MRI-Based Distinction Between AL and ATTR Cardiac Amyloidosis: The Value of Strain Imaging and Contrast Enhancement Patterns

Presenting Author(s)

• 

  Ekaterina Pershina, PhD

  Radiologist
  City Clinical Hospital №1 named after N.I. Pirogov
  Moscow, Moskva, Russia

Primary Author(s)

• 

  Ekaterina Pershina, PhD

  Radiologist
  City Clinical Hospital №1 named after N.I. Pirogov
  Moscow, Moskva, Russia

Co-Author(s)

• 

  Zainab Magomedova, MD

  Radiologist
  City Clinical Hospital №1 named after N.I. Pirogov
  Moscow, Moskva, Russia

Co-Author(s)

• KK

  Konstantin Kovalev

  Radiologist
  City Clinical Hospital №1 named after N.I. Pirogov, Russia
• DS

  Dmitry Shchekochikhin, PhD

  Cardiologist
  Sechenov First Moscow State Medical University (Sechenov University), Russia
• DA

  Denis Andreev, MD

  Cardiologist
  Sechenov First Moscow State Medical University (Sechenov University), Russia

Background: Cardiac amyloidosis is a progressive and life-threatening disease that requires precise differentiation between AL and ATTR subtypes to guide appropriate therapy. Cardiac MRI, particularly when incorporating contrast enhancement and myocardial strain imaging, plays a pivotal role in diagnosis.
The aim of this study was to assess the utility of cardiac MRI parameters—including myocardial strain and late gadolinium enhancement (LGE) patterns—in distinguishing AL from ATTR cardiac amyloidosis.

Methods: This retrospective study included 25 patients with biopsy-confirmed cardiac amyloidosis (12 AL and 13 ATTR). Quantitative MRI parameters analyzed included myocardial wall thickness, left ventricular (LV) mass and volumes, regional and global 2D strain, and LGE distribution patterns. A p-value < 0.05 was considered statistically significant.

Results: Patients with ATTR amyloidosis demonstrated significantly increased myocardial thickness (interventricular septum: 17.8 ± 2.3 mm vs. 13.8 ± 2.4 mm; posterior wall: 14.2 ± 2.4 mm vs. 10.8 ± 2.0 mm, p < 0.01) and higher LV myocardial mass (110 ± 30 vs. 83 ± 17 g/m², p < 0.01) compared to those with AL.

Strain imaging revealed marked differences between groups:

• Circumferential strain: AL −13.46 ± 3.46% vs. ATTR −10.65 ± 3.95% (p = 0.029); cutoff value −14.51% (100% sensitivity, 56% specificity)


• Longitudinal strain: AL −10.95 ± 3.81% vs. ATTR −8.38 ± 2.19% (p = 0.048); cutoff −10.98% (100% sensitivity, 50% specificity)

LGE patterns also varied notably:

• ATTR patients more frequently exhibited transmural enhancement in the basal and mid inferolateral segments.


• AL amyloidosis was associated with predominant subendocardial enhancement, especially in the mid anterolateral and inferolateral walls (p < 0.05).


• Simultaneous subendocardial involvement of both LV and RV within the interventricular septum was a specific feature of ATTR (100% vs. 50%, p < 0.01).


• Right ventricular involvement was also more commonly observed in ATTR cases (100% vs. 58%, p < 0.05).

Using the QALE scoring system for quantifying LGE, ATTR cases yielded significantly higher scores (median = 13 [12; 14]) compared to AL (10.5 [1.75; 12], p < 0.01). A QALE score >13 distinguished ATTR from AL with 69% sensitivity and 83% specificity (AUC = 0.83; 95% CI: 0.64–0.97).

Conclusion:





A comprehensive cardiac MRI evaluation—integrating myocardial strain analysis with LGE assessment—enhances the ability to distinguish AL from ATTR cardiac amyloidosis. Circumferential and longitudinal strain parameters, along with characteristic contrast enhancement patterns and quantitative LGE scoring (QALE), offer valuable diagnostic criteria that can significantly improve accuracy in subtype differentiation, which is essential for guiding appropriate patient management.
















ROC curves for strains.
ROC curve for QALE scale
LGE in MRI of the heart in ATTR-amyloidosis. A subendocardial accumulation of the contrast agent in IVS on both the LV and RV (dotted red lines).