Cardiac Troponin I: A Valuable Biomarker Indicating the Cardiac Involvement in Fabry Disease.

OBJECTIVES: Assessment of the clinical severity of Fabry disease (FD), an X-linked, rare, progressive disorder based on a genetic defect in alpha-galactosidase is challenging, especially regarding cardiac involvement. The aim of the study was to evaluate the diagnostic value of cardiac troponin I (cTnI) in discriminating FD patients with cardiac involvement in a large FD patient cohort. METHODS: cTnI levels were measured with a contemporary sensitive assay in plasma samples taken routinely from FD patients. The assay was calibrated to measure cTnI levels ≥0.01 ng/ml. Elevated cTnI values (cut-off ≥0.04 ng/ml) were correlated with clinical data. RESULTS: cTnI was assessed in 62 FD patients (median age: 47 years, males: 36%). Elevated cTnI levels were detected in 23 (37%) patients. Patients with a cTnI elevation were older (median 55 years versus 36 years, p<0.001). Elevated cTnI levels were associated with the presence of a LVH (16/23 versus 1/39; OR 65.81, CI: 6.747-641.859; p<0.001). In almost all patients with a left ventricular hypertrophy (LVH) elevated cTnI levels were detected (16/17, 94%). Absolute cTnI levels in patients with LVH were higher than in those without (median 0.23 ng/ml versus 0.02 ng/ml; p<0.001). A cTnI level <0.04ng/ml had a high negative predictive value regarding the presence of a LVH (38/39, 97%). In a control group of non-FD patients (n = 17) with LVH (due to hypertension) none showed cTnI levels ≥0.01 ng/ml. CONCLUSIONS: Elevated cTnI levels are common in FD patients, reflecting cardiac involvement. FD patients might benefit from a continuous cTnI monitoring.

Baseline characteristics in stroke patients with atrial fibrillation: clinical trials versus clinical practice.

BACKGROUND: When applying information gathered from medical research to the clinical setting, it is imperative that the sample of the investigated patients be representative of the clinical population. Because of this fact, it is necessary to closely examine the sample's baseline characteristics in clinical trials. METHODS: We analysed baseline data of relevant trials investigating considerable proportions of patients with atrial fibrillation (AF) in the secondary stroke prevention: EAFT, SIFA, Active-W, BAFTA, RE-LY, AVERROES, ARISTOTLE and ROCKET AF. For comparing baseline data stroke patients with AF documented in a statutory stroke registry were considered. In a subgroup of patients (members of a large insurance) data on subsequent prescription for oral anticoagulants (oAK) were available. RESULTS: In the stroke registry (n = 15,886) the mean age was higher than in the selected clinical trials (mean 77.7 versus 70-72 years). Among insurance members (n = 1,828), those with a prescription for oAK (n = 827) were older than patients recruited in clinical trials (mean 75.1 versus 70-72 years). Results also showed that the male sex was overrepresented in clinical trials (59-63% versus 46%). The distribution of vascular risk factors in recent clinical trials was comparable to proportions in the registry (hypertension: 77-85% versus 80%; diabetes mellitus: 20-26% versus 27%). CONCLUSIONS: The majority of stroke patients with AF in the clinical setting are considerably older than those included in clinical trials. While the distribution of vascular risk factors in clinical trials corresponds to proportions observed in clinical practice, an overrepresentation of the male sex in clinical trials is evident.

Secondary stroke prevention in atrial fibrillation: a challenge in the clinical practice.

