Atypical Case of Wild-Type Cardiac Amyloidosis with Septal Predominance and a Nonapical Sparing Strain Pattern

Introduction: Both hereditary (hATTR) and wild-type (wtATTR) transthyretin amyloidosis are under-recognized causes of cardiomyopathy (CM) and heart failure. Certain findings on Transthoracic Echocardiography (TTE) and cardiac Magnetic Resonance Imaging (cMRI) are suggestive but not diagnostic of ATTR. Although biopsy historically has been the gold standard for diagnosis, patients can be diagnosed with the highly sensitive and specific technetium-99m pyrophosphate scan (Tc-99m PYP). Genetic testing is recommended to confirm hATTR in patients diagnosed with ATTR cardiac amyloidosis. Despite growing awareness of this condition, many cases remain undiagnosed. This study evaluated if patients with TTEs concerning for infiltrative CM received appropriate diagnostic testing for ATTR-CM. Methods: Our echocardiography registry was queried from January 2011 to March 2020 for patients with our echo lab’s embedded infiltrative CM code. Data on demographics, comorbidities, TTE variables, cMRI results, PYP scans, genetic testing and biopsy results were retrieved from electronic medical records. Thorough manual chart review excluded other causes of CM. Data was expressed as mean ± SD and n (%). Results: We retrieved 510 patients (mean age 64 ± 16 years; 43% female) with TTEs suspicious for infiltrative CM revealing a mean interventricular septal diameter (IVSd) of 1.6 ± 0.3 cm. Only 67 (13%) patients underwent cMRI with 11 (16%) suggestive of cardiac amyloidosis. Of the patients with suspicious TTEs, 16 (3.1%) had PYP scans and 24 (4.7%) had tissue biopsy, with positive results in 7 (44%) and 11 (46%), respectively. Genetic testing in 31 (6%) patients revealed known hATTR mutations in 2 (6.5%) patients. Cardiac amyloidosis was diagnosed in 23 (4.5%) with 11 ATTR (2 hATTR), 5 amyloid light chain, and 7 unknown subtype. Conclusion: Despite clinical and TTE findings suspicious for ATTR-CM, many patients did not undergo appropriate confirmatory testing (see Figure 1).

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Association Between Ruptured Distal Biceps Tendon and Wild-Type Transthyretin Cardiac Amyloidosis

JAMA ◽

10.1001/jama.2017.9236 ◽

2017 ◽

Vol 318 (10) ◽

pp. 962 ◽

Cited By ~ 42

Author(s):

Hallie I. Geller ◽

Avinainder Singh ◽

Kevin M. Alexander ◽

Tara M. Mirto ◽

Rodney H. Falk

Keyword(s):

Cardiac Amyloidosis ◽

Biceps Tendon ◽

Wild Type ◽

Distal Biceps Tendon ◽

Distal Biceps

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Determination of strain pattern in patients with cardiac amyloidosis secondary to Multiple myeloma: a feature tracking study

Journal of Cardiovascular Magnetic Resonance ◽

10.1186/1532-429x-18-s1-p273 ◽

2016 ◽

Vol 18 (S1) ◽

Cited By ~ 1

Author(s):

Sabha Bhatti ◽

Srikanth Vallurupalli ◽

Stephanie Ambach ◽

Adam Z Magier ◽

Abdul Hakeem ◽

...

Keyword(s):

Multiple Myeloma ◽

Feature Tracking ◽

Cardiac Amyloidosis ◽

Strain Pattern

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Cardiac amyloidosis

ESC CardioMed ◽

10.1093/med/9780198784906.003.0373 ◽

2018 ◽

pp. 1545-1549

Author(s):

Martha Grogan

Keyword(s):

Heart Failure ◽

Median Survival ◽

Cardiac Amyloidosis ◽

Beta Blockers ◽

Angiotensin Converting Enzyme Inhibitors ◽

Wild Type ◽

Transthyretin Amyloidosis ◽

Converting Enzyme Inhibitors ◽

Right Ventricular Wall ◽

Immunoglobulin Light Chain Amyloidosis

Cardiac amyloidosis is an important cause of heart failure and cardiac arrhythmias, yet cardiologists often miss the diagnosis. Immunoglobulin light-chain amyloidosis (AL) is relatively rare, but likely underdiagnosed. The median survival of untreated patients with cardiac AL is 6 months after the onset of heart failure, highlighting the importance of early diagnosis. Wild-type transthyretin amyloidosis (ATTR) is increasingly recognized, especially in males over the age of 60 years. Although the clinical course of wild-type ATTR is more indolent, the median survival is approximately 3.5 years from diagnosis. Typical echocardiographic findings of increased left and right ventricular wall thickness, diastolic dysfunction, and pericardial effusion may suggest cardiac amyloidosis, along with abnormal delayed gadolinium enhancement and difficulty nulling the myocardium on cardiac magnetic resonance imaging. For AL, a tissue diagnosis is required. In contrast, ATTR may be diagnosed non-invasively with grade 2/3 uptake by nuclear scintigraphy in the absence of a monoclonal protein. Treatment of cardiac amyloidosis is entirely dependent on the type of amyloid and is directed at the underlying precursor protein or disrupting existing deposits. Cardiac care is supportive and challenging. Standard heart failure medications such as beta blockers and angiotensin-converting enzyme inhibitors are not routinely indicated and often cause haemodynamic deterioration. Outcomes of source-directed therapy for AL are improving and several clinical trials of treatment for ATTR are ongoing.

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