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Cardiomyopathy & Amyloidosis

Cardiomyopathy is a broad term that is used to describe disease of the heart muscle, making it difficult for the heart to provide the body with an adequate blood supply. It can lead to heart failure and even death. In this article, we’ll discuss the types of cardiomyopathy and its connection to amyloidosis. 


Risk Factors 

It has no ideal target, as it can affect a person of any age, race, or gender. However, there are a number of risk factors that can put one at an increased chance of developing cardiomyopathy. 

  • Genetic History → Family history of cardiomyopathy, heart failure, or sudden cardiac arrest
  • High Blood Pressure → Over a long period of time
  • Heart Conditions → Past history of heart attack, coronary artery disease, or infection of the heart
  • Obesity → Tends to make the heart work harder to perform its normal function
  • Alcohol Use → Long period of alcohol use
  • Drug Use → Use of illicit drugs, such as cocaine, amphetamines, and anabolic steroids
  • Medications → Drugs used in the treatment of cancer, such as chemotherapy and radiation

Additionally, there are a number of diseases that increase the risk of developing cardiomyopathy, including:

  • Amyloidosis
  • Connective Tissue Disorders
  • Diabetes
  • Hemochromatosis (excess iron storage)
  • Sarcoidosis
  • Thyroid Disease


Types of Cardiomyopathy

  • Dilated Cardiomyopathy → Dilation of the left ventricle prevents the heart from pumping effectively. It most commonly occurs in middle-aged men and is typically the result of coronary artery disease, heart attack, or genetic defects.

  • Hypertrophic Cardiomyopathy → Abnormal thickening of heart muscle, most commonly affecting the muscles surrounding the left ventricle. This type of cardiomyopathy is strongly associated with a family history of the disease. There have been genetic mutations linked specifically with this type of cardiomyopathy.

  • Restrictive Cardiomyopathy → Stiffening of the heart muscle results in an inelasticity, making it difficult for the heart to expand and fill. It is most commonly seen in the elder population. The disease can be of idiopathic origin or of disease such as amyloidosis. This is the least common type of cardiomyopathy. 
  • Arrhythmogenic Right Ventricular Dysplasia → Scar tissue replaces healthy tissue of the right ventricle. This form of cardiomyopathy is rare and often the result of genetic mutations.
  • Unclassified Cardiomyopathy → All other forms of cardiomyopathy fall within this category.



Cardiomyopathy is one of the hallmarks of amyloidosis, often seen in the transthyretin form of amyloidosis (ATTR). ATTR-CM, or transthyretin amyloid cardiomyopathy, is a disease where the transthyretin protein becomes unstable and misfolds. This unstable protein (“amyloid”) then deposits in the heart muscle, resulting in thickening and stiffening of the heart. 

The two types of ATTR-CM are wild-type ATTR-CM (wtATTR) or hereditary ATTR-CM (hATTR). wtATTR-CM is the most common form of ATTR-CM, affecting predominantly white males 60+ years old. hATTR-CM is genetic affecting both men and women, and presents as early as 50+ years old. Interestingly, one of the mutations causing hATTR, V122I, is seen almost exclusively in individuals of African ancestry. It is believed that approximately 3-4% of African Americans carry this mutation, regardless of whether or not they develop symptoms. 

Most importantly, these are the most common and important signs and symptoms to be aware of, in order to diagnose ATTR amyloidosis.


Expert Insights – Cardiac Clues and Clinical Signs

In part 1 of a 2-part series, Dr. Keyur Shah, cardiologist from VCU Health’s cardiac amyloidosis care team, discusses the two most common types of transthyretin (TTR) amyloidosis: hereditary and wild-type. He details how ATTR cardiomyopathy amyloidosis presents and manifests itself to impair the heart. Dr. Shah lists clinical clues, “red flags,” and biomarkers which can raise suspicion of the presence of amyloidosis. Next he discusses insights that can be gained from echocardiograms, electrocardiograms, and cardiac MRIs and how they offer possible indicators of the disease presence. Once amyloidosis is suspected, definitive diagnosis testing is next.

