Abstract 9710: Contractile Reserve Assessed by Three-Dimensional Global Circumferential Strain as a Predictor of Cardiovascular Events in Patients with Idiopathic Dilated Cardiomyopathy

Abstract

Background: Two-dimensional global circumferential strain (GCS) from mid-left ventricular (LV) short-axis view has been reported as a powerful predictor of cardiac events and appeared to be a better parameter than ejection fraction in heart failure (HF) patients. However, this technique is limited to two-dimensional tomographic imaging planes, which may oversimplify the complexities of left ventricular function. On the other hand, novel three-dimensional (3-D) speckle-tracking system can quantify 3 different strains simultaneously from all 16 LV segments. Accordingly, our objective was to investigate the ability of GCS with dobutamine stress using 3-D speckle-tracking to predict cardiac events in HF patients with idiopathic dilated cardiomyopathy (DCM).

Methods: We prospectively recruited 54 consecutive DCM patients with ejection fraction of 34±8%. We measured GCS, global radial, and longitudinal strains using 3-D speckle-tracking echocardiography at baseline and during dobutamine infusion (20µg/kg/min). Event-free survival was pre-specified as primary end points of death from worsening HF, hospitalization for deteriorating HF, and was tracked over 12.3 months.

Results: The primary endpoint occurred in 7 (17%) of patients. Of individual measures, the increase in 3-D GCS with dobutamine stress (ΔGCS) ≤2.71% was the best predictor of cardiac events with sensitivity of 90%, specificity of 81%, and the area under the curve of 0.927 (p<0.001). In multivariate Cox proportional hazard model, ΔGCS was the strongest predictor of cardiac events (hazard ratio: 0.375, 95% confidential interval: 0.202-0.695, p=0.002). Furthermore, patients with ΔGCS>2.71% had a significantly better prognosis than those with ΔGCS≤2.71% (Log rank p<0.001).

Conclusion: 3-D GCS with dobutamine stress would have potential to predict cardiac events in HF patients with DCM. These observations may have clinical implications for management of such patients.