Potential role of vitamin D deficiency on Fabry cardiomyopathy.

Patients with Fabry disease frequently develop left ventricular (LV) hypertrophy and renal fibrosis. Due to heat intolerance and an inability to sweat, patients tend to avoid exposure to sunlight. We hypothesized that subsequent vitamin D deficiency may contribute to Fabry cardiomyopathy. This study investigated the vitamin D status and its association with LV mass and adverse clinical symptoms in patients with Fabry disease. 25-hydroxyvitamin D (25[OH]D) was measured in 111 patients who were genetically proven to have Fabry disease. LV mass and cardiomyopathy were assessed by magnetic resonance imaging and echocardiography. In cross-sectional analyses, associations with adverse clinical outcomes were determined by linear and binary logistic regression analyses, respectively, and were adjusted for age, sex, BMI and season. Patients had a mean age of 40 ± 13 years (42% males), and a mean 25(OH)D of 23.5 ± 11.4 ng/ml. Those with overt vitamin D deficiency (25[OH]D ≤ 15 ng/ml) had an adjusted six fold higher risk of cardiomyopathy, compared to those with sufficient 25(OH)D levels >30 ng/ml (p = 0.04). The mean LV mass was distinctively different with 170 ± 75 g in deficient, 154 ± 60 g in moderately deficient and 128 ± 58 g in vitamin D sufficient patients (p = 0.01). With increasing severity of vitamin D deficiency, the median levels of proteinuria increased, as well as the prevalences of depression, edema, cornea verticillata and the need for medical pain therapy. In conclusion, vitamin D deficiency was strongly associated with cardiomyopathy and adverse clinical symptoms in patients with Fabry disease. Whether vitamin D supplementation improves complications of Fabry disease, requires a randomized controlled trial.

Tei index 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.

The right ventricle in Fabry disease: natural history and impact of enzyme replacement therapy.

BACKGROUND: Storage of globotriaosylceramides is present in the left and right ventricles of patients with Fabry disease. Improvement of left ventricular morphology and function during enzyme replacement therapy (ERT) has previously been reported. OBJECTIVES: To analyse the effects of long term ERT on right ventricular morphology and function. METHODS: This was a prospective follow-up of 75 genetically confirmed consecutive Fabry patients for 3.1±1.8 years. According to treatment guidelines the natural history was followed in 18 patients, whereas 57 patients received ERT. Standard echocardiography, strain rate imaging for regional deformation of the right and left ventricle, and magnetic resonance tomography with late enhancement (LE) imaging for the detection of fibrosis were all performed at yearly intervals. RESULTS: Right ventricular hypertrophy was evident in 53 patients (71%) at baseline. A significant positive correlation was found between left and right ventricular wall thickness (r=0.76; p<0.0001). LE was detected in half of the patients (n=38) in the left ventricle at baseline while no patient ever had LE of the right ventricle. Patients with LE in the left ventricle presented with the lowest right ventricular deformation properties. In contrast to the left ventricle, there was no change in right ventricular wall thickness (baseline 6.9±1.6 mm vs follow-up 6.7±1.5 mm; p=0.44) or systolic strain rate (2.2±0.7/s vs 2.1±0.8/s; p=0.31) during follow-up with ERT. CONCLUSION: The degree of right ventricular involvement in Fabry disease is related to the left ventricular cardiomyopathy stage. ERT seems to have no direct impact on right ventricular morphology and function.

Heart valve involvement in Fabry cardiomyopathy.

Fabry disease is a rare X-linked lysosomal storage disorder leading to an accumulation of glycosphingolipids in all tissues and organs including the heart. Among the pathologies of myocardial involvement, reviews and registry data list affection of heart valves and its hemodynamic significance as predominant alterations during progression of the disease. We thought to approach this uncertainty with a systematic observational study. In a single center study, 111 patients with genetically proven Fabry disease were systematically investigated by echocardiography for abnormalities of the valves in the left (aortic and mitral valve) and right heart (pulmonary and tricuspid valve). In addition, 60 patients were followed by echocardiography for 2.7 +/- 1.5 y (range 1 to 6). Both valve stenosis and regurgitation were classified as mild, moderate or severe. Overall, no patient had severe heart valve abnormalities. The most frequent findings were mild aortic (n = 17), mitral (n = 57) and tricuspid (n = 38) valve regurgitation. Only two patients showed mild aortic valve stenosis. Moderate aortic (n = 1), mitral (n = 2) or tricuspid (n = 1) regurgitation were rarely detected. All Fabry patients in advanced stages (n = 9) had only mild mitral regurgitation and one of them had mild aortic and mitral regurgitation, moderate tricuspid regurgitation and mild aortic stenosis. Thirty patients had completely normal valve function. There was no significant change toward hemodynamic relevant heart valve abnormalities during follow-up. Mild left ventricular valve regurgitations are frequent in Fabry disease. However, these valve abnormalities are not the major limitations for the Fabry heart.