title: Comparison of adenosine and high-dose dipyridamole both combined with low-level exercise stress for 99Tcm-MIBI SPET myocardial perfusion imaging.
abstract: Intravenously administered adenosine and high-dose dipyridamole, both combined with low-level exercise stress, were compared in a head-to-head fashion using 99Tcm-methoxyisobutyl isonitrile (99Tcm-MIBI) single photo emission tomography (SPET) myocardial perfusion imaging. Thirty-nine consecutive patients who had undergone coronary arteriography underwent 99Tcm-MIBI (740 Mbq) SPET after dipyridamole (0.84 mg kg-1) and after adenosine (0.84 mg kg-1), both combined with low-level exercise (30 W load), and under resting conditions. Our results demonstrate that adenosine and dipyridamole combined with exercise have comparable haemodynamic effects, with a low incidence of side-effects. The time of recovery from the stress protocol was not significantly different: adenosine, 5.7 +/- 3.9 min; dipyridamole, 6.6 +/- 4.9 min. However, aminophylline was significantly (P < 0.05) more often administered to reverse side-effects using the dipyridamole protocol (36% of patients) compared with the adenosine protocol (8% of patients). The results of 99Tcm-MIBI SPET imaging were highly concordant and demonstrated a high diagnostic accuracy for identifying coronary artery disease (CAD). The sensitivity was 90% (95% confidence intervals 79-100%) with adenosine SPET and 93% (95% confidence intervals 84-100%) with dipyridamole SPET for identifying patients with CAD (i.e. luminal stenosis > 50%); their specificities were both 100% (95% confidence intervals 66-100%). The sensitivity of identifying angiographically diseased vessels was 81% (95% confidence intervals 70-92%) using adenosine SPET and 85% (95% confidence intervals 75-95%) using dipyridamole; the specificity for both stress modalities was 94% (95% confidence intervals 89-100%). The combination of exercise with adenosine and high-dose dipyridamole appears to be a feasible and safe method to alleviate some of the undesirable A1-receptor-mediated side-effects of adenosine. The choice of the pharmacological stress will depend on local expertise and availability.
authors.affiliation: Department of Cardiology, St Antonius Hospital, Nieuwegein, The Netherlands.
authors.forename: M J
authors.initials: MJ
authors.lastname: Cramer
authors.forename: J F
authors.initials: JF
authors.lastname: Verzijlbergen
authors.forename: E E
authors.initials: EE
authors.lastname: van der Wall
authors.forename: P H
authors.initials: PH
authors.lastname: Vermeersch
authors.forename: M G
authors.initials: MG
authors.lastname: Niemeyer
authors.forename: A H
authors.initials: AH
authors.lastname: Zwinderman
authors.forename: C A
authors.initials: CA
authors.lastname: Ascoop
authors.forename: E K
authors.initials: EK
authors.lastname: Pauwels
mesh_terms: D000241:Adenosine / Q000008:administration & dosage / Q000009:adverse effects; D000328:Adult; D000368:Aged; D002985:Clinical Protocols; D003327:Coronary Disease / Q000000981:diagnostic imaging; D004176:Dipyridamole / Q000008:administration & dosage / Q000009:adverse effects; D005080:Exercise Test / Q000009:adverse effects / Q000379:methods; D005260:Female; D006321:Heart / Q000000981:diagnostic imaging*; D006439:Hemodynamics / Q000187:drug effects; D006801:Humans; D007275:Injections, Intravenous; D008297:Male; D008875:Middle Aged; D012449:Safety; D017256:Technetium Tc 99m Sestamibi / Q000008:administration & dosage; D015899:Tomography, Emission-Computed, Single-Photon / Q000379:methods*; D014665:Vasodilator Agents / Q000008:administration & dosage / Q000009:adverse effects
chemical_list: D014665:Vasodilator Agents; D004176:Dipyridamole; D017256:Technetium Tc 99m Sestamibi; D000241:Adenosine