Radionuclide cineangiography in acute myocardial infarction: role in prognostication

Radionuclide-based procedures have achieved frequent application in acute myocardial infarction (MI). While these methods can be employed in diagnosis and assessment of therapy, diagnosis usually can be made more easily and with less expense when other methods are employed. Assessment of therapy, while potentially of value, has not been evaluated in a manner which can provide practical guidelines for clinical application. Practical utility has been associated with the use of radionuclide-based techniques in prognostication after infarction; this application is crucial to the formulation and optimization of management decisions. While myocardial perfusion scintigraphy and infarct-avid-agent imaging have been employed in prognostication after infarction, the largest body of prognostic data are available in association with radionuclide cineangiography. When determined in the early hours after infarction, a left ventricular ejection fraction (LVEF) less than 30% indicates a high likelihood of in-hospital mortality, irrespective of the site of infarction. When determined shortly prior to hospital discharge, LVEF less than 30% indicates a high likelihood of posthospital mortality, perhaps as high as 25% during the first year, and reaching 30% by the end of 2 years after infarction. Conversely, LVEF greater than or equal to 30% indicates an 8% 2-year postinfarction mortality risk. While LVEF is a highly potent risk descriptor, considerable evidence suggests the LVEF determined during exercise prior to hospital discharge also provides risk stratification, and may be superior to, or at least additive to, LVEF at rest as a prognostic index.(ABSTRACT TRUNCATED AT 250 WORDS)