Nuclear imaging techniques for the assessment of myocardial viability.
Regional and global left ventricular dysfunction caused by coronary artery disease may be reversible in a significant proportion of cases. This fact has important clinical implications. Apart from symptoms of angina and angiographic severity of coronary artery disease, potential for an improvement in left ventricular dysfunction should be taken into account when considering revascularization for the management of patients with coronary artery disease. Because left ventricular function is an important determinant of long-term prognosis in patients with coronary artery disease, identification and appropriate treatment of reversible left ventricular dysfunction may improve prognosis in many patients with significant left ventricular dysfunction. Table 1 describes the impact of myocardial viability in relation to the clinical objectives in various groups of patients with coronary artery disease. The choice of the optimal technique for the detection of myocardial viability is a matter of ongoing debate. There is no consensus in the literature for an optimal investigative approach to predict an improvement in left ventricular function following revascularization. Most of the studies in this field are based on small numbers of patients. Further studies in larger patient populations are needed. This debate is further complicated by the fact that none of the available technologies provides a quantitative estimate of viable myocardium or the extent of improvement that can be expected following revascularization. Currently the choice of technique depends on the clinical question to be answered, the local availability of the technique, and local expertise. Obviously, cost considerations may also play an important role in choice of technique. In patients with chronic stable coronary artery disease in whom reversibility of stress-induced perfusion abnormalities is the question, stress-redistribution-rest Tl-201 imaging may be the preferred modality. In patients with congestive heart failure, in whom reversibility of left ventricular function is the issue, PET imaging or rest Tl-201 imaging may provide the appropriate answer. In post-infarction patients, choice of test may depend on whether detection of residual ischemia or stunned myocardium is the issue.
Jain
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Section of Cardiovascular Medicine, Yale University School of Medicine, New Haven, CT 06510, USA.
Zaret
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BL
D000085:Acetates; D002250:Carbon Radioisotopes; D003327:Coronary Disease / Q000000981:diagnostic imaging*; D003847:Deoxyglucose / Q000031:analogs & derivatives; D004452:Echocardiography; D005260:Female; D005462:Fluorine Radioisotopes; D019788:Fluorodeoxyglucose F18; D006321:Heart / Q000000981:diagnostic imaging*; D006333:Heart Failure / Q000000981:diagnostic imaging*; D006801:Humans; D007457:Iodine Radioisotopes; D008297:Male; D017682:Myocardial Stunning / Q000000981:diagnostic imaging*; D013670:Sodium Pertechnetate Tc 99m; D013794:Thallium Radioisotopes; D014055:Tomography, Emission-Computed
D000085:Acetates; D002250:Carbon Radioisotopes; D005462:Fluorine Radioisotopes; D007457:Iodine Radioisotopes; D013794:Thallium Radioisotopes; D019788:Fluorodeoxyglucose F18; D003847:Deoxyglucose; D013670:Sodium Pertechnetate Tc 99m