21 January 2003
Chronic myocardial dysfunction, Dobutamine echocardiography, F-18 deoxyglucose, Positron emission tomography, Viability testing, Receiver-operating characteristic curve analysis, Single photon emission computed tomography, 99mTc sestamibi
Background: Currently, several modalities are available to predict viability, however, studies comparing various modalities validated by functional recovery after revascularization are scarce. This study analyzed the relative merits of low-dose dobutamine echocardiography, F-18 deoxyglucose (FDG) positron emission tomography (PET) and <sup>99m</sup>Tc sestamibi single-photon emission computed tomography to predict functional recovery after revascularization in patients with chronic myocardial infarction. Methods: Patients with chronic coronary occlusion (duration: 3.1 ± 4.8 years) and impaired left ventricular function (ejection fraction: 42 ± 13%) underwent low-dose dobutamine echocardiography (20 µg/kg/min), FDG-PET and <sup>99m</sup>Tc sestamibi imaging before revascularization. Revascularization was performed irrespective of any viability data. Follow-up angiography was obtained 4.8 ± 2.5 months after revascularization. Results: Viability analysis was performed in 34 patients with patent target vessel at follow-up, of whom 9 (27%) exhibited functional recovery on left ventricular angiography. For dobutamine echocardiography, improvement of ≧2 adjacent akinetic segments resulted in improved sensitivity of 89% and specificity of 80% to predict functional recovery. For glucose metabolism, FDG uptake >55% was an optimal threshold yielding a sensitivity of 89% and a specificity of 68%. With respect to perfusion, <sup>99m</sup>Tc sestamibi uptake >60% was the best cutoff resulting in a sensitivity and a specificity of 56 and 88%, respectively. A concordant match of FDG >55% and of <sup>99m</sup>Tc sestamibi >50% resulted in optimized sensitivity (78%) and specificity (80%) with dual imaging. Conclusions: Recovery of chronically dysfunctional myocardium can be predicted with high accuracy by stimulation of contractile reserve or by concordant match of preserved glucose metabolism and residual perfusion.