IS 40-PERCENT TO 70-PERCENT DIAMETER HARROWING AT THE SITE OF PREVIOUS STENTING OR DIRECTIONAL CORONARY ATHERECTOMY CLINICALLY SIGNIFICANT

Traditional binary definitions of coronary restenosis based on 6-month continuous angiographic measurements (e.g., >50% diameter stenosis) m ay give confusing results for lesions whose late percent stenosis fall s near the arbitrary threshold. To determine the long-term clinical co nsequences of such lesions, the overall correlation between follow-up percent stenosis and the performance of subsequent ischemia-driven tar get vessel revascularization (triggered by significant angina or a pos itive exercise study result, or both) was examined in 443 consecutive lesions treated with directional coronary atherectomy or Palmaz-Schatz coronary stenting Followup angiograms (available in 355 lesions, 82%) were stratified into 3 groups: severe late stenosis (>70% stenosis, n = 59), moderate late stenosis (40% to 70% stenosis, n = 72), and mini mal late stenosis (<40% stenosis, n = 224). With an average clinical f ollow-up of 933+/-394 days, 92% of lesions in the ''severe late stenos is'' group were treated with ischemia-driven target vessel revasculari zation, compared with 0% of the lesions in the ''minimal late stenosis '' group. ischemia-driven target vessel revascularization was performe d in 38% of patients In the ''moderate late stenosis'' group. However, patients In this group who did not undergo revascularization (despite the fact that 43% of them had a late stenosis of >50%) showed a simil arly favorable longterm clinical outcome to patients with a minimal la te stenosis. These results support a strategy of conservative manageme nt for the 20% of patients who have a moderate (40% to 70%) late steno sis after stenting or atherectomy, M do not have evidence of ischemia.