Reduced Right Ventricular Peak Circumferential Strain Measured by MRI Predicts Wild-Type Transthyretin Amyloidosis in Patients With Ventricular Hypertrophy

Background: Wild-type transthyretin amyloidosis (ATTRwt) is often overlooked in elderly patients with left ventricular hypertrophy (LVH). Cardiac magnetic resonance (CMR)-tagging is established technique to evaluate LV local intra-myocardial motion, however usefulness to assess RV function by CMR is unknown. We assessed the hypothesis that the peak RV strain by CMR can distinguish ATTRwt. Methods: We analyzed 11 ATTRwt and 7 non-ATTRwt consecutive patients. We excluded patients younger than 50 years old, less than left ventricular ejectionfraction (LVEF) 50%, without LVH, old myocardial infarction, and with other types ofcardiac amyloidosis. To evaluate circumferential strain (CS), CMR-tagging images were analyzed on a post-processing workstation. The peak CS (%) and peak CS time (msec) of each segment were recorded. Results: LVEF was significantly lower in ATTRwt than non-ATTRwt (59.1 ± 4.0 vs66.2 ± 5.0, P = .004). The average of RV peak CS was significantly lower in ATTRwt than non-ATTRwt (−8.46 ± 2.32 vs −11.7 ± 2.86, P = .017). Univariate logistic regression analysis identified LVEF (odds ratio [OR]: 0.67, 95% confidence interval [95%CI]: 0.47–0.97, P = .49) and average of RV peak CS (OR: 1.74, 95%CI: 1.00–3.02, P = .49) were correlated with ATTRwt. In receiver operating characteristic analysis, the area under the curve for average of RV peak CS in discrimination between ATTRwt and non-ATTRwt were 0.83 (P = .02). Conclusion: Reduced RV peak CS predicts the presence of ATTRwt in elderly patients with LVH.