Diagnostic value of left ventricular function after adenosine triphosphate loading and at rest in the detection of multi-vessel coronary artery disease using myocardial perfusion imaging

Background. Although transient left ventricular (LV) dilation is a well-known marker for extensive coronary artery disease (CAD), few studies performed quantitative analysis of LV function of post adenosine triphosphate (ATP) stress and at rest to detect extensive CAD. Methods. One hundred nineteen patients with suspected CAD underwent post-stress and resting gated single-photon emission computed tomography (SPECT). Myocardial perfusion was assessed with a 20-segment model, and the changes in LV volume and function with ATP were analyzed. In addition, the stress-induced volume ratio (SIVR), defined as stress-to-rest ratios (end-systolic volume x 5 + end-diastolic volume), was calculated. All the patients underwent coronary angiography within 3 months of gated SPECT. Results. In the 62 patients with multi-vessel CAD, the summed stress score (SSS) (16.6 +/- 8.7 vs 11.5 +/- 9.1; P <.002), summed difference score (SDS) (9.6 +/- 5.8 vs 3.9 +/- 4.2; P <.0001), the post-stress increase in end-diastolic volume (EDV) (7.7 +/- 7.9 vs 2.2 +/- 5.3 mL; P <.0001), the post-stress increase in end-systolic volume (ESV) (9.4 +/- 6.0 vs 2.7 +/- 4.0 mL; P <.0001), and the (SIVR) (1.21 +/- 0.14 vs 1.06 +/- 0.10; P <.0001) were greater than in the 57 patients with insignificant or single-vessel CAD, whereas the post-stress increase in ejection fraction (EF) was less (26.0 +/- 4.9 vs 22.0 +/- 4.4%; P <.0001). In the detection of multi-vessel CAD, an SSS of 14 and an SDS of 9 showed sensitivities of 57% and 52%, respectively, and specificities of 63% and 88%, respectively, while increase in EDV of >= 6 mL, increase in ESV of >= 6 mL, decrease in EF of >= 5% after stress, and SIVR of >= 1.13 demonstrated sensitivities of 60%, 81%, 60%, and 74% and specificities of 74%, 77%, 77%, and 79%, respectively. The multivariate discriminant analysis revealed that the combination of post-stress increase in ESV and the SDS best identified multi-vessel CAD, with 81% sensitivity and 77% specificity (chi(2)= 63.6), whereas the SDS alone showed 52% sensitivity and 88% specificity (chi(2)= 22.4). Conclusions. The addition of "post-ATP stress'' and "at rest'' LV functional analysis using gated SPECT to conventional perfusion analysis helps to better identify patients with multi-vessel CAD. (J Nucl Cardiol 2009; 16: 20-7)