Contemporary management of patients with atrial fibrillation in the Netherlands and Belgium: a report from the EORP-AF long-term general registry.

BACKGROUND: Contemporary data regarding the characteristics, treatment and outcomes of patients with atrial fibrillation (AF) are needed. We aimed to assess these data and guideline adherence in the EURObservational Research Programme on Atrial Fibrillation (EORP-AF) long-term general registry. METHODS: We analysed 967 patients from the EORP-AF long-term general registry included in the Netherlands and Belgium from 2013 to 2016. Baseline and 1­year follow-up data were gathered. RESULTS: At baseline, 887 patients (92%) received anticoagulant treatment. In 88 (10%) of these patients, no indication for chronic anticoagulant treatment was present. A rhythm intervention was performed or planned in 52 of these patients, meaning that the remaining 36 (41%) were anticoagulated without indication. Forty patients were not anticoagulated, even though they had an indication for chronic anticoagulation. Additionally, 63 of the 371 patients (17%) treated with a non-vitamin K antagonist oral anticoagulant (NOAC) were incorrectly dosed. In total, 50 patients (5%) were overtreated and 89 patients (9%) were undertreated. However, the occurrence of major adverse cardiac and cerebrovascular events (MACCE) was still low with 4.2% (37 patients). CONCLUSIONS: Overtreatment and undertreatment with anticoagulants are still observable in 14% of this contemporary, West-European AF population. Still, MACCE occurred in only 4% of the patients after 1 year of follow-up.

Characteristics of patients with atrial fibrillation prescribed edoxaban in Belgium and the Netherlands: insights from the ETNA-AF-Europe study.

BACKGROUND: Studies on the use of non-vitamin K antagonist oral anticoagulants in unselected patients with atrial fibrillation (AF) show that clinical characteristics and dosing practices differ per region, but lack data on edoxaban. METHODS: With data from Edoxaban Treatment in routiNe clinical prActice for patients with AF in Europe (ETNA-AF-Europe), a large prospective observational study, we compared clinical characteristics (including the dose reduction criteria for edoxaban: creatinine clearance 15-50 ml/min, weight ≤60 kg, and/or use of strong p­glycoprotein inhibitors) of patients from Belgium and the Netherlands (BeNe) with those from other European countries (OEC). RESULTS: Of all 13,639 patients in ETNA-AF-Europe, 2579 were from BeNe. BeNe patients were younger than OEC patients (mean age: 72.3 vs 73.9 years), and had lower CHA2DS2-VASc (mean: 2.8 vs 3.2) and HAS-BLED scores (mean: 2.4 vs 2.6). Patients from BeNe less often had hypertension (61.6% vs 80.4%), and/or diabetes mellitus (17.3% vs 23.1%) than patients from OEC. Moreover, relatively fewer patients in BeNe were prescribed the reduced dose of 30 mg edoxaban (14.8%) than in OEC (25.4%). Overall, edoxaban was dosed according to label in 83.1% of patients. Yet, 30 mg edoxaban was prescribed in the absence of any dose reduction criteria in 36.9% of 30 mg users (5.5% of all patients) in BeNe compared with 35.5% (9.0% of all patients) in OEC. CONCLUSION: There were several notable differences between BeNe and OEC regarding clinical characteristics and dosing practices in patients prescribed edoxaban, which are relevant for the local implementation of dose evaluation and optimisation. TRIAL REGISTRATION: NCT02944019; Date of registration 24 October 2016.

Are there consistent relationships between major connective tissue components, intramuscular fat content and muscle fibre types in cattle muscle?

Intramuscular connective tissue (IMCT) is mainly composed of several fibrils (known as total collagen (TCol)) linked between each other by different chemical cross-links (CLs), the whole being embedded in a matrix of proteoglycans (PGs). In the field of beef quality, there is limited information on the role of CLs and PGs. Accordingly, several authors suggest that, to investigate the role of IMCT, it is important to investigate them just like TCol and insoluble collagen (ICol). In muscle, there are two other components, the muscle fibres and intramuscular fat (IMF) content. There are limited data on the relationships between these three components of muscle and then on possibility to independently manipulate these characteristics in order to control the final quality of meat. The present study aimed to investigate whether consistent relationships exist between these different components of muscle. Therefore, the present study compared four muscles of two cattle types (dairy and beef) to determine associations between TCol, ICol, CLs and PGs. Data were analysed across and within muscle (M) and animal type (AT) based on residuals. There was a strong M and AT effect for all muscle characteristics and an interaction M × AT for type I muscle fibres and IMF. Correlations between TCol, ICol and their CLs were M- and AT-independent. Total proteoglycans were positively correlated with TCol and ICol in a muscle-dependent manner irrespective of AT, but no correlation was found with CLs. On the contrary, CLs were negatively correlated with the ratio TPGs : TCol in an M-dependent manner, irrespective of AT. TCol, ICol and CLs were positively and negatively correlated with type IIA and IIB+X muscle fibres only in longissimus thoracis (LT) muscle, regardless the AT. Insoluble collagen was the only parameter of IMCT to be correlated with type I muscle fibres but only in LT muscle, irrespective of AT. There was no correlation between PGs and muscle fibre types, but PGs were the only IMCT component to be related with IMF in an M-dependent manner, irrespective of AT. Finally, there was no correlation between muscle fibre types and IMF content within M and AT. This study revealed that there is a strong relationship between IMCT components irrespective of M, an M-dependent relationship between the IMCT components and muscle fibre types and few (only with PGs) or no relationship between IMF and IMCT and muscle fibres.

