T1 mapping: useful for treatment monitoring in patients with senile systemic amyloidosis?

Abstract

Background Recent reports indicate that epigallocatechin-3-gallate (EGCG), the most abundant catechin in green tea, is potent to inhibit fibril formation of several amyloidogenic proteins in vitro. In vivo studies revealed reduction of left ventricular myocardial mass (LVM) after 12 months of daily consumption of 450 mg EGCG. However, the underlying process of LVM reduction, either due to reduction of amyloid or due to atrophy of cardiomyocytes, remained unknown. T1-mapping has the potential to monitor the extent of the extracellular volume (ECV). We sought to investigate the use of T1 mapping for monitoring of treatment effects in a cohort of patients with senile systemic amyloidosis (SSA) treated with EGCG for 12 months. Methods CMR examinations were performed in 8 patients (70 ± 8 years, 7 males) with histologically proven SSA before and 12 months after daily consumption of 450 mg EGCG using a 1.5 T CMR scanner (Achieva, Philips Healthcare). Short axis slices were acquired using SSFPsequences to measure left ventricular volumes, ejection fraction (EF) and LVM. T1-maps were created out of 11 mid-ventricular short axis views with increasing inversion times (TI; 100-4400 msec) using a single breathhold modified Look-Locker inversion-recovery sequence (MOLLI, TR/TE = 3,5/1,8 msec, flip angle = 35°) in late diastole before and 15 minutes after injection of gadolinium-DTPA contrast agent (0.2 mmol/kg body weight). ECV was calculated using the formula given in Figure 1. Results After 12 months of EGCG consumption a significant decrease of LVM (-14.5 ± 12.9 g, p < 0.05, Figure 2) was observed. Moreover, a significant decrease of native T1 (-63.3 ± 64.1 ms, p < 0.05, Figure 2) was noticed. There was no significant change in ECV and EF. Conclusions