The identification of reversible dysfunctional myocardium is influenced by the severity of contractile dysfunction and by the length of follow-up

Objectives To evaluate the influence of the severity of regional myocardial dysfunction and of the length of follow-up on the identification of myocardial viability with rest-redistribution 201 Tl single photon emission computed tomography (SPECT) and low-dose dobutamine echocardiography (LDDE). Methods Twenty-six patients with chronic coronary artery disease and wall motion abnormalities, candidates for revascularization, were included in this study. All patients underwent, in the same week, 201 Tl SPECT and LDDE for pre-revascularization evaluation of myocardial viability. Reversibility of regional dysfunction was assessed by twodimensional echocardiography, 40±20 days (early follow-up) and 12±5 months (late follow-up) after revascularization. Results In a/dyskinetic segments, 201 Tl SPECT showed similar values of sensitivity (78% vs. 71%, P=NS) and slightly higher values of specificity (43% vs. 18%, P<0.01) compared to hypokinetic segments, in predicting functional recovery at early follow-up. No significant changes were observed in the diagnostic accuracy of 201 Tl SPECT at late follow-up. On the contrary, LDDE provided significantly lower values of sensitivity (56% vs. 94%, P<0.05) and higher values of specificity (73% vs. 9%, P<0.01) in