Cardiac amyloidosis: the disease diagnosed when signals stop being seen in isolation
Cardiac amyloidosis remains frequently underdiagnosed because its signs are scattered across specialties. This article summarizes key cardiac and extracardiac red flags, the role of different clinical areas, and the recommended diagnostic pathway.
When signals stop being seen in isolation
Cardiac amyloidosis can no longer be treated as an academic rarity. It is now recognized as a relevant, progressive and potentially treatable cause of heart failure, arrhythmias, increased ventricular wall thickness and valvular disease in older adults 2023 ACC Expert Consensus Decision Pathway on Comprehensive Multidisciplinary Care for the Patient With Cardiac AmyloidosisJournal of the American College of CardiologyConsenso prático sobre suspeição, avaliação multidisciplinar e cuidados de doentes com amiloidose cardíaca.Abrir fonteDiagnosis and treatment of cardiac amyloidosis: a position statement of the ESC Working Group on Myocardial and Pericardial DiseasesEuropean Heart JournalDocumento de posição da ESC sobre diagnóstico, subtipagem e tratamento da amiloidose cardíaca.Abrir fonte.
The challenge is that it rarely presents as an obvious diagnosis. It often appears disguised as common entities: heart failure with preserved ejection fraction, left ventricular hypertrophy, degenerative aortic stenosis, atrial fibrillation, conduction disease, peripheral neuropathy or carpal tunnel syndrome.
This is precisely why it remains underdiagnosed: the signs appear scattered over time, across specialties and clinical episodes. The problem is not only detecting signs. It is recognizing patterns.
Suspect the pattern
An isolated sign is rarely enough. Suspicion increases when heart failure, increased wall thickness, arrhythmia or extracardiac signs appear together 2023 ACC Expert Consensus Decision Pathway on Comprehensive Multidisciplinary Care for the Patient With Cardiac AmyloidosisJournal of the American College of CardiologyConsenso prático sobre suspeição, avaliação multidisciplinar e cuidados de doentes com amiloidose cardíaca.Abrir fonteDiagnosis and treatment of cardiac amyloidosis: a position statement of the ESC Working Group on Myocardial and Pericardial DiseasesEuropean Heart JournalDocumento de posição da ESC sobre diagnóstico, subtipagem e tratamento da amiloidose cardíaca.Abrir fonte.
Separate AL from ATTR
Excluding AL amyloidosis should enter the reasoning early because it changes urgency, prognosis and therapeutic approach Diagnosis and treatment of cardiac amyloidosis: a position statement of the ESC Working Group on Myocardial and Pericardial DiseasesEuropean Heart JournalDocumento de posição da ESC sobre diagnóstico, subtipagem e tratamento da amiloidose cardíaca.Abrir fonte.
Refer early
When several red flags coexist, the useful step is to start structured investigation and refer to teams experienced in the disease 2023 ACC Expert Consensus Decision Pathway on Comprehensive Multidisciplinary Care for the Patient With Cardiac AmyloidosisJournal of the American College of CardiologyConsenso prático sobre suspeição, avaliação multidisciplinar e cuidados de doentes com amiloidose cardíaca.Abrir fonteDiagnosis and treatment of cardiac amyloidosis: a position statement of the ESC Working Group on Myocardial and Pericardial DiseasesEuropean Heart JournalDocumento de posição da ESC sobre diagnóstico, subtipagem e tratamento da amiloidose cardíaca.Abrir fonte.
International recommendations reinforce one central idea: diagnosis requires structured clinical suspicion, integration of cardiac and extracardiac signs, exclusion of light-chain amyloidosis and appropriate referral 2023 ACC Expert Consensus Decision Pathway on Comprehensive Multidisciplinary Care for the Patient With Cardiac AmyloidosisJournal of the American College of CardiologyConsenso prático sobre suspeição, avaliação multidisciplinar e cuidados de doentes com amiloidose cardíaca.Abrir fonteDiagnosis and treatment of cardiac amyloidosis: a position statement of the ESC Working Group on Myocardial and Pericardial DiseasesEuropean Heart JournalDocumento de posição da ESC sobre diagnóstico, subtipagem e tratamento da amiloidose cardíaca.Abrir fonte.
What is cardiac amyloidosis?
Cardiac amyloidosis is an infiltrative cardiomyopathy caused by extracellular deposition of amyloid fibrils in the myocardium.
