The relationship of left ventricular trabeculation to ventricular function and structure over a 9.5-year follow-up: the MESA study.

BACKGROUND: Left ventricular (LV) trabeculation is highly variable among individuals and is increased in some diseases (e.g., congenital heart disease or cardiomyopathies), but its significance in population-representative individuals is unknown.
OBJECTIVES: The goal of this study was to determine if excessive LV trabeculation in population-representative individuals is associated with preceding changes in cardiac volumes and function.
METHODS: For technical reasons, the extent of trabeculation, which is expressed as the ratio of noncompacted to compacted (NC/C) myocardium, was measured on cardiac magnetic resonance (CMR) long-axis cine images in 2,742 participants in the MESA (Multi-Ethnic Study of Atherosclerosis) (mean age 68.7 years; 52.3% women; 56.4% with hypertension; 16.8% with diabetes) at examination 5. These were considered in quintiles of trabeculation extent; the NC/C ratio of quintile 5 was 2.46 to 5.41. We determined the relationship between the maximal NC/C ratio and the preceding change (9.5 years between examinations 1 and 5) in end-systolic volume indexed (ESVi) to body surface area. Secondary analyses assessed the associations between the maximal NC/C ratio and preceding changes in end-diastolic volume indexed (EDVi) to body surface area and the ejection fraction (EF).
RESULTS: Over 9.5 years, the ESVi decreased by 1.3 ml/m(2), the EDVi decreased by 5.1 ml/m(2), and the EF decreased by 0.6% (p < 0.0001). Even in subjects with excessive trabeculation, there were no clinically relevant differences in LV volumes and systolic function changes among the quintiles of trabeculation extent.
CONCLUSIONS: Greater extent of, and even excessive, LV trabeculation measured in end-diastole in asymptomatic population-representative individuals appeared benign and was not associated with deterioration in LV volumes or function during an almost 10-year period.