Abstract 19946: Implications of Increased Trabeculated Myocardium in Otherwise Healthy Adults
Introduction: Diagnostic criteria for non-compaction cardiomyopathy (NCC) rely on increased non-compacted (NC, trabeculated) vs compacted (C, dense) myocardium. Improved resolution with magnetic resonance imaging (MRI) increases detection of trabeculated myocardium in healthy adults, with unknown implications.
Hypothesis: Increased trabeculated myocardium may be associated with decreased cardiac function in apparently healthy adults.
Methods: 100 adults without known cardiovascular disease were studied by 1.5T MRI. Steady-State Free Precession was performed in short axis (SA), 2 and 4 chambers (2CH and 4CH). Left ventricular volumes (LVEDV/SV) and ejection fraction (LVEF), left atrial volumes (LAEDV/SV) and ejection fraction (LAEF) were determined. Maximum thickness and areas of NC and C myocardium, ratios NC/C and %NC were determined for each standardized LV segment. N-terminal proBNP (ProBNP) was measured.
Results: Subjects were 28±4 years (56% females). Mean LVEF: 61±5.8%, LAEF: 47±6.2%, Nt-ProBNP: 168±103 pmol/L. NC/C ratios in ED and ES: SA (1.38 ±0.55 and 0.58 ± 0.25, respectively), 2CH (0.74±0.60 and 0.39±0.15) and 4CH (0.60±0.21 and 0.3 ±0.10) (p<0.0001 between planes). NC/C ratios were greater in ED compared to ES (0.90±0.25 vs 0.42 ±0.13, p<0.0001) and in women compared to men (1.49±0.64 vs 1.22±0.37, p=0.01). 18% of segments possessed NC/C ratio>2 (traditional cutoff for disease), more common in anterior midventricular and apical and in females (p<0.05). Positive associations were found between ProBNP quartiles and mean NC/C ratios at ED and ES (p=0.0001 for both). Inverse associations were identified between number of segments with NC/C ratios>90th percentile and LVEF (p=0.003). Segments with greater %NC ratios were associated with decreased wall function (systolic thickening <30%) (p<0.0001). For all imaging planes, the strongest predictor of decreased segmental function was ED NC/C ratio ≥1 in 2CH (specificity 87%, sensitivity 43%, accuracy 81%).
Conclusions: Ratios of trabeculated to compacted myocardium that surpass current diagnostic criteria for NCC are common in apparently healthy adults. Increased trabeculated myocardium is associated with increase in ProBNP and decrease in global and segmental LV function.
- © 2010 by American Heart Association, Inc.