Prognosis of Very Low Dose SPECT

Nuclear stress testing evaluates whether the heart receives enough blood, by injection of a
nuclear isotope during a stress on the heart that permits taking pictures of the heart
muscle. A low-radiation-dose protocol for nuclear stress testing involves injecting less of
the nuclear isotope than standard protocols, by utilizing a new, more efficient camera
(called an Alcyone camera) which could decrease radiation dose to patients while still
providing excellent clinical information. Subjects will undergo imaging under the Alcyone
camera after undergoing stress testing with exercise or a standard medication simulating
exercise, and then at rest if needed. Subjects will have follow-up to measure events
occurring after the test, such as death, heart attack, unstable angina, repeat emergency
department visit for chest pain evaluation, or repeat imaging needed to evaluation for
coronary artery disease. Radiation doses and quality of the images from the imaging with the
new protocol will be recorded to compare to those used in standard nuclear imaging
protocols. The primary study hypothesis is that greater than 90% of patients who have a
normal very low dose stress first myocardial perfusion scintigraphy (MPS) will be free at 3
months after study of death, nonfatal myocardial infarction, unstable angina, and repeat
emergency department visit for chest pain evaluation or repeat anatomical or functional
cardiac imaging.