Comparison of adenosine triphosphate and dipyridamole in diagnosis by thallium-201 myocardial scintigraphy.

ABSTRACT

UNLABELLED We examined whether 201Tl myocardial scintigraphy with intravenous infusion of adenosine triphosphate (ATP) can be substituted for dipyridamole (DIP) in the diagnosis of coronary artery disease CAD). METHODS: The coronary flow reserve (CFR) during intravenous infusion of ATP (0.10-0.20 mg/kg/min) was compared with that during intravenous infusion of DIP (0.56 mg/kg) using a Doppler flow wire in 19 subjects with normal coronary arteries. The highest CFR level was found in the ATP dose range of 0.16-0.20 mg/kg/min. The CFR at the ATP dose of 0.16 mg/kg/min was significantly higher than that during DIP infusion (4.2 versus 3.6) (p < 0.01), for which reason we adopted this dose of ATP. According, 201Tl SPECT in 140 patients with suspected CAD was performed after infusion of 0.16 mg/kg/min of ATP in 70 of them and 0.56 mg/kg of DIP in the 70 others. RESULTS: ATP stress 201Tl SPECT showed no significant difference in sensitivity and accuracy from DIP stress 201Tl SPECT (87.0% versus 82.9, and 87.1% versus 78.6, respectively). Adverse effects occurred at higher frequency when ATP was used, but they were mild and disappeared rapidly after administration was stopped. CONCLUSION: ATP stress 201Tl SPECT is accurate and safe. The optimal ATP regimen for this purpose is considered to be a 5-min infusion at 0.16 mg/kg/min. However, our data in CAD patients suggest that ATP stress 201Tl SPECT is equivalent to DIP stress 201Tl SPECT in the detection of CAD.