Pharmacologic stress radionuclide myocardial perfusion imaging in the diagnosis and prognosis of coronary heart disease

INTRODUCTION

Stress radionuclide myocardial perfusion imaging (MPI) can, via the presence and extent of perfusion defects, be used to demonstrate the presence of coronary disease and to risk stratify and guide management of patients with known disease. Treadmill or bicycle exercise is the preferred form of stress for patients who can attain an adequate level of exercise (defined as ≥85 of their predicted maximal heart rate) because it provides the most information concerning patient symptoms, cardiovascular function, and the hemodynamic response during usual forms of activity [1-3]. The inability to perform an exercise test is itself a negative prognostic factor in patients with coronary heart disease (CHD). (See "Exercise ECG testing to determine prognosis of coronary heart disease", section on 'Exercise capacity' and "Exercise radionuclide myocardial perfusion imaging in the diagnosis and prognosis of coronary heart disease".)

However, many patients (particularly those who are elderly) are unable to exercise to an adequate level or have contraindications to such testing. Inadequate exercise may lead to an underestimation of the presence and/or severity of CHD. In addition to reducing symptoms and electrocardiographic (ECG) changes, submaximal exercise may reduce the diagnostic accuracy of exercise rMPI [4,5].

The clinical use of pharmacologic stress rMPI for the diagnosis of CHD, for prognosis, and for use in specific settings will be reviewed here. Issues specific to the different pharmacologic agents, such as study protocol, safety, contraindications, and drug interactions, are discussed separately. (See "Pharmacologic stress radionuclide myocardial perfusion imaging: Testing methodologies and safety".)

Pharmacologic stress echocardiography and general discussions on the use of stress testing for the diagnosis and prognosis of known or suspected CHD, including its prognostic role after an acute coronary syndrome or revascularization, and the advantages and limitations of the different stress tests are also discussed elsewhere. (See "Stress echocardiography in the diagnosis and prognosis of coronary heart disease" and "Stress testing for the diagnosis of coronary heart disease" and "Stress testing to determine prognosis and management of patients with known or suspected coronary heart disease" and "Role of stress testing after coronary revascularization" and "Advantages and limitations of different stress testing modalities".)

CHOICE OF TEST MODALITY

The choice among the different types of stress tests is based upon the patient's ability to exercise to a level high enough to produce meaningful results on exercise ECG testing, the possible presence of baseline electrocardiographic abnormalities that could interfere with the interpretation of exercise ECG testing, and whether or not it is important to localize ischemia or assess myocardial viability (algorithm 1 and algorithm 2). As noted above, treadmill or bicycle exercise is the preferred stress in patients who are able to exercise [1-3].