The Journal of the Arkansas Medical Society Issue 3 Vol 115 | Page 20

Amyloid cardiomyopathy with concomitant
atrial fibrillation has an increased risk of atrial
thrombus, and risk should not be estimated based
on CHADs2VASC score alone.
References
1. Connors LH, Sam F, Skinner M, Salinaro F, Sun
F, Ruberg FL, et al. Heart Failure Resulting From
Age-Related Cardiac Amyloid Disease Associ-
ated With Wild-Type Transthyretin: A Prospec-
tive, Observational Cohort Study. Circulation
2016 Jan 19,;133(3):282.
2. Tanskanen M, Peuralinna T, Polvikoski T, Not-
kola I, Sulkava R, Hardy J, et al. Senile systemic
amyloidosis affects 25% of the very aged and
associates with genetic variation in alpha2-
macroglobulin and tau: a population-based
autopsy study. Ann Med 2008;40(3):232-239.
3. Ruberg FL, Berk JL. Transthyretin (TTR) car-
diac amyloidosis. Circulation 2012 Sep
4;126(10):1286-1300.
Figure 3: Cardiac MR showing abnormal late gadolinium enhancement.
loidosis as they can potentially bind to transthyre-
tin amyloid fibrils and can cause toxicity. 7,8 Atrial
fibrillation can be managed either by rate control
strategy or by rhythm control strategy along with
anticoagulation. Amiodarone can be safely used
in ATTR amyloidosis. Amyloidosis patients have
a higher incidence of intra-atrial thrombus. It is
postulated that the presence of chronic amyloid in
atria along with systolic and diastolic ventricular
dysfunction causes atrial mechanical dysfunction
and increases the risk of thrombus in addition to
usual risk in atrial fibrillation. In fact, atrial throm-
bus has been reported in patients with cardiac
amyloidosis in the absence of atrial fibrillation. 9
In view of this, all patients with cardiac amyloi-
dosis and AF should be anticoagulated irrespec-
tive of their risk status based on a score such as
CHA2DS2-Vasc score. Anticoagulation with novel
oral anticoagulants, though popular, is not studied
in this patient population.
Earlier, liver transplantation was the only avail-
able therapy as it improved survival and reduced
transthyretin production. But it was found that
amyloid deposition continues to occur in heart and
neural tissues from the transthyretin produced by
donor liver. Newer therapies specific to ATTR type
amyloid are currently in phase two and three clini-
cal trials. Revisiran utilizes RNA silencing to inhibit
transthyretin mRNA in hepatocytes. Phase two tri-
als showed a decrease of >85% in ATTRwt and AT-
TRm cardiomyopathy patients. Tafamidis has been
shown to halt disease progression in terms of neu-
ropathy by stabilizing the structure transthyretin
and preventing formation of amyloid beta pleated
sheets. However, its effect on cardiomyopathy
is not known. Diflunisal, an NSAID, has shown to
decrease the progression of cardiac and neurologi-
cal disease in small studies. 10 It acts by stabilizing
transthyretin through its anti-aggregating effect.
This case illustrates the importance of con-
sidering an underlying cardiomyopathy in patients
with suspected TCM due to arrhythmias. Patients
with reduced LVEF from an arrhythmia such as
AF may either achieve normal LV systolic function
(“pure” TCM) or merely an improved but impaired
LV systolic function (”impure” TCM) with control of
the arrhythmia. Once the arrhythmia is controlled,
a search for underlying cardiomyopathy should be
considered.
4. Syed IS, Glockner JF, Feng D, Araoz PA, Mar-
tinez MW, Edwards WD, et al. Role of cardiac
magnetic resonance imaging in the detection
of cardiac amyloidosis. JACC Cardiovasc Imag-
ing 2010 Feb;3(2):155-164.
5. Quarta C, Solomon S, Uraizee I, Kruger J, Longhi
S, Ferlito M, et al. Left Ventricular Structure and
Function in Transthyretin-Related Versus Light-
Chain Cardiac Amyloidosis. Circulation 2014
May 6;129(18):1840-1849.
6. (Castaño A, Drachman BM, Judge D, Maurer
MS. Natural history and therapy of TTR-cardi-
ac amyloidosis: emerging disease-modifying
therapies from organ transplantation to stabi-
lizer and silencer drugs. Heart Fail Rev 2015
-3;20(2):163-178.
7. Rubinow A, Skinner M, Cohen AS. Digoxin sen-
sitivity in amyloid cardiomyopathy. Circulation
1981 Jun;63(6):1285-1288.
8. Pollak A, Falk RH. Left ventricular systolic dys-
function precipitated by verapamil in cardiac
amyloidosis. Chest 1993 Aug;104(2):618-620.
Learning Points 9. Dubrey S, Pollak A, Skinner M, Falk RH. Atrial
thrombi occurring during sinus rhythm in
cardiac amyloidosis: evidence for atrial elec-
tromechanical dissociation. Br Heart J 1995
Nov;74(5):541-544.
Atrial fibrillation is present in around 50% of
patients with ATTR type cardiac amyloidosis and
can cause tachycardia mediated reduction in LV
ejection fraction, which can improve with achieving
sinus rhythm. 10. Liu PP, Smyth D. Wild-Type Transthyretin Amy-
loid Cardiomyopathy: A Missed Cause of Heart
Failure With Preserved Ejection Fraction With
Evolving Treatment Implications. Circulation
2016 Jan 19;133(3):245.
68 • THE JOURNAL OF THE ARKANSAS MEDICAL SOCIETY
VOLUME 115