Endomyocardial Biopsy and Prevalence of Acute Cellular Rejection in Heart Transplantation.

BACKGROUND: Percutaneous endomyocardial biopsy (EMB) remains the criterion standard method for surveillance of allograft rejection after heart transplant (HT). However, data regarding utility of EMBs and prevalence of acute cellular rejection (ACR) in Asian populations are still limited. We aimed to report our experience in the use of EMBs and prevalence of ACR in HT recipients.

METHODS: We retrospectively evaluated all EMBs from consecutive HT recipients between January 2008 and December 2018. EMB pathology results were according to International Society for Heart and Lung Transplantation 2004 revision of biopsy grading. We also divided patients into previous era and current era group (underwent HT before and after 2015) to compare prevalence of ACR and survival outcome.

RESULTS: A total of 832 EMBs from 81 HT recipients were included. Pathologic reports revealed ACR grade 1R 22.8%, 2R 4.2%, and 3R 0.6%. At patient level, at least 1 episode of ACR grade 1R, 2R, and 3R were found in 70.6%, 24.7%, and 3.5% of the patients, respectively. When compared between era, frequency of EMB during the first year after HT in current era was significantly higher (9.74 ± 3.38 vs 4.93 ± 3.29, P < .001), but lower frequency of rejection grade ≥ 2R were found (2.3% vs 8.1%, P < .001). However, 1-year survival was not statistically different (76% in previous era vs 80% in current era, P = .37).

CONCLUSIONS: From our study, prevalence of grade ≥ 2R rejection was approximately 5%, which is comparable with previous studies. Further studies are needed to evaluate proper interval and number of EMBs in HT recipients.