Breeds and muscle types modulate performance of near-infrared reflectance spectroscopy to predict the fatty acid composition of bovine meat.

This study aims to assess near-infrared reflectance spectroscopy feasibility for predicting beef fatty acid (FA) composition. Experimental scheme included four breeds (Angus, Blond d'Aquitaine, Charolais, Limousin) and three muscles, Longissimus thoracis (LT), Rectus abdominis (RA), Semitendinosus (ST). The results showed that 1) increasing FA content variability with several breeds increased calibration model reliability (R(2)CV>0.86) for the major individual and groups of FA unless polyunsaturated FAs, 2) Longissimus thoracis FAs were better predicted than RA FAs while no ST FAs were correctly predicted (R(2)CV<0.71). This difference could be explained by FA content, FA variability or specific muscle physico-chemical characteristics.

Prospective evaluation of a simplified approach for common atrial flutter radio frequency ablation with only two catheters.

UNLABELLED: Intra-atrial conduction block within the inferior vena cava-tricuspid annulus isthmus (IVCT) has been shown to predict successful common atrial flutter ablation. However, its demonstration requires the use of several electrode catheters and mapping of the line of block. The aim of this study was prospectively to test the feasibility of a simplified ablation procedure using only two catheters. METHODS: Radio frequency (RF) ablation of common atrial flutter was performed in 30 patients with the sole use of a catheter for atrial pacing and a RF catheter. RF ablation lesions were created in the IVCT. Surface ECG criteria were used to monitor the conduction within the IVCT. The end point during low lateral atrial pacing was an increment in the interval between the pacing artefact and the peak of the R wave in surface lead II >50 ms and clockwise rotation of the P wave axis beyond -30 degrees and inferiorly. Then, the line of lesions was mapped during atrial pacing with the RF catheter. Additional RF lesions were applied if mapping disclosed a zone of residual conduction. Otherwise the procedure was stopped if mapping showed parallel double potentials all along the line. Finally, the block was reassessed with a 'Halo' catheter. RESULTS: Surface ECG criteria were met in 26 patients. Mapping the line of lesions showed a complete corridor of parallel double potentials in these 26 cases and in 3 of the 4 patients in whom ECG criteria were not met. Conduction evaluated with the Halo catheter showed bi-directional complete block in these 29 patients. After a follow-up of 16 +/- 4 months there was no recurrence of atrial flutter. CONCLUSION: Surface ECG criteria combined with mapping of the line of block demonstrate evidence of bi-directional IVCT block. This simplified RF ablation of common atrial flutter is feasible with a low recurrence rate.

[Mapping and radiofrequency ablation in different forms of right peri-atriotomy flutter]. / Cartographie et ablation par radiofréquence des différentes formes du flutter péri-atriotomie droite.

Peri-atriotomy flutter is a possible complication of surgical atriotomy. This tachycardia in an indication for radiofrequency ablation. The aim of this study was to determine the mechanism of the flutter, evaluate the possibility of mapping and the role of radiofrequency ablation in its treatment. Eleven patients with a mean age of 45 years (26-70) were referred for ablation of atrial flutter observed on average 15 years after surgical atriotomy. In 7 patients (Group I), the ECG appearances before the procedure were that of a rare flutter. Endocavitary mapping showed a circuit limited to the free wall of the right atrium with a posterior caudo-cranial and an anterior cranio-caudal front. A series of radiofrequency applications joining the atriotomy scar to the inferior vena cava interrupted the flutter in all patients and created a bidirectional block around the atriotomy. In 4 patient (Group II), the ECG appearances were that of a common flutter. A series of radiofrequency ablations in the cavo-tricuspid isthmus led to sudden change in polarity of the F wave in all patients. Repeat mapping then showed a peri-atriotomy circuit identical to that described in Group I. The whole was interpreted as a figure-of-eight circuit. The primary success rate was 100%. There were no complications but the early recurrence rate remained high. This preliminary experience confirms the value of radiofrequency ablation in the treatment of peri-atriotomy flutter and shows ECG polymorphism related to a figure-of-eight reentry circuit.