In part 2 of a 2-part series, Sarah Paciulli, Heart Failure Nurse Practitioner, from VCU Health’s cardiac amyloidosis care team, continues from where Dr. Keyur Shah ended in Part I and discusses here in Part II the non-cardiac clues of transthyretin (TTR) amyloidosis. She expands the list of clinical clues and “red flags” that clinicians should be alert to, including orthopedic manifestations, erectile dysfunction, and polyneuropathy.











A Patient Guide for Understanding Amyloidosis

Amyloidosis is a multi-system disease, making diagnosis challenging. In this informative patient guide, the American Society of Nuclear Cardiology (ASNC) discusses common symptoms, types of amyloidosis, red flags to be aware of, diagnostic tests and available treatment options. 

CLICK HERE to read/download ASNC’s Guide for Understanding Amyloidosis


Multidisciplinary Care for Cardiac Amyloidosis Patients

Multi-systemic diseases such as amyloidosis are complex to diagnose, but also complex in treatment and ongoing patient care. It takes a village. In this seminal piece, the American College of Cardiology (ACC) provides an Expert Consensus Decision Pathway on Comprehensive Multidisciplinary Care for the Patient With Cardiac Amyloidosis. 

According to Dr. Vaishali Sanchorawala, Director of the Amyloidosis Center at Boston Medical Center, “The results and progress in the therapeutic landscape of systemic amyloidosis are unbelievable, unprecedented and unheard of for this uniformly fatal disease of the 1990s. But they are not enough, and therefore we need to work together to make a difference.

This paper is an absolute must-read for cardiologists and other specialties such as neurology, gastroenterology, nephrology and hematology.

To read, CLICK HERE.


Thank you.

Kittleson M, Ruberg F, et al. 2023 ACC Expert Consensus Decision Pathway on Comprehensive Multidisciplinary Care for the Patient With Cardiac Amyloidosis. J Am Coll Cardiol. 2023 Mar, 81 (11) 1076–1126.

ATTR-CM: Don’t Assume it’s Wild-Type TTR Amyloidosis

Historically it has been thought that the majority of elderly cardiomyopathy patients diagnosed with amyloidosis, ATTR-CM, transthyretin amyloid cardiomyopathy, suffered from wild-type, a non-genetic version of the disease that most commonly affects but is not exclusive to men over seventy years of age. A study in the UK conducted from January 2010 through August 2022 was conducted to determine whether this was true. It is thought that this study was the first time such a large population of ATTR-CM patients was studied to consider the actual prevalence of the differing disease types. The researchers stated purpose was “ …to estimate the prevalence, clinical characteristics and prognostic implications of transthyretin (TTR) variants among elderly patients diagnosed with ATTR-CM.”1

A paper detailing the results of the study, ‘Prevalence, characteristics and outcomes of older patients with hereditary versus wild-type transthyretin amyloid cardiomyopathy’ by A. Porcari et al.1, published January 16, 2023 in the European Journal of Heart Failure provide specifics about the methodology, statistical analysis of the results, and an analysis of the findings. An invited editorial about that article, ‘Variant and wild type transthyretin amyloidosis: two sides of the same coin or different currencies in different pockets?’, by Osnat Itzhaki Ben Zadok and Rodney H. Falk provides comments and an assessment of the study discussed in the A. Porcari paper.2  A helpful summary of the differences between wild-type and hereditary amyloidosis can be found here.3

With increased awareness of amyloidosis and the various types as well as developments in the technology used to diagnose and type ATTR amyloidosis, it has now become relatively easy to determine whether a patient is suffering from the hereditary version or the wild-type. Imaging has become preferred over the previous “gold standard” of endomyocardial biopsy. The study population was selected from those for whom ATTR-CM was established as the diagnosis using echocardiography, nuclear scintigraphy, and TTR gene sequencing at the National Amyloidosis Center (NAC) in London, the single center for diagnosing and treating amyloidosis patients in the UK. Correct diagnosis and typing of the disease could allow for appropriate treatment to begin resulting in the likelihood of an improved disease management and outcome for the patient.

