THE EFFECTS OF IMPROVED HEMODYNAMICS ON AORTIC DIMENSIONS IN PATIENTSUNDERGOING HEART-TRANSPLANTATION

Purpose: Retrospective studies have demonstrated an accelerated growth rate of abdominal aortic aneurysms in heart transplant patients. This prospective study was undertaken to define the relationship between c ardiac hemodynamics and posttransplant aortic dilation. Methods: Sixty -eight patients undergoing heart (n = 60) or heart-lung (n = 8) transp lantation were prospectively evaluated with abdominal ultrasonography before transplantation and annually after transplantation. Risk factor s implicated in aneurysm growth, including age, indication for transpl antation, immunosuppression, posttransplantation hypertension, and abd ominal aortic dimension before transplantation were recorded. Ah patie nts underwent annual coronary artery catheterization and multiple gate d acquisition scanning. Results: Thirty-seven patients (54%) had no ch ange in aortic diameter after transplantation (pretransplantation and posttransplantation diameter = 1.8 +/- 0.3 cm), over a mean follow-up period of 28 +/- 14 months. In the remaining 31 (46%) patients, aortic diameter increased by 0.5 +/- 0.6 cm over 31 +/- 15 months (p < 0.05) . Pour (6%) of these 31 patients had abdominal aortic aneurysms (mean aortic diameter = 5.0 +/- 0.8 cm). The mean increase in aortic diamete r among these 4 patients was 1.8 +/- 0.2 cm (annual rate of growth = 0 .96 +/- 0.3 cm/year). Patients experiencing an increase in aortic dime nsion after transplantation had significantly lower (p < 0.005) pretra nsplantation ejection fractions (17.1% +/- 10.5% vs 28.6% +/- 18.1%) a nd, as a consequence, significantly greater (p < 0.05) increases in th eir ejection fractions after transplantation compared with patients wi th stable aortic dimensions (42.7% +/- 12.6% vs 31.8% +/- 18.0%). Conc lusions: Of 68 heart transplant patients prospectively evaluated, aort ic diameter increased in 31 (46%); new aneurysms developed in four of these patients. Greater incremental increases in cardiac ejection frac tion were significant correlates with aortic enlargement.