Native T1 mapping for the diagnosis of cardiac amyloidosis in patients with left ventricular hypertrophy

Background Cardiac magnetic resonance (CMR) with parametric mapping can improve the characterization of myocardial tissue. We studied the diagnostic value of native T1 mapping to detect cardiac amyloidosis in patients with left ventricular (LV) hypertrophy. Methods One hundred twenty-five patients with increased LV wall thickness (>= 12 mm end-diastole) who received clinical CMR in a 3 T scanner between 2017 and 2020 were included. 31 subjects without structural heart disease served as controls. Native T1 was measured as global mean value from 3 LV short axis slices. The study was registered at German clinical trial registry (DRKS00022048). Results Mean age of the patients was 66 +/- 14 years, 83% were males. CA was present in 24 patients, 21 patients had hypertrophic cardiomyopathy (HCM), 80 patients suffered from hypertensive heart disease (HHD). Native T1 times were higher in patients with CA (1409 +/- 59 ms, p < 0.0001) compared to healthy controls (1225 +/- 21 ms), HCM (1266 +/- 44 ms) and HHD (1257 +/- 41 ms). HCM and HHD patients did not differ in their native T1 times but were increased compared to control (p < 0.01). ROC analysis of native T1 demonstrated an area under the curve for the detection of CA vs. HCM and HHD of 0.9938 (p < 0.0001), which was higher than that of extracellular volume (0.9876) or quantitative late gadolinium enhancement (0.9406; both p < 0.0001). The optimal cut-off value of native T1 to diagnose CA was 1341 ms (sensitivity 100%, specificity 97%). Conclusion Non-contrast CMR imaging with native T1 mapping provides high diagnostic accuracy to diagnose cardiac amyloidosis in patients with left ventricular hypertrophy.