Myocardial triglycerides in cardiac amyloidosis assessed by proton cardiovascular magnetic resonance spectroscopy

Abstract

BackgroundCardiac involvement of amyloidosis leads to left-ventricular (LV) wall thickening with progressive heart failure requiring rehospitalization. Cardiovascular magnetic resonance (CMR) is a valuable tool to non-invasively assess myocardial thickening as well as structural changes. Proton CMR spectroscopy (1H-CMRS) additionally allows assessing metabolites including triglycerides (TG) and total creatine (CR). However, opposing results exist regarding utilization of these metabolites in LV hypertrophy or thickening. Therefore, the aim of this study was to measure metabolic alterations using 1H-CMRS in a group of patients with thickened myocardium caused by cardiac amyloidosis.Methods1H-CMRS was performed on a 1.5 T system (Achieva, Philips Healthcare, Best, The Netherlands) using a 5-channel receive coil in 11 patients with cardiac amyloidosis (60.5 ± 11.4 years, 8 males) and 11 age- and gender-matched controls (63.2 ± 8.9 years, 8 males). After cardiac morphology and function assessment, proton spectra from the interventricular septum (IVS) were acquired using a double-triggered PRESS sequence. Post-processing was performed using a customized reconstruction pipeline based on ReconFrame (GyroTools LLC, Zurich, Switzerland). Spectra were fitted in jMRUI/AMARES and the ratios of triglyceride-to-water (TG/W) and total creatine-to-water (CR/W) were calculated.ResultsBesides an increased LV mass and a thickened IVS concomitant to the disease characteristics, patients with cardiac amyloidosis presented with decreased global longitudinal (GLS) and circumferential (GCS) strain. LV ejection fraction was preserved relative to controls (60.0 ± 13.2 vs. 66.1 ± 4.3%, p = 0.17). Myocardial TG/W ratios were significantly decreased compared to controls (0.53 ± 0.23 vs. 0.80 ± 0.26%, p = 0.015). CR/W ratios did not show a difference between both groups, but a higher standard deviation in patients with cardiac amyloidosis was observed. Pearson correlation revealed a negative association between elevated LV mass and TG/W (R = − 0.59, p = 0.004) as well as GCS (R = − 0.48, p = 0.025).ConclusionsA decrease in myocardial TG/W can be detected in patients with cardiac amyloidosis alongside impaired cardiac function with an association to the degree of myocardial thickening. Accordingly, 1H-CMRS may provide an additional diagnostic tool to gauge progression of cardiac amyloidosis along with standard imaging sequences.Trial registrationEK 2013–0132.

Cardiac magnetic resonance imaging: insights into developmental programming and its consequences for aging

“…4a), although the process is more time-consuming and technologically demanding. 55 Fig. 4 depicts an example of a hydrogen-1 CMR spectrum obtained from the interventricular septum of a baboon heart.…”

Nonenhanced Chemical Exchange Saturation Transfer Cardiac Magnetic Resonance Imaging in Patients With Amyloid Light‐Chain Amyloidosis

“…CEST is an emerging MRI technique for myocardial metabolic imaging with better spatial resolution and higher sensitivity than MR spectroscopy. 11,23 We found that the CEST signal was decreased in AL amyloidosis patients compared to the controls, and that it correlated significantly with clinical stage, LGE pattern and ECV. None of age, heart rate, BMI, or other MR parameters correlated significantly with global or septal CEST in the healthy controls, suggesting that the decreased CEST signal may associated with amyloid infiltration.…”

“…Previous studies have utilized cardiac MR spectroscopy to detect the creatine concentration with controversial results. Gastl et al found that creatine/water ratios did not show a difference between the patients and control, 11 while Nakae et al found that myocardial creatine concentration was lower in cardiac amyloidosis patients. 12 This inconsistency may due to relatively small cohorts and different disease stages, which was not reported in these studies.…”

“…9,10 Previous studies have utilized cardiac MR spectroscopy to detect the creatine concentration in relatively small patient cohorts, with controversial results and limited clinical application. 11,12 Chemical exchange saturation transfer (CEST) is an emerging metabolic technique to map creatine distribution in the myocardium. [13][14][15][16] A preliminary study has presented a clinically translatable contrast-free CEST technique validated in an animal model and in patients with chronic myocardial infarction.…”

Water‐suppression cycling 3‐T cardiac 1H‐MRS detects altered creatine and choline in patients with aortic or mitral stenosis

“…1,2 Therefore, most published cardiac 1 H-MRS studies have focused on quantifying lipid concentrations. [3][4][5] However, with sufficient data quality, 1 H-MRS can also assess lower concentration metabolites such as creatine (Cr) and choline* (Cho) that are of high clinical interest. [6][7][8] Cr is an important component in the creatine kinase (CK) enzyme system.…”