UCLA

Background

Intravascular ultrasound (IVUS) is a sensitive method for assessing allograft vasculopathy in heart transplant recipients, but it is not known whether this instrumentation traumatizes the transplanted arteries and affects progression of arteriopathy.

Methods and results

Yearly coronary angiograms were obtained in 86 patients who underwent heart transplantation between January 1991 and May 1995. Patients were divided into 3 groups: (1) no IVUS performed after transplantation (group 1, n = 47); (2) IVUS of the left anterior descending artery (LAD) performed only at year 1 (group 2, n = 13); and (3) IVUS of the LAD performed at both baseline (within 2 months after transplantation) and year 1 after transplantation (group 3, n = 26). Coronary angiography measurements of lumen diameter were performed at 5 segments along the length of the LAD and left circumflex artery (LCX) from baseline through the second-year studies except in group 2, which did not receive a baseline angiogram; IVUS measurements were obtained at 10 cross sections from each artery. At baseline, there was no significant difference in vessel diameter for either the LAD or the LCX artery between the IVUS (group 3) and no IVUS (group 1) groups. Within each group, the lumen of both the LAD and LCX narrowed from baseline to year 1 (group 1: 3.3 +/- 0.6 mm to 2.8 +/- 0.5 mm in LAD, P =.001; 3. 3 +/- 0.6 mm to 3.0 +/- 0.5 mm in LCX, P =.006; group 3: 3.5 +/- 0.7 mm to 3.1 +/- 0.6 mm in LAD, P =.01; 3.1 +/- 0.6 mm to 2.8 +/- 0.5 mm in LCX, P = 0.07), but there were no significant differences between the instrumented artery (LAD) and control artery (LCX) or further changes observed at year 2. There were also no significant differences in the percent reductions at year 1 and year 2 between arteries or between groups. By IVUS, from baseline to year 1 in group 3, the plaque cross-sectional area (CSA) increased (1.6 +/- 1. 9 to 2.3 +/- 1.7 mm(2), P <.0001), the lumen CSA decreased (12.7 +/- 3.7 to 11.7 +/- 3.3 mm(2), P =.04), and the maximum lumen diameter decreased (4.2 +/- 0.6 to 4.0 +/- 0.6 mm, P =.04).

Conclusions

The use of IVUS is not associated with acceleration of arteriopathy in heart transplantation recipients. Luminal narrowing occurs predominantly during the first year after transplantation. There was no significant change in lumen dimensions during the second year.