A total of 2,029 patients were accepted into the study, none of whom had previously received genetic testing for the disease. Patients identified through gene sequencing as having the hereditary version of the disease, 141 total, were moved to medication as soon as it became available. Of note, all patients who had been treated with any of the then available medication for ATTR amyloidosis — tafamidis, inotersen, diflunisal, or patisiran, and all patients who were participating in clinical trials for therapies for the disease — were excluded from the study. This was to remove the possibility of the therapies skewing the results. All participants were 70 years of age or older. The patients were all followed at the NAC in London, the only center for the diagnosis and treatment of Amyloidosis in the UK. This allowed for unprecedented access to what is thought to be the majority of ATTR-CM in the country. All causes of death were tracked for the duration of the study.

The table below illustrates the number of ATTM-CM patients in the study who were thought to be suffering from wild-type amyloidosis but after testing were actually found to have a hereditary, variant, version of the disease instead. Specific data from the tests used to make this determination can be found in the article where the following table is found.

Correcting the diagnosis then allowed the patients to be moved to more appropriate therapies.

Further discussion in the Porcari article considers the study population and those currently listed in the THAOS registry4  by percentage of total ATTR-CM  patients in the United Kingdom, the United States, and the rest of the World for both wild-type and variant disease with the more common variants also identified. It is thought that as many as 20% of ATTR-CM identified as having the wild-type disease likely have a variant version but have not had genetic testing to correctly determine that.1

The article goes on to discuss the most commonly seen demographics and presentations of  ATTRwt-CM and ATTRv-CM in the elderly, and the effects of the various therapies currently available as well as their mechanisms and limitations.

While some symptoms of wild-type amyloidosis and hereditary, variant, amyloidosis are similar, it is easy to differentiate between the two diseases. With careful testing, as noted in the article, this then allows for the proper management and treatment of the disease. The concluding paragraph of the paper really sums up the findings and sends an important message.

In conclusion, up to 20.7% of elderly patients with ATTR-CM carry a pathogenic TTR mutation with a higher proportion still among specific ethnic groups. Among patients diagnosed with ATTR-CM, younger age at diagnosis, female gender, Afro-Caribbean ethnicity, AF, IHD, polyneuropathy and orthostatic hypotension are independently associated with ATTRv-CM. A diagnosis of ATTR-CM should prompt sequencing of the TTR gene in all patients, regardless of age, gender and ethnicity.”1


1.     https://onlinelibrary.wiley.com/doi/full/10.1002/ejhf.2776  Prevalence, characteristics and outcomes of older patients with hereditary versus wild-type transthyretin amyloid cardiomyopathy, Aldostefano Porcari, Yousuf Razvi, Ambra Masi, Rishi Patel, Adam Ioannou, Muhammad U. Rauf, David F. Hutt, Dorota Rowczenio, Janet Gilbertson, Ana Martinez-Naharro, Lucia Venneri, Carol Whelan, Helen Lachmann, Ashutosh Wechalekar, Candida Cristina Quarta, Marco Merlo, Gianfranco Sinagra, Philip N. Hawkins, Marianna Fontana, Julian D. Gillmore, January 2023

2.     https://onlinelibrary.wiley.com/doi/10.1002/ejhf.2808  Variant and wild type transthyretin amyloidosis: two sides of the same coin or different currencies in different pockets?
Osnat Itzhaki Ben Zadok, Rodney H. Falk, February 2023

3.     https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7500251/   Transthyretin Amyloidosis: Update on the Clinical Spectrum, Pathogenesis, and Disease-Modifying Therapies
Haruki Koike  and Masahisa Katsuno, September 2020

4.     https://www.jns-journal.com/article/S0022-510X(15)00745-5/fulltext THAOS – The Transthyretin Amyloidosis Outcome Survey , F. Barroso, M. Waddinton-Cruz, et. Al., October 2015


Heart Failure & Amyloidosis


We would like to thank the Cleveland Clinic for this information, unless specifically noted otherwise.



Heart failure occurs when the heart muscle doesn’t pump blood as well as it should. Heart failure can occur if the heart cannot pump (systolic) or fill (diastolic) adequately.

Almost six million Americans have heart failure, and more than 870,000 people are diagnosed with heart failure each year. Heart failure (congestive heart failure) is the leading cause of hospitalization in people older than 65.



