Positron emission tomography for myocardial viability assessment before myocardial revascularization in a patient with extremely impaired left ventricular systolic function – advanced diagnosis and therapy in heart failure

摘要

In patients with heart failure caused by coronary artery disease (CAD), assessment of myocardial viability and successful revascularization seems to be crucial to improve the function of the left ventricle. Importantly, available data are inconclusive regarding the usefulness of myocardial viability tests for the decision concerning revascularization in patients with left ventricular (LV) dysfunction and CAD [1]. Multiple observational studies have reported that viability imaging will be instrumental in such patients. However, data from prospective studies failed to confirm that [2]. A 55-year-old man, a former smoker with a history of CAD and arterial hypertension, was admitted to our department to assess myocardial viability and the possibility of coronary revascularization. Two years before, he suffered from ST-segment elevation myocardial infarction of the antero-lateral wall successfully treated with percutaneous coronary intervention (PCI) of the left anterior descending artery (LAD). Six months prior to admission the patient was hospitalized again at another ward due to unstable angina and underwent PCI of the right coronary artery. In the coronary angiogram ostial left circumflex artery (Cx) stenosis was found (Figure 1A). The patient reported symptoms of chronic heart failure (NYHA class III) and angina (CCS class II) with marked limitation of activities during normal exertion, with no symptoms at rest. The echocardiography showed severe systolic dysfunction of the LV with LV ejection fraction of 13%, akinesis with thinning of the medial segment of lateral wall, akinesis of the septum, 2/3 distal of the anterior and posterior walls and significant hypokinesis of the inferior wall and basal segments of the posterior and anterior walls of the LV. No significant valvular disease was revealed. Dobutamine stress echocardiography (DSE) (15 μg/kg/min) did not confirm the presence of contractile reserve of the LV. However, due to symptoms of angina the diagnostics were expanded by single-photon emission computed tomography (SPECT) and F18-fluorodeoxyglucose positron emission tomography (PET). The SPECT examination, using technetium-99m sestamibi, was performed. The level of the pharmaceutical agent uptake at rest in the lateral wall (more than 50% of maximal uptake) suggested preserved viability. The patient exercised on the treadmill to a maximum load of 7.9 MET. After exercise, the examination revealed evidence of a transient perfusion defect... View full text...