Prognostic Implications of the Systolic To Diastolic Duration Ratio in Children with Idiopathic or Familial Dilated Cardiomyopathy
Background—Childhood dilated cardiomyopathy (DCM) carries high morbidity and mortality. The echocardiographic systolic: diastolic (S:D) duration ratio, an indicator of global cardiac performance, is elevated in DCM; however, its prognostic implications have not been investigated in this population.
Methods and Results—We investigated systolic and diastolic durations and the resultant S:D ratio using pulsed tissue Doppler imaging (TDI) in children with idiopathic or familial DCM. We studied serial echocardiograms from presentation until the last follow-up echo. Results were compared to heart-rate matched controls and between DCM sub-groups based on an acute or insidious presentation. The association between S:D ratio and death or need for transplant was analyzed. All analyses were adjusted for repeated measures per patient. We studied 200 serial echocardiograms of 48 children with DCM (7.0±6.0 years) and 25 controls. Adjusted for repeated measures through an compound symmetry covariance structure the S:D ratio was higher in DCM patients (EST: -0.425 (0.072), p<0.001)) due to shortened diastole. A S:D ratio >1.2, at presentation, and on serial evaluation, was associated with a hazard ratio of 10.5 (95% CI 3.9-27.8, p<0.001) for death or transplant. In combined multivariable analysis, S:D ratio >1.2 remained significantly associated with hazard of death/transplant (HR: 9.1, p=0.04) after adjustment for ejection fraction (HR: 2.2/per -10%, p<0.001).
Conclusions—A high S:D ratio is associated with increased risk for death or need for transplant in children with DCM across the spectrum of heart rates and may be a useful prognostic index for serial evaluation of children with DCM.
- Received December 4, 2013.
- Accepted August 11, 2014.