INTRACORONARY ULTRASOUND ASSESSMENT OF MORPHOLOGICAL AND FUNCTIONAL ABNORMALITIES ASSOCIATED WITH CARDIAC ALLOGRAFT VASCULOPATHY

Background The diffuse nature of cardiac allograft vasculopathy makes early detection of the disease by traditional noninvasive methods or c oronary angiography difficult. The aim of this study was to determine if there is a relation between abnormalities in vessel wall morphology , as assessed by intracoronary ultrasound, and a decreased vasodilator y response to the endothelium-dependent vasodilator papaverine hydroch loride and if cardiac allograft vasculopathy detected by coronary angi ography is associated with specific intracoronary ultrasound findings. Methods and Results Twenty-three heart transplant recipients underwen t 25 intracoronary ultrasound studies and 24 studies of coronary vasom otor tone 10 days to 8.3 years after surgery using a 20-mHz intracoron ary ultrasound catheter. The studies were divided in two groups accord ing to the presence (n=7, group I) or absence (n=18, group 2) of angio graphically evident cardiac allograft vasculopathy. Qualitative assess ment of vessel wall morphology and quantitative analysis of the vasodi lator response to the injection of papaverine hydrochloride into the c oronary artery distal to the imaging site were performed off-line, and results for the two study groups were compared. A significantly highe r percentage of patients with than without angiographic evidence of ca rdiac allograft vasculopathy had a three-interface vessel wall morphol ogy by intracoronary ultrasound (100% versus 11%, P<.001). In two reci pients who underwent two serial studies, the appearance of three inter faces in the vessel wall or a progressive thickening of the inner inte rface of the vessel wall occurred in conjunction with the appearance o f angiographic cardiac allograft vasculopathy. The vasodilator respons e to papaverine was less in patients with than in those without angiog raphically evident cardiac allograft vasculopathy both in terms of abs olute and relative increases in lumen diameter (+0.1+/-0.12 mm versus +0.3+/-0.17 mm, P<.05, and +5.1+/-5.3% versus +8.2+/-5.3%, P-NS) and l umen cross-sectional area (+0.5+/-0.6 mm(2) versus +1.7+/-1.1 mm(2), P <.02, and +7.1+/-8.8% versus 16.6+/-11.0%, P=.055), respectively. Conc lusions Intracoronary ultrasound assessment of vessel wall morphology and evaluation of vascular response to endothelium-dependent vasodilat ors are useful techniques for detecting cardiac allograft vasculopathy .