Prediction of functional recovery in patients with chronic coronary arterydisease and left ventricular dysfunction combining the evaluation of myocardial perfusion and of contractile reserve using nitrate-enhanced technetium-99m sestamibi gated single-photon emission computed tomography and dobutamine stress

This study aimed to assess whether contractile reserve evaluation using dob utamine gated single-photon emission computed tomography (SPECT) improves t he capability of quantitative perfusion analysis to predict functional reco very of viable hibernating myocardium. Resting and dobutamine nitrate-enhan ced technetium-99m sestamibi (sestamibi) gated SPECI studies were performed in patients with coronary artery disease who had left ventricular dysfunct ion. Tracer activity was quantified, and wall motion and thickening visuall y scored. Reversible dysfunction wets identified with gated SPECT repeated after coronary revascularization. Using the best activity threshold, perfus ion quantification achieved 85% sensitivity and 55% specificity. Contractil e reserve detection was significantly less sensitive (64%, p < 0.0005), but more specific (88%, p < 0.00001) than perfusion quantification. However, i n the subgroup of hypokinetic segments, the sensitivity of contractile rese rve assessment was just slightly lower than perfusion quantification (72% v s 91%, p = NS), whereas specificity was significantly higher (94% vs 23%, p < 0.00001). Conversely, in the adyskinetic segments, perfusion quantificat ion was significantly more sensitive than contractile reserve (82% vs 59%, p < 0.005), but similarly specific (76% vs 85%, p = NS). Therefore, the ide ntification of reversible dysfunction based on perfusion quantification in adyskinetic segments and on contractile reserve detection in hypokinetic se gments was significantly more specific (83% vs 55%, p < 0.00001) than stand ard quantitative perfusion SPECT, without major loss in sensitivity (78% vs 85%, p = NS). In conclusion, contractile reserve evaluation using dobutami ne gated SPECT enhances the reliability of nitrate-enhanced sestamibi SPECT when used to predict reversible dysfunction in hypokinetic segments, where as perfusion quantification remains superior in adyskinetic segments. (C) 2 001 by Excerpta Medico, Inc.