Prospective Identification of Cardiac Amyloidosis by Cardiac Magnetic Resonance Imaging
Prospective Identification of Cardiac Amyloidosis by Cardiac Magnetic Resonance Imaging
Cardiac amyloidosis describes a process by which abnormally folded proteins infiltrate the
 heart tissue. Given the insidious nature of this disease process, diagnosis is often too late
 for a meaningful intervention. Advances in the treatment of the amyloidoses have improved
 outcomes for patients with these conditions. The focus of this study is to identify the
 involvement of the heart, most closely associated with mortality, so that aggressive
 management can be instituted improving prognosis.
RESEARCH PROTOCOL

 Hypothesis:

 The presence of amyloid protein in the myocardium changes its function and tissue
 characteristics. These changes are responsible for the poor prognosis of patients with
 cardiac amyloidosis. Cardiac magnetic resonance imaging (CMR) offers a novel, non-invasive
 approach to identify cardiac involvement that may impact patient management. This study will
 include the prospective validation of CMR parameters qualified as being abnormal in the
 retrospective study (study ID 2012-3315) and the current literature. The myocardium/blood
 pool inversion time null point ratio (Myo/BlP TI0 ratio), has been qualified as being
 significantly different when compared to controls in the retrospective study.

 Specific Aims:

 1. Validate the diagnostic accuracy of CMR parameters in a prospective manner for cardiac
 amyloidosis patients.

 2. CMR parameters, including the Myo/BlP TI0 ratio, will be compared to serum biomarkers
 (TroponinT, NT-proBNP, serum lambda/kappa free light chain concentration), established
 to have prognostic value in cardiac amyloidosis. Subjects will be followed via death
 registry and/or medical records to compare the prognostic value of the CMR parameter
 with the biomarkers.

 3. CMR parameters will be used to assess for the presence of early cardiac involvement in
 amyloidosis patients without clinically apparent cardiac involvement (as determined by
 symptoms, biomarkers and/or cardiac imaging).

 4. CMR will be used to follow patients undergoing treatment, when available, to determine
 whether CMR parameters consistent with the presence of cardiac amyloidosis, change
 during treatment.

 Background and Significance:

 Matthias Schleiden, a German botanist and co-creator of the cell theory, used the term
 amyloid in 1834 to characterize the waxy starch in plants. Today, amyloid is used to describe
 any of a number of small proteins which when aggregated lead to insoluble fibrillar deposits.
 Many mechanisms of protein dysfunction contribute to amyloidogenesis, including
 "non-physiologic proteolysis, defective physiologic proteolysis, mutations involving changes
 in thermodynamic or kinetic properties, and pathways that are yet to be defined". Amyloid
 deposits are identified on the basis of their apple-green birefringence under a polarized
 light microscope after staining with Congo red. They can also be identified based on the
 presence of rigid, non-branching fibrils using electron microscopy. Amyloidosis describes the
 infiltration of organs by these insoluble deposits. In humans, about 27 different unrelated
 proteins are known to form amyloid fibrils in vivo. The organs involved and clinical
 presentations are dependent on the precursor protein. A small number of the amyloidoses can
 have cardiac involvement with a significant impact on mortality. The clinically most
 significant cardiac amyloidoses include immunoglobulin light chain amyloidosis (AL) and the
 transthyretin amyloidoses (ATTR); ATTR being either hereditary secondary to mutations in the
 transthyretin gene or acquired secondary to wild type transthyretin protein.

 AL amyloidosis, the most common type of systemic amyloidosis, is associated with plasma cell
 dyscrasias. In AL amyloidosis, fifty percent of affected patients will have cardiac
 involvement. Despite the potential for amyloid deposition in multiple organs, cardiac
 involvement continues to dictate the poorest prognosis. Once congestive heart failure
 develops in a patient with AL amyloidosis, survival is less than 6 months if untreated.
 Therefore, patients with AL amyloidosis are screened, by assessing serum troponins and brain
 natriuretic peptides, to determine whether cardiac involvement is present. Patients with ATTR
 amyloidosis typically has a more insidious onset in comparison. ATTR amyloidosis also
 responds better to traditional congestive heart failure management. However, neither AL nor
 the ATTR amyloidoses are managed like traditional heart failure making appropriate diagnosis
 critical for best care. Furthermore, early diagnosis of cardiac involvement may improve
 outcomes but requires heightened suspicion and a systematic clinical approach to evaluation
 [3].

 In cardiac amyloidosis, there can be evidence of disease on routine testing. Restrictive
 physiology by echocardiography, low EKG voltage as well as additional EKG abnormalities are
 often identified in advanced cardiac amyloidosis. Routine nuclear cardiac imaging has not
 proven to be helpful in diagnosis, although 123I-MIBG does appear to demonstrate
 co-localization of denervation with amyloid deposition. Unfortunately, no routine cardiac
 testing is specific for cardiac amyloidosis. Therefore, in the absence of high clinical
 suspicion for cardiac amyloidosis, the appropriate diagnosis will often be missed.

