Myocardial strain measurement with feature-tracking cardiovascular magnetic resonance: Normal values

Abstract

Aims: Myocardial deformation is a key to clinical decision-making. Feature-tracking cardiovascular magnetic resonance (FT-CMR) provides quantification of motion and strain using standard steady-state in free-precession (SSFP) imaging, which is part of a routine CMR left ventricular (LV) study protocol. An accepted definition of a normal range is essential if this technique is to enter the clinical arena. Methods and results: Onehundred healthy individuals, with 10menandwomenin each of 5 age deciles from20 to 70 years, without a history of cardiovascular disease, diabetes, renal impairment, or family history of cardiovascular disease, and with a normal stress echocardiogram, underwent FT-CMR assessment of LV myocardial strain and strain rate using SSFP cines. Peak systolic longitudinal strain (Ell) was -21.3±4.8%, peak systolic circumferential strain (Ecc) was 226.1±3.8%, and peak systolic radial strain (Err ) was 39.8±8.3%. On Bland-Altman analyses, peak systolic Ecc had the best inter-observer agreement (bias 0.63±1.29% and 95% CI-1.90 to 3.16) and peak systolic Err the least inter-observer agreement (bias 0.13±6.41 and 95%CI-12.44 to 12.71). Therewas an increase in the magnitude of peak systolic Ecc with advancing age, which was greatest in subjects over the age of 50 years (R2 = 0.11, P = 0.003). There were significant gender differences (P < 0.001) in peak systolic Ell, with a greater magnitude of deformation in females (-22.7%) than in males (-19.3%). Conclusion: Normal values for myocardial strain measurements using FT-CMR are provided. All circumferential and longitudinal based variables had excellent intra- and inter-observer variability.