BACKGROUND: Despite clear evidence for the effectiveness of oral anticoagulation (OA) in patients with atrial fibrillation (AF), there is evidence for the underutilisation of this therapy in the secondary stroke prevention. We therefore investigate the link between the use of OA in stroke patients with AF and favourable clinical outcome following the acute event. METHODS: The study population was determined by identifying the overlap of two different databases: a stroke registry and claims data of a health insurance company. Baseline data originated from the registry; documented dementia and the prescriptions for OA were derived from the insurance database. Patients with AF, minor physical impairment, and evidence of more than 30 days without further hospitalisation within the subsequent 90 days after the acute event were selected for the analysis. RESULTS: 1828 patients were selected (mean age 77.6 years), 1064 patients (58.2%) were female. 827 patients (45%) received a prescription for OA. The following factors were independently associated with no prescription for oral anticoagulants: increased age (OR: 0.54, CI: 0.46-0.63; P < 0.0001), female sex (OR: 0.77, CI: 0.63-0.94; P < 0.011), worsening disability status at discharge (OR: 0.88, CI: 0.81-0.96; P < 0.006), and documented dementia (OR: 0.54, CI: 0.39-0.73; P < 0.001). Conversely, treatment in a neurological department was associated with prescription for OA (OR: 1.47, CI: 1.19-1.81; P < 0.003). CONCLUSIONS: In more than half of the patients with AF who suffered a stroke OA was not prescribed. The factors associated with reluctance in prescribing anticoagulants are increasing age, female sex, treatment at a non-neurological department, worsening disability, and dementia.

Continuous cardiac troponin I release in Fabry disease.

BACKGROUND: Fabry disease (FD) is a rare lysosomal storage disorder also affecting the heart. The aims of this study were to determine the frequency of cardiac troponin I (cTNI) elevation, a sensitive parameter reflecting myocardial damage, in a smaller cohort of FD-patients, and to analyze whether persistent cTNI can be a suitable biomarker to assess cardiac dysfunction in FD. METHODS: cTNI values were determined at least twice per year in 14 FD-patients (6 males and 8 females) regularly followed-up in our centre. The data were related to other parameters of heart function including cardiac magnetic resonance imaging (cMRI). RESULTS: Three patients (21%) without specific vascular risk factors other than FD had persistent cTNI-elevations (range 0.05-0.71 ng/ml, normal: <0.01). cMRI disclosed late gadolinium enhancement (LGE) in all three individuals with cTNI values ≥0.01, while none of the 11 patients with cTNI <0.01 showed a pathological enhancement (p<0.01). Two subjects with increased cTNI-values underwent coronary angiography, excluding relevant stenoses. A myocardial biopsy performed in one during this procedure demonstrated substantial accumulation of globotriaosylceramide (Gb3) in cardiomyocytes. CONCLUSION: Continuous cTNI elevation seems to occur in a substantial proportion of patients with FD. The high accordance with LGE, reflecting cardiac dysfunction, suggests that cTNI-elevation can be a useful laboratory parameter for assessing myocardial damage in FD.

Cardiac Troponin I elevation after epileptic seizure.

BACKGROUND: Cardiac troponin-I (cTNI) is highly specific biomarker to prove myocardial damage, e.g. in acute coronary syndrome (ACS). However, it occurs in other conditions as well. We therefore analysed cTNI increase in patients after generalized convulsive seizure. METHODS: Consecutive patients admitted with acute generalized convulsive seizure were included in case of cTNI measurement on admission. Among 898 selected cases, 53 patients were referred secondary to our department; in 845 cases cTNI measurements on admission were available. In case of multiple admissions (81 cases), only the first admission entered our analysis. In 17 patients elevated cTNI was determined due to ACS; in one patient a myocarditis was found. 5 patients suffered of relevant renal insufficiency. Finally 741 patients were included in the analysis. A cTNI cut-off level of ≥ 0.1 ng/ml was considered. Factors associated with a cTNI increase were analysed subsequently. RESULTS: The mean age of the study population (n = 741) was 47.8 years (SD ± 18.6), 40.9% were female. In 50 patients (6.7%) a cTNI elevation of unknown origin was found; no obvious cardiac involvement could be detected in these patients who all remained asymptomatic. A vascular risk profile (including at least hypertension, hypercholesterolemia or diabetes) (OR = 3.62; CI: 1.59 to 8.21; p = 0.001) and elevated creatine kinase on admission (OR = 2.36; CI: 1.26 to 4.39; p = 0.002) were independent factors associated with cTNI release. CONCLUSION: cTNI release occurs in patients with generalized convulsive seizure with predominance in patients with vascular risk profile.

Factors associated with shunt dynamic in patients with cryptogenic stroke and patent foramen ovale: an observational cohort study.

