Current advances in vasodilator pharmacological stress perfusion imaging.

More than 7 million stress perfusion studies are performed in the United States annually, 44% with pharmacological vasodilator stress agents. Both adenosine and dipyridamole are nonselective coronary vasodilators that are commonly used for stress perfusion imaging. These agents are safe and provide an effective means to diagnose coronary artery disease. A newer agent, regadenoson, is an adenosine receptor agonist that is selective for coronary vasodilation. Regadenoson is noninferior to adenosine for the detection of ischemia and is better tolerated by patients. Recent trials such as INSPIRE (Adenosine Sestamibi Post-Infarction Evaluation) and the COURAGE (Results from Clinical Outcomes Utilizing Revascularization and Aggressive Guideline-driven Drug Evaluation) Nuclear Imaging Substudy have established clearly that noninvasive risk stratification with vasodilator testing is an important and appropriate step in guiding medical therapy and invasive coronary intervention.