Cardiac amyloidosis: Hopes and challenges

Abstract

Cardiac amyloidosis (CA) is an infiltrative and restrictive cardiomyopathy subsequent to extracellular deposition of amyloid fibrils in cardiac tissues. CA is many a times associated with the involvement of other organs, especially the kidneys and nervous system and that may be the initial clinical manifestation. CA has two main subtypes—light‐chain amyloidosis (AL) and transthyretin amyloidosis (ATTR). ATTR-CA is further subdivided into two, based on the presence or absence of the transthyretin gene. The wild-type transthyretin CA causes the deposition of the normal transthyretin protein, a condition previously called senile CA. The second type is now called variant transthyretin CA and is caused by transthyretin harboring mutations. This was previously referred to as familial CA. The interest in CA especially the ATTR variety has increased due to the availability of easier noninvasive diagnostic methods and therapeutic avenues. CA is relatively rare, it presents with varying symptoms, which mimic other common diseases, and this leads to missing the diagnosis early in nearly 50% of cases. Many patients spend 3–4 years to reach a diagnosis. Since the prognosis, once there is cardiac involvement is dismal, early identification and treatment becomes very important. In this issue with the theme, amyloidosis, there is a state-of-the-art review contributed by Omar Siddiqui and team from Boston University, USA—“Cardiac Amyloidosis in 2023: A Review of Pathophysiology, Diagnosis and Treatment.” This article gives a detailed overview of epidemiology, pathophysiology, diagnosis, and management of CA. This comprehensive review written by the cardiology team from the Amyloidosis Center from the Boston University will be very helpful to our readers. The second article is a review on the “Disease burden, management challenges and proposed approach” by Akash Batta and team from Dayanand Medical College, Ludhiana, India. They discuss the challenges faced in the detection and management of CA in a low-middle-income country (LMIC) such as India. They propose a diagnostic algorithm and suggest the development of an amyloid reference network with a central amyloid reference center with peripheral clinical sites, something like a hub and spoke model. I am sure this suggestion will be discussed in the academic circles and also in the health system management forums. Two research articles, which are related to CA, are also published in this issue. The first one is a tertiary care center experience of cardiac amyloidosis. The series from Apollo Hospitals, Chennai, which is one of the leading tertiary referral care centers in the country, describes the outcome of 31 patients with cardiac amyloidosis. Since this is one of the larger series on this rare condition from India, it will be helpful to the readers to understand the pattern of the disease and the varying modes of presentation. The challenges in genetic testing, nuclear scintigraphy, and the accessibility and affordability issues are also discussed. The other one is a case series on the clinical profile and 10-year follow-up of patients with amyloid degeneration on excised valve tissue specimens detected on histopathology. This “dystrophic” amyloid deposition, which the authors try to term it, is found to be of no long-term consequences. There is another case report describing a 34-year-old lady with AL amyloidosis, who presented with restrictive cardiomyopathy, on endomyocardial biopsy showed deposition of amyloid fibrils, which ultimately led to the diagnosis of free light chain deposition disorder secondary to plasma cell myeloma with free kappa light chain restriction. She became better with chemotherapy. This highlights the importance of invasive diagnostic techniques in cases where no leads are pointing to an etiology. We hope that this theme issue will help our readers to have an overview of cardiac amyloidosis and help in clinical suspicion and early identification of the condition. A few suggestions can be put forward, which can aid in streamlining the management of CA in India and similar LMIC. Increasing awareness about the clinical condition facilitated by publications. CME programs on CA can help in improving the awareness among physicians and GPs. Establishing a referral pathway and network will streamline the patient flow—will reduce the timelines and facilitate early diagnosis and treatment. Establishing national diagnostic and therapeutic protocols. Heart Failure Association of India is planning to take initiatives in this regard. Since amyloidosis is a multisystem disease, involvement of specialists from allied specialities in educational programs and in referral pathways will be useful. Accessibility and affordability of diagnostic modalities and treatment play an important part in the management of CA. Genetic analysis, nuclear scintigraphy, etc. should be made available at affordable costs. Last but not least, the cost of therapy—currently the cost of the therapy is unaffordable to vast majority in LMIC who spend mostly out of pocket for their health expenditure. We hope that the cost of therapy may come down in the future and will penetrate to all sections of the society. Financial support and sponsorship Nil. Conflicts of interest There are no conflicts of interest.