Novel echocardiographic strategies for rejection diagnosis.

PURPOSE OF REVIEW

A noninvasive detection of allograft rejection is one of the major objectives in the management of heart transplant recipients. Endomyocardial biopsy still remains the gold standard for diagnosing rejection; however, it is invasive, expensive, and subject to sampling error and interobserver variability. Advances in echocardiographic techniques provide an important role for the reliable detection of rejection. This article reviews recently developed echocardiographic modalities and their clinical utility for rejection monitoring in transplant recipients.

RECENT FINDINGS

Conventional two-dimentional (2D)-echocardiographic and Doppler echocardiographic parameters can be useful to detect an increase in left ventricular (LV) mass and diastolic and/or systolic dysfunction associated with acute rejection; however, these parameters are not sufficiently reliable to guide the treatment strategy of asymptomatic, clinically stable patients. Tissue-Doppler Imaging (TDI), which is now widely used, has been reported to detect rejection more accurately than conventional parameters. More recently, 2D speckle-tracking echocardiography (2D-STE)-derived LV torsion and strain parameters, which are calculated by off-line using conventional 2D images, are expected to detect subclinical rejection.

SUMMARY

Considering the advantages of TDI and 2D-STE over conventional echocardiograms, including pre-load and after-load independency, angle-independency and simple-offline calculation, such newly developed echocardiographic modalities will emerge as useful follow-up tools for monitoring rejection in transplant recipients.