Association between Native Myocardial T1 Mapping and Cardiac Function and Macroscopic Fibrosis in Thalassemia Major

Background.Cardiovascular magnetic resonance (CMR) is the only available technique for the non-invasive quantification of MIO. The native T1 mapping has recently been proposed as an alternative to the universally adopted T2* technique, due to the higher sensitivity for detection of changes associated with mild or early iron overload. Objective.To study the association between T1 values and left ventricular (LV) function in thalassemia major (TM) and to evaluate for the first time if T1 measurements quantifying MIO are influenced by macroscopic myocardial fibrosis. Methods.146 TM patients (87 females, 38.7±11.1 years) consecutively enrolled in the Extension-Myocardial Iron Overload in Thalassemia Network underwent CMR. Native T1 values were obtained by Modified Look-Locker Inversion recovery (MOLLI) sequence in all 16 myocardial segments and the global value was the mean. LV function parameters were quantified by cine images. Late gadolinium enhancement (LGE) technique was used to detect macroscopic myocardial fibrosis. Results.No correlation was detected between global heart T1 values and LV volume indexes, LV mass index, or LV ejection fraction. Foourteen (9.6%) patients had an abnormal LV motion (13 hypokinesia and 1 dyskinesia) and they showed significantly lower global heart T1 values than patients without LV motion abnormalities (883.8±139.7 ms vs 959.0±91.3 ms; P=0.049). LGE images were acquired in 88 patients (60.3%) and macroscopic myocardial fibrosis was detected in 36 patients (40.9%). The 72.2% of patients had two or more foci of fibrosis. Patients with macroscopic myocardial fibrosis had significantly lower global heart T1 values (921.3±100.3 ms vs 974.5±72.7 ms; P=0.027) (Figure 1A). Data about the LGE was present for 1408 segments (88 patients x 16 segments) and 105 (7.5%) were positive. Segments with LGE had significantly lower T1 values than segments LGE-negative (905.6±110.6 ms vs 956.9±103.8 ms; P<0.0001) (Figure 1B). Conclusion.No correlation between T1 values and LV function parameters was detected, probably because the majority of the patients had normal or mild abnormal LV parameters. TM patients with macroscopic myocardial fibrosis showed significantly lower T1 values suggesting that T1 measurements for quantifying MIO are not influenced by macroscopic myocardial fibrosis and an association between myocardial iron and macroscopic fibrosis, previously detected only in pediatric TM patients. Figure Disclosures Pepe: Chiesi Farmaceutici S.p.A.:Other: no profit support and speakers' honoraria;Bayer:Other: no profit support;ApoPharma Inc.:Other: no profit support.Pistoia:Chiesi Farmaceutici S.p.A.:Other: speakers' honoraria.Meloni:Chiesi Farmaceutici S.p.A.:Other: speakers' honoraria.

Native T1 Values and Cardiac Involvement in Patients with Thalassemia Major

Background.The T2* cardiovascular magnetic resonance (CMR) is the gold standard for the non invasive detection of myocardial iron overload (MIO). The native myocardial T1 mapping has been proposed as a complementary tool, thanks to its higher sensitivity in presence of small amounts of iron, but no data are available in literature about its clinical impact. Objective:To explore the clinical impact of T1 mapping for detecting cardiac complications in thalassemia major (TM). Methods.We considered 146 TM patients (87 females, 38.7±11.1 years) consecutively enrolled in the Extension-Myocardial Iron Overload in Thalassemia Network. Three parallel short-axis slices of the left ventricle (LV) were acquired with the Modified Look-Locker Inversion recovery (MOLLI) sequence. The native T1 values in all 16 myocardial segments were obtained and the global value was the mean. Results.Twenty-one patients had an history of cardiac complications: 11 heart failure, 8 arrhythmias (7 supraventricular and 1 ventricular), and 2 pulmonary hyperthension. Patients with cardiac complications had significantly lower global heart T1 values (879.3±121.9 ms vs 963.2±98.5 ms; P<0.0001) (Figure) but comparable T2* values (33.32±11.66 ms vs 37.17±9.15 ms; P=0.116). Cardiac complications were more frequent in the group of patients with reduced global heart T1 value (<928 ms for males and <989 ms for females) compared to the group with normal global heart T1 value (71.4% vs 39.5%; P=0.009). Odds ratio (OR) for cardiac complications was 3.8 (95%CI=1.3-10.9) for patients with reduced global heart T1 value versus patients with normal global heart T1 value. Conclusion:We found out a significant association between decreased native global heart T1 values and a history of cardiac complications, suggesting that an early detection of myocardial iron burden by native T1 can support the clinicians in modifing chelation therapy earlier. Figure Disclosures Pepe: ApoPharma Inc.:Other: no profit support;Bayer:Other: no profit support;Chiesi Farmaceutici S.p.A.:Other: no profit support and speakers' honoraria.Pistoia:Chiesi Farmaceutici S.p.A.:Other: speakers' honoraria.Meloni:Chiesi Farmaceutici S.p.A.:Other: speakers' honoraria.

