Protocol Endomyocardial Biopsy Beyond Six Months - It's Time to Move On.

The optimal duration and frequency of routine surveillance endomyocardial biopsy (EMB) have been questioned in the current era of heart transplantation (HT), where the advances in immunosuppression and donor selection strategies have led to decline in acute allograft rejection. We investigated the utility of routine EMB beyond 6-months post-HT. A single center retrospective review was performed on 2963 EMBs from 220 HT recipients over 10 years. Each EMB was categorized into protocol or symptom-triggered biopsy and reviewed for rejection. HT recipients with ≥2 known risk factors for rejection were designated as an elevated risk group. Majority of rejections occurred within 3 months following HT. The yield of routine protocol EMBs was significantly lower than symptom-triggered EMBs not only during the first 6 months post-HT (1.6% vs. 33.3%, p < 0.0001), but more so during the 6-12 months (0.1% vs. 83.0%, p < 0.0001). A similar pattern was observed in HT recipients at both elevated and standard risk for rejection. In conclusion, EMB was found to be a low-yield screening modality for rejection beyond 6 months post-HT.