Pharmacologic Stressors in Coronary Artery Disease

The use of pharmacologic agents to stress patients who are unsuitable for maximal exercise stress has evolved into an essential clinical tool for the diagnosis of coronary artery disease (CAD) and for noninvasive cardiac risk assessment. The initial administration of a drug to create differential coronary hyperemia (using oral then intravenous dipyridamole), as an adjunct to planar 201Tl myocardial perfusion imaging for the diagnosis of CAD in stable patients, has been extended to include the following: use with single photon and positron nuclear tomography, 2-D echocardiography, and MRI; use with 99mTc-labeled myocardial radiotracers (sestamibi, tetrofosmin, etc.); Food and Drug Administration-approved indication for the definition of the risk of future cardiac events (ie, prognosis); development of short-acting, highly specific hyperemic agents (adenosine and its analogues); use of catecholamine infusion in patients with contraindications to hyperemic agents (dobutamine, arbutamine); protocols combining drug stress with submaximal exercise stress (isometric or dynamic); and safe use early after uncomplicated acute coronary syndromes (unstable angina, myocardial infarction).