Echocardiographic evaluation of left ventricular structure and function: new modalities and potential applications in clinical trials.

Advances in modern echocardiography for quantification of cardiac structure and function have not been translated in clinical trial or practice applications to date. Imaging endpoints are especially well-suited for early trials with investigational therapies for heart failure as most drugs and devices approved for heart failure have shown favorable effects on cardiac structure and function also. Echocardiography is versatile and can be performed in most clinical settings. The modest interobserver and test-retest reproducibility of specific structural and functional parameters with conventional echocardiography can be improved on by using contemporary modalities, including 3-dimensional (3D) echocardiography for assessment of volumes and ejection fraction and speckle tracking for detailed functional assessment of the ventricles with mechanics-based parameters (strain and strain rate). The appropriate imaging endpoints (global vs. regional, systolic vs. diastolic) should be tailored to the specific research question and the mode of action of the therapy under investigation. The newer echocardiographic modalities, namely 3D echocardiography and speckle tracking, are more demanding in terms of equipment and personnel and therefore are better suited for implementation in experienced research centers with central interpretation. However, these modalities provide the best opportunity currently available to demonstrate treatment effects on the myocardium with investigational therapies and provide mechanistic insights for future directions.