IRON IN THE HUMAN HEARTS: DISTRIBUTION AND ASSOCIATION WITH R2* VALUES BY CMR
Author(s): ,
Antonella Meloni
Affiliations:
Fondazione G. Monasterio CNR-Regione Toscana,Pisa,Italy
,
Aurelio Maggio
Affiliations:
Ospedale 'V. Cervello',Palermo,Italy
,
Vincenzo Positano
Affiliations:
Fondazione G. Monasterio CNR-Regione Toscana,Pisa,Italy
,
Annalisa Angelini
Affiliations:
University of Padua Medical School,Padova,Italy
,
Maria Caterina Putti
Affiliations:
University of Padua Medical School,Padova,Italy
,
Emiliano Maresi
Affiliations:
University of Palermo,Palermo,Italy
,
Angela Pucci
Affiliations:
University of Pisa,Pisa,Italy
,
Cristina Basso
Affiliations:
University of Padua Medical School,Padova,Italy
,
Filippo Leto
Affiliations:
Ospedale 'V. Cervello',Palermo,Italy
,
Martina Perazzolo
Affiliations:
University of Padua Medical School,Padova,Italy
,
Laura Pistoia
Affiliations:
Fondazione G. Monasterio CNR-Regione Toscana,Pisa,Italy
Alessia Pepe
Affiliations:
Fondazione G. Monasterio CNR-Regione Toscana,Pisa,Italy
EHA Library. Meloni A. Jun 15, 2019; 266912; PS1295
Dr. Antonella Meloni
Dr. Antonella Meloni
Contributions
Abstract

Abstract: PS1295

Type: Poster Presentation

Presentation during EHA24: On Saturday, June 15, 2019 from 17:30 - 19:00

Location: Poster area

Background
T2* (or R2*=1000/T2*) cardiac magnetic resonance (CMR) allows the non-invasive and reproducible measurement of myocardial iron and has been established as fundamental to the best practice management of iron loaded patients to improve morbidity and mortality.

Aims
In the present study we calibrated cardiac R2* values against myocardial tissue -measured iron concentration by using a segmental approach and we assessed the distribution and regional variations in iron distribution.

Methods

Five hearts of patients with thalassemia were donated after death (N=4) or cardiac transplantation (N=1) to the CoreLab of the MIOT (Myocardial Iron Overload in Thalassemia) Network. A multislice multiecho T2* approach was adopted. After CMR, used as guidance, the heart was cut in three short-axis slice and each slice was cut into different equiangular segments accordingly with AHA segmentation and differentiated  into endocardial and epicardial layer, the same ones in which the T2* was assessed. Tissue iron concentration in the segments was measured with an atomic absorption spectrometer.

Results
55 samples were used since it was possible to analyze all the 16 samples only from  two hearts due to medical-forensic reasons. The mean iron concentration in all samples was 4.71±4.67 mg/g dw. Segmental iron levels ranged from 0.24 to 13.78 mg/g dw. Mean iron concentration was significantly higher in the epicardial than in the endocardial layer (5.99±6.01 mg/g dw vs 4.84±4.87 mg/g dw; P=0.042).

The coefficient of variability (CoV) of iron for myocardial segments ranged from 8.08% to 24.54%, with a mean value for all patients of 13.49±6.93%. Four different main circumferential regions (anterior, septal, inferior and lateral) were defined. A circumferential heterogeneity was noted, with more iron observed in the anterior region, followed by the inferior region. The heterogeneity in circumferential iron concentration expressed as percentage deviation of the regions from the global value is shown in the Figure 1A.

A strong linear correlation (R-square=0.956) was found by plotting ln(R2*-ROI) and ln[Fe] with a slope s=0.654 (95% confidence intervals-CI=0.616-0.693) and intercept i=4.216 (95% CI=4.150-4.281) (Figure 1B). The linear relation was converted to the calibration curve: [Fe] = 0.001591 X (R2*)1.529.

Conclusion
Our data suggests an heterogeneous pattern of cardiac iron distribution with higher epicardial layer involvement. Heart R2* provided a robust calibration against chemically assayed cardiac iron, further validating the current clinical practice of monitoring cardiac iron in vivo by CMR.

Session topic: 29. Iron metabolism, deficiency and overload

Keyword(s): Iron overload, Thalassemia

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