Diffuse Myocardial Fibrosis at Cardiac MRI in Young Adults Born Prematurely: A Cross-sectional Cohort Study.

Purpose: To measure native T1 values, a marker of diffuse fibrosis, by using cardiac MRI (CMR) in young adults born prematurely. Materials and Methods: This secondary analysis of a prospective cohort study included young adults born moderately to extremely preterm and age-matched, term-born participants. CMR was performed with a 3.0-T imager that included cine imaging for the quantification of left ventricular (LV) and right ventricular (RV) volumes and function and native saturation recovery T1 mapping for the assessment of diffuse myocardial fibrosis. Values between preterm and term were compared by using the Student t test. Associations between T1 values and other variables were analyzed by using linear regression and multivariate regression. Results: Of the 50 young-adult participants, 32 were born preterm (mean age, 25.8 years & PLUSMN; 4.2 [SD]; 23 women) and 18 were born at term (mean age, 26.2 years & PLUSMN; 5.4; 10 women). Native T1 values were significantly higher in participants born preterm than in participants born at term (1477 msec & PLUSMN; 77 vs 1423 msec & PLUSMN; 71, respectively; unadjusted P = .0019). Native T1 values appeared to be positively associated with indexed LV end-diastolic and end-systolic volumes (f3 = 2.1, standard error = 0.7 and f3 = 3.8, standard error = 1.2, respectively), the RV end-diastolic volume index (f3 = 1.3, standard error = 0.6), and the LV mass index (f3 = 2.5, standard error = 0.9). Higher T1 values may be associated with reduced cardiac systolic strain measures and diastolic strain measures. Five-minute Apgar scores were inversely associated with native T1 values. Conclusion: Young adults born moderately to extremely preterm exhibited significantly higher native T1 values than age-matched, term -born young adults.