Speckle-tracking-based global longitudinal and circumferential strain detect early signs of antibody-mediated rejection in heart transplant patients

AIMS: Acute rejection is an important cause of mortality after heart transplant (HTx), but symptoms develop only when myocardial damage is already extensive. We sought to investigate if echocardiographic parameters can detect and predict an acute cellular rejection (ACR) or antibody-mediated rejection (AMR) episode in HTx patients. METHODS AND RESULTS: Data of 403 consecutive HTx recipients between 2003 and 2020 from our centre were reviewed. Patients with severe ACR (n = 10) and AMR (n = 7) were identified. Each HTx patient presenting with rejection was matched to a control HTx patient. Echocardiographic variables from the moment of rejection and 3, 6, and 12 months before were analysed and compared among groups. At acute rejection episode, patients with rejection had lower values of global longitudinal strain (GLS), global circumferential strain (GCS), and left ventricular ejection fraction (LVEF) compared to controls. HTx patients with AMR showed a progressive decline of GLS and GCS in the months preceding acute rejection, while controls and ACR patients had stable strain values except for the moment of rejection. In our cohort, a GLS cut-off lower than 15.5% and a GCS cut-off lower than 15.2% could distinguish with a sensitivity and specificity of 100.0% AMR from controls 3 months before rejection. LVEF and other conventional echo parameters could not differentiate among groups. CONCLUSION: GLS and GCS show a progressive decrease months before AMR becomes clinically apparent. Our data suggest that global strain assessment by echocardiography allows an early detection of a developing AMR, which could improve the clinical management of HTx patients.