Age- and gender-related normal left ventricular deformation assessed by cardiovascular magnetic resonance feature tracking

BACKGROUND Assessment of left (LV) ventricular function is one of the most important tasks of cardiovascular magnetic resonance (CMR). Impairment of LV deformation is a strong predictor of cardiovascular outcome in various cardiac diseases like ischemic heart disease or cardiomyopathies. The aim of the study was to provide reference values for myocardial deformation derived from the CMR feature tracking imaging (FTI) algorithm in a reference population of healthy volunteers. METHODS FTI was applied to standard short axis and 2-, 3- and 4-chamber views of vector-ECG gated CMR cine SSFP sequences of 150 strictly selected healthy volunteers (75 male/female) of three age tertiles (mean age 45.8 yrs). Global peak and mean radial, circumferential and longitudinal endo- and myocardial systolic strain values as well as early diastolic strain rates were measured using FTI within a standard protocol on a 1.5T whole body MR scanner. RESULTS Global peak systolic values were 36.3 ± 8.7% for radial, -27.2 ± 4.0% for endocardial circumferential, -21.3 ± 3.3% for myocardial circumferential, -23.4 ± 3.4% for endocardial longitudinal and -21.6 ± 3.2% for myocardial longitudinal strain. Global peak values were -2.1 ± 0.5 s(-1) for radial, 2.1 ± 0.6 s(-1) for circumferential endocardial, 1.7 ± 0.5 s(-1) for circumferential myocardial, 1.8 (1.5-2.2) s(-1) for longitudinal endocardial, 1.6 (1.4-2.0) s(-1) for longitudinal myocardial early diastolic strain rates. Men showed a higher radial strain than women whereas the circumferential and longitudinal strains were lower resulting in less negative values. Circumferential and longitudinal strain rates were significantly higher in female subjects. Radial strain increased significantly with age whereas the diastolic function measured by the radial, circumferential and longitudinal strain rates showed a decrease. The coefficients of variation determined in ten further subjects, who underwent two CMR examinations within 12 days, were -4.8% for circumferential and -4.5% for longitudinal endocardial mean strains. CONCLUSIONS Myocardial deformation analysis using FTI is a novel technique and robust when applied to standard cine CMR images providing the possibility of a reliable, objective quantification of global LV deformation. Since strain values and strain rates differed partly between genders as well as between age groups, the application of specific reference values as provided by this study is recommendable.