IMMEDIATE EVALUATION OF ENDOMYOCARDIAL BIOPSIES FOR CLINICALLY SUSPECTED REJECTION AFTER HEART-TRANSPLANTATION

Background Acute rejection may be suspected in heart transplant recipi ents in the setting of new onset of clinical symptoms or alterations i n cardiac function. Immediate diagnosis may be obtained by performing a frozen section on endomyocardial biopsy (EMB) specimens. However, li ttle is known about the indications for, and the diagnostic reliabilit y of, this procedure. Methods and Results EMBs with frozen section (n= 98) from 65 of 214 consecutive orthotopic heart transplant recipients were reviewed and divided into early (less than or equal to 45 days; n =47) and late (>45 days; n=51) posttransplant periods. Frozen section diagnoses (($) over bar x=1.5 EMB samples) were compared with correspo nding permanent section diagnoses ($) over bar x=4.4 EMB samples), and clinical indications were analyzed. Comparison of frozen and permanen t section interpretation revealed concordant pathological processes-re jection (n=31) versus no rejection (n=37) versus ischemic injury (n=20 ) -in 88 of 98 (90%) cases. Discordant pathological processes on froze n versus permanent section in 10 of 98 (10%) cases could be attributed to ischemic injury (n=5), sampling (n=4), and infection (n=1). In the 92 cases with defined clinical indications, the indication and number of EMBs positive for rejection early and late after transplantation w ere arrhythmia: 2 of 12 early, 4 of 10 late; congestive heart failure: 1 of 2 early, 5 of 12 late; fever: 0 of 2 early, 1 of 4 late; echo ab normality: 0 of 5 early, 0 of 1 late; syncope: 1 of 5 early, 0 of 1 la te; hypotension: 1 of 3 early, 1 of 2 late; noncompliance: 0 of 0 earl y, 4 of 5 late; more than one pf the above: 3 of 7 early, 2 of 5 late; other: 1 of 7 early, 1 of 9 late; total: 9 of 43 early, 18 of 49 late . Conclusions Frozen section on EMB specimens accurately reflected the permanent section diagnosis in 90% of cases. No specific clinical ind ication predicted EMB rejection positivity with high sensitivity in ei ther the early or late posttransplant periods.