Myocardial viability: What do we need?

Abstract

Coronary revascularization in patients with chronic coronary heart disease (CHD) or acute myocardial infarction (AMI) is mainly based on factors such as coronary anatomy, ventricular function, accompanying diseases and the patient's biological age. Rest- or exercise-induced ischaemia should be proven before a bypass operation or percutaneous transluminal coronary angioplasty. Although a significant amount of ischaemic but still viable myocardium is a necessary condition for successful revascularization, the detection of viable myocardium is of major importance in a rather small subset of patients. These are patients with hibernating (or a combination of hibernating and stunned) myocardium in whom the aforementioned parameters do not yield an unequivocal result. Thallium-201 myocardial scintigraphy with re-injection or rest-redistribution is an established, proven and cost-effective way of detecting viable myocardium. Other methods such as positron emission tomography with different tracers or technetium-99m sestamibi SPET are discussed and compared to thallium-201 SPET. In conclusion, the detection of ischaemic but still viable myocardium is of importance in only a rather small subset of patients with CHD. In this context thallium-201 myocardial SPET is and still remains the method of choice.

Highlights of the annual meeting of the European Association of Nuclear Medicine, Lausanne 1993

“…An alternative was Amrinone-Echo, which correlated with dipyridamole 99~Tc-MIBI studies (*375). For 2°1T1, it is generally agreed that stress-reinjection is superior to stress-redistribution [16,17]. A 33% increase in viability in 175 patients was shown by Rioja (*202).…”

MR Contrast Agents for Cardiac Imaging

“…In nuclear scintigraphic tomography, active uptake of radioactive thallium-201 ( 201 Tl) as a potassium analog (Schoeder et al 1993), and manganese 52 m ( 52m Mn) and manganese 54 ( 54 Mn) as calcium antagonists (Chauncey et al 1977;Atkins et al 1979) by viable myocytes has been applied for assessment of myocardial viability (MV). Similar approach has been adopted in cardiac MRI using cold cation Mn 2+ preparations as intracellular contrast agents for infarct imaging, since Mn 2+ is potent for T1 shortening and is taken up only in cells capable of active calcium (Ca 2+ ) transport, and thereby provides an analog to 201 Tl imaging in cardiac scintigraphy (Bremerich et al 2000;Karlsson et al 2001;Flacke et al 2003;Storey et al 2003;Krombach et al 2004).…”

Thallium and indium antimyosin dual-isotope single-photon emission tomography in acute myocardial infarction to identify patients at further ischaemic risk

“…However, in accordance with the relevant guidelines [41,42], this procedure was performed in only two patients because of discordance between (a) coronary angiography and dual-isotope SPET pattern and (b) results of thallium exercise study. Both patients had a further, significant fill-in of 2°~T1 after reinjection.…”

“…Today thallium scintigraphy with re-injection remains the easiest and a cost-effective method of detecting viable myocardium [34,41,42]. Dual-isotope imaging, on the other hand, is far from being a universal approach to answer this question.…”