F18-fluorodeoxglucose single-photon emission computed tomography predicts functional outcome of dyssynergic myocardium after surgical revascularization

Background. Prediction of functional recovery after revascularization is possible with positron emission tomography and F18-fluorodeoxyglucose (FDG). Recently, the use of FDG in combination with single-photon emission computed tomography (SPECT), with 511 keV collimators, has been proposed to allow more widespread use of FDG. In the current study we aimed to predict improvement of regional left ventricular function after surgical revascularization with FDG and SPECT. Methods and Results. Twenty-seven patients with regional wall motion abnormalities (on echocardiography) underwent early thallium-201 (Tl-201) SPECT to assess perfusion and FDG SPECT to assess regional glucose uptake. The left ventricular myocardium was divided into 13 segments. For each segment, tracer uptake was evaluated visually (with the use of a 4-point scoring system) by consensus of two observers. Myocardial viability was determined in dyssynergic segments on echocardiography and defined as normal perfusion or increased FDG uptake in a perfusion defect (mismatch). Absence of viability was defined as a perfusion defect without increased FDG uptake (match). Improvement of regional wall motion was assessed 3 months after revascularization. In the group of segments that were viable on FDG/Tl-201 SPECT (n = 64), the segmental wall motion score decreased from 1.4 ± 0.5 to 0.6 ± 0.7 (p < 0.01), whereas the segmental wall motion score remained unchanged in nonviable segments (n = 72): 1.6 ± 0.5 versus 1.5 ± 0.6 (not significant). Forty-six (72%) of the 64 segments that were viable on FDG/Tl-201 SPECT demonstrated improved contractile function after coronary revascularization. In contrast, only 7 (10%) of 72 nonviable segments on FDG/Tl-201 SPECT showed improvement in function after revascularization (p < 0.01 versus viable segments). The sensitivity, specificity, and positive and negative predictive values were 87%, 78%, 72%, and 90%, respectively. Conclusion. This study shows that FDG/Tl-201 SPECT can identify patients who improve in regional ventricular function after revascularization