Cardiac manifestations of fabry disease in female patients: a single centre experience
Authors: Peter C U , Zhao T X , Deegan P B , Rusk R A 
Published: October 2021

Abstract

Introduction
Fabry disease is a lysosomal storage disorder resulting in multisystemic effects due to deposition and accumulation of glycosphingolipids. Although an X linked disorder, it is recognised that female heterozygotes can express clinical manifestations. Cardiac expression in the female Fabry population remains incompletely understood. Data from the Fabry Outcome Survey suggests that up to a quarter of female patients demonstrate left ventricular hypertrophy (LVH) on echocardiography. Although LVH is the most commonly cited cardiac finding, other abnormalities from clinical surveillance can include electrocardiographic abnormalities, fibrosis and elevated troponin levels.

Purpose
To establish the prevalence and extent of cardiac involvement amongst our cohort of female Fabry patients.

Methods
Heterozygous females, confirmed by genetic testing, were identified in our single centre Fabry database. Data was collected retrospectively on their 12 lead ECG, high sensitivity troponin I level and echocardiography performed at their most recent cardiac Fabry clinic visit, along with the most recent cardiac magnetic resonance imaging (CMR). Values are expressed as mean ± SD.

Results
51 female heterozygotes were identified, ranging from 23 to 83 years (mean age 49.3±15.4). 28 (54.9%) were established on enzyme replacement therapy. On echocardiography LVH of ≥13mm was identified in 14 (27.5%) patients (mean 14.6±1.9 mm). 44 patients had CMR and of these, 17 (38.6%) had findings in keeping with a Fabry cardiomyopathy (34.1% had fibrosis, 15.9% hypertrophy, 13.6% both). Of the 17 patients with abnormalities on CMR, 8 had normal left ventricular wall thickness on echocardiography.
All patients had a high sensitivity troponin I measurement and this was above upper reference limits (&gt;40ng/L) in 21 (41.1%) patients in the absence of chest pain. Of 21 patients with abnormal troponin I levels, 9 had normal left ventricular wall thickness on echocardiography.
Abnormalities identified on 12 lead ECG are summarised in Table 1. All patients with ECG abnormalities listed in Table 1 had an abnormal troponin and/or abnormal imaging, except for 5 patients who had an isolated short PR interval. 6 patients had a permanent pacemaker and 1 had a primary prevention implantable cardioverter defibrillator.
25 (49%) of the 51 patients were classed as having cardiac involvement based on raised troponin levels and/or abnormal imaging findings.

Conclusion
Although Fabry disease is traditionally thought to be a male predominant disease, in our cohort nearly half of our female heterozygotes showed evidence of cardiac involvement. The use of CMR, cardiac biomarkers and 12 lead ECG are helpful adjuncts to identify cardiac involvement, which could otherwise be missed if stand-alone echocardiography was used. Timely identification and monitoring of cardiac involvement has clinical implication, especially with regards to prognosis and treatment.

Funding Acknowledgement
Type of funding sources: None.