Tricuspid regurgitation after cardiac transplantation: how many biopsies are too many?

Background: Tricuspid regurgitation (TR) is common in patients after orthotopic cardiac transplantation (OHT). Endomyocardial biopsy (EMB) used to monitor for rejection may be a cause of TR. The purpose of this study was to identify a correlation between the severity of TR and the number of EMBs.

Methods: We studied 101 patients with OHT at our institution between May 1987 and August 2001. The number of EMBs performed in each patient was determined. Data on technique of anastomosis, liver and renal function, ejection fraction, and pulmonary artery pressure were also extracted. Echocardiography reports were reviewed to determine the presence and severity of TR. Symptoms of right heart failure were assessed by the amount of diuretic intake.

Results: Twenty-five (25%) of 101 patients had evidence of severe TR, whereas 76 (75%) had non-severe TR. Multivariate analysis identified EMB as the only independent predictor of the severity of TR (p < 0.0001). At last follow-up, 60% of patients with more than 31 EMBs had developed severe TR, whereas none of the patients with less than 18 EMBs had severe TR. Of the 25 patients who had severe TR, 15 (61%) needed high doses of daily diuretics, and 4 (16%) required tricuspid valve replacement.

Conclusions: The development of TR after OHT is in large part due to EMBs used to monitor for rejection. There is a direct correlation between the number of EMBs and the severity of TR. We suggest a cutoff of less than 31 EMBs to reduce the risk of severe TR.