Multiparametric Cardiac Magnetic Resonance Imaging Detects Altered Myocardial Tissue and Function in Heart Transplantation Recipients Monitored for Cardiac Allograft Vasculopathy

Abstract

BACKGROUND Cardiac allograft vasculopathy (CAV) is a complication beyond the first-year post-heart transplantation (HTx). We aimed to test the utility of cardiac magnetic resonance (CMR) to detect functional/structural changes in HTx recipients with CAV. METHODS Seventy-seven prospectively recruited HTx recipients beyond the first-year post-HTx and 18 healthy controls underwent CMR, including cine imaging of ventricular function and T1- and T2-mapping to assess myocardial tissue changes. Data analysis included quantification of global cardiac function and regional T2, T1 and extracellular volume based on the 16-segment model. International Society for Heart and Lung Transplantation criteria was used to adjudicate CAV grade (0–3) based on coronary angiography. RESULTS The majority of HTx recipients (73%) presented with CAV (1: n = 42, 2/3: n = 14, 0: n = 21). Global and segmental T2 (49.5 ± 3.4 ms vs 50.6 ± 3.4 ms, p < 0.001;16/16 segments) were significantly elevated in CAV-0 compared to controls. When comparing CAV-2/3 to CAV-1, global and segmental T2 were significantly increased (53.6 ± 3.2 ms vs. 50.6 ± 2.9 ms, p < 0.001; 16/16 segments) and left ventricular ejection fraction was significantly decreased (54 ± 9% vs. 59 ± 9%, p < 0.05). No global, structural, or functional differences were seen between CAV-0 and CAV-1. CONCLUSIONS Transplanted hearts display functional and structural alteration compared to native hearts, even in those without evidence of macrovasculopathy (CAV-0). In addition, CMR tissue parameters were sensitive to changes in CAV-1 vs. 2/3 (mild vs. moderate/severe). Further studies are warranted to evaluate the diagnostic value of CMR for the detection and classification of CAV.

Cardiac Allograft Vasculopathy: Challenges and Advances in Invasive and Non-Invasive Diagnostic Modalities

“…Cardiac magnetic resonance imaging (CMR) is a non-invasive imaging modality that can provide comprehensive information about the structure and function of the heart that is relevant for the diagnosis and prognosis of CAV ( Figure 3 ) [ 8 ]. CMR can provide information about structural changes by measuring parameters such as extracellular volume (ECV) fraction, fibrosis, and edema [ 58 ]. However, functional parameters such as myocardial perfusion reserve (MPR), diastolic strain (DS) rate by CMR, and peak filling rate (PFR) carry more importance for CAV diagnosis, as most studies using CMR have focused on MPI and strain imaging [ 59 , 60 ].…”

Multiparametric Cardiac Magnetic Resonance Imaging for Diagnosing Cardiac Allograft Vasculopathy

“…Although several studies have shown that elevated native T1, T2, and extracellular volume fraction (ECV) may be markers of acute rejection, 10) 11) few studies have focused on the relationships between these parameters and CAV. In this issue of Journal of Cardiovascular Imaging , Abbasi and colleagues 12) demonstrated structural (T1, T2, and ECV values) and functional parameters of CMR in patients monitored for CAV beyond the first-year post heart transplantation. The study included 77 heart transplantation recipients and 18 matched controls who underwent CMR.…”