The prevalence and natural history of aortic aneurysms in heart and abdominal organ transplant patients.

OBJECTIVE: The purpose of this study was to document the prevalence and clinical features of aortic aneurysms in heart and abdominal transplant patients.
METHODS: We undertook a retrospective review of 1557 patients who had heart, liver, or kidney transplantation between January 1, 1987, and December 31, 2000. Aortic aneurysms were identified by computed tomographic scan, ultrasound scan, or at the time of surgery for rupture. An aortic diameter of 3.5 cm was used as the threshold for the definition of aneurysmal disease. We compared dichotomous variables with Fisher's exact test and continuous variables with the Wilcoxon rank-sum test.
RESULTS: There were 296 heart, 450 liver, and 811 kidney transplants performed on adult patients during the study period. We identified 18 transplant patients who had an aortic aneurysm (13 heart, three liver, two kidney). Seven patients (41%) had rupture of the aortic aneurysm, and five of these patients died. There were no deaths from causes other than aortic aneurysm rupture. The rate of aneurysm rupture was 22.5% per year. Eight patients had the aortic aneurysm repaired electively with no deaths and no hospital stay greater than 15 days. The mean aortic aneurysm size at rupture was 6.02 +/- 0.86 cm, and the smallest aneurysm that ruptured was 5.1 cm. The pretransplant rate of aortic aneurysm expansion was 0.46 cm/y, but this increased to 1.00 cm/y after transplantation (P =.08). The rate of aortic aneurysm expansion among heart transplant patients and abdominal transplant patients was the same (P =.51). The prevalence of aortic aneurysm was 4.1% in cardiac transplant patients and 0.4% in abdominal transplant patients. Earlier in our series (1987 to 1996), 11% of the cardiac transplant patients were screened for aortic aneurysms, and the prevalence rate of diagnosis was 3.0%. Screening of cardiac transplant candidates became more frequent in 1997 (87% screened), with an associated increase in the aortic aneurysm prevalence rate to 5.8% in the patients who were screened.
CONCLUSION: Aortic aneurysms in cardiac and abdominal transplant patients have an aggressive natural history with high expansion and rupture rates. Screening transplant patients for aortic aneurysms will increase detection and facilitate elective repair, which is generally well tolerated. These findings support programs for early detection and elective treatment of aortic aneurysms in organ transplant patients, particularly those having heart transplants.