Abstract 11269: Uridine Triphosphate More Accurately Estimates Fractional Flow Reserve in Humans
Background_ Fractional flow reserve (FFR) is a highly recommended diagnostic method to guide stent treatment. Adenosine (ADO) is the preferred pharmacologic vasodilator agent for the measurement of FFR, but its use is associated with many side effects and contraindications due to its widespread receptor stimulation, limiting the method's clinical application. Furthermore, ADO may not induce maximal hyperemia which is crucial for the estimation of an accurate FFR. We therefore investigated whether the receptor-selective and potent vasodilator Uridine triphosphate (UTP) was more effective with regards to lowering FFR in comparison to ADO during intracoronary infusion.
Methods and Results_ We studied 43 patients scheduled for percutanous coronary intervention (PCI). A pressure/flow wire was inserted across the stenotic lesion. FFR was measured at steady-state hyperemia. Equimolar concentrations of ADO(240 + 360 µg/min) and UTP were infused intracoronarily in randomized order via the guiding catheter. In ∼10 patients, a dose response curve (40, 80,160 and 320 µg/min) was performed. FFR was lower during UTP vs. ADO infusion during 240 µg/min 0.75±0.16 vs. 0.78±0.16 (P<0.05) (n=21) respectively, but not during 360 µg/min (n=11). During the incremental dose response, the concentration of 160 µg/min produced the lowest FFR for both drugs, but UTP had a lower FFR (0.79±0.11 vs. 0.82±0.13, P<0.05). Thus, when using the current cut-off FFR level of 0.8 for guiding treatment over a wide dose response range, UTP was superior to ADO in detecting significant coronary artery disease (59% vs. 39%, respectively (P<0.05)). Furthermore, three patients experienced side effects during ADO infusion, but no patients had side effects during UTP infusion.
Conclusions_ Intracoronary UTP infusion is safe and a more effective pharmacological agent to induce maximal coronary hyperemia and thus for correct measurements of FFR. This leads to a diagnostic advantage for the clinicians in the PCI lab as more patients may be correctly diagnosed and with limited side effects.
- © 2011 by American Heart Association, Inc.