Photo Credit: Selvanegra

The following is a summary of “Tissue mapping by cardiac magnetic resonance imaging for the prognostication of cardiac amyloidosis: A systematic review and meta-analysis,” published in the May 2024 issue of Cardiology by Cai et al.

Cardiac amyloidosis is known to affect heart health significantly. With new treatments available, there is an increased interest in using cardiac magnetic resonance imaging (CMR) to predict outcomes in these patients.

Researchers conducted a retrospective study understanding how myocardial native T1 and T2 and extracellular volume (ECV) on cardiac MRI can predict outcomes in cardiac amyloidosis. 

They used observational cohort studies or single arms of clinical trials. MEDLINE, EMBASE, and CENTRAL were searched until January 2023. No exclusions were made based on publication date, outcomes, or language. Adult patients with amyloid cardiomyopathy were studied using CMR to assess myocardial native T1, T2, and ECV, linked with all-cause mortality. The inverse variance method was used to extract data for meta-analysis. 

The results showed that 3,852 citations were reviewed and 9 studies were selected (seven 1.5T MRI scanners, two 3.0T MRI scanners), including 955 patients (mean age 65 ± 10 years old, 32% female, mean left ventricular ejection fraction (LVEF) 59 ± 12%) with cardiac amyloidosis. Most had light chain (AL) amyloidosis (50%) or transthyretin (ATTR) amyloidosis (49%). The follow-up period was between 8 to 64 months (median follow-up=25 months). The mortality rate was 33%, with 320 deaths. Patients with ATTR amyloid had higher left ventricular mass index (127 ± 37 g/m²) than patients with AL (102 ± 34 g/m²)(P=0.02). NT-proBNP, troponin T, native T1, ECV, and T2 values were similar between ATTR and AL amyloid (all P>0.25). Higher T1 time had a hazard ratio of 1.33 (95% CI [1.10, 1.60], P=0.003, I²=29%). A 3% increase in ECV was associated with a hazard ratio of 1.16 (95% CI [1.09, 1.23], P<0.0001, I²=76%). A myocardial-to-skeletal T2 ratio below the mean had a hazard ratio of 5.23 (95% CI [2.27, 12.02], P<0.0001, I²=0%).

Investigators concluded that higher native T1 time and ECV, as well as a lower myocardial-to-skeletal T2 ratio on CMR, predict worse outcomes in cardiac amyloidosis. CMR tissue mapping can noninvasively monitor disease and predict prognosis in these patients.

Source: sciencedirect.com/science/article/pii/S0167527324003383