Changes in desmin expression in patients with cardiac diastolic dysfunction and preserved or reduced ejection fraction.

PURPOSE: Desmin regulates function of mitochondria, T-tubular system and cytosolic Ca(2+) transients. We investigated whether desmin remodeling correlates with diastolic dysfunction and whether progressive desmin abnormalities are accompanied by increasing diastolic dysfunction stages.

PATIENTS AND

METHODS

Eighty five patients with idiopathic dilated cardiomyopathy and suspected myocarditis without confirmed cardiac tissue inflammation in histopathology assays were included and divided into groups: with preserved EF and reduced EF. After echocardiographic analysis of diastolic dysfunction we identified 2 preserved EF subgroups (normal diastolic function (NDF) and impaired relaxation (IR)) and 3 reduced EF subgroups (NDF, IR, and pseudonormalization). Patients with preserved EF and NDF formed the control group. Tissue desmin staining revealed 4 types of desmin expression: I - normal, with regular pattern of cross-section, IIA - increased with regular pattern, IIB - increased, with irregular pattern and presence of aggregates, III - decreased/lack desmin.

RESULTS

Desmin I was observed only in patients with NDF n=8 (100%) in preserved EF and reduced EF, desmin IIA in NDF n=8 (33%) in preserved EF and n=5 (33%) in reduced EF and IR n=16 (66%) in preserved EF and n=10 (66%) in reduced EF. Desmin IIB and III were observed in patients with reduced EF and diastolic dysfunction: IR and pseudonormalization n=9 (39%) and n=2 (29%); n=14 (61%) and n=5 (71%), respectively. Desmin was found to be an independent predictor of diastolic function parameters β=-0.63, R(2)=0.52 for E'; β=0.54, R(2)=0.42 for E/E'.

CONCLUSIONS

Increasing desmin abnormalities were correlated with diastolic dysfunction progression. Desmin expression represents a novel factor contributing or paralleling the development of diastolic dysfunction.