Angiografia versus fluxo fracionado de reserva na avaliação do grau de importância das estenoses coronárias

Abstract

Angiography versus Fractional Flow Reserve in the Evaluation of Coronary Stenoses Introduction: In complex coronary artery disease, it is sometimes difficult to determine which lesions are associated with reversible ischemia. Despite this, the selection of lesions to be stented is often based on the subjectively interpreted angiogram alone. Fractional flow reserve (FFR) is an established objective methodology to indicate which lesions are ischemia-producing. Objective: The aim of this study, in patients admitted for elective percutaneous coronary intervention (PCI), was to evaluate the accuracy of angiography in defining culprit lesions, taking FFR as the gold standard, and also its correlation with FFR. Methods: Two hundred and fifty consecutive patients (471 arteries) scheduled for PCI were included in this study. All stenoses ≥ 50% by visual estimation, initially selected to be stented by 3 independent reviewers were assessed by measurement of the FFR. When the FFR was < 0.75, stenting was performed; when the FFR was ≥ 0.75, no interventional treatment was given. Offline quantitative coronary angiography (QCA) was performed for all stenoses, divided into intermediate (< 70%-327) and severe (125). The correlation coefficient between the degree of stenosis (%DS) and FFR was determined as was the accuracy of the visual assessment of angiography in evaluating ischemia taking FFR as the gold standard. Results: Optimal FFR readings were obtained in 452 lesions (96%). %DS and FFR were 56 ± 8% and 0.74 for moderate and 76 ± 6% and 0.49 for severe stenosis. Concordance between QCA and FFR was poor especially in intermediate stenosis (Spearman's rho =-0.33, p<.0001). Visual assessment resulted in accuracies of 57% and 96% for intermediate and severe lesions, respectively. Conclusions: Thus, neither visual assessment of an angiogram nor QCA can accurately predict the significance of most intermediate coronary stenoses, stressing the importance of associating these to a functional evaluation of the coronary circulation which can correctly guide treatment of stenosis.