 Endomyocardial biopsy remains the gold standard for making the diagnosis of cardiac
 involvement. However, given the invasive nature of endomyocardial biopsy and associated risks
 (including death), the diagnosis of cardiac amyloidosis is usually made by non-invasive
 means; this diagnosis being supported by a non-cardiac biopsy demonstrating amyloid deposits.
 The most frequently biopsied site is the abdominal fat pad, usually positive in patients with
 AL amyloidosis. However, ATTR amyloidosis is not reliably identified with fat pad biopsy.
 Therefore, a negative fat pad biopsy requires further work up including endomyocardial biopsy
 with associated immunostaining and genetic testing for transthyretin mutations. Supporting
 the diagnosis of cardiac amyloidosis by noninvasive techniques such as EKG, echocardiography
 and serum amyloid component scintigraphy has been shown to have significant limitations. A
 novel non-invasive approach is required to ensure accurate diagnosis. Given the limitations
 of previously used non-invasive techniques, there has been interest over the last decade in
 using cardiovascular magnetic resonance (CMR) imaging in the diagnosis of cardiac
 amyloidosis.

 The utility of CMR in evaluating patients with cardiac amyloidosis was first proposed in the
 1990s. However, evaluation was limited to the assessment of myocardial morphology and
 function. It was not until the turn of the century that the powerful diagnostic potential of
 delayed gadolinium enhancement (DGE) was realized. The first utility of DGE was in the
 evaluation of myocardial viability in patients with coronary artery disease. It quickly
 became apparent that DGE could also be used to evaluate patients with non-ischemic
 cardiomyopathies. The characterization of cardiac amyloidosis with DGE was first described as
 global sub-endocardial enhancement. Abnormal T1 transmyocardial maps were used to both
 describe the abnormality and to assist in the determination of prognosis. However, these
 studies were limited by inclusion of only patients with biopsy-proven amyloidosis who also
 met the echocardiographic criteria for restrictive physiology, common to advanced cardiac
 amyloidosis. More recent work precluding the use of echocardiographic diagnosis supported the
 concept that the inability to null the myocardium relative to the blood pool may be an early
 sign of cardiac amyloidosis. In addition, to the DGE data, studies have utilized T1 and T2
 weighted imaging to identify abnormal extracellular volume (ECV) and myocardial edema in the
 cardiac amyloidosis population.

 It has been the culmination of these findings, in addition to our own experience studying
 cardiac amyloidosis that led to the hypothesis that the presence of amyloid protein, known to
 increase the ECV, may also change the inversion time curves of both the blood pool and the
 myocardium. These features, as well as abnormal functional parameters, will help detect
 cardiac amyloidosis earlier than would otherwise be possible by morphologic assessment. The
 possibility of diagnosing sub-clinical disease has implications for screening patients with
 known amyloidosis for early cardiac involvement. Also, CMR parameters may be useful in
 assessing response to treatment of the plasma cell dyscrasias, such as cardiac amyloidosis,
 that may be complicated by heart failure and ventricular tachycardia. Lastly, the
 relationship of the MRI findings to cardiac biomarkers has yet to be described and will be
 assessed in this study.

 Preliminary Data:

 The investigators have observed a significant difference between the Myo/BlP TI0 ratio in
 patients with cardiac amyloidosis when compared with controls both with preserved LV function
 (CTL) and non-amyloid cardiomyopathies (CTL-CMP). The Myo/BlP TI0 ratio of the CA group is
 close to 1 to 1 (0.95 +/- 0.16) leading to poor myocardium and blood pool contrast in the
 corresponding delayed enhancement images acquired following the TI scout (Figure 7). The
 Myo/BlP TI0 ratio provides a quantitative method to support the diagnosis of cardiac
 amyloidosis in patients presenting with cardiac symptoms.

 Estimated Period of Time to Completion:

 Estimated time to completion of aim 1, 2 and 4 will depend on power calculations following
 the acquisition of pilot prospective data. The estimated timing of completion of aim 3 will
 be 12-18 months from the start of data acquisition.
Inclusion Criteria:

 -  Subjects meeting diagnostic criteria for the target population will be recruited for
 the study. Age range will be 18 to 85 years of age.

 Exclusion Criteria:

 -  Exclusion criteria will include history of heart transplantation as well as any
 contraindications for 1.5T CMR. For the use of GBCA, patients with acute renal failure
 or stage IV/V chronic renal failure will be excluded. Patients with end stage renal
 failure receiving peritoneal dialysis will also be excluded. Women who are pregnant or
 breast feeding will also be excluded.