Association of Longitudinal Changes in Left Ventricular Structure and Function With Myocardial Fibrosis

Abstract

The association of longitudinal changes in left ventricular (LV) structure and function with myocardial fibrosis is unclear. We relate temporal changes in body size–indexed LV mass (LVMi) and end-diastolic volume indexed to body surface area, LV mass-to-volume ratio, and LV ejection fraction (LVEF) from cine cardiac magnetic resonance for 10 years, with replacement scar assessed from late gadolinium enhancement, and lower postcontrast T1 times reflecting greater diffuse myocardial fibrosis measured at the end of the follow-up period. All participants (n=1813) who underwent cardiac magnetic resonance twice as part of the Multi-Ethnic Study of Atherosclerosis 10 years apart were included. Multivariable logistic and linear regression models adjusted for cardiovascular risk factors measured the association of 10-year changes in LV structure and function, with fibrosis measured at follow-up. The presence of LV scar at year 10 was cross-sectionally associated with higher LVMi (≈10 g/m 2 ), higher mass-to-volume ratio (0.1–0.2 g/mL), but lower LVEF (≈4%) and longitudinally with 3% decrease in LVEF and 0.7% greater end-diastolic volume indexed to body surface area in men for 10 years. Lower postcontrast T1 times at year 10 were associated cross-sectionally with lower LVMi ( r =0.33), end-diastolic volume indexed to body surface area ( r =0.25), and LVEF (in men only: r =0.14) and longitudinally with a decrease in LVMi ( r =0.20) and reduction in LVEF (in men only: r =0.15). Sustained hypertension for 10 years was associated with increased LVMi and higher diffuse and replacement fibrosis at follow-up. During a 10-year period, increased concentric hypertrophy in women and LV dilatation in men were associated with replacement fibrosis, whereas decreasing LVMi was associated with diffuse fibrosis. Hypertension-induced remodeling was related to enhanced replacement and diffuse fibrosis, as well as hypertrophy.