Prognostic value of absolute versus relative measures of the procedural result after successful coronary stenting: Importance of vessel size in predicting long-term freedom from target vessel revascularization

Background The procedural result is a major determinant of the incidence of 6-month target vessel revascularization (NR) after successful coronary ste nting. However, the prognostic implications of the different measures of th e procedural result or procedural end points have not been directly compare d. In this study, we sought to assess and compare the impact of achieving d ifferent procedural end points on the long-term (2-year) incidence of TVR. Methods and Results We studied 234 patients in whom 1 or 2 stents were succ essfully deployed and ultrasound imaging performed after angiographic optim ization. End points included a visually estimated angiographic residual ste nosis <10% and ultrasound stent-to-mean reference lumen area >80%. After 2 years, TVR was required in 48 (20.5%) patients. Qualitative predictors of T VR were vein graft lesions, 3-vessel disease, and baseline TIMI flow grade <3. Quantitatively, reference diameter by quantitative coronary angiography (QCA), final minimum lumen diameter (MLD) by QCA, and in-stent minimum lum en area (MLA) by ultrasound were predictive of TVR. Stent-to-reference rati os were not significantly predictive of TVR. By multivariable analysis, vei n graft location and MLA by ultrasound were the only significant predictors of TVR (relative risk, 2.9 [1.5, 5.4] and 0.72 [0.6, 0.9], respectively). Receiver operator curves for MLD by QCA and MLA by ultrasound were similar in predicting TVR. Neither was significantly superior to reference vessel d iameter. Conclusions Commonly used angiographic and ultrasound stent-to-reference ra tios do not predict the incidence of TVR. Absolute measures of the lumen si ze (MLA by ultrasound and MLD by QCA) were the most important quantitative predictors of TVR within 2 years. This emphasizes the role of the vessel si ze as the limiting factor in determining the long-term outcome of coronary stenting.