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Four- versus 6-minute infusion protocol for adenosine thallium-201 single photon emission computed tomography imaging

1995; Elsevier BV; Volume: 129; Issue: 3 Linguagem: Inglês

10.1016/0002-8703(95)90272-4

1097-6744

James H. O’Keefe, Timothy M. Bateman, Larry R. Handlin, Carrie Barnhart,

Acute Myocardial Infarction Research

Intravenous adenosine infusion results in immediate maximal coronary arteriolar vasodilatation. Side effects occur in most patients who receive adenosine. For these reasons, a shorter infusion for pharmacologic stress thallium-201 testing may improve patient tolerability without compromising diagnostic accuracy. In a retrospective, unblinded evaluation, we compared side effects and accuracy of a standard 6-minute adenosine infusion single photon emission computed tomography (SPECT) study with a 4-minute protocol in 730 and 621 patients, respectively. Adenosine was infused at 140 μg/kg/minute in both groups; thallium-201 was injected at the 3-minute mark oof the 4-minute protocol and at the 4-minute mark of the 6-minute protocol. Angiographic follow-up (mean 8 days) after thallium-201 testing was available in 233 (32%) of the patients in the 6-minute protocol and in 174 (28%) of the patients in the 4-minute protocol (p not significant (NS). Side effects occurred in 90% of the patients in the 6-minute protocol and in 91% of the patients in the 4-minute protocol (p = NS). Premature termination of the infusion was required in 4% of the patients in the 6-minute protocol and 2% of the patients in the 4-minute protocol (p = 0.02). Second- or third-degree atrioventricular block was noted in 4.5% and 3.0% of the 6- and 4=minute groups, respectively (p = NS). The duration of symptoms averaged 2.9 ± 4.4 minutes in the patients in the 6-min protocol and 2.1 ± 1.6 minutes in the patients in the 4-minute protocol (p < 0.05). Diagnostic accuracies of the two protocols were virtually identical: 93% for the 6-minute versus 92% for the 4-minute protocol (p = NS). Correct localization of disease in the three major epicardial coronary distributions was equivalent with the two protocols. In conclusion, the four-minute adenosine SPECT protocola was as accurate as and was better tolerated and safer than the traditional 6-minute protocol.