In early stages of the disease, light chain and transthyretin (both wild-type and hereditary transthyretin amyloidosis) cardiac amyloidosis share more similarities than differences, especially in terms of survival outcomes, when a referral is made early to the UK National Amyloidosis Center (NAC), according to a UK study published in the journal Heart.
The diagnosis of cardiac amyloidosis is primarily made via cardiac magnetic resonance and technetium-labeled scintigraphy; both of these imaging modalities provide physicians with the tools they need to conclusively diagnose the condition in a noninvasive and accurate manner.
Light chain and transthyretin cardiac amyloidosis often have been contrasted in the medical literature. However, the differences highlighted tend to become more apparent in later stages of the disease. When diagnosed early, both conditions appear to share many striking similarities. This point is augmented by using disease-modifying therapies in treating both conditions, resulting in a less severe disease course.
Khweir and her team sought to compare light chain and transthyretin cardiac amyloidosis cases in greater depth; they also sought to investigate if an early referral to the UK NAC made a difference in terms of survival outcomes. They recruited 35 patients with cardiac amyloidosis; 19 had the light chain form of the condition, and 16 had transthyretin cardiac amyloidosis. Of the 35 patients, only 3 were diagnosed using endomyocardial biopsy; the rest were diagnosed via a noninvasive algorithm of echocardiogram, cardiac magnetic resonance, and/or scintigraphy.
Read more about hereditary transthyretin amyloidosis etiology
The research team discovered that, among patients who were less symptomatic, no significant differences were noted among a number of key parameters: age, gender, ejection fraction, median survival from diagnosis, total heart failure hospitalizations, and diastolic dysfunction grade 2 and above. When comparing both conditions, the researchers also found that they shared markedly similar cardiac comorbidities, with the exception of atrial fibrillation and conduction diseases, which were more pronounced in transthyretin cardiac amyloidosis.
In addition, the researchers found that an early referral to the NAC persisted as a significant contributor to better survival for patients with either subtype of cardiac amyloidosis. Hence, the goal should be for physicians to diagnose the condition early with the purpose of an early referral to the NAC to improve life expectancy.
Reference
Khweir L. 143 A contemporary comparative analysis between AL and ATTR cardiac amyloidosis and the survival impact of referral to the National Amyloidosis Center: a UK tertiary centre experience. Heart. Published online June 2, 2023. doi:10.1136/heartjnl-2023-BCS.143
