Intravascular ultrasound imaging after cardiac transplantation: Advantage of multi-vessel imaging

Background: Intravascular ultrasound is a sensitive tool to study transplant vasculopathy. However, there is no consensus regarding the methodology for imaging protocol. The impact of single versus multiple epicardial vessel imaging in determining the prevalence of transplant vasculopathy has not been determined. This study examines the benefit of three-vessel imaging versus one-vessel imaging in detecting transplant vasculopathy. Methods and Results: One hundred eleven transplant recipients with intravascular ultrasound imaging at baseline (within 2 months of transplantation) were studied: 107 at 1-year, 53 at 2-year and 41 at 3-year follow-up. A total of 222 arteries, 519 segments and 772 sites were analyzed (94 LAD, 65 LCX and 65 RCA). The prevalence of transplant vasculopathy lesions was 27%, 41% and 58% at 1 year, 39%, 55% and 71% at 2 years and 39%, 55% and 74% at 3 years for patients with one-, two- and three-vessel imaging, respectively. Single- or two-vessel, disease was present in 23% (7) and 32% (10) patients with three-vessel imaging, leading to the potential mislabeling of these 17 (55%) patients as "disease free" if they underwent only single-vessel imaging. Conclusions: Multivessel imaging is more sensitive in detecting the transplant vasculopathy lesions compared to single-vessel, imaging. This important variable should be considered when designing and interpreting trials utilizing intravascular imaging derived end-point.