In this article van't Veer et al .1 present a comprehensive and detailed study comparing the haemodynamic characteristics of drug-eluting stents (DES) with those obtained by conventional bare metal stents (BMS). After DES, long-term physiological parameters including fractional flow reserve (FFR), hyperaemic gradient, and wall shear stress (WSS) were superior to those found in equivalent BMS implanted in the same patients.1 Although these findings are of major interest, most of the new information provided could be perceived as well expected considering the large body of evidence demonstrating the superb late results after DES implantation. Nevertheless, as will be highlighted in this editorial, some study findings and their potential implications are rather provocative . Furthermore, on the basis of their results, these investigators from the Catharina Hospital (Eindhoven)1 dare to challenge some widely accepted strategies in the management of patients with diffuse coronary artery disease (CAD). Previous land-mark studies from the same group have unequivocally established the superiority of FFR over conventional angiography to assess the functional severity of coronary stenosis.2 Even intravascular ultrasound (IVUS), able to provide a thorough anatomic coronary assessment, can only be used as a surrogate of lesion physiology.3 Large-scale serial morphological studies have consistently demonstrated the unique ability of DES to prevent restenosis and to inhibit neointimal proliferation. However, functional studies after DES implantation using direct haemodynamic assessment are scarce.4,5 The elegant study of van't Veer et al .,1 assessing FFR, stent-induced gradients, Doppler-derived intracoronary velocities, and WSS, fills the gap in our understanding of DES influence on coronary physiology. The study design, randomly allocating in pairs DES and BMS in well-selected matched lesions of patients with two-vessel disease, circumvents the potential confounding influence of systemic and anatomic factors on outcome measures. This sound methodology enables to obtain meaningful … *Corresponding author: Cardiologia Intervencionista, Instituto Cardiovascular, Hospital Universitario Clinico San Carlos, Plaza de Cristo Rey, Madrid 28040, Spain. Tel: +3491 3303289; fax: +3491 3303289. E-mail address : falf{at}hotmail.com