Prognostic significance of tissue Doppler imaging-derived myocardial performance index in pediatric patients with dilated cardiomyopathy

TDI-MPI has been shown to predict cardiovascular mortality in adults; there are a paucity of data on its use in children. We sought to determine the prognostic significance of TDI-MPI at time of DCM diagnosis in children. Patients aged <= 18 years diagnosed with DCM were included along with age- and sex-matched controls. Echo at diagnosis was analyzed to obtain standard measures of LV function, PW-MPI, and septal and LV free wall TDI-MPI. Survival analysis was used to assess the time to composite outcome of death, VAD, or transplant, stratified by TDI-MPI z-score. The study included 79 patients with DCM and 79 controls. During a median follow-up of 182 days (IQR 41-815 days), 16 underwent VAD placement, 21 underwent cardiac transplant, 6 died, and 36 had event-free survival. The median septal TDI-MPI for cases was 0.70 for patients with DCM vs 0.45 for controls (P < .001). Those with septal TDI-MPI z-scores >= 2 develop events significantly earlier than those with z-score <2 (P = .014). In multivariable analysis, TDI-MPI z-score >= 2 was significantly associated with poor outcomes (HR 2.12, 95% CI 1.06-4.23). TDI-MPI can be reliably performed in pediatric patients with DCM. A TDI-MPI z-score >= 2 at diagnosis may be associated with earlier poor outcome. Further studies evaluating the use of TDI-MPI in longitudinal follow-up of patients with DCM may be helpful in refining its clinical use.