BACKGROUND: As previously reported there is evidence for a reduction in right to left shunt (RLS) in stroke patients with patent foramen ovale (PFO). This occurs predominantly in patients with cryptogenic stroke (CS). We therefore analysed factors associated with a shunt reduction on follow-up in stroke patients suffering of CS. METHODS: On index event PFO and RLS were proven by transesophageal echocardiography and contrast-enhanced transcranial Doppler-sonography (ce-TCD). Silent PE was proved by ventilation perfusion scintigraphy (V/Q) within the stroke work-up on index event; all scans were re-evaluated in a blinded manner by two experts. The RLS was re-assessed on follow-up by ce-TCD. A reduction in shunt volume was defined as a difference of ≥20 microembolic signals (MES) or the lack of evidence of RLS on follow-up. For subsequent analyses patients with CS were considered; parameters such as deep vein thrombosis (DVT) and silent pulmonary embolism (PE) were analysed. RESULTS: In 39 PFO patients suffering of a CS the RLS was re-assessed on follow-up. In all patients (n = 39) with CS a V/Q was performed; the median age was 40 years, 24 (61.5%) patients were female. In 27 patients a reduction in RLS was evident. Silent PE was evident in 18/39 patients (46.2%). Factors such as atrial septum aneurysm, DVT or even silent PE were not associated with RLS dynamics. A greater time delay from index event to follow-up assessment was associated with a decrease in shunt volume (median 12 vs. 6 months, p = 0.013). CONCLUSIONS: In patients with CS a reduction in RLS is not associated with the presence of a venous embolic event such as DVT or silent PE. A greater time delay between the initial and the follow-up investigation increases the likelihood for the detection of a reduction in RLS.

Cerebral vein thrombosis: clinical manifestation and diagnosis.

BACKGROUND: Cerebral venous thrombosis (CVT) is a disease with a wide spectrum of symptoms and severity. In this study we analysed the predictive value of clinical signs and symptoms and the contribution of D-dimer measurements for diagnosis. METHODS: We evaluated consecutive patients admitted with suspected CVT receiving non-invasive imaging. Symptoms and symptom combination as well as D-dimer levels were evaluated regarding their diagnostic value. RESULTS: 239 patients were included in this study, 170 (71%) were females. In 39 patients (16%) a CVT was found. For identifying a CVT patients underwent either a venous CT-angiography or MR-angiography or both. No combination of symptoms either alone or together with the D-dimer measurements had a sensitivity and positive predictive value as well as negative predictive value and specificity high enough to serve as red flag. D-dimer testing produced rates of 9% false positive and of 24% false negative results. For D-dimer values a Receiver Operating Characteristic curve (ROC) and the area under the curve (AUC = 0.921; CI: 0.864-0.977) were calculated. An increase of sensitivity above 0.9 results in a relevant decrease in specificity; a sensitivity of 0.9 matches a specificity value of 0.9. This corresponds to a D-dimer cut-off level of 0.16 µg/ml. CONCLUSION: Imaging as performed by venous CT-angiography or MR-angiography has a 1 to 2 in 10 chance to detect CVT when typical symptoms are present. D-dimer measurements are of limited clinical value because of false positive and negative results.

Persistent increase in cardiac troponin I in Fabry disease: a case report.

BACKGROUND: Hypertrophic cardiomyopathy is a frequent manifestation in Fabry disease (FD) - an X-linked lysosomal storage disorder caused by reduced activity of the enzyme α-galactosidase A. In FD an elevation of specific cardiac biomarkers, such as cardiac troponin I (cTNI) has been reported in case of clinical manifestation suggestive of myocardial ischemia. In diagnosing acute myocardial infarction cTNI is considered the most reliable parameter. CASE PRESENTATION: In the referred case we present a 59 years old female patient with the diagnosis of FD presenting with persistently increased cTNI level (lowest value 0.46 ng/ml, highest value 0.69 ng/ml; normal range <0.05 ng/ml) over a period of 5 months lacking cardiac clinical signs. Since renal insufficiency did not explain the degree of cTNI elevation, this was interpreted as a result of cardiac involvement in FD. Cardiac MRI showed marked left ventricular hypertrophy and focal late Gadolinium enhancement. CONCLUSIONS: Our case report demonstrates a persistent cTNI release in FD with cardiac involvement. Proving the persistence in a symptom free interval, it might be related to a direct damage of myocytes. In FD cTNI could serve as a beneficial long term parameter providing new perspectives for screening strategies.