Evaluating the Prevalence of Cardiac Amyloidosis in Internal Medicine Patients with Heart Failure

Amyloidosis identified as the cause of heart failure in nearly 1 in 10 internal medicine patients.

A high degree of clinical suspicion is needed to detect transthyretin amyloid cardiomyopathy (ATTR-CM) that remains an underdiagnosed disease. In internal medicine patients with heart failure (HF), the prevalence of cardiac amyloidosis is unknown, despite the availability of some data on the prevalence in patient populations that are considered subgroups, such as HF with preserved left ejection fraction and aortic stenosis. Hueso and colleagues estimated the prevalence of cardiac amyloidosis in internal medicine patients with HF and described their clinical, echocardiographic, and laboratory findings.

The investigators used a cross-sectional, prospective, observational study that is unicentric. Patients with HF who were included in the study were either inpatient or outpatient, were aged ≥65 years, and had left ventricular hypertrophy (defined as interventricular septum or posterior wall >12 mm). The specific inclusion criteria for the study were specified as an echocardiogram performed in the previous 24 months or at time of inclusion and diuretic treatment in the past 6 months, New York Heart Association class II-IV, and N-terminal proB-type natriuretic peptide (NT-proBNP) level >1800 pg/mL in acute HF or NT-proBNP level >600 pg/mL in stable condition.

Between February 2020 and 2021, all patients who met the inclusion criteria were assessed. To rule out abnormalities of light chains and monoclonal bands, patients who consented to participation in the study were evaluated using a combination of a 99mTechnetium-3,3-diphosphono-1,2-propanodicarboxylic acid (99mTc-DPD) scintigraphy in addition to blood and urine analysis. Transthyretin (TTR) gene sequencing was performed in patients with a positive scan. If the treating physician considered it appropriate, extracardiac biopsies were performed. A total of 150 patients were included in the study.

The 99mTc-DPD scintigraphy detected a grade 2 or 3 uptake in the 13 patients, consisting of 5 women and 8 men. Overall, the prevalence of cardiac amyloidosis was determined to be 9%, with 84.4% of these cases being wild-type ATTR-CM, 7.7% being hereditary ATTR-CM, and 7.7% being light chain amyloidosis.

Patients were evaluated for clinical markers or “red flags” of the disease. Compared with patients with negative scintigraphy, patients with ATTR-CM more frequently had beta-blocker intolerance (30% vs 7.2%, respectively; P = .012), carpal tunnel syndrome (30% vs 5.8%, respectively; P = .006), diarrhea (23% vs 7.3%, respectively; P = .05), fatigue (15.8 vs 4.3%, respectively; P = .015), glaucoma (7.6% vs 0%, respectively; P = .001), mitral regurgitation (69% vs 65%, respectively; P = .026), pacemakers (38% vs 13%, respectively; P = .037), aortic stenosis (23% vs 19.7%, respectively; P = .024), and aortic regurgitation (69% vs 45.9%, respectively; P = .003). Additional differences between groups included the relative septal and posterior wall thickness.

Hueso and colleagues concluded that in approximately 1 in 10 patients, amyloidosis was the cause of HF. Therefore, if a patient exhibits any clinical signs or signals that may be considered red flags, evaluation for ATTR-CM should be included in the differential diagnosis of elderly patients with heart failure and myocardial thickening, irrespective of left ventricular ejection fraction status.

Source: Ruiz Hueso RR, Candela IB, Moron CC, et al. Prevalence of cardiac amyloidosis in internal medicine patients with heart failure. Eur J Heart Fail. 2021;23(suppl S2):2-322.

Related Items

Amyloidosis News
Subscribe to Amyloidosis News

Stay up to date with Amyloidosis News by subscribing to receive the free AMN e‑Newsletter.