Endomyocardial biopsy in heart transplantation: schedule or event?

Endomyocardial biopsy is the gold standard to identify rejection after heart transplantation. Due to its invasiveness, discomfort, and difficult vascular access, some patients are not willing to accept routine scheduled biopsies years after heart transplantation. The purpose of this study was to identify whether there was a difference in outcomes among the scheduled versus event biopsy groups.

We studied 411 patients who underwent heart transplantation from 1987 to 2011, reviewing biopsy results and pathology reports. There were 363 patients who followed the scheduled biopsy protocol, and 48 patients who were assigned to the event biopsy group. We extracted data on biopsy results, rejection episodes, rejection types, and survival time.

The 2481 reviewed biopsies over 24 years, showed most rejection episodes (86.4%) to occur within 2 years after heart transplantation. The rejection incidence was low (2.1%) at 3 years after transplantation. The major reason for an event biopsy was poor vascular access, such as tiny central vein or congenital disease without a suitable central vein. Event biopsy group patients were younger than schedule biopsy patients (19.7 years old vs 47.6 years old; P < .05). The 10-year survival rates were 64% among the event versus 53% among the scheduled biopsy group (P = .029). The 10-year rates of freedom from rejection were similar.

The rejection rate was low after 3 years; episodes occurred within 2 years. Although the long-term survival in the event group was better, they had a younger man age. The rejection and freedom from rejection rates were similar. As the rejection rate was low at 3 years after transplantation, we suggest that the event principle could be applied for biopsy at 3 years after heart transplantation.