Predictors of event-free survival after repeat intracoronary procedure for in-stent restenosis. Study with angiographic and intravascular ultrasound imaging

AIMS: Lumen enlargement during repeat percutaneous coronary intervention for in-stent restenosis has been shown to be the result of both stent over-expansion and decrease in neointimal tissue. How these two different mechanisms of action may influence outcome and target lesion revascularization after repeat intervention for in-stent restenosis is unclear. METHODS: Intravascular ultrasound guided repeat intervention for in-stent restenosis was carried out either with balloon angioplasty, or with a combination of rotational atherectomy plus balloon angioplasty. Clinical follow-up at 1 year, including death, myocardial infarction, or need for revascularization, was obtained. RESULTS: Seventy patients were included in this study; 40 were treated by balloon alone, and 30 by combination of rotational atherectomy plus balloon. Event-free survival probability was 76+/-5%. The mechanism of lumen enlargement, be it stent over-expansion or tissue removal, had no influence on long-term clinical evolution. The only independent predictor was the minimal lumen cross-sectional area at the end of the procedure, the larger the lumen cross-sectional area, the higher the event-free probability. The cut-off point of the lumen cross-sectional area was set at 4.7 mm(2)by discriminant analysis. Event-free survival was 69+/-15% in patients with <4.7 mm(2)lumen cross-sectional area and 91+/-8% in patients with >4.7 mm(2)lumen cross-sectional area (P=0. 008). CONCLUSIONS: This study showed that the only independent predictor of late clinical outcome after percutaneous re-intervention for in-stent restenosis was final lumen size, no matter which means were used to achieve it.