Tt. Lim et al., ROLE OF COMPENSATORY ENLARGEMENT AND SHRINKAGE IN TRANSPLANT CORONARY-ARTERY DISEASE - SERIAL INTRAVASCULAR ULTRASOUND STUDY, Circulation, 95(4), 1997, pp. 855-859
Background Compensatory enlargement of the vessel wall has been descri
bed in the early stages of native atherosclerosis. Whether compensator
y enlargement plays a role in transplant coronary artery disease is no
t known. The objective of this study was to determine, by use of seria
l intravascular ultrasound (IVUS), whether compensatory dilation occur
s in transplant coronary artery disease over time. Methods and Results
Seventy-five heart transplant recipients with 151 matched coronary se
gments were selected for the presence of intimal disease progression a
s detected by serial IVUS examinations 1 to 3 years apart. Intimal dis
ease progression was defined as a >10% increase in intimal area (IA).
IVUS catheter location in follow-up studies was verified angiographica
lly in relation to branch vessels. Luminal area (LA) and total vessel
area (TA) were measured at each site. Intimal area (IA=TA-LA) was calc
ulated. Changes in IA (Delta IA) and TA (Delta TA) between baseline an
d follow-up IVUS were compared: Delta IA, 2.9+/-0.2 mm(2), Delta TA, 2
.7+/-0.4 mm(2). A remodeling index (RI) was defined as RI=Delta TA/Del
ta IA. Three subgroups could be distinguished: overcompensation (RI >1
), partial compensation (RI 0 to 1), and no compensation or shrinkage
(RI less than or equal to 0). Seventy-four segments (49%) showed overc
ompensation, 44 (29%) showed partial compensation, and 33 (22%) showed
no compensation or shrinkage. Conclusions In this study, serial IVUS
shows that early after cardiac transplantation, a large proportion of
the coronary segments with progression of intimal thickening have comp
ensatory dilation of the vessel wall. However, a substantial number of
coronary segments (22%) show no compensatory dilation or shrinkage. T
he progressive luminal narrowing in transplant patients may be due in
part to vessel shrinkage or the lack of compensatory dilation over tim
e.