Does myocardial perfusion imaging provide incremental prognostic information to left ventricular ejection fraction?

Cardiac nuclear imaging studies such as gated single photon emission computed tomography can offer assessment of myocardial perfusion and ventricular function. These two types of data can provide valuable information for the diagnosis of coronary artery disease, prognosis, and optimal treatment strategies. Ejection fraction and other measures of ventricular function generally are the best predictors of mortality, whereas perfusion parameters and estimates of ischemic burden are often the best predictors of nonfatal cardiac events and response to revascularization; the combination of both can provide increased sensitivity and specificity for diagnosis of significant coronary disease, and increased predictive power for outcomes. Recent data show that together they also add incremental value in predicting sudden cardiac death. Less commonly used modalities such as positron emission tomography may offer additional tools for quantification of perfusion and function at rest and at stress, with important clinical implications.