Usefulness of Phase Analysis to Differentiate Ischemic and Non-Ischemic Etiologies of Left Ventricular Systolic Dysfunction in Patients With Heart Failure

Abstract

The detection of significant coronary artery disease (CAD) in patients with heart failure (HF) from left ventricular (LV) systolic dysfunction is crucial. We evaluated the usefulness of LV mechanical dyssynchrony as assessed by phase analysis compared with conventional gated single-photon emission computed tomography to identify ischemic etiology in patients with HF. Forty-one consecutive patients who were initially admitted to hospital due to HF resulting from systolic dysfunction were evaluated. All patients underwent cardiac catheterization. LV mechanical dyssynchrony was evaluated using SyncTool™ to obtain the phase SD and histogram bandwidth. The changes in phase SD and histogram bandwidth with stress were calculated. The summed stress score, summed difference score, and changes in phase SD and histogram bandwidth with stress were greater in 26 patients with CAD than in 15 patients without CAD (P=0.001 and P=0.01). On multivariate analysis a phase SD of >14° (odds ratio [OR], 16.7) and a summed stress score of >17 (OR, 8.0) best differentiated LV dysfunction of ischemic and non-ischemic etiologies, with a sensitivity of 89% and a specificity of 87% (χ(2)=20), compared with summed stress score only (sensitivity, 46%; specificity, 87%; χ(2)=4.5). The addition of phase analysis to conventional perfusion analysis enables better differentiation of the etiology of HF in patients with systolic dysfunction.