Value of the American College of Cardiology/American Heart Association angiographic classification of coronary lesion morphology in patients with in-stent restenosis. Insights from the Restenosis Intra-stent Balloon angioplasty versus elective Stenting (RIBS) randomized trial.

ABSTRACT

BACKGROUND: The implications of the American College of Cardiology/American Heart Association (ACC/AHA) lesion classification in patients with in-stent restenosis (ISR) are unknown. METHODS: Four hundred fifty patients included in the RIBS randomized study were analyzed. A centralized core laboratory assessed ISR classifications including ACC/AHA, the classification of Mehran et al (Circulation 1999;1001872-8), diffuse/focal, and a new quantitative ISR index (lesion length/stent length). Logistic regression models were constructed for prespecified outcome measures including (1) unsatisfactory acute results and (2) recurrent restenosis rate. RESULTS: Complex (B2/C) lesions (78%) more frequently obtained unsatisfactory acute results (20% vs 8%, P = .007), smaller minimal lumen diameter after the procedure (2.45 +/- 0.5 vs 2.73 +/- 0.5 mm, P = .001) and at follow-up (1.48 +/- 0.8 vs 1.94 +/- 0.8 mm, P = .0001), and had a higher restenosis rate (43 vs 24%, P = .001) than simple (A/B1) lesions. On logistic regression analysis, all classification schemes were useful to predict unsatisfactory initial results (area under the curve 0.63, 0.61, 0.59, and 0.62) and recurrent restenosis (area under the curve 0.60, 0.64, 0.61, and 0.63). The predictive ability of these schemes persisted despite adjustment for potential confounders. Although the ACC/AHA classification was a better predictor of acute results, the classification of Mehran was superior to predict restenosis. CONCLUSIONS: The ACC/AHA classification provides a useful tool to determine acute procedural results and the long-term angiographic outcome of patients with ISR.