This deposition progressively changes cardiac structure and function, potentially causing increased ventricular wall thickness, diastolic dysfunction, heart failure, arrhythmias, conduction disease and a restrictive phenotype Diagnosis and treatment of cardiac amyloidosis: a position statement of the ESC Working Group on Myocardial and Pericardial DiseasesEuropean Heart JournalDocumento de posição da ESC sobre diagnóstico, subtipagem e tratamento da amiloidose cardíaca.Abrir fonte.
AL amyloidosis
Associated with immunoglobulin light chains produced by a clonal plasma-cell disorder. It should be actively excluded when clinical suspicion exists because diagnostic delay may have important prognostic consequences Diagnosis and treatment of cardiac amyloidosis: a position statement of the ESC Working Group on Myocardial and Pericardial DiseasesEuropean Heart JournalDocumento de posição da ESC sobre diagnóstico, subtipagem e tratamento da amiloidose cardíaca.Abrir fonte.
TTR genetic variant
Associated with variants in the TTR gene, which encodes transthyretin. It may combine cardiac, neurological and systemic manifestations, changing risk, family counselling and the diagnostic pathway 2023 ACC Expert Consensus Decision Pathway on Comprehensive Multidisciplinary Care for the Patient With Cardiac AmyloidosisJournal of the American College of CardiologyConsenso prático sobre suspeição, avaliação multidisciplinar e cuidados de doentes com amiloidose cardíaca.Abrir fonteDiagnosis and treatment of cardiac amyloidosis: a position statement of the ESC Working Group on Myocardial and Pericardial DiseasesEuropean Heart JournalDocumento de posição da ESC sobre diagnóstico, subtipagem e tratamento da amiloidose cardíaca.Abrir fonte.
Older adults
A form frequently observed in older adults, especially men, and associated with cardiac, neurological and musculoskeletal manifestations 2023 ACC Expert Consensus Decision Pathway on Comprehensive Multidisciplinary Care for the Patient With Cardiac AmyloidosisJournal of the American College of CardiologyConsenso prático sobre suspeição, avaliação multidisciplinar e cuidados de doentes com amiloidose cardíaca.Abrir fonteDiagnosis and treatment of cardiac amyloidosis: a position statement of the ESC Working Group on Myocardial and Pericardial DiseasesEuropean Heart JournalDocumento de posição da ESC sobre diagnóstico, subtipagem e tratamento da amiloidose cardíaca.Abrir fonte.
This distinction is not merely classificatory. It changes risk, prognosis, the diagnostic pathway and therapeutic strategy. Therefore, when cardiac amyloidosis is suspected, ESC recommendations propose an initial assessment combining monoclonal protein testing with appropriate imaging, such as echocardiography, cardiac magnetic resonance and cardiac bone scintigraphy, according to the clinical context Diagnosis and treatment of cardiac amyloidosis: a position statement of the ESC Working Group on Myocardial and Pericardial DiseasesEuropean Heart JournalDocumento de posição da ESC sobre diagnóstico, subtipagem e tratamento da amiloidose cardíaca.Abrir fonte.
Why does it remain underdiagnosed?
Cardiac amyloidosis is difficult to diagnose because many of its signs are common when analysed in isolation.
- Carpal tunnel
- Atrial fibrillation
- HFpEF
- Aortic stenosis
- Neuropathy
- Older adult
- Increased ventricular wall thickness
- HFpEF or arrhythmia
- Previous extracardiac signs
- Need for targeted investigation
Suspicion begins when signs stop being seen in isolation.
The error is often not in each individual assessment. It is in the absence of aggregation. Cardiac amyloidosis becomes clinically more suspicious when different signals stop being interpreted as independent episodes and start being read as parts of the same pattern.
Selected HFpEF
Prevalence of ATTR-CM in patients with heart failure, advanced age, preserved ejection fraction and increased ventricular wall thickness Prevalence of Transthyretin Amyloid Cardiomyopathy in Heart Failure With Preserved Ejection FractionJAMA CardiologyEstudo de prevalência que encontrou ATTR-CM numa proporção relevante de doentes com HFpEF e espessamento ventricular.Abrir fonte.
Men with the same profile
Prevalence observed in the male subgroup with heart failure, HFpEF and increased ventricular wall thickness Prevalence of Transthyretin Amyloid Cardiomyopathy in Heart Failure With Preserved Ejection FractionJAMA CardiologyEstudo de prevalência que encontrou ATTR-CM numa proporção relevante de doentes com HFpEF e espessamento ventricular.Abrir fonte.