There are many causes of heart failure, but the condition is generally broken down into these types:

Left-sided heart failure

Heart failure with reduced left ventricular function (HF-rEF)

The lower left chamber of the heart (left ventricle) gets bigger and cannot squeeze (contract) hard enough to pump the right amount of oxygen-rich blood to the rest of the body.

Heart failure with preserved left ventricular function (HF-pEF)

The heart contracts and pumps normally, but the bottom chambers of the heart (ventricles) are thicker and stiffer than normal. Because of this, the ventricles can’t relax properly and fill up all the way. Because there’s less blood in the ventricles, the heart pumps out less blood to the rest of the body when it contracts.

Right-sided heart failure

Heart failure can also affect the right side of the heart. Left-sided heart failure is the most common cause of this. Other causes include certain lung problems and issues in other organs.



Symptoms of heart failure include:

  • Shortness of breath.
  • Feeling tired (fatigue) and having leg weakness when active.
  • Swelling in ankles, legs and abdomen.
  • Weight gain.
  • Need to urinate while resting at night.
  • Rapid or irregular heartbeats (palpitations).
  • A dry, hacking cough.
  • A full (bloated) or hard stomach, loss of appetite or upset stomach (nausea).

Symptoms of heart failure can range from mild to severe and may come and go. Unfortunately, heart failure usually gets worse over time. As it worsens, patients may have more or different signs or symptoms.



Although the risk of heart failure doesn’t change with age, you’re more likely to have heart failure when older. Many medical conditions that damage the heart muscle can cause heart failure. Common conditions include:



Common tests include:



Ejection fraction (EF) is one way to measure the severity of the condition. If it’s below normal, it can mean the patient has heart failure. The ejection fraction tells the healthcare provider how good of a job the left or right ventricle is doing at pumping blood. Usually, the EF number is talking about how much blood the left ventricle is pumping out because it’s the heart’s main pumping chamber.

Several non-invasive tests can measure the EF. A normal left ventricular ejection fraction (LVEF) is 53% to 70%. An LVEF of 65%, for example, means that 65% of the total amount of blood in the left ventricle is pumped out with each heartbeat. The EF can go up and down, based on the heart condition and how well the treatment works.



As stated by the Cleveland Clinic, cardiomyopathy is one of the medical conditions that damage the heart muscle and can cause heart failure. Cardiomyopathy refers to conditions that affect the myocardium (heart muscle). Cardiomyopathy can make your heart stiffen, enlarged or thickened and can cause scar tissue. As a result, your heart can’t pump blood effectively to the rest of your body. In time, your heart can weaken and cardiomyopathy can lead to heart failure. 

One of the common types of cardiomyopathy is Transthyretin amyloid cardiomyopathy (ATTR-CM), characterized by an abnormal protein buildup (ATTR amyloidosis) in the heart’s left ventricle (primary blood-pumping chamber). ATTR-CM is a life-threatening, underrecognized, and underdiagnosed type of amyloidosis that affects the heart and is associated with heart failure. It was once considered a rare disease, but recently, improved diagnostic tools and greater attention to early manifestations of the disease are leading to an increasing number of diagnosed cases. (3)


Listen to an American Heart Association podcast (12 minutes) titled “What is ATTR-CM?”


ATTR-CM Basics (5)


Recent Research (4)

Davies et al.(2022) published an informative paper titled “A Simple Score to Identify Increased Risk of Transthyretin Amyloid Cardiomyopathy in Heart Failure with Preserved Ejection Fraction.” In conclusion, they believe their findings can increase recognition of ATTR-CM among patients with HFpEF in the community.

Key Points

Question.  Which patients with heart failure and preserved ejection fraction (HFpEF) have an increased risk of transthyretin amyloid cardiomyopathy (ATTR-CM) warranting technetium Tc 99m pyrophosphate scintigraphy?

Findings.  The study team developed and validated an ATTR-CM score comprising of 3 clinical (age, male sex, hypertension diagnosis) and 3 echocardiographic (ejection fraction, posterior wall thickness, relative wall thickness) variables to predict increased risk of ATTR-CM in HFpEF cohorts with variable ATTR-CM prevalence.

Meaning.  Because specific and highly effective therapy for ATTR-CM exists, the ATTR-CM score can provide a simple tool to guide use of technetium Tc 99m pyrophosphate scintigraphy and increase recognition and appropriate therapy of ATTR-CM in patients with HFpEF.