Pathophysiologic mechanisms underlying dobutamine- and exercise-induced wall motion abnormalities.

BACKGROUND: Dobutamine and exercise echocardiography are accepted as tests of comparable efficacy for the diagnosis of coronary artery disease. Although dobutamine has been classified as "exercise simulating," the mechanisms of ischemia with dobutamine and exercise have not been well studied. This study sought to compare the determinants of myocardial oxygen consumption. METHODS AND RESULTS: We studied 54 patients with coronary artery disease undergoing dobutamine and exercise stress. A subgroup of 13 patients with comparable degrees of wall motion abnormalities and ST-segment changes during both stresses were selected to compare the determinants of ischemia in comparable circumstances. Dobutamine was infused to a mean maximal dose of 32+/-8 microg/kg/min, and exercise was stopped at an average of 135+/-25 W. The mean regional wall motion score was not statistically different between the two protocols (p = 0.27). At the onset of wall motion abnormalities and peak stress, the heart rate increased significantly less during dobutamine than during exercise (106+/-23 vs 126+/-19 beats/min, p < 0.001). The same was true of systolic blood pressure (155+/-21 vs 205+/-24 mm Hg, p < 0.001) and the rate-pressure product (16.5+/-4.6 vs 25.9+/-5, p < 0.001). Cardiac volumes were similar during both tests. CONCLUSIONS: Ischemia occurs at a lower level of external cardiac work during dobutamine than during exercise stress. We suspect that additional mechanisms, such as the oxygen wasting effect of dobutamine, may be responsible for this observation.

Improved identification of coronary artery disease in patients with left bundle branch block by use of dobutamine stress echocardiography and comparison with myocardial perfusion tomography.

This study compared the efficacy of dobutamine stress testing using 2-dimensional echocardiography and perfusion tomography for the noninvasive identification of coronary artery disease (CAD) in patients with left bundle branch block (LBBB). Twenty-four patients with permanent, complete LBBB (11 with previous myocardial infarction) were studied prospectively with dobutamine echocardiography and perfusion tomography. The presence of > 50% luminal diameter coronary stenosis was compared with the presence of dobutamine-induced fixed or reversible perfusion defects, and with resting or dobutamine-induced abnormalities of wall thickening. For each test, the left anterior coronary artery territory was compared with the circumflex and/or right coronary artery. Significant CAD was found in the left anterior descending coronary artery in 12 patients; all (100%) were identified by perfusion imaging, and 10 (83%, p = NS) by 2-dimensional stress echocardiography. In the 12 patients without left anterior descending CAD, scintigraphy was also positive in all (specificity: 0%), and echocardiography in only 1 (specificity: 92%, p < 0.01). The diagnostic accuracy was 50% and 87% (p < 0.05), respectively. This low specificity of perfusion tomography was improved by requiring an associated apical defect to indicate left anterior descending CAD and was corrected by restricting the diagnosis of coronary disease to those patients with partially reversible defects. In the circumflex and/or right coronary artery territory, sensitivity and specificity were similar using both techniques. We conclude that dobutamine-stress echocardiography is a specific and accurate test for the noninvasive identification of CAD, even in the left anterior descending artery territory of patients with LBBB.

Use of exercise electrocardiography, technetium-99m-MIBI perfusion tomography, and two-dimensional echocardiography for coronary disease surveillance in a low-prevalence population of heart transplant recipients.

BACKGROUND: Coronary artery disease has been reported to be a significant cause of long-term morbidity and mortality after heart transplantation. However, the diagnosis of coronary disease by means of noninvasive procedures has shown disappointing accuracy, and many centers currently recommend an annual surveillance coronary angiogram. METHODS: We prospectively studied the accuracy and feasibility of a symptom-limited upright bicycle exercise, combined with computerized electrocardiogram analysis, echocardiography, and perfusion scintigraphy in 37 consecutive heart transplant recipients at 2.8 +/- 1.4 years after transplantation for routine follow-up coronary angiography. RESULTS: No patient had any hemodynamically significant (> 50% diameter) coronary stenosis, but luminal irregularities were detectable in four patients. The exercise electrocardiogram was interpretable in only 22 patients (59%), and two of the remaining patients (9%) had false-positive results. The feasibility of perfusion tomography (100%) and two-dimensional echocardiography (97%) were greater than for stress electrocardiogram (p < 0.001 and p < 0.01 respectively). False-positive results were obtained at stress echocardiography in one patient (3%), and at scintigraphy in six patients (16%, p = not significant). None of these methods detected coronary artery stenoses of less than 50% diameter. CONCLUSIONS: Both exercise perfusion tomography and two-dimensional echocardiography are feasible and can be used with adequate specificity for the noninvasive diagnosis of coronary artery disease in heart transplant recipients. However further studies are needed to determine their respective sensitivity.

