balloon restenosis.