Advanced Imaging in Cardiac Amyloidosis

The Incremental Value of Native T1 Mapping-Derived Radiomics for The Diagnosis of Amyloid Light-Chain Cardiac Amyloidosis

RATIONALE AND OBJECTIVES

This study aimed to assess the incremental diagnostic value of non-contrast T1 mapping-derived radiomics in patients with amyloid light-chain cardiac amyloidosis (AL-CA).

METHODS

We retrospectively collected 86 patients with suspected AL-CA and 28 control patients who underwent cardiac MRI at 3.0 T in our institution, and the MRI data were divided into a training set and a test set. Radiomic features were extracted based on native T1 maps using a freely available software package. We applied LASSO logistic regression method to select radiomic features with high diagnostic value of AL-CA and develop a predictive model. The diagnostic performance of the radiomics model was evaluated using receiver operating characteristic curve analysis and compared to T1 values.

RESULTS

A total of 70 people were diagnosed with AL-CA, and cardiac involvement was observed in 202 myocardial slicers. The accuracy of T1 values for the diagnosis of myocardial involvement was 0.886, with a threshold value of 1375 ms. The radiomics score comprised a total of three features. The radiomics score demonstrated significantly higher sensitivity in detecting myocardial involvement compared to T1 values in both the training set (AUC 0.886 vs. 0.924, P = 0.025) and the test set (0.862 vs 0.915, P = 0.026). The combined model comprising T1 values and a radiomic feature named S(4,-4) Correlat showed higher diagnostic performance in comparison to T1 values alone both in the training and test sets, with AUC values of 0.929 and 0.909, respectively.

CONCLUSION

The radiomic features derived from native T1 mapping demonstrated incremental value for the diagnosis of AL-CA, which may be an alternative to T1-derived ECV to avoid the use of contrast in patients with suspected myocardial involvement in systemic amyloidosis.

Challenges and Uncertainties in the Diagnosis of Cardiac Amyloidosis: A Case Report

Amyloidosis is the condition when starch-like misfolded proteins form insoluble fibrils that deposit in tissues and cause dysfunction. Cardiac amyloidosis occurs due to the deposition of amyloid fibrils at the cardiac level and is an important cause of heart failure. This case reveals a patient with significant heart failure and arrhythmia, which later on turned out to be caused by cardiac amyloidosis. While regarded as a rare disease in practice, in retrospect, there are a lot of signs and imaging indicators, particularly in echocardiography that warrant an investigation of cardiac amyloidosis. In this case review, red flags in echocardiography that should endorse further testing for underlying cardiac amyloidosis are highlighted.

A review of recent advances in the diagnosis of cardiac amyloidosis, treatment of its cardiac complications, and disease-modifying therapies

Cardiac amyloidosis (CA), a significant condition resulting in infiltrative cardiomyopathy and heart failure with preserved ejection fraction (HFpEF), is caused by extracellular deposition of amyloid fibrils in the heart. Even though this has been known for an extended period, its prevalence in elderly patients with heart failure is increasingly being recognized. Recent advances in diagnosis with non-invasive methods like technetium pyrophosphate-labeled cardiac scintigraphy (i.e., Tc-PYP scan) and treatment options with tafamidis have played a pivotal role in awareness of the burden of this disease. Management of cardiac complications like heart failure, atrial arrhythmias, conduction block, ventricular arrhythmias, coronary artery disease, and aortic stenosis is now more critical than ever. We aim to review and outline the recent advances in diagnoses of CA. We also review management strategies for cardiac complications of CA with a brief summary of disease-modifying therapies.

Non-LGE Cardiac Magnetic Resonance Imaging in Patients with Cardiac Amyloidosis

Cardiac involvement is the leading cause of death in patients with cardiac amyloidosis. Early recognition is crucial as it can significantly change the course of the disease. Until now, the imaging modality of choice for diagnosing cardiac amyloidosis has been cardiac magnetic resonance imaging (CMR) with late gadolinium enhancement (LGE). LGE-CMR in patients with cardiac amyloidosis reveals characteristic LGE patterns that lead to a diagnosis while also correlating well with disease prognosis. However, LGE-CMR has numerous drawbacks that the newer CMR modality, T1 mapping, aims to improve. T1 mapping can be further subdivided into native T1 mapping, which does not require the use of contrast, and ECV measurement, which requires the use of contrast. Numerous T1 mapping techniques have been developed, each one with its own advantages and disadvantages when it comes to procedure difficulty and image quality. A literature review to identify relevant published articles was performed by two authors. This review aimed to present the value of T1 mapping in diagnosing cardiac amyloidosis, quantifying the amyloid burden, and evaluating the prognosis of patients with amyloidosis with cardiac involvement.

Noncardiac Manifestations of Hereditary Amyloidosis

The most common forms of cardiac amyloidosis are progressive, life threatening, and underrecognized. Symptoms affect a variety of organs and overlap with those of more common conditions, complicating and postponing diagnosis. Cardiac disease generally determines mortality, but noncardiac manifestations typically surface before cardiac symptoms, often several years before diagnosis. Familiarity with noncardiac manifestations may lead to early diagnosis, enabling treatment and improving prognosis.