Aortic stenosis
Coexistence described between ATTR-CM and aortic stenosis in patients older than 65 years, especially in populations undergoing TAVICardiac amyloidosis and aortic stenosis: a state-of-the-art reviewEuropean Heart Journal OpenRevisão sobre coexistência, diagnóstico e implicações clínicas da associação entre amiloidose cardíaca e estenose aórtica.Abrir fonteCardiac amyloidosis and aortic stenosis: common symptoms, dual pathology?ESC CardioPracticeArtigo educativo da ESC sobre a sobreposição clínica entre estenose aórtica e amiloidose cardíaca.Abrir fonte.
The practical conclusion is direct: cardiac amyloidosis should not be searched for indiscriminately in every patient. But it should be actively considered when several red flags coexist.
The signs that should raise suspicion
Suspicion should arise when cardiac and extracardiac signs accumulate in a coherent pattern.
When should suspicion switch on?
Structural phenotype
- HFpEF.
- Increased ventricular wall thickness.
- Diastolic dysfunction.
- Aortic stenosis.
Conduction and arrhythmia
- Atrial fibrillation.
- Conduction blocks.
- Pacemaker.
- Low voltage.
Previous signs
- Bilateral carpal tunnel.
- Spinal stenosis.
- Biceps tendon rupture.
Neuropathy and dysautonomia
- Peripheral neuropathy.
- Dysautonomia.
- Orthostatic hypotension.
Proteinuria and clone
- Proteinuria.
- Nephrotic syndrome.
- MGUS.
- Abnormal light chains.
The ACC consensus highlights clinical clues such as increased ventricular wall thickness without sufficient explanation by hypertension or valvular disease, heart failure symptoms, diastolic dysfunction, atrial fibrillation, conduction system disease and elevated cardiac biomarkers2023 ACC Expert Consensus Decision Pathway on Comprehensive Multidisciplinary Care for the Patient With Cardiac AmyloidosisJournal of the American College of CardiologyConsenso prático sobre suspeição, avaliação multidisciplinar e cuidados de doentes com amiloidose cardíaca.Abrir fonte. The association between ATTR-CM and musculoskeletal manifestations, including carpal tunnel, spinal stenosis and biceps tendon rupture, has also been reinforced in recent literature Musculoskeletal manifestations associated with transthyretin-mediated (ATTR) amyloidosis: a systematic reviewBMC Musculoskeletal DisordersRevisão sistemática sobre manifestações musculoesqueléticas associadas à amiloidose ATTR, incluindo túnel cárpico e outras pistas clínicas.Abrir fonte.
A single red flag may be non-specific; the co-occurrence of several red flags in an older adult should change the clinical reasoning.
It is not only a Cardiology topic
Cardiology is central to phenotypic confirmation, stratification and management of cardiac amyloidosis. But suspicion cannot depend on cardiology alone.
General practice, internal medicine and geriatrics
These areas can integrate progressive fatigue, treatment intolerance, syncope, atrial fibrillation, frailty, proteinuria, neuropathy, orthostatic hypotension and valvular disease.
Phenotype and stratification
Central to phenotypic confirmation and assessment of heart failure, arrhythmias, increased ventricular wall thickness, conduction disease and aortic stenosis.
Systemic signs
Peripheral or autonomic neuropathy, proteinuria, nephrotic syndrome, monoclonal protein or abnormal light chains should connect cardiac suspicion to systemic assessment Diagnosis and treatment of cardiac amyloidosis: a position statement of the ESC Working Group on Myocardial and Pericardial DiseasesEuropean Heart JournalDocumento de posição da ESC sobre diagnóstico, subtipagem e tratamento da amiloidose cardíaca.Abrir fonte.
Signs that may precede the heart
Bilateral carpal tunnel, spinal stenosis, spontaneous biceps rupture or multiple musculoskeletal interventions may appear years before the cardiac diagnosis.
Cardiac amyloidosis may be confirmed within the cardiology circuit, but it may start being suspected much earlier, in another consultation.
What should happen when suspicion exists?
When clinical suspicion exists, the goal is not to diagnose by intuition. The goal is to start a structured pathway.
From suspicion to diagnostic pathway
The clinical pattern gains weight when cardiac and extracardiac signs coexist.
Test for monoclonal protein, immunofixation and free light chains when appropriate.
Use echocardiography, cardiac MRI or scintigraphy depending on context and availability.
Refer early to teams experienced in cardiac amyloidosis.
Define AL, hereditary ATTR or wild-type ATTR before therapeutic decision-making.
