Comparison of Left Ventricular Curvedness Derived from CMR Imaging with the Wall Motion Score Index for Male Patients after First-time Myocardial Infarction

Abstract

The wall motion score index (WMSI) is an important clinical measure to assess the aggregate function of left ventricle (LV) wall segments after myocardial infarction (MI). Compared to global LV ejection fraction, WMSI provides additional information about regional functions that corresponds to myocardium contractility. Studies have shown that the WMSI yields powerful prognostic information after MI. However, one limitation of the WMSI is that manual assessment has to be performed by clinicians resulting in potential intra- and inter-observer variabilities. In this study, we compared the geometry-derived curvedness at end-systole based on cardiac magnetic resonance (CMR) imaging with clinical WMSI in a group of 25 male patients presenting with first-time MI. Our computational method for calculating curvedness has the following advantages: it is automated and robust for a given set of inputs. Comparing across basal, mid and distal segments, the mean values of curvedness at end-systole for segments with WMSI = 1 (normokinetic) were significantly different compared to segments with WMSI = 3 (akinetic) and above (p-value <0.05, 1-way ANOVA). We also observed significant difference in curvedness at end-systole for segments with WMSI = 1 compared to segments with WMSI = 2 (hypokinetic) at the mid segments (p-value <0.05, 1-way ANOVA). Our results suggest that automatically-generated curvedness may potentially be used for correlating to manually-assessed WMSI for patients after MI. Future work will include expanding the sample size of the patient group to validate our initial results.