CMR Imaging With Rapid Visual T1 Assessment Predicts Mortality in Patients Suspected of Cardiac Amyloidosis

Abstract

OBJECTIVES This study tested the diagnostic and prognostic utility of a rapid, visual T1 assessment method for identification of cardiac amyloidosis (CA) in a “real-life” referral population undergoing cardiac magnetic resonance for suspected CA. BACKGROUND In patients with confirmed CA, delayed-enhancement cardiac magnetic resonance (DE-CMR) frequently shows a diffuse, global hyperenhancement (HE) pattern. However, imaging is often technically challenging, and the prognostic significance of diffuse HE is unclear. METHODS Ninety consecutive patients referred for suspected CA and 64 hypertensive patients with left ventricular hypertrophy (LVH) were prospectively enrolled and underwent a modified DE-CMR protocol. After gadolinium administration a method for rapid, visual T1 assessment was used to identify the presence of diffuse HE during the scan, allowing immediate optimization of settings for the conventional DE-CMR that followed. The primary endpoint was all-cause mortality. RESULTS Among patients with suspected CA, 66% (59 of 90) demonstrated HE, with 81% (48 of 59) of these meeting pre-specified visual T1 assessment criteria for diffuse HE. Among hypertensive LVH patients, 6% (4 of 64) had HE, with none having diffuse HE. During 29 months of follow-up (interquartile range: 12 to 44 months), there were 50 (56%) deaths in patients with suspected CA and 4 (6%) in patients with hypertensive LVH. Multivariable analysis demonstrated that the presence of diffuse HE was the most important predictor of death in the group with suspected CA (hazard ratio: 5.5, 95% confidence interval: 2.7 to 11.0; p < 0.0001) and in the population as a whole (hazard ratio: 6.0, 95% confidence interval 3.0 to 12.1; p < 0.0001). Among 25 patients with myocardial histology obtained during follow-up, the sensitivity, specificity, and accuracy of diffuse HE in the diagnosis of CA were 93%, 70%, and 84%, respectively. CONCLUSIONS Among patients suspected of CA, the presence of diffuse HE by visual T1 assessment accurately identifies patients with histologically-proven CA and is a strong predictor of mortality.

Role of Cardiac Magnetic Resonance in the Diagnosis and Prognosis of Nonischemic Cardiomyopathy

“…However, in cardiac amyloidosis, the LV cavity and myocardium often have very similar inversion times and occasionally the inversion time of the myocardium is shorter than that of the LV cavity. These characteristic alterations in inversion time can be readily recognized on inversion time scouts acquired after the administration of gadolinium-based contrast agents and have a very high sensitivity for the diagnosis of CA (73). The difference in inversion time between the LV cavity and the myocardium is also an important prognostic marker, as it provides insight into the burden of CA (74).…”

Transthyretin Cardiac Amyloidosis in Black Americans

“…White and colleagues recently published a study in CMR to assess prognosis in cardiac amyloidosis. 63 They employed the observation that in contradistinction to normal myocardium which crosses the null point (becomes black) after the blood pool, in cardiac amyloidosis, there is “failure to null the myocardium” represented as greater than 50% of myocardial tissue becoming black at an earlier inversion time as compared to blood. (Figure 5) The inversion time, an accurate indicator of global myocardial hyper-enhancement, was a strong predictor of mortality (HR of 6.0, 95% CI: 3.0–12.1).…”

Cardiovascular magnetic resonance for amyloidosis

“…Presence of LGE is predictive of prognosis in virtually all the cardiac pathologies, except for amyloidosis where studies have conflicting results and have been small and in AL only with non-standardised LGE approaches [10,12,13,37]. As discussed above, the LGE can be problematic in amyloid with global infiltration and altered wash-in and wash-out kinetics.…”