Follow-up after heart transplantation presently requires invasive techniques to assess graft viability and function. As the heterotopic transplant technique assumes a more important therapeutic role for patients not eligible for an orthotopic allograft, an understanding of the inherent challenges associated with management of these patients is mandatory to optimize patient care. Heterotopic transplant technique was used in 19 of 135 (14%) consecutive heart transplant procedures over a 41 month period. Invasive diagnostic procedures performed in follow-up revealed 1) adequate tissue for histologic evaluation in 140/158 (89%) biopsy procedures, 2) successful pulmonary wedge pressure measurements in 142/158 (90%) right heart catheterizations, and 3) successful coronary arteriography in 18 patients undergoing angiography (both vessels in 12 and one vessel in six patients). Thus, biopsy and surveillance procedures are feasible and productive in patients who have undergone heterotopic heart transplantation. BACKGROUND Although heterotopic heart transplantation has become an increasingly utilized therapy for some patients with heart failure, there are no guidelines for routine biopsy and angiographic techniques in these patients. The objective of this study was to determine the feasibility of angiographic and endomyocardial biopsy procedures in heterotopic heart transplant recipients. METHODS The complete experience with heterotopic heart transplant recipients at Baylor College of Medicine and The Methodist Hospital over a 41 month period including endomyocardial biopsy, right heart catheterization, and selective coronary arteriography results were analyzed. RESULTS Eighteen patients underwent 310 procedures without significant complications. Of 158 biopsy procedures, 140 (89%) yielded tissue adequate for histologic evaluation. Right heart pressures were obtained in almost all patients undergoing right heart catheterization. Pulmonary wedge pressures were obtained in 137 (90%). A rapid decrease in right heart pressures was noted following transplant; however, a gradual but significant rise in mean arterial pressure occurred. Eighteen selective coronary arteriogram procedures were performed; 12 (66%) resulted in successful cannulation of both coronary arteries. Of 12 patients followed for at least 1 year, five (40%) have developed evidence of allograft arteriopathy. The 1 and 2 year survival rates were 67% and 53%, respectively. CONCLUSIONS Invasive diagnostic techniques can be performed safely and reliably and should not preclude the use of heterotopic heart transplantation in selected patients who are otherwise unsuitable for orthotopic transplantation.