Improvement of LV Function by a PET based Revascularization Strategy: A Prospective Randomized Comparison with SPECT

Abstract

Treatment of patients with coronary artery disease (CAD) and evidence of ischemia is an important clinical issue. Patients benefit from revascularization if viable or jeopardized myocardium is present. Various myocardial perfusion imaging techniques with different radioisotopes [thallium-201, ^99mTc (technetium-99m)-sestamibi, ¹³N (nitrogen-13)- ammonia, ¹⁸F-fluoro-deoxyglucose (FDG)] have been proven to delineate myocardium that shows functional recovery after revascularization ^1-9. Dobutamine stress echocardiography is also used to detect myocardium that could benefit from revascularization ¹⁰. However, for all these techniques varying numbers for sensitivity and specificity for recovery of left ventricular function are reported. This has also been demonstrated in a recent meta-analysis ¹¹. Stress/rest sestamibi single photon emission computed tomography (SPECT) imaging is a widely used technique to detect myocardial perfusion abnormalities. In revascularization strategies, sestamibi SPECT results are frequently used to demonstrate whether viable myocardium with stress induced ischemia is present. For prediction of recovery of left ventricular function good sensitivity and specificity have been reported ¹¹. Nitrogen-ammonia/FDG positron emission tomography (PET) myocardial perfusion imaging is used for detection of hibernating myocardium and/or stress induced ischemia. Since FDG imaging represents myocardial glucose metabolism, PET is thought to detect viability better than sestamibi SPECT. Moreover PET imaging has a higher resolution and higher energy emission voltage resulting in better image quality.