Incremental value of left ventricular ejection fraction for detection of multivessel coronary artery disease in exercise (201)Tl gated myocardial perfusion imaging

Assessment of reversible defects in exercise (201)Tl perfusion SPECT has low sensitivity and high specificity for detection of multivessel coronary artery disease (CAD). The goal of this study was to evaluate whether the left ventricular ejection fraction (LVEF) in exercise (201)Tl gated SPECT had incremental diagnostic value over perfusion data for detection of multivessel CAD. One hundred eighty-two patients underwent exercise (201)Tl gated SPECT. Automated LV function analysis software was used for calculation of the postexercise and the rest LVEF. The best threshold between 0- to 1-vessel CAD and 2- to 3-vessel CAD was determined as the cutoff that on receiver-operating-characteristic analysis resulted in the best sensitivity for detection of multivessel CAD with an associated specificity of >90%. Only 18 (26.9%) of 67 patients with multivessel CAD had reversible defects in multiple territories. Sensitivities of the postexercise and the rest LVEF and the worsening of the LVEF by exercise did not differ from those of perfusion data alone. Sensitivities of the combination of perfusion data and the postexercise and rest LVEF did not differ from those of perfusion data alone, whereas the sensitivity of the combination of perfusion data and worsening of the LVEF (i.e., reversible defects in multiple territories or worsening of the LVEF >5.6% [or both]) was significantly greater than that of perfusion data alone (43.3% vs. 26.9%; P < 0.05), with an acceptable level of specificity (90.4%). The worsening of the LVEF by exercise has the potential to detect patients with multivessel CAD among those without multivessel patterns of reversible defects.