Medically reviewed by Dr. Shani S. Saks, D.O. on July 27, 2023
Cardiac amyloidosis is a common cause of heart failure and should be screened in elderly heart failure patients with myocardial thickening.
Cardiac amyloidosis (CA) has emerged as an underdiagnosed cause of heart failure (HF) in recent years. The available studies on CA prevalence have heterogeneous designs and are mostly retrospective or single-center; therefore, not allowing the exact determination of CA prevalence in HF patients.
A study in the Journal of Clinical Medicine conducted by the Heart Failure and Atrial Fibrillation Working Group of the Spanish Society of Internal Medicine has estimated the current prevalence of CA in elderly HF patients treated in the internal medicine setting.
The study included 453 heart failure (HF) patients aged 65 or older recruited from 30 hospitals in Spain. The participants consisted of 229 females and 224 males. The median age of the study population was 85 years.
CA Prevalence in the Heart Failure Cohort
The prevalence of CA was 20.1%, with 91 patients in the study diagnosed with CA. Among those diagnosed with CA, 76 (84.6%) patients had transthyretin amyloid cardiomyopathy (ATTR-CM), while only two (2.2%) had primary amyloidosis. It was not possible to determine the type of cardiac amyloidosis in 13 (13.2%) patients who remained untyped.
At least 5.2% of the ATTR-CM patients had a hereditary cause; however, a significant proportion did not undergo genetic testing. The prevalence of CA was significantly higher in males than females (60.1% vs. 39.9%) and increased progressively with age. Although heart failure with preserved ejection fraction predominated (73.5%), 26.5% of the CA patients in the study had a left ventricular ejection fraction <50%.
Characteristics of Patients With and Without Cardiac Amyloidosis
CA patients were significantly older, more often male, and experienced more fatigue and muscle weakness than those without the pathology. Regarding red flags, CA patients more frequently exhibited carpal tunnel syndrome, lumbar spinal stenosis, biceps tendon rupture, and monoclonal gammopathy of uncertain significance.
Moreover, intolerance to angiotensin-converting enzyme inhibitors, angiotensin receptor blockers, and beta-blockers was more common in CA patients. CA patients more frequently showed a low-voltage electrocardiogram. Echocardiography findings most suggestive of CA were the presence of pericardial effusion and speckled myocardium, along with a thicker interventricular septum and posterior wall. Mild aortic stenosis was significantly more frequent in CA patients, but severe cases were more frequent in patients without CA.
Barriers and Improvement Opportunities
In the study, there were difficulties in establishing the CA subtype. Barriers to further exploration included patients’ wishes, poor accessibility to genetic tests, difficulty providing a disease-modifying treatment, or limited access to specialists. However, advances are being made in diagnostic tools and multidisciplinary collaboration programs for improved awareness and early diagnosis.
Ruiz-Hueso, R., Salamanca-Bautista, P., Quesada-Simón, M. A., Yun, S., Conde-Martel, A., Morales-Rull, J. L., Suárez-Gil, R., García-García, J. A., Llàcer, P., Fonseca-Aizpuru, E. M., Amores-Arriaga, B., Martínez-González, Á., Armengou-Arxe, A., Peña-Somovilla, J. L., López-Reboiro, M. L., & Aramburu-Bodas, Ó. (2023). Estimating the Prevalence of Cardiac Amyloidosis in Old Patients with Heart Failure—Barriers and Opportunities for Improvement: The PREVAMIC Study. Journal of Clinical Medicine, 12(6), 2273. https://doi.org/10.3390/jcm12062273