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Tei index in fabry disease
Markus Niemann1, Frank Breunig, Meinrad Beer
1Department of Internal Medicine, University of Würzburg, Würzburg, Germany.
Insights
The Tei index detects left ventricular (LV) functional reduction in Fabry disease patients, reflecting cardiomyopathy progression. However, it has limited value for detecting fibrosis or monitoring enzyme replacement therapy.
Area of Science:
- Cardiology
- Genetics
- Biomarkers
Background:
- Fabry disease (FD) is a genetic disorder causing left ventricular (LV) systolic and diastolic dysfunction.
- Cardiac involvement in FD necessitates reliable markers for early detection and monitoring.
Purpose of the Study:
- To evaluate the diagnostic utility of the Tei index, a measure of global cardiac function, in patients with Fabry disease.
- To assess the Tei index's ability to detect cardiac involvement, including hypertrophy and fibrosis, and monitor disease progression.
Main Methods:
- Sixty-six genetically confirmed Fabry disease patients underwent echocardiography (including Tei index) and cardiac MRI.
- Patients were categorized into three groups based on cardiac involvement: none, LV hypertrophy without fibrosis, and LV hypertrophy with fibrosis.
- Follow-up included assessment of enzyme replacement therapy (ERT) and natural history.
Main Results:
- The Tei index was significantly elevated in patients with LV hypertrophy and/or fibrosis compared to those without cardiac involvement (P < .001).
- Ejection fraction remained normal across all groups, rendering it ineffective for detecting cardiac involvement.
- A positive correlation existed between LV wall thickness and Tei index; ROC analysis showed high accuracy for Tei index in detecting hypertrophy but low accuracy for fibrosis.
Conclusions:
- The Tei index effectively detects global LV functional impairment and LV hypertrophy progression in Fabry disease, outperforming ejection fraction.
- The Tei index has limited value in detecting myocardial fibrosis or monitoring the efficacy of enzyme replacement therapy.
- The Tei index serves as a valuable global functional parameter for assessing cardiac involvement in Fabry disease.
Background:
Systolic and diastolic dysfunction of the left ventricle are present in patients with cardiac involvement in Fabry disease. The aim of this study was to investigate the diagnostic value of the Tei index, a marker for combined diastolic and systolic function, in patients with Fabry disease.
Methods:
A total of 66 consecutive patients with genetically confirmed Fabry disease were included in this study. Standard echocardiography, including the Tei index, and magnetic resonance imaging were performed. Patients were followed for 2.9 ± 1.9 years; 56 patients received enzyme replacement therapy, and 10 patients had natural history follow-up. Patients were subdivided into three groups: (1) those without cardiac involvement, (2) those with left ventricular (LV) hypertrophy and without late enhancement on magnetic resonance imaging, and (3) those with late enhancement on magnetic resonance imaging.
Results:
The Tei index was significantly higher in the groups 2 (0.56 ± 0.10) and 3 (0.60 ± 0.16) compared with patients without cardiac involvement (0.44 ± 0.10) (P < .001). All patients with Tei indexes > 0.64 showed signs of cardiomyopathy. In contrast, ejection fractions were normal in all three patient groups and therefore not useful for the detection of cardiac involvement. A significant positive correlation was observed between LV wall thickness and the Tei index in the complete patient cohort. Moreover, receiver operating characteristic analysis revealed a large area under the curve for Tei index and hypertrophy, while the area under the curve for fibrosis was small. The Tei index remained unchanged in the natural history and enzyme replacement therapy groups during follow-up.
Conclusions:
In this cohort, the Tei index was of limited value to detect myocardial fibrosis and monitor enzyme replacement therapy. However, the progression of cardiomyopathy toward LV hypertrophy seems to be paralleled by global functional impairment, which can be assessed by the Tei index but not by ejection fraction. Thus, the Tei index seems to be a global parameter that can detect LV functional reduction in patients with Fabry disease.
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