Importance.  Transthyretin amyloid cardiomyopathy (ATTR-CM) is a form of heart failure (HF) with preserved ejection fraction (HFpEF). Technetium Tc 99m pyrophosphate scintigraphy (PYP) enables ATTR-CM diagnosis. It is unclear which patients with HFpEF have sufficient risk of ATTR-CM to warrant PYP.

Objective  To derive and validate a simple ATTR-CM score to predict increased risk of ATTR-CM in patients with HFpEF.

Design, Setting, and Participants.  Retrospective cohort study of 666 patients with HF (ejection fraction ≥ 40%) and suspected ATTR-CM referred for PYP at Mayo Clinic, Rochester, Minnesota, from May 10, 2013, through August 31, 2020. These data were analyzed September 2020 through December 2020. A logistic regression model predictive of ATTR-CM was derived and converted to a point-based ATTR-CM risk score. The score was further validated in a community ATTR-CM epidemiology study of older patients with HFpEF with increased left ventricular wall thickness ([WT] ≥ 12 mm) and in an external (Northwestern University, Chicago, Illinois) HFpEF cohort referred for PYP. Race was self-reported by the participants. In all cohorts, both case patients and control patients were definitively ascertained by PYP scanning and specialist evaluation.

Main Outcomes and Measures.  Performance of the derived ATTR-CM score in all cohorts (referral validation, community validation, and external validation) and prevalence of a high-risk ATTR-CM score in 4 multinational HFpEF clinical trials.

Results.  Participant cohorts included were referral derivation (n = 416; 13 participants [3%] were Black and 380 participants [94%] were White; ATTR-CM prevalence = 45%), referral validation (n = 250; 12 participants [5%]were Black and 228 participants [93%] were White; ATTR-CM prevalence = 48% ), community validation (n = 286; 5 participants [2%] were Black and 275 participants [96%] were White; ATTR-CM prevalence = 6% ), and external validation (n = 66; 23 participants [37%] were Black and 36 participants [58%] were White; ATTR-CM prevalence = 39%). Score variables included age, male sex, hypertension diagnosis, relative WT more than 0.57, posterior WT of 12 mm or more, and ejection fraction less than 60% (score range −1 to 10). Discrimination (area under the receiver operating characteristic curve [AUC] 0.89; 95% CI, 0.86-0.92; P < .001) and calibration (Hosmer-Lemeshow; χ2 = 4.6; P = .46) were strong. Discrimination (AUC ≥ 0.84; P < .001 for all) and calibration (Hosmer-Lemeshow χ2  = 2.8; P = .84; Hosmer-Lemeshow χ2  = 4.4; P = .35; Hosmer-Lemeshow χ2 = 2.5; P = .78 in referral, community, and external validation cohorts, respectively) were maintained in all validation cohorts. Precision-recall curves and predictive value vs prevalence plots indicated clinically useful classification performance for a score of 6 or more (positive predictive value ≥25%) in clinically relevant ATTR-CM prevalence (≥10% of patients with HFpEF) scenarios. In the HFpEF clinical trials, 11% to 35% of male and 0% to 6% of female patients had a high-risk (≥6) ATTR-CM score.

Conclusions and Relevance  A simple 6 variable clinical score may be used to guide use of PYP and increase recognition of ATTR-CM among patients with HFpEF in the community.


In closing … a known condition of heart failure is cardiomyopathy, of which one type – Transthyretin Amyloid Cardiomyopathy (ATTR-CM) – may be the underlying cause. In seeking answers to heart failure, keep this in mind.




