The role of echocardiography and 99mTc-HDP scintigraphy in non-invasive diagnosis of cardiac amyloidosis

Abstract

Rationale:Cardiac amyloidosis, considered for the last years to be a rare disease, is one of the determinants of HFpEF. The non-specific clinical presentation and the difficulties related to endomyocardial biopsy have made cardiac amyloidosis an underdiagnosed clinical entity. Improvement of non-invasive diagnostic techniques and the development of new therapies increased clinical awareness for this form of restrictive cardiomyopathy. We here summarize echocardiography and 99mTc-HDP scintigraphy findings in 6 cases of cardiac amyloidosis and review the literature data of this progressive and fatal cardiomyopathy.Patients concerns:The main clinical manifestations were fatigue, low exercise tolerance and edemas. The right heart failure symptoms usually dominated the clinical picture.Diagnoses:All cases were evaluated by echocardiography; 3 cases were further examined by bone scintigraphy and 4 cases a peripheral biopsy was performed. Electrocardiography showed low-voltage QRS complexes and “pseudo-infarct” pattern in the precordial leads, contrary to the echocardiographic aspect, which revealed thickening of ventricle walls. Biatrial dilation and diastolic disfunction were observed. Impaired systolic function was detected in advanced stages of the disease. 99mTc-HDP scintigraphy revealed cardiac uptake of radiopharmaceutical and managed to confirm the diagnosis in 1 case of cardiac amyloidosis in which salivary gland biopsy was negative.Interventions:The treatment was based on managing fluid balance, with the mainstream therapy represented by diuretics. Neurohormonal agents, usually used in heart failure treatment were avoided, due to poor tolerance and worsening of disease course. The management of these 6 cases was challenging due to the refractory manifestation of congestive heart failure.Outcomes:During follow-up, 4 of the 6 patients from the current study died in the first year after the final diagnosis was established.Lessons:Nuclear imaging of cardiac amyloidosis has a revolutionary development nowadays. Bone scintigraphy presents promising results for identifying patients at early stages of disease and to differentiate between cardiac amyloidosis types. Further studies are necessary for the standardization of imaging protocol and development of non-invasive diagnostic tools, especially in assessing the response to treatment and disease progression, for which little is known.

The Role of Echocardiogram and Cardiac Rhythm Analysis for Early Detection of Cardiac Amyloidosis

“…Six of the studies reported on low-voltage QRS complexes. Costache and colleagues (2019 ) in the Roman case series identified low-voltage QRS complexes in all six subjects. In the Zhang and colleagues (2021 ) retrospective cohort study EKG of the CA group, low-voltage QRS complexes were found in 52% of limb leads and 21% in precordial leads.…”

“…LV hypertrophy was evaluated in four of the studies. In the Costache and colleagues (2019 ) case series, absence of LV hypertrophy was identified on EKG in all six subjects. In contrast, in the Pagourelias and colleagues (2017 ) study, only 5 of the 40 patients demonstrated LV hypertrophy on EKG.…”

“…Nearly 70% of their subjects demonstrated a pseudo-infarct pattern. Costache and colleagues (2019 ) performed a case series in a Romanian Hospital of six patients with a diagnosis of CA, confirmed by either bone scintigraphy or peripheral biopsy, to evaluate the role of both echocardiogram and scintigraphy in evaluating CA. All six subjects underwent evaluation via 12-lead EKG, and pseudo-infarct pattern in precordial leads was identified in all six subjects.…”

Cardiac amyloidosis awareness among residents/specialists in Geriatrics: an Italian national survey

“…Furthermore, there is inadequate knowledge on how to diagnose CA and to interpret bone scintigraphy results. This non-invasive diagnostic technique, easy to perform also among older adults 14 , has 99% sensitivity and 86% specificity for cardiac ATTR 15 and has been included as a screening tool for ATTR-CA in the 2016 European Society of Cardiology guidelines for the treatment of heart failure 16 . Worthy of note also are the really poor physicians' awareness of how to diagnose ATTRwt, the most common form of CA among older adults 4 , and the relatively low number of patients sent for specific treatments (already documented among Cardiologists 8 ), probably due to the poor knowledge of which is the target for ATTRwt treatment.…”

Diagnosis of Cardiac Involvement in Amyloid A Amyloidosis by Cardiovascular Magnetic Resonance Imaging

“…Early diagnosis of cardiac involvement in amyloidosis can be challenging due to unspecific or missing clinical manifestations. Although non-invasive imaging modalities such as echocardiography (with speckle-based strain measurement), bone scintigraphy ( 10 ) as well as multi-parametric CMR are widely used today and promise both early and specific detection of cardiac amyloidosis ( 11 , 12 ), invasive EMB still constitutes the gold-standard for the final diagnosis of non-ischemic heart diseases including cardiac amyloidosis ( 13 ). Noteworthy, imaging modalities such as bone scintigraphy and multi-parametric CMR were shown to be valuable tools in differentiating cardiac ATTR from AL amyloidosis if additional information on monoclonal protein studies are available and promise early detection of cardiac amyloidosis ( 9 , 14 ).…”