In patients with coronary artery disease and left ventricular dysfunction, quantified sestamibi activity 1 hour after rest injection parallels redistribution 201Tl activity after a resting injection, suggesting that uptake and subsequent handling of sestamibi are more complex than can be explained by a pure flow tracer with no redistribution. Quantitative analysis of regional activities of both 201Tl and sestamibi after resting injections can differentiate viable from nonviable myocardium, and the two agents comparably predict reversibility of significant regional wall motion abnormalities after revascularization in such patients to a similar degree.

and adenosine cause frequent side effects as a result of nonspecific adenosine receptor stimulation. Selective agonism of the adenosine A 2A receptor should result in a similar degree of coronary vasodilation (and thus similar perfusion images) with fewer side effects. Methods and Results-In a multicenter, randomized, single-blind, 2-arm crossover trial, 240 patients underwent 2 single photon emission computed tomographic (SPECT) imaging studies in random order, first after pharmacological stress with adenosine and a second study with the selective adenosine A 2A receptor agonist binodenoson, using 1 of 4 dosing regimens. Safety, tolerability, and SPECT image concordance between the 2 agents were examined. Exact categorical agreement in the extent and severity of reversible perfusion defects ranged from 79% to 87%, with kappa values from 0.69 to 0.85, indicating very good to excellent agreement between binodenoson and adenosine. The risk of any safety event/side effect was significantly lower with any dose of binodenoson than with adenosine (PՅ0.01) because of a dose-related reduction in subjective side effects, as objective events were infrequent. There was a reduction in the severity of chest pain, dyspnea, and flushing in all binodenoson doses compared with adenosine (PϽ0.01), and the magnitude of severity reduction was dose-related. Conclusions-The

These data demonstrate the durable efficacy and safety of E-ZES compared with PES for the treatment of de novo coronary lesions. Significant improvements in late safety outcomes were observed with E-ZES but should be considered hypothesis-generating, given the limited statistical power of the trial. (The ENDEAVOR IV Clinical Trial: A Trial of a Coronary Stent System in Coronary Artery Lesions; NCT00217269).