Non-Invasive Quantitation of Myocardial Fibrosis Using Combined Tissue Harmonic Imaging and Integrated Backscatter Analysis in Dilated Cardiomyopathy

Abstract

Background: Echocardiographic modalities have challenged the myocardial tissue characterization, but this reliability has not reached to the clinical use. This study investigated whether combined tissue harmonic imaging (THI) and integrated backscatter analysis (IB) provide the reliable and quantitative information about myocardial fibrosis in idiopathic dilated cardiomyopathy (DCM) in comparison with myocardial biopsy findings. Methods: We studied 56 patients with DCM. All patients underwent left ventricular endomyocardial biopsy and IB with fundamental imaging (FI) and THI. Results: In patients with good echocardiographic image quality, excellent correlations between the percentage of area occupied by myocardial fibrosis (% fibrosis) and the mean of integrated backscatter during a cardiac cycle (m-IB) measured with FI or THI were seen, and the correlation was closer with THI compared with FI. While in patients with poor image quality the correlation between m-IB and % fibrosis was only modest with FI, but the correlation was excellent with THI. Four cut-off values of m-IB with THI obtained from receiver operating characteristic curve discriminated between % fibrosis of more and less than 25, 30, 35, and 40% with high sensitivity and specificity. Multivariate analysis revealed that m-IB with THI was an independent predictor for discrimination of the severity of myocardial fibrosis. Conclusion: Combined IB and THI are a clinically applicable method and may be an alternative to myocardial biopsy in evaluating quantitatively myocardial fibrosis in DCM.

Recommendations on the Use of Echocardiography in Adult Hypertension: A Report from the European Association of Cardiovascular Imaging (EACVI) and the American Society of Echocardiography (ASE)†

“…Thus, feasibility can be limited. 70 Moreover, these changes in early hypertensive heart disease may be subtle. 71 Two other imaging methods are probably superior to echocardiography for myocardial tissue characterization.…”

Imaging in hypertensive heart disease

“…Echocardiography with integrated backscatter show good correlation with collagen volume fraction, recognizing that slightly less than half of patients may have suitable backscatter signal for ana lysis [77]. A more robust approach for visualization of myocardial fibrosis is late gadolinium enhancement (LGE)-CMR ( Figure 6 ) [78].…”

Caracterização tecidual ultra-sônica em síndromes coronarianas agudas

“…Corrected coefficient is associated to the basic composition of tissue structure, and is most likely related to collagen level, although it is also affected by collagen tridimensional organization 1,11 . In nosologic models of chronic cardiopathy -as in previous infarctions scars 8,12 -in structural damage resulting from hypertension 5 and diabetes mellitus 13 , as well as in dilated 14 and chagasic 11 cardiopathies -corrected coefficient is successful in identifying structural damage. In the present work, however, corrected coefficient was not successful in differentiating infarcted areas from healthy areas in myocardial tissue.…”