Left Ventricular Global Function Index by Magnetic Resonance Imaging—A Novel Marker for Assessment of Cardiac Performance for the Prediction of Cardiovascular Events

Abstract

LV function is generally assessed independent of structural remodeling and vice versa. The purpose of this study was to evaluate a novel LV global function index (LVGFI) that integrates LV structure with global function and to assess its predictive value for cardiovascular (CV) events throughout adult life in a multi-ethnic population of men and women without history of cardiovascular diseases at baseline. A total of 5004 participants in the Multi-Ethnic Study of Atherosclerosis underwent a cardiac magnetic resonance (CMR) study and were followed up for a median of 7.2 years. The LVGFI by CMR was defined by the ratio of stroke volume divided by LV total volume defined as the sum of mean LV cavity and myocardial volumes. Cox proportional hazard models were constructed to predict the end points of heart failure (HF), hard CV events and a combined endpoint of all CV events after adjustment for established risk factors, calcium score and biomarkers. A total of 579 (11.6%) incident events were observed during the follow-up period. In adjusted models, the end points of HF, hard CV events and all events were all significantly associated with LVGFI (HF, hazard ratio [HR]= 0.64, p<0.0001; hard CV events, HR=0.79, p=0.007; all events, HR=0.79, p<0.0001). LVGFI had a significant independent predictive value in the multivariable models for all CV event categories. The LVGFI was a powerful predictor of incident heart failure, hard CV events and a composite endpoint including all events in this multiethnic cohort.

Whole-body cardiovascular MRI for the comparison of atherosclerotic burden and cardiac remodelling in healthy South Asian and European adults

“…Both LVMVR and LVGFI are measures of LV function that encompass both cavity dimension and myocardial remodelling and are better prognostic markers of incident cardiac events and stroke than LV mass or volumes. 11,24 Given that these values are preserved in the SA cohort indicates that despite much smaller ventricular dimensions, there is continued efficient functionality of the left ventricle. LV mass is known to correlate strongly with lean body mass which is known to be lower in SAs than WEs, thus some of the observed differences may be due to differences in body composition.…”

“…Left ventricular global function index (LVGFI) was calculated as LVGFI = [left ventricular stroke volume (LVSV)/LV global volume] × 100. 24 Late gadolinium enhanced images of the left ventricle were inspected for evidence of myocardial signal enhancement using Carestream PACS Client Suite v. 10.1 sp1 (Carestream Health, Rochester, NY). Epicardial adipose tissue (EAT) and paracardial adipose tissue (PAT) were measured in the four-chamber balanced steady state free precession sequence at end diastole using Segment v. 1.9 R1917; (http://segment.heiburg.se).…”

Cardiac steatosis in patients with dilated cardiomyopathy

“…The most frequently used index of LV function in clinical practice, the LV EF, does not account for the relationship between LV mass and dimension. Recently, an LVGFI has been introduced as a novel parameter to integrate LV structure with global function 15. An LVGFI value <37% has been associated with a significant risk of cardiovascular events.…”

“…The concentric remodelling of LV was estimated as a ratio of LV mass to LV end-diastolic volume 14. LV global function index (LVGFI) was derived from the following formula: LVGFI=[LVSV/((LVEDV+LVESV)/2+LV mass/1.05)]×100 15. LV early diastolic peak filling rate was obtained from the LV volume versus time curve.…”

Prognostic Importance of a New Measure of Global Systolic Heart Function in Healthy Adults

“…Would LVGFI be clinically useful in patients with abnormalities in ventricular volume (eg, chronic heart failure) or mass (eg, left ventricular hypertrophy)? In the study by Mewton et al, 14 LVGFI has been calculated using MRI data. Would the potential clinical use of LVGFI be maintained with less precise imaging methods, such as 2D echocardiography which is more widely used than MRI?…”