Background: Vascular wall shear stress (WSS) has been implied in the pathogenesis of atherosclerosis and vascular remodeling. Our aim was to calculate WSS after balloon angioplasty and evaluate its predictive value for long-term outcome.
Methods: WSS was calculated proximal to, in, and distal to the lesion after angiographically successful balloon dilatation and at follow-up with the Hagen-Poiseuille formula (WSS = 4 microQ/piR3) in 202 patients. Volumetric blood flow (Q) and lumen radius (R) were derived from Doppler scanning velocities and videodensitometric cross-sectional areas.
Results: Postprocedural proximal and in-lesion values were higher in vessels that developed restenosis (n = 72; 1.22 +/- 0.61 N/m2 and 3.61 +/- 2.38 N/m2, respectively) than in those without restenosis (n = 130, 1.05 +/- 0.51 N/m2 and 2.46 +/- 1.39 N/m2, respectively; P <.05). In-lesion WSS was revealed to be predictive of restenosis by means of logistic regression analysis (odds ratio [OR] = 1.42, P <.05), whereas WSS of the proximal segment was associated with an increased rate of target lesion revascularization (OR = 2.33, P <.005). In the multivariate regression model, WSS of the proximal segment was the only independent predictor when entered with known predictors such as diameter stenosis and coronary flow reserve (OR = 2.15, P <.05).
Conclusions: WSS in the lesion after balloon angioplasty is predictive of angiographic restenosis. Moreover, the proximal value is an independent predictor of target lesion revascularization. This study opens perspectives for the on-line use of WSS as a combined parameter of anatomy and physiology to assess the necessity of adjunctive therapy after successful balloon dilatation.