Validation and feasibility of liver T1 mapping using free breathing MOLLI sequence in children and young adults

We investigated the feasibility of free-breathing modified Look-Locker inversion recovery (MOLLI) sequence for measuring hepatic T1 values in children and young adults. To investigate the accuracy and the reproducibility of the T1 maps, a phantom study was performed with 12 different gadoterate meglumine concentrations and the T1 relaxation times of phantoms measured with the MOLLI sequence were compared against those measured with three different sequences: spin-echo inversion recovery, variable flip angle (VFA), and VFA with B1 correction. To evaluate the feasibility of free-breathing MOLLI sequence, hepatic T1 relaxation times obtained by free-breathing and breath-hold technique in twenty patients were compared. The phantom study revealed the excellent accuracy and reproducibility of MOLLI. In twenty patients, the mean value of hepatic T1 values obtained by free-breathing (606.7 ± 64.5 ms) and breath-hold (609.8 ± 64.0 ms) techniques showed no significant difference (p > 0.05). The Bland–Altman plot between the free-breathing and breath-hold revealed that the mean difference of T1 values was − 3.0 ms (− 0.5%). Therefore, T1 relaxation times obtained by MOLLI were comparable to the values obtained using the standard inversion recovery method. The hepatic T1 relaxation times measured by MOLLI technique with free-breathing were comparable to those obtained with breath-hold in children and young adults.

P1604 T1 mapping in asymptomatic patients with extracardiac sarcoidosis

Funding Acknowledgements LQ1605 from the National Program of Sustainability II (MEYS CR) Introduction Sarcoidosis is a systemic granulomatous disease affecting in particular the respiratory tract. Estimated 5% of these patients have clinical symptoms of heart involvement. Real number of patients with cardiac sarcoidosis is thought to be higher (around 20-30%), because the granulomatous process is sometimes asymptomatic. Cardiac magnetic resonance (CMR) including T1 relaxation time measurement could potentially detect early asymptomatic stadia of sarcoidosis of the heart. Purpose The aim of this study was to assess T1 mapping in detection of early cardiac involvement in asymptomatic patients with sarcoidosis. Methods One hundred twenty patients with sarcoidosis of the respiratory tract and/or extrapulmonary sarcoidosis and without any heart disease history were included. One hundred thirteen of them underwent CMR examination at 3,0 MR scanner. Cine images for assessment of left ventricular (LV) volumetric and functional parameters, and pre- and post-contrast Saturation method using adaptive recovery times for cardiac T1 mapping (SMART1map) and Modified Look-Locker Inversion recovery (MOLLI) images were acquired for assessment of native T1 relaxation time and extracellular volume (ECV). The measured parameters were compared between sarcoidosis patients and 22 healthy controls. Results Sarcoidosis patients had not enlarged LV (end-diastolic volume 119 ± 24ml vs 97 ± 20ml, p = NS) and normal global and regional systolic LV function – LV ejection fraction (EF) 65 ± 5% vs 66 ± 7% (p = NS). Mean native T1 relaxation time was not prolonged - 1464 ± 93 msec vs 1482 ± 88msec (p = NS) measured by SMART1map and 1317 ± 60 msec vs 1313 ± 83msec (p = NS) measured using MOLLI sequence. Similarly, mean ECV value was not increased - 16,3 ± 3,4% vs 17,9 ± 3,7% (p = NS) measured by SMART1map and 30,9 ± 2,9msec vs 30,7 ± 5,0% (p = NS) measured using MOLLI sequence. Conclusion Myocardial native T1 relaxation time was not prolonged and ECV was not increased in asymptomatic patients with extracardiac sarcoidosis.

Abstract 11232: Assessment of Diffuse Myocardial Fibrosis With Native T1 Values on Cardiovascular Magnetic Resonance and Its Relationship With Myocardial Function in Asymptomatic Aortic Stenosis Patients

Introduction: Aortic stenosis (AS) typically provokes diffuse myocardial fibrosis (DMF). Methods to evaluate DMF using cardiovascular magnetic resonance (CMR) are yet to be made easier and validated for wide clinical use. Hypothesis: To test whether T1 mapping, without the use of gadolinium contrast, may be useful for assessment of DMF and whether it correlates with subclinical myocardial dysfunction in asymptomatic AS patients. Methods: 80 asymptomatic patients with moderate or severe AS and normal LVEF and 15 sex-matched control subjects were prospectively enrolled. Patients underwent 2D-echocardiography, speckle tracking imaging and CMR in a 3.0T scanner including mapping of T1 relaxation time with modified Look-Locker Inversion-recovery (MOLLI) sequence. Patients were divided into three groups according to the native T1 value. Results: Native T1 values correlated well with the degree of DMF on intraoperative myocardial biopsy specimens (r=0.777, p-value<0.001) and differed significantly between AS and control subjects (1208±45 vs. 1169±21(msec), p-value<0.001). LV volumes and mass were significantly different between the tertiles (80.8±10.3 vs. 93.4±23.1 vs. 121.5±37.9(mL/m2), 78.0±18.3 vs. 93.4±29.7 vs. 121.1±44.3(g/m2) for LV end-diastolic volume index and LV mass index, all p-value<0.001) as well as the degree of AS severity (0.55±0.14 vs. 0.46±0.12 vs. 0.45±0.13(cm2/m2), p-value=0.008 for indexed aortic valve area on echocardiography). Native T1 significantly correlated with global longitudinal strain by 2D-speckle trackle imaging (r=0.598, p-value<0.001), e’ velocity (r=-0.437, p-value<0.001) and indexed left atrial volume (r=0.475, p-value<0.001). Conclusion: Native T1 value using MOLLI sequence in asymptomatic AS patients enables noninvasive, simple quantification of DMF and correlates well with subclinical LV systolic and diastolic dysfunction.