  1. https://my.clevelandclinic.org/health/diseases/17069-heart-failure-understanding-heart-failure
  2. https://my.clevelandclinic.org/health/diseases/16841-cardiomyopathy
  3. https://www.emergency-live.com/health-and-safety/cardiac-amyloidosis-what-it-is-and-tests-for-diagnosis/?fbclid=IwAR0lNrxqubUbFAhNcew233YU_CqN6Udf_RYj1FhBAErSrqou5CKjypZPk4A
  4. Davies DR, Redfield MM, Scott CG, et al. A Simple Score to Identify Increased Risk of Transthyretin Amyloid Cardiomyopathy in Heart Failure With Preserved Ejection Fraction. JAMA Cardiol. 2022;7(10):1036–1044. doi:10.1001/jamacardio.2022.1781
  5. https://www.yourheartsmessage.com/about-attr-cm 
  6. American Heart Association – What is ATTR-CM



ATTR-CM (cardiomyopathy) vs ATTR-PN (peripheral neuropathy)


Over the course of the past two months, we spent time discussing two of the most common hallmark symptoms of ATTR amyloidosis: cardiomyopathy and peripheral neuropathy. In this article, we’ll briefly recap both hallmark symptoms as well as bring it all together by discussing the two most common forms of ATTR amyloidosis: ATTR cardiomyopathy (ATTR-CM) and ATTR peripheral neuropathy (ATTR-PN).

To recap …



Cardiomyopathy is a broad term that is used to describe disease of the heart muscle, making it difficult for the heart to provide the body with an adequate blood supply. It is a common cause of sudden cardiac arrest and sudden cardiac death, which can lead to heart failure and even death. 

Types of Cardiomyopathy:

  • Dilated Cardiomyopathy → dilation of the left ventricle prevents the heart from pumping effectively
  • Hypertrophic Cardiomyopathy → abnormal thickening of the heart muscle most commonly surrounding the left ventricle
  • Restrictive Cardiomyopathy → stiffening of the heart muscle results in an inelasticity
  • Arrhythmogenic Right Ventricular Dysplasia → scar tissue replaces healthy tissue of the right ventricle
  • Unclassified Cardiomyopathy → all other forms of cardiomyopathy fall within this category


Peripheral Neuropathy

Peripheral neuropathy, also referred to as polyneuropathy, is a very broad term used to describe damage of the peripheral nerves. Damage to these nerves most commonly causes numbness, pain, and weakness but can affect other areas of the body including, but not limited to, circulation, digestion, and urination. 

Types of Neuropathy:

  • Motor Neuropathy → damage to the motor nerves 
  • Sensory Neuropathy → damage to sensory nerves 
  • Autonomic Nerve Neuropathy → damage to autonomic nerves that control involuntary functions 
  • Combination Neuropathies → damage to a mix of 2 or 3 of these other types of neuropathies


ATTR Amyloidosis

The origin of this disease can be genetic (hATTR) or non-genetic, or “wild-type” (wtATTR). Regardless, in ATTR amyloidosis, the transthyretin (TTR) protein is misfolded and aggregates, forming amyloid fibers that deposit into tissues and organs. The deposition of protein causes organ dysfunction and can even cause organ failure and death. 



Depending on the location of protein deposition, the disease is referred to in different ways. For instance, when the primary location of amyloid deposit is in the heart, the disease is referred to as ATTR cardiomyopathy (ATTR-CM). On the other hand, when the primary location of amyloid deposit is in the nerves, the disease is referred to as ATTR peripheral neuropathy (ATTR-PN).

ATTR-CM impairs the heart’s ability to pump effectively. A major challenge surrounding this disease is that symptoms of ATTR-CM are often similar to other heart conditions like enlarged heart and heart failure. This makes diagnosing the disease increasingly more difficult. Individuals with hATTR typically present symptoms in their 50s and 60s, whereas those with wtATTR may not present symptoms until their 70s and later. 

Common Symptoms of ATTR-CM:

  • Fatigue
  • Swelling of legs, ankle, or abdomen
  • Shortness of breath with activity
  • Orthostatic hypotension
  • Difficulty breathing when lying down
  • Arrhythmia

ATTR-PN impairs the function of the nervous system. While amyloid most commonly builds up in the peripheral nervous system, deposition can also occur in the autonomous system. This results in a diversity of symptoms that are specific to the site of amyloid deposition. Symptom presentation is much more diverse, occurring as early as the 20s, or as late in life as the 70s. 

Common Symptoms of ATTR-PN:

  • Carpal tunnel syndrome
  • Diarrhea and/or constipation
  • Nausea, vomiting
  • Loss of appetite
  • Sexual dysfunction
  • Muscle weakness
  • Eye problems
  • Orthostatic hypotension















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