Effect of prior coronary restenosis on the risk of subsequent restenosis after stent placement or directional atherectomy

Lesions that have developed restenosis after a prior intervention may be more likely to develop restenosis after subsequent percutaneous interventions. To determine if this is an independent effect, the clinical characteristics and immediate angiographic outcomes of 179 prior restenosis lesions were compared with those of 254 primary lesions after stenting or directional atherectomy. Six-month angiographic follow-up was obtained for 79% of successfully treated lesions. Univariable and muttivariable logistic regression was used to determine how binary restenosis (defined as $ ̌-50% diameter stenosis at follow-up) was influenced by postprocedure luminal diameter, left anterior descending artery location, diabetes mellitus, as well as prior restenosis. At 6-month follow-up, prior restenosis lesions had a significantly smaller late diameter (1.77 vs 2.18 mm, p < 0.001), more absolute late loss (1.35 vs 1.14 mm, p = 0.051), a higher loss index (0.58 vs 0.45, p < 0.02), and a higher binary restenosis rate (37.3% vs 24.4%, p = 0.01). Whereas univariable analysis revealed that left anterior descending artery location, diabetes mellitus, postprocedure luminal diameter < 3.1 mm, and prior restenosis were each strong predictors of binary restenosis (all p < 0.02), muttivariable analysis showed that after adjustment for left anterior descending artery location, diabetes, and postprocedure luminal diameter, prior restenosis was no longer an independent predictor of restenosis (odds ratio 1.57, 95% confidence interval 0.95-2.60, p = 0.073). In conclusion, although prior restenosis lesions do show more restenosis than primary lesions, much of this effect is due to preselection of a population enriched in other known factors that predispose to restenosis.