Heart failure with preserved ejection fraction (HFpEF), also known as diastolic heart failure, is a type of heart failure characterized by the inability of the heart to fill with and adequately pump blood while the ejection fraction—the percentage of blood pumped out of the heart during each contraction—is normal or near-normal. In HFpEF, the main problem lies in the impaired ability of the heart to relax and fill with blood during the resting phase between heartbeats (diastole).

Normal Thickness of the LV

Cardiac amyloidosis is a condition where abnormal proteins called amyloid fibrils build up in the heart tissue, leading to heart dysfunction. There are different types of amyloidosis, and one specific type associated with heart failure with preserved ejection fraction (HFpEF) is called transthyretin amyloidosis (ATTR).

ATTR amyloidosis can be further classified into two main subtypes based on the source of the amyloid fibrils:

1. Wild-type ATTR (ATTRwt): In this subtype, the amyloid fibrils are derived from the normal or wild-type transthyretin protein. Wild-type ATTR primarily affects older individuals and is typically associated with HFpEF. The exact mechanisms underlying the development of HFpEF in wild-type ATTR are not fully understood, but the infiltration of amyloid deposits in the heart muscle can result in diastolic dysfunction and impaired relaxation, leading to symptoms of heart failure.
2. Hereditary ATTR (ATTRm): This subtype of ATTR amyloidosis is caused by genetic mutations in the transthyretin gene. The mutated transthyretin protein forms amyloid fibrils that can accumulate in various organs, including the heart. While hereditary ATTR can also cause heart failure, it is more commonly associated with heart failure with reduced ejection fraction (HFrEF), where the ejection fraction is significantly decreased.

It’s worth noting that while cardiac amyloidosis, particularly ATTR amyloidosis, can contribute to HFpEF, there are various other causes of HFpEF unrelated to amyloidosis. These causes can include hypertension, obesity, diabetes, coronary artery disease, and other structural or functional abnormalities of the heart.

Diagnosing the specific type of amyloidosis causing HFpEF requires a comprehensive evaluation by a healthcare professional, including a thorough medical history, physical examination, imaging tests (such as echocardiography and cardiac MRI), and sometimes a biopsy to confirm the presence of amyloid deposits and determine the specific subtype. Treatment approaches for amyloidosis-associated HFpEF may involve managing symptoms, controlling underlying conditions, and, in some cases, targeting the specific amyloid protein with emerging therapies.

 

 

Here are some key points about heart failure with preserved ejection fraction:

1. Ejection Fraction: Ejection fraction (EF) is a measurement of the percentage of blood pumped out of the left ventricle with each heartbeat. In HFpEF, the ejection fraction is typically normal or mildly reduced, usually above 50%, indicating that the heart’s ability to contract and pump blood is preserved.
2. Diastolic Dysfunction: The primary issue in HFpEF is impaired diastolic function, which refers to the heart’s ability to relax and fill with blood during diastole. The stiffness of the heart muscle (ventricular stiffness) and reduced ventricular compliance hinder proper filling, resulting in elevated pressures within the heart and lungs.
3. Symptoms: The symptoms of HFpEF are similar to those of other types of heart failure and may include shortness of breath, fatigue, exercise intolerance, fluid retention, swollen ankles, and a reduced ability to engage in physical activities. However, some individuals with HFpEF may remain asymptomatic or have atypical symptoms.
4. Risk Factors: HFpEF is commonly associated with certain risk factors, including older age, hypertension (high blood pressure), obesity, diabetes, coronary artery disease, atrial fibrillation, and chronic kidney disease. These conditions can contribute to the development of structural and functional changes in the heart Elderly with amyloidosis
5. Diagnosis: The diagnosis of HFpEF involves a comprehensive evaluation, including a medical history review, physical examination, echocardiography (ultrasound of the heart), and other tests to assess heart function, identify potential underlying causes, and rule out other conditions with similar symptoms.
6. Treatment: The management of HFpEF focuses on controlling symptoms, preventing exacerbations, and addressing underlying causes. This typically involves lifestyle modifications such as regular exercise, dietary changes (e.g., reducing salt intake), managing comorbidities (e.g., hypertension, diabetes), and medications to control blood pressure and heart rate. In some cases, medications that reduce symptoms and improve outcomes in heart failure with reduced ejection fraction (HFrEF) may also be used. Additionally, close monitoring and regular follow-up with a healthcare provider are crucial.
7. Prognosis: HFpEF has been considered more challenging to treat compared to HFrEF, and there are currently no specific therapies that have shown consistent benefits in reducing mortality or hospitalizations. The prognosis of HFpEF can vary, but it is generally associated with a substantial burden of symptoms and an increased risk of hospitalization and cardiovascular events.