%0 Journal Article
%T Low Resolution Limits and Inaccurate Algorithms Decrease Significantly the Value of Late Loss in Current Drug-Eluting Stent Trials
%A Johannes B. Dahm
%A Frank van Buuren
%J International Journal of Vascular Medicine
%D 2012
%I Hindawi Publishing Corporation
%R 10.1155/2012/417250
%X Quantitative coronary and vascular angiography (QCA resp., QVA) remains the current gold standard for evaluation of restenosis. Late loss as one of the most commonly accepted parameters to highlight efficacy of the various devices has shown high correlation to clinical parameters but, surprisingly, has no impact on the evaluation of the remaining amount of restenostic tissue. The current clinical practice leads to unrealistic late loss calculations. Smaller late loss differences are usually not greater than the inherited resolution limits of QCA, which is especially the case in small differences between the various stents in the drug-eluting stent era. Late loss include additional systematic and random errors, due to the fact that measurements were taken at two different time points including the inherited resolution and calibration limits of QCA on two occasions. Due to the limited value of late loss in discriminating the small differences between the one and other DES, late lumen area loss and clearly defined calculation algorithms (e.g., MLD-relocation) should be used in future DES studies also to fulfill the more stringent regulatory requirements. 1. Text Endovascular therapy is a rapidly evolving field for the treatment of patients with peripheral arterial occlusive disease (PAOD) or coronary artery disease (CAD), and a magnitude of studies on technical improvements and innovative developments have been published during the last 15 to 20 years. Studies assessing endovascular therapy of peripheral or coronary arteries are tending to hover however on uniformly defined clinical and QCA-derived endpoints, which became clinical practice on the basis of positive correlations to clinical parameters over the last years. Although these QCA-derived parameters were predominantly used to reflect on the neointimal process and to predict restenosis, their values were never evaluated or validated independently. Unfortunately, in order to provide a comparison with the already published studies, most of the subsequently conducted studies used exactly the same QCA-derived study endpoints. Moreover, because the guideline-relevant studies are frequently based on exactly these QCA-derived study endpoints, not only the outcomes of the studies but also the guidelines themselves could therefore be biased by the limitations of these surrogate parameters described in this paper. In this paper we highlight the algorithm and limitations of late loss as one of the most frequently used QCA-derived surrogate study endpoint in the description of restenosis after interventional
%U http://www.hindawi.com/journals/ijvm/2012/417250/