The impact of tissue-tracking strain on the left atrial dysfunction in the patients with left ventricular dysfunction.

Background: The extracellular volume (ECV) calculated by T1 mapping, and tissue-tracking strain using cardiac magnetic resonance (CMR) are useful for assessing the left ventricular (LV) function. However, those parameters are controversial for assessing left atrial (LA) function. This study aimed to investigate the usefulness of CMR to evaluate the LA function using those parameters. Furthermore, those LA function parameters were compared in each LV function.

Methods: A total of 65 consecutive patients who underwent contrast CMR were prospectively enrolled (age 55.7 ± 14. 6 years, males 67.7%). Among the 65 patients, there were 15 without hypertension, diabetes, or atrial fibrillation (Healthy group). The remaining 50 patients were divided into two groups according to a left ventricular ejection fraction (LVEF) of 50%. We assessed the correlations between the LV- and LA-CMR parameters among the three groups (LVEF < 50%; n = 20, LVEF ≥ 50%; n = 30, and Healthy; n = 15).

Results: The LA-longitudinal strain for an LVEF < 50% was lower than that for the others (LVEF < 50%; 13.6 ± 7.9%, LVEF ≥ 50%; 24. 5 ± 13.5%, Healthy; 24.5 ± 9.8%, p = 0.003). However, the LA-ECV did not significantly differ among the three groups (LVEF < 50%; 50.3 ± 3.6%, LVEF ≥ 50%; 53.1 ± 4.9%, Healthy; 53.2 ± 6.5%, p = 0.12). A multiple regression model after adjusting for the patient background revealed that a worse LA-longitudinal strain was correlated with a low LVEF and large LA-volume, but the LA-ECV was not associated with those.

Conclusions: The LA-strain in LV dysfunction patients was significantly lower. However, the LA-ECV did not significantly differ from that in those without LV dysfunction. Tissue-tracking strain is more useful for evaluating the LA dysfunction than T1 mapping.