Clinical Trial: Radioisotope Scintigraphy to Establish Incidence of Cardiac Amyloidosis Among Patients With Otherwise Unexplained Cardiac Disease

Study Status: Not yet recruiting
Recruit Status: Not yet recruiting
Study Type: Interventional

Official Title: Tc99m-PYP Scintigraphy in Order to Establish Incidence of Cardiac Transthyretin Amyloidosis Among Patients With Otherwise Unexplained Cardiomyopathies

Brief Summary:

Cardiac amyloidosis is a multi-organ syndrome, which usually presents as restrictive cardiomyopathy (RCM). Transthyretin (TTR) amyloidosis (or ATTR) is a subtype of amyloidosis which frequently involves heart. Cardiac ATTR, though infrequently diagnosed during lifetime, may represent a prevalent cause of RCM, especially in elderly. Several medications that can limit progression of the disease are currently under investigation. Presently the golden standard for diagnosis of ATTR is endomyocardial biopsy (EMB) which may entail severe adverse complications causing under-diagnosis of ATTR.

Several papers support the evidence that Tc99m-labeled tracers can be used to detect myocardial deposits of TTR amyloid. It was suggested that Tc99m scintigraphy might be a highly sensitive diagnostic tool for cardiac ATTR. In this study the patients with otherwise unexplained cardiomyopathy or heart block will undergo Tc99m scan, which will establish the incidence of this largely underdiagnosed condition in the population.

Detailed Summary:

Amyloidosis is a multi-organ syndrome, which usually presents as a restrictive cardiomyopathy (RCM). Transthyretin (TTR) amyloidosis is a subtype of amyloidosis, further subdivided into familial type and senile type. Its pathophysiology consists primarily of abnormal precipitation of transthyretin - a protein that normally acts as transporter for thyroid hormone and retinoids - in tissues. TTR amyloidosis frequently involves heart, bringing about the same clinical and pathophysiological picture of RCM. Another presentation of TTR Amyloidosis can be atrio-ventricular block or bundle-branch block [1].

There is evidence that the cardiac TTR amyloidosis, though infrequently diagnosed during the lifetime, may represent a widespread cause of restrictive cardiomyopathy especially in elderly. An autopsy study in octogenarians having suffered of heart failure with preserved left ventricular ejection fraction (HFpEF) suggested that up to 25% of them had TTR amyloid deposit in myocardium, though a negligible minority of them had been diagnosed with TTR amyloidosis during their lifetime [2-3]. HFpEF is a very widespread diagnosis, which represents a considerable burden of morbidity, and usually harbours populations of patients poorly responding to treatment. Most of patients with the diagnosis of HFpEF have little or no explanation concerning the aetiology of their disease, especially if they do not respond to conventional treatment. Most of them can benefit only from symptomatic treatment which does not alter the course of the disease. Thus a more widespread diagnosis of TTR amyloidosis could have been very promising as to a better management of this hard-to-treat patient population.

Several medications that can limit progression of TTR amyloidosis are currently under investigation. Until now, the golden standard for diagnosis of the
Sponsor: Kaplan Medical Center

Current Primary Outcome: diagnosis or exclusion of any type of cardiac amyloidosis; [ Time Frame: immediately at the Tc99m scan performing or within a year form beginning of the recruitment ]

Original Primary Outcome: Same as current

Current Secondary Outcome:

Original Secondary Outcome:

Information By: Kaplan Medical Center

Dates:
Date Received: March 28, 2017
Date Started: April 15, 2017
Date Completion: April 15, 2018
Last Updated: April 3, 2017
Last Verified: April 2017