How accurate is dobutamine stress electrocardiography for detection of coronary artery disease? Comparison with two-dimensional echocardiography and technetium-99m methoxyl isobutyl isonitrile (mibi) perfusion scintigraphy.

OBJECTIVES: This study was designed to establish the appropriate diagnostic criteria for positive dobutamine electrocardiographic (ECG) stress test results and to compare their accuracy with those of dobutamine two-dimensional echocardiography and perfusion scintigraphy. BACKGROUND: Conventional criteria for positive findings on ECG exercise testing may not be appropriate for use with dobutamine ECG stress testing. METHODS: One hundred twenty-nine consecutive patients with an interpretable ECG and without previous myocardial infarction were prospectively studied at the time of coronary arteriography. All completed a standard dobutamine protocol (5 to 40 micrograms/kg body weight per min in 3-min dose increments) without side effects. Significant coronary artery disease, defined as > 50% lumen diameter stenosis of a major epicardial coronary artery on coronary angiography, was present in 83 patients. Empiric receiver operating curves were generated for various ECG criteria derived from computer-averaged signals. RESULTS: The best ECG criterion, with a sensitivity of 42% and a specificity of 83%, was an ST segment shift, relative to baseline, of 0.5 mm 80 ms after the J point. The sensitivity of this criterion was greater than that of the conventional criterion of 1-mm ST segment depression 60 (23%) or 80 (18%) ms after the J point, was comparable to that of chest pain occurring during the test (44%, p = NS) but remained inferior to the sensitivities of technetium-99m methoxyl isobutyl isonitrile (mibi) perfusion (76%) or stress echocardiography (76%, p < 0.001, for both). The specificity of this criterion was not significantly different from that of technetium-99m mibi perfusion tomography (65%) or stress echocardiography (89%) but was superior to that of chest pain (59%, p < 0.025). CONCLUSIONS: We conclude that this new criterion for dobutamine electrocardiography is specific but that an imaging technique is still required to accurately predict coronary artery disease.

Comparative ability of dobutamine and exercise stress in inducing myocardial ischaemia in active patients.

OBJECTIVE: To compare the ability of dobutamine and exercise stress to induce myocardial ischaemia and perfusion heterogeneity under routine clinical circumstances. DESIGN: 86 active patients without previous myocardial infarction were studied by dobutamine and exercise stress protocols and coronary angiography. During both tests patients underwent electrocardiography, digitised echocardiography, and perfusion scintigraphy using Tc-99m methoxybutylisonitrile (MIBI) single photon emission computed tomography. MAIN OUTCOME MEASURE: Coronary disease defined as an ST segment depression of > or = 0.1 mV, a resting or stress induced perfusion defect, or a resting or stress induced wall motion abnormality on exercise and dobutamine stress testing. RESULTS: Dobutamine stress was submaximal in 51 patients because of ingestion of beta adrenoceptor blocking agents on the day of the test (n = 25) or failure to attain the peak dose owing to side effects (n = 28). Exercise was limited in 23 patients by non-cardiac symptoms. The peak heart rate with dobutamine was less than that attained with exercise (105 (25) v 132 (24) beats/min, P < 0.0001); the response to maximal dobutamine stress significantly exceeded that to submaximal stress. Peak blood pressure was greatest with exercise (206 (27) v 173 (25) mm Hg, P < 0.001), values at maximal and submaximal dobutamine stress being comparable. Electrocardiographic evidence of ischaemia was induced less frequently by dobutamine than exercise (32% v 77% of the 56 patients with significant coronary disease, P < 0.01), as was abnormal wall motion (54% v 88%, P < 0.001). Ischaemia was induced more readily with maximal stress of either type; thus the sensitivities of dobutamine and exercise echocardiography were comparable only in patients undergoing a maximal dobutamine testing (73% v 77%, NS). Perfusion heterogeneity was induced in 58% of patients with coronary disease at submaximal dobutamine stress, 73% at maximal dobutamine stress, and 73% at exercise stress (NS). Among 30 patients without coronary stenoses, normal function was obtained in 83% of echocardiography studies with dobutamine and in 80% with exercise (NS). Normal perfusion was identified in 70% of these patients at exercise MIBI, and 68% at dobutamine stress (NS). CONCLUSIONS: In a group of patients studied under normal clinical circumstances antianginal treatment and inability to complete the stress protocol are frequent and compromise the capacity of dobutamine stress to induce ischaemia. In contrast, the induction of perfusion heterogeneity is less susceptible to submaximal stress.

Post traumatic myocardial infarction.

We report the history of a young man who developed an acute anterolateral myocardial infarction secondary to blunt chest trauma in an automobile accident. Arteriography demonstrated that the patient had sustained a left anterior descending artery tear and a coronary-ventricular fistula from the first septal branch. Different pathogenetic mechanisms with their specific complications and diagnostic features are discussed.