Z-score of Mitral Annular Plane Systolic Excursion is a Useful Indicator of Evaluation of Left Ventricular Function in Patients with Acute-Phase Kawasaki Disease

We previously reported the clinical usefulness of the mitral annular plane systolic excursion (MAPSE) to evaluate the left ventricular (LV) function in patients with Kawasaki disease (KD) in the acute-phase. However, the feasibility of the MAPSE z-score has not been evaluated in patients with acute KD. We prospectively studied 60 KD patients without coronary aneurysms. The MAPSE z-scores were calculated using our standard MAPSE data. Brain natriuretic peptide (BNP) was measured as a parameter of LV function. In total, 281 healthy age- and body size-matched subjects were chosen as the control group. The MAPSE z-score decreased in the acute-phase (median value, −1.4) and increased in the convalescent phase (median value, 0.18; P < 0.0001). However, there was no significant difference in the MAPSE z-score between patients in the convalescent phase and the control patients (0.18 vs. 0.02, P = 0.199). Multivariate regression analysis revealed that BNP was an independent predictor of the MAPSE z-score (β = 0.40, P < 0.005). According to the receiver operating characteristic (ROC) analysis, the optimal cutoff value for the MAPSE z-score to judge LV dysfunction was −0.9. The MAPSE z-score is a useful index to evaluate LV function, and the cutoff value of −0.9 can be an indicator to judge LV dysfunction in the patients with acute-phase KD.