Adequate intracoronary adenosine doses to achieve maximum hyperaemia in coronary functional studies by pressure derived fractional flow reserve: a dose response study: Figure 1

Coronary pressure derived fractional flow reserve (FFR) is an increasingly used invasive index of the functional significance of coronary lesions. FFR expresses maximum achievable blood flow to the myocardium, supplied by a stenotic artery, as a fraction of normal maximum flow.1,2 Achievement of maximal hyperaemia is essential for calculation of FFR. Intracoronary adenosine is widely used to obtain maximal hyperaemia. Although standard doses of intracoronary adenosine to achieve maximal hyperaemia have been well established in previous studies3 (15–40 μg left coronary artery, 10–30 μg right coronary artery), doubts about maximal hyperaemia achieved with these doses have led to the empirical use of higher than standard doses in clinical practice.4,5 The aim of this study was to analyse the effects of incremental doses of intracoronary adenosine on FFR measurements. Patients with angiographically intermediate lesions (visual percentage diameter stenosis 50–75%) in a principal coronary artery and indication for study with pressure wire to determine functional significance of lesions were included. The study started on November 2001 and 50 lesions were prospectively and consecutively included. Informed consent was obtained from all patients. Coronary pressure measurements were performed using a 0.014 inch pressure guidewire (PressureWire, Radi Medical Systems, Uppsala, Sweden), according to a previously described technique.1 Special attention was …