umu.sePublications
Change search
ReferencesLink to record
Permanent link

Direct link
Right ventricular involvement in transthyretin amyloidosis
Umeå University, Faculty of Medicine, Department of Public Health and Clinical Medicine, Cardiology.
Umeå University, Faculty of Medicine, Department of Public Health and Clinical Medicine, Cardiology.
Umeå University, Faculty of Medicine, Department of Public Health and Clinical Medicine, Medicine.
Show others and affiliations
(English)Manuscript (preprint) (Other academic)
Abstract [en]

Objectives

Right heart involvement and dysfunction is frequently encountered in cardiomyopathies. In immunoglobulin light chain (AL) amyloidosis, right ventricular (RV) function has been described as a strong determinant of survival. However, RV involvement in transthyretin related amyloidosis (ATTR) has been somewhat overlooked. We therefore sought to establish the degree of RV involvement in ATTR amyloidosis and compare the findings with sarcomeric hypertrophic cardiomyopathy (HCM).

Patients and methods

Forty-two patients with diagnosed ATTR and echocardiographic evidence of cardiac amyloidosis (cardiac ATTR), 19 ATTR patients with normal left ventricular (LV) wall thickness (non-cardiac ATTR), 25 patients with diagnosed sarcomeric HCM and 30 healthy controls were included in the study. Echocardiographic examinations were analysed and standard measurements of LV and RV dimensions and function were carried out. In addition, LV global and RV global and segmental strain were analysed. The degree of cardiac involvement and function was compared between non-cardiac ATTR patients and healthy controls and between cardiac ATTR patients and with those having HCM.

Results

Non-cardiac ATTR amyloidosis patients did not differ from healthy controls, either in geometrical or functional measurements of the LV and RV. HCM patients had significantly thicker interventricular septal thickness (p=0.017) and thinner posterior wall thickness (p=0.004) as compared to cardiac ATTR. When comparing cardiac ATTR and HCM patients by means of RV structure and function only segmental strain differed between the two patient groups. In cardiac ATTR we found an RV apex-to-base strain gradient with highest deformation in the apex whereas the pattern was inverse in patients with HCM.

Conclusions

RV involvement is common only in ATTR patients with concomitant LV involvement. The present study also detected an apical sparing pattern for the RV in patients with ATTR cardiomyopathy, similar to what has previously been described for the LV. This pattern was not seen in HCM patients. Further studies are warranted to assess the clinical importance of these findings.

Keyword [en]
Cardiac amyloidosis, hypertrophic cardiomyopathy, HCM, strain, apical sparing
National Category
Cardiac and Cardiovascular Systems
Identifiers
URN: urn:nbn:se:umu:diva-113889OAI: oai:DiVA.org:umu-113889DiVA: diva2:890741
Available from: 2016-01-04 Created: 2016-01-04 Last updated: 2016-01-08
In thesis
1. Cardiac function in hereditary transthyretin amyloidosis: an echocardiographic study
Open this publication in new window or tab >>Cardiac function in hereditary transthyretin amyloidosis: an echocardiographic study
2016 (English)Doctoral thesis, comprehensive summary (Other academic)
Alternative title[sv]
Hjärtfunktion vid ärftlig transtyretin-amyloidos : en ekokardiografisk studie
Abstract [en]

Background: Hereditary transthyretin amyloidosis (ATTR) is a lethal disease in which misfolded transthyretin (TTR) proteins accumulate as insoluble aggregates in tissues throughout the body. A common mutation is the exchange of valine to methionine at place 30 (TTR V30M), a form endemically found in the northern parts of Sweden. The main treatment option for ATTR amyloidosis is liver transplantation as the procedure halts production of mutated transthyretin. The disease is associated with marked phenotypic diversity ranging from predominant cardiac complications to pure neuropathy. Two different types of fibril composition – one in which both fragmented and full-length TTR are present (type A) and one consisting of only full-length TTR (type B) have been suggested to account for some phenotypic differences. Cardiac amyloidosis is associated with increased myocardial thickness and the disease could easily be mistaken for other entities characterised by myocardial thickening, such as sarcomeric hypertrophic cardiomyopathy (HCM). The aims in this thesis were to investigate echocardiographic characteristics in Swedish ATTR amyloidosis patients, and to identify markers aiding in differentiating ATTR heart disease from HCM. Another objective was to examine the impact of fibril composition and sex on the phenotypic variation in amyloid heart disease.

Methods: A total of 122 ATTR amyloidosis patients that had undergone thorough echocardiographic examinations were included in the studies. Analyses of ventricular geometry as well as assessment of systolic and diastolic function were performed, using both conventional echocardiographic methods and speckle tracking technique. ECG analysis was conducted in study I, allowing measurement of QRS voltage. In study I and study II ATTR patients were compared to patients with HCM. In addition, 30 healthy controls were added to study II.

Results: When parameters from ECG and echocardiography were investigated, the results revealed that the combination of QRS voltage <30 mm (<3 mV) and an interventricular/posterior wall thickness quotient <1.6 could differentiate cardiac ATTR amyloidosis from HCM. Differences in degree of right ventricular involvement were also demonstrated between HCM and ATTR amyloidosis, where ATTR patients displayed a right ventricular apical sparing pattern whereas the inverse pattern was found in HCM. Analysis of fibril composition revealed increased LV wall thickness in type A patients compared to type B, but in addition type A women displayed both lower myocardial thickness and more preserved systolic function as compared to type A males. When cardiac geometry and function were evaluated pre and post liver transplantation in type A and B patients, significant deterioration was detected in type A but not in type B patients after liver transplantation.

Conclusions: Increasing awareness of typical cardiac amyloidotic signs by echocardiography is important to reduce the risk of delayed diagnosis. Our classification model based on ECG and echocardiography could aid in differentiating ATTR amyloidosis from HCM. Furthermore, the apical sparing pattern found in the right ventricle may pose another clue for amyloid heart disease, although it requires to be studied further. Furthermore, we disclosed that type A fibrils, male sex and increasing age were important determinants of increased myocardial thickness. As type A fibril patients displayed rapid cardiac deterioration after liver transplantation other treatment options should probably be sought for this group of patients.

Place, publisher, year, edition, pages
Umeå: Umeå universitet, 2016. 56 p.
Series
Umeå University medical dissertations, ISSN 0346-6612 ; 1774
Keyword
Amyloid, echocardiography, ECG, HCM, fibril type, strain, ATTR, cardiomyopathy, speckle tracking
National Category
Cardiac and Cardiovascular Systems Other Clinical Medicine
Identifiers
urn:nbn:se:umu:diva-113891 (URN)978-91-7601-399-1 (ISBN)
Public defence
2016-01-29, Hörsal Betula Unod L0, Umeå, 09:00 (Swedish)
Opponent
Supervisors
Available from: 2016-01-08 Created: 2016-01-04 Last updated: 2016-01-07Bibliographically approved

Open Access in DiVA

No full text

Search in DiVA

By author/editor
Arvidsson, SandraHenein, Michael YSuhr, Ole B
By organisation
CardiologyMedicineClinical Physiology
Cardiac and Cardiovascular Systems

Search outside of DiVA

GoogleGoogle Scholar
The number of downloads is the sum of all downloads of full texts. It may include eg previous versions that are now no longer available

Total: 42 hits
ReferencesLink to record
Permanent link

Direct link