784-3 Prognostic Significance of Intimal Thickening Detected by Intracoronary Ultrasound in Heart Transplant Recipients

Intracoronary ultrasound (ICUS) is a sensitive tool for the detection of intimal thickening in coronary arteries of heart transplants recipients. However, the prognostic significance of this intimal thickening has not been proven.During a one year period, 90 transplant recipients had ICUS examination at the time of their annual angiogram. For each ICUS study an intimal index (II), defined as the ratio of the plaque area to the area within the media, was measured for the most diseased segment imaged. The angiogram at the time of ICUS was reviewed for the presence of visually apparent coronary artery disease (V-CADI· Those patients (n=19) with V-CAD present at the time of ICUS were excluded from the study. The time since transplantation for the 71 pts without V-CAD ranged from 1 to 15 yrs, with a mean of 4.2 yrs and median of 3.9 yrs. The subsequent annual follow-up angiograms of the 71 patients without V-CAD at the time of ICUS were reviewed for the development of V-CAD. Mean duration of angiographic follow-up was 2.0 yrs (range 1–3 yrs).V-CAD developed on follow-up angiograms in 13 of the 71 pts. Mean time to development of V-CAD was 1.5 yrs. Forty-six patients had II<0.3, 4 (9%) of whom subsequently developed V-CAD. Twenty-five patients had II ≥0.3, 9 (36%) of whom developed V-CAD. Odds ratio for future V-CAD between pts with II<0.3 and II 2: 0.3 was 5.9 (95% CI 1.8 to 19.0, difference significant at p<0.01 by Fisher's Exact test).In a subgroup of 22 patients more than 5 years post transplantation at the time of ICUS, 12 had II<0.3 and 10 had II 2≥0.3. In this subgroup none of the 12 pts with II<0.3 developed V-CAD and only 1 of the 10 with II >0.3 developed V-CAD (difference not significant).Conclusion — Among patients more than 1 year and less than 5 years post-transplantation without visually apparent angiographic coronary artery disease, the presence of moderate to severe intimal thickening by ICUS is predictive of the future development of angiographically apparent CAD. Intimal thickening as detected by ICUS is of prognostic significance in patients with angiographically silent transplant coronary artery disease