Association of speckle tracking echocardiography with acute cellular rejection in cardiac transplant patients: a systematic review and meta-analysis

Abstract Background: Myocardial strain imaging by speckle tracking echocardiography (STE) has demonstrated prognostic utility in several disease states. However, the association of strain measurements with acute cellular rejection (ACR) after cardiac transplantation is not well established. This meta-analysis aims to evaluate the association of myocardial strain measurements with acute cellular rejection in cardiac transplant patients. Methods: A literature search was conducted using Ovid MEDLINE, EMBASE, and Web of Science for studies reporting on the association of left ventricular (LV) global longitudinal (GLS), radial (GRS), and circumferential (GCS) strain in cardiac transplant patients with and without acute cellular rejection. Subgroup analysis was performed by ISHLT standardized ACR grading to compare grade 1R versus Grade 2R and higher. Results: A total of 21 studies with 2502 transplant patients (1465 without ACR versus 1037 with ACR) were included. Patients with ACR had significantly lower GLS compared to patients without ACR on biopsy (MD 2.84, 95% CI 1.5-4.18; p<0.01). Patients with ACR grade ≥2R had significantly lower GLS compared to patients with ACR grade 1R (MD 2.36, 95% CI 1.49-3.23; p<0.01). Patients with ACR had a significantly lower GCS compared to patients without ACR and GCS was significantly lower in patients with ACR grade ≥2R compared to patients with ACR grade 1R (MD 2.29, 95% CI 1.08, 3.51; MD 2.83, 95% CI 0.08-5.59; p=0.04). Conclusions: Left ventricular GLS and GCS may represent useful markers to identify cardiac transplant patients with ACR.