Diagnostic value of left ventricular dyssynchrony in patients with multivessel coronary artery disease and its impact on detecting patients with reduced left ventricular ejection fraction.

There are no reports on the diagnostic value of left ventricular (LV) mechanical dyssynchrony, including phase entropy, in Japanese patients with multivessel coronary artery disease (CAD), nor on the difference in added value compared to conventional perfusion analysis. The study examined 969 patients with known or suspected CAD who underwent rest 201Tl and stress 99mTc-tetrofosmin electrocardiogram (ECG)-gated single-photon emission computed tomography (SPECT) myocardial perfusion imaging (MPI) and coronary angiography (CAG) within a three-month period. Of these patients, 86 had no significant coronary artery stenosis and normal SPECT MPI findings, while 883 had significant coronary artery stenosis of 75% or greater based on CAG results. We excluded patients undergoing revascularization within 3 months before the SPECT and those with non-sinus rhythm. Poststress phase standard deviation (SD), bandwidth, and entropy were calculated by phase analysis using Heart Risk View-F software. Patients with stenotic lesions detected by CAG were classified as having 1-vessel CAD (n = 266), 2-vessel CAD (n = 268), and 3-vessel or left main CAD (n = 349). Two-vessel CAD or greater was defined as multivessel CAD. Multivariate analysis showed that estimated glomerular filtration rate (eGFR), summed difference score, stress LV ejection fraction (EF) and, stress phase entropy were independent predictors of multivessel CAD. The results of the receiver operating characteristic (ROC) analysis on the diagnostic accuracy of multivessel CAD using phase variables showed that all phase variables were useful, particularly for detecting multivessel CAD with LVEF < 40%. The global chi-squared value for detecting multivessel CAD was highest in the model adding entropy to clinical factors and the summed stress score, showing a significant improvement compared to models adding phase SD or bandwidth in patients with LVEF < 40%. LV mechanical dyssynchrony indices were useful in detecting multivessel CAD in Japanese patients, and stress phase entropy was an independent predictor. Combining these indices with perfusion analysis could potentially improve diagnostic accuracy, particularly in patients with reduced LVEF who have poor prognosis.