From the Guidelines
The use of permanent pacemakers and ICD devices may not influence long-term outcome in patients with cardiac amyloidosis, but may be considered in familial cases as a bridge to transplantation. When considering the management of patients with cardiac amyloidosis, it is essential to prioritize morbidity, mortality, and quality of life as the primary outcomes. According to the acc/aha/esc 2006 guidelines for management of patients with ventricular arrhythmias and the prevention of sudden cardiac death 1, cardiac involvement in amyloidosis carries a very poor prognosis, with a median survival of 6 months and a 6% 3-year survival rate. Some key points to consider in the management of cardiac amyloidosis include:
- Cardiac troponins, especially troponin T, may be independent predictors of mortality 1
- The presence of couplets on Holter recordings, LV wall thickness, and prolonged infra-His conduction time on EP studies may also be independent predictors of mortality 1
- Elevated cardiac troponins may influence the final decision, as median survival in patients with detectable values is 6 to 8 months compared with 21 to 22 months in those with undetectable levels 1
- The use of permanent pacemakers and ICD devices may not influence long-term outcome, but may be used as a bridge to transplantation in familial cases 1
From the Research
Amyloid and AICD
- Amyloidosis is a condition caused by interstitial infiltration of misfolded proteins structured into amyloid fibrils, with transthyretin (ATTR) and immunoglobulin light chain (AL) amyloidosis being the most common forms of cardiac amyloidosis (CA) 2.
- The standard of care for ATTR-CA includes agents capable of selectively stabilizing the precursor protein, such as tafamidis, whereas the plasma cell clone is the main target of chemotherapy for AL-CA 2.
- Recent advances in treatment options for CA have improved the prognosis, but early diagnosis is still crucial for timely initiation of treatment and participation in clinical trials 3, 4.
- The diagnosis of amyloidosis is complex and generally requires histological confirmation, but non-invasive methods such as bone scintigraphy can be used to diagnose cardiac ATTR amyloidosis once a monoclonal gammopathy has been excluded 5.
- Several novel therapies are being tested for the treatment of CA, including CRISPR-Cas9-based drugs, monoclonal antibodies targeting misfolded ATTR or AL, and amyloid degradation agents, which may change the prognostic landscape of this condition in the next few years 2, 3.
Treatment Options
- The mainstay of AL-CA treatment is proteasome inhibitor-based chemotherapy with daratumumab and, when feasible, autologous stem cell transplantation 3.
- For ATTR-CA, the stabilizer tafamidis is the only US Food and Drug Administration (FDA)-approved treatment, but other novel therapies such as acoramidis and patisiran are being developed 2.
- Advanced interventions, including heart, heart-kidney, and heart-liver transplantation, may be considered for end-stage CA 3.
Diagnosis and Red Flags
- Electrocardiographic and imaging techniques, such as echocardiography, cardiac magnetic resonance, and scintigraphy, are useful tools for diagnosing CA, along with the presence of orthopedic issues, peripheral neuropathy, or plasma cell dyscrasia 4.
- Red flags, such as valvular disorder, heart failure, or cardiomyopathy, can raise suspicion of CA and prompt an early diagnosis and targeted treatment strategy 4.