Noninvasive assessment of left ventricular remodeling: Concepts, techniques, and implications for clinical trials

Background: Over the past decade, our understanding of the cellular and biochemical mechanisms that underlie global changes in ventricular morphology and function has grown enormously. Nevertheless, although the sequence of events that lead to overt changes in the ventricle begin at the cellular level, in living patients we rarely have the opportunity to assess these phenomena as they occur. Thus, to study the process of remodeling in practice and in clinical trials, we have relied on assessments and measurements derived from cardiac imaging tests. Methods and Results: Since the initial angiographic based methods for assessing ventricular remodeling in humans, a variety of techniques has been developed that have been used for assessment of ventricular size, shape, and function for both clinical and research studies. As two-dimensional echocardiography has emerged as the predominant noninvasive diagnostic method for clinical use in evaluating left ventricular function, this modality has become the most widely used technique to assess ventricular remodeling. Nevertheless, nuclear techniques that have proven both reliable and highly reproducible have also been used in clinical and research setting and, more recently, cardiac magnetic resonance imaging has offered the potential to obtain extremely high-quality images of the heart at much higher resolution than either of the other techniques. Conclusions: Each of these techniques carries specific advantages and disadvantages for assessment of remodeling in individual patients and in the context of large-scale clinical trials.