Myocardial T1 and T2 Mapping by Magnetic Resonance in Patients With Immune Checkpoint Inhibitor-Associated Myocarditis
Paaladinesh Thavendiranathan 1 , Lili Zhang 2 , Amna Zafar 3 , Zsofia D Drobni 4 , Syed S Mahmood 5 , Marcella Cabral 6 , Magid Awadalla 7 , Anju Nohria 8 , Daniel A Zlotoff 7 , Franck Thuny 9 , Lucie M Heinzerling 10 , Ana Barac 11 , Ryan J Sullivan 12 , Carol L Chen 13 , Dipti Gupta 13 , Michael C Kirchberger 14 , Sarah E Hartmann 3 , Jonathan W Weinsaft 15 , Hannah K Gilman 3 , Muhammad A Rizvi 16 , Bojan Kovacina 6 , Caroline Michel 6 , Gagan Sahni 17 , Ana González-Mansilla 18 , Antonio Calles 18 , Francisco Fernández-Avilés 18 , Michael Mahmoudi 19 , Kerry L Reynolds 12 , Sarju Ganatra 20 , Juan José Gavira 21 , Nahikari Salterain González 21 , Manuel García de Yébenes Castro 21 , Raymond Y Kwong 22 , Michael Jerosch-Herold 22 , Otavio R Coelho-Filho 23 , Jonathan Afilalo 6 , Eduardo Zataraín-Nicolás 18 , A John Baksi 24 , Bernd J Wintersperger 25 , Oscar Calvillo-Arguelles 26 , Stephane Ederhy 27 , Eric H Yang 28 , Alexander R Lyon 29 , Michael G Fradley 30 , Tomas G Neilan 31
Background: Myocarditis is a potentially fatal complication of immune checkpoint inhibitor (ICI) therapy. Data on the utility of cardiovascular magnetic resonance (CMR) T1 and T2 mapping in ICI myocarditis are limited.
Objectives: This study sought to assess the value of CMR T1 and T2 mapping in patients with ICI myocarditis.
Methods: In this retrospective study from an international registry of patients with ICI myocarditis, clinical and CMR findings (including T1 and T2 maps) were collected. Abnormal T1 and T2 were defined as 2 SD above site (vendor/field strength specific) reference values and a z-score was calculated for each patient. Major adverse cardiovascular events (MACE) were a composite of cardiovascular death, cardiogenic shock, cardiac arrest, and complete heart block.
Results: Of 136 patients with ICI myocarditis with a CMR, 86 (63%) had T1 maps and 79 (58%) also had T2 maps. Among the 86 patients (66.3 ± 13.1 years of age), 36 (41.9%) had a left ventricular ejection fraction <55%. Across all patients, mean z-scores for T1 and T2 values were 2.9 ± 1.9 (p < 0.001) and 2.2 ± 2.1 (p < 0.001), respectively. On Siemens 1.5-T scanner (n = 67), native T1 (1,079.0 ± 55.5 ms vs. 1,000.3 ± 22.1 ms; p < 0.001) and T2 (56.2 ± 4.9 ms vs. 49.8 ± 2.2 ms; p < 0.001) values were elevated compared with reference values.
Abnormal T1 and T2 values were seen in 78% and 43% of the patients, respectively. Applying the modified Lake Louise Criteria, 95% met the nonischemic myocardial injury criteria and 53% met the myocardial edema criteria. Native T1 values had excellent discriminatory value for subsequent MACE, with an area under the curve of 0.91 (95% confidence interval: 0.84 to 0.98). Native T1 values (for every 1-unit increase in z-score, hazard ratio: 1.44; 95% confidence interval: 1.12 to 1.84; p = 0.004) but not T2 values were independently associated with subsequent MACE.
Conclusions: The use of T1 mapping and application of the modified Lake Louise Criteria provides important diagnostic value, and T1 mapping provides prognostic value in patients with ICI myocarditis.
CITATION J Am Coll Cardiol. 2021 Mar 30;77(12):1503-1516. doi: 10.1016/j.jacc.2021.01.050