Excluding AL is a critical step: assessment of monoclonal protein with serum and urine immunofixation and free light chains can radically change the diagnostic and therapeutic pathway Diagnosis and treatment of cardiac amyloidosis: a position statement of the ESC Working Group on Myocardial and Pericardial DiseasesEuropean Heart JournalDocumento de posição da ESC sobre diagnóstico, subtipagem e tratamento da amiloidose cardíaca.Abrir fonte. In an appropriate context, cardiac bone scintigraphy may allow non-invasive diagnosis of ATTR when uptake is compatible and there is no evidence of monoclonal protein Diagnosis and treatment of cardiac amyloidosis: a position statement of the ESC Working Group on Myocardial and Pericardial DiseasesEuropean Heart JournalDocumento de posição da ESC sobre diagnóstico, subtipagem e tratamento da amiloidose cardíaca.Abrir fonte.
Echocardiography with strain, cardiac magnetic resonance and biopsy may be needed in specific scenarios Diagnosis and treatment of cardiac amyloidosis: a position statement of the ESC Working Group on Myocardial and Pericardial DiseasesEuropean Heart JournalDocumento de posição da ESC sobre diagnóstico, subtipagem e tratamento da amiloidose cardíaca.Abrir fonte.
In the ATTR-ACT trial, published in the New England Journal of Medicine, tafamidis was associated with reduced all-cause mortality and cardiovascular hospitalizations in patients with transthyretin amyloid cardiomyopathy Tafamidis Treatment for Patients with Transthyretin Amyloid CardiomyopathyNew England Journal of MedicineEnsaio clínico que avaliou tafamidis em cardiomiopatia amiloide por transtirretina e demonstrou benefício em mortalidade e hospitalizações cardiovasculares.Abrir fonte.
Earlier diagnosis is not merely an academic issue. It is a condition for enabling appropriate therapeutic decisions in time.
Awareness is not overdiagnosis
Talking about cardiac amyloidosis does not mean turning every older adult with heart failure into a suspect.
It means recognizing combinations of signs that deserve another level of attention. An isolated carpal tunnel, isolated aortic stenosis or HFpEF may have multiple explanations. But the combination of HFpEF, increased ventricular wall thickness, atrial fibrillation, conduction disease, aortic stenosis, bilateral carpal tunnel, neuropathy, proteinuria or haematologic abnormalities should change the reasoning.
Cardiac amyloidosis is often missed not because signs are absent, but because care is fragmented. The challenge is to stop seeing isolated episodes and start recognizing patterns.
This content is intended for education and clinical awareness. It does not replace medical assessment, local guidelines, clinical judgement or specialist referral. Suspicion of cardiac amyloidosis should lead to structured investigation, particularly exclusion of AL amyloidosis when clinically appropriate.
References
- ACC 2023. 2023 ACC Expert Consensus Decision Pathway on Comprehensive Multidisciplinary Care for the Patient With Cardiac Amyloidosis. Journal of the American College of Cardiology.2023.https://www.jacc.org/doi/10.1016/j.jacc.2022.11.022
- ESC 2021. Diagnosis and treatment of cardiac amyloidosis: a position statement of the ESC Working Group on Myocardial and Pericardial Diseases. European Heart Journal.2021.https://academic.oup.com/eurheartj/article/42/16/1554/6212698
- JAMA Cardiol 2021. Prevalence of Transthyretin Amyloid Cardiomyopathy in Heart Failure With Preserved Ejection Fraction. JAMA Cardiology.2021.https://jamanetwork.com/journals/jamacardiology/fullarticle/2783400
- Review 2023. Cardiac amyloidosis and aortic stenosis: a state-of-the-art review. European Heart Journal Open.2023.https://pmc.ncbi.nlm.nih.gov/articles/PMC10630099/
- ESC CardioPractice. Cardiac amyloidosis and aortic stenosis: common symptoms, dual pathology?. ESC CardioPractice.2024.https://www.escardio.org/communities/councils/cardiology-practice/education/cardiopractice/cardiac-amyloidosis-and-aortic-stenosis-common-symptoms-dual-pathology/
- BMC 2023. Musculoskeletal manifestations associated with transthyretin-mediated (ATTR) amyloidosis: a systematic review. BMC Musculoskeletal Disorders.2023.https://pubmed.ncbi.nlm.nih.gov/38130034/
- ATTR-ACT 2018. Tafamidis Treatment for Patients with Transthyretin Amyloid Cardiomyopathy. New England Journal of Medicine.2018.https://www.nejm.org/doi/full/10.1056/NEJMoa1805689
