Midterm results of percutaneous transluminal coronary angioplasty in graft coronary artery disease in cardiac transplant patients
Marelli M., Rábago G., Calabuig J., Martínez Caro D., Coma-Canella I., Martín Trenor A.
Graft coronary artery disease (CAD), an accelerated form of coronary disease, is characterized as a diffuse, multifocal, and heterogeneous myointimal hyperplasy and remolded vasculature. It portrays an exaggeration of the immunological mechanism in the development of coronary arteriosclerosis.
Previously known as chronic rejection, owing to its etiology as being the most frequent chronic dysfunction of the graft, and also known as accelerated graft atherosclerosis, owing to the speed of its development, sometimes a few months following cardiac transplant (CT), it is the major cause of death in the long term. In one study, graft CAD was found in 78% of autopsies of children after 2 years of heart transplantation.
Some investigators suggest that the precocious appearance of the graft CAD after CT could be a sign of a more aggressive disease and that the infection by cytomegalovirus is also associated with a more precocious beginning. The rate of progression is not well documented, but it is frequently quite progressive. Considering the graft CAD as an angiographic affectation, the prevalence is rated from 19% to 36% after 1 year of the CT and 50% after 5 years. However, it is rated to be 100% if we consider autopsy studies in long-term survivors. In the Stanford series, the hearts of 36 recipients who survived less than 1 year posttransplantation were examined at autopsy, and 29 (80.6%) were found to have graft CAD, being the major cause of graft failure after 5 years of the CT. In this series, incidences of a failure heart attack, congestive heart failure, or arrhythmias were considered to be caused by graft CAD (11%). Both the presence and the severity of the disease are seriously underestimated by routine angiography, by the diffuse, concentric, and distal graft CAD affectation, in comparison with the nontransplanted coronary disease, which is focal, eccentric, and proximal. It could be that the disease is not as evident with use of conventional angiography. First, it is detected macroscopically and later on with the angiography when there is a decrease more than 25% of the size of the artery, underlining a diffuse narrowing of the vessels. Intravascular ultrasound imaging (IVUS) is a more sensitive means of detecting the intimal vascular wall (early stage) than is angiographic imaging. It shows qualitative information of the vascular wall morphology and measurement of vessel lumen dimensions.
The use of the noninvasive test is limited. The treadmill test on its own or combined with myocardial perfusion does not provide good sensitivity. In some studies echocardiography with dobutamine is useful owing to its high sensitivity screening; however, this has not been shown in other studies. Overall, given the characteristics of the lesions, they usually are not sensitive to angioplasty or conventional surgery for revascularization of the coronary.
In selected patients, revascularization with percutaneous transluminal coronary angioplasty (PTCA) could be beneficial, but in multifocal coronary stenoses it use is limited. At present, retransplantation is considered to be the most effective treatment for end-stage graft CAD.
CITATION Transplant Proc. 1999 Sep;31(6):2539-41