Impact of pre-admission oral anticoagulation on ischaemic stroke volume, lesion pattern, and frequency of intracranial arterial occlusion in patients with atrial fibrillation.

Aims: Therapeutic oral anticoagulation on hospital admission reduces morbidity and mortality after acute ischaemic stroke in patients with atrial fibrillation (AF). The underlying mechanism is not fully understood. In order to assess the impact of INR-level on admission on stroke volume, lesion pattern and the frequency of intracranial arterial occlusion, we analysed serial MRI measurements in AF patients suffering acute ischaemic stroke. Methods and results: This subgroup analysis of the prospective '1000Plus' study included patients with acute ischaemic stroke and known AF or a first episode of AF in hospital. All patients underwent serial brain magnetic resonance imaging. Stroke patients were categorized as follows: Group1, phenprocoumon intake, international normalized ratio (INR) ≥1.7 on admission, no thrombolysis; Group2, INR < 1.7 on admission, thrombolysis; and Group3, INR < 1.7, no thrombolysis. In 98 AF patients {77 ± 9 years, 60% male; median National Institute of Health Stroke Scale [NIHSS] score on admission 5 (interquartile range [IQR] 2-8)} with known AF before admission, territorial infarction was less often found in Group 1 (n = 20) compared with Group 2 + 3 (20% vs. 47%, P = 0.022). Arterial occlusion rate on admission differed among groups (30%, 75%, and 35%, respectively, P = 0.004) but not between Group 1 vs. Group 2 + 3 (30% vs. 45%, P = 0.31). Median FLAIR volume on Days 5-7 was lower in Group1 compared with Group 2 (n = 20) [3.2 cm3 (IQR 1.1-11.3) vs. 18.6 cm3 (IQR 8.2-49.4); P = 0.009] but not compared with Group 2 + 3 [7.8 cm3 (IQR 1.6-25.9); P = 0.23]. An INR ≥ 1.7 on admission was not associated with smaller stroke volume in multivariable regression analysis. Adding 57 patients with a first AF episode during the in-hospital stay, similar results were observed in 155 AF patients. Conclusion: In this AF cohort, an INR ≥ 1.7 at stroke onset affects lesion pattern but does not affect significantly lower stroke volume and the frequency of arterial occlusion on admission.

Feasibility and Diagnostic Value of Cardiovascular Magnetic Resonance Imaging After Acute Ischemic Stroke of Undetermined Origin.

BACKGROUND AND PURPOSE: Etiology of acute ischemic stroke remains undetermined (cryptogenic) in about 25% of patients after state-of-the-art diagnostic work-up. METHODS: One-hundred and three patients with magnetic resonance imaging (MRI)-proven acute ischemic stroke of undetermined origin were prospectively enrolled and underwent 3-T cardiac MRI and magnetic resonance angiography of the aortic arch in addition to state-of-the-art diagnostic work-up, including transesophageal echocardiography (TEE). We analyzed the feasibility, diagnostic accuracy, and added value of cardiovascular MRI (cvMRI) compared with TEE for detecting sources of stroke. RESULTS: Overall, 102 (99.0%) ischemic stroke patients (median 63 years [interquartile range, 53-72], 24% female, median NIHSS (National Institutes of Health Stroke Scale) score on admission 2 [interquartile range, 1-4]) underwent cvMRI and TEE in hospital; 89 (86.4%) patients completed the cvMRI examination. In 93 cryptogenic stroke patients, a high-risk embolic source was found in 9 (8.7%) patients by cvMRI and in 11 (11.8%) patients by echocardiography, respectively. cvMRI and echocardiography findings were consistent in 80 (86.0%) patients, resulting in a degree of agreement of κ=0.24. In 82 patients with cryptogenic stroke according to routine work-up, including TEE, cvMRI identified stroke etiology in additional 5 (6.1%) patients. Late gadolinium enhancement consistent with previous myocardial infarction was found in 13 (14.6%) out of 89 stroke patients completing cvMRI. Only 2 of these 13 patients had known coronary artery disease. CONCLUSIONS: Our study demonstrated that cvMRI was feasible in the vast majority of included patients with acute ischemic stroke. The diagnostic information of cvMRI seems to be complementary to TEE but is not replacing echocardiography after acute ischemic stroke. CLINICAL TRIAL REGISTRATION: URL: http://www.clinicaltrials.gov. Unique identifier: NCT01917955.

Cardiac Magnetic Resonance Imaging in Patients with Acute Ischemic Stroke and Elevated Troponin: A TRoponin ELevation in Acute Ischemic Stroke (TRELAS) Sub-Study.

BACKGROUND: Elevated high-sensitive cardiac troponin (hs-cTn) can be found in more than 50% of the patients with acute ischemic stroke. The observational TRoponin ELevation in Acute ischemic Stroke (TRELAS) study revealed that about 25% of all stroke patients with elevated troponin had a coronary angiography-detected culprit lesion affording immediate intervention, and about 50% of all patients did not have any obstructive coronary artery disease. Given the risk of procedure-related complications, the identification of stroke patients in urgent need of invasive coronary angiography is desirable. METHODS: TRELAS patients were prospectively enrolled into this sub-study. In addition to conventional coronary angiography, a cardiac magnetic resonance imaging (MRI) at 3T was performed during the in-hospital stay after acute ischemic stroke to compare the diagnostic value of both imaging modalities. RESULTS: Nine stroke patients (median age 73 years [range 58-87]; four females; median NIH Stroke Severity score on admission 4 [range 0-6] with elevated hs-cTnT [median 74 ng/L, interquartile range 41-247] on admission) completed cardiac MRI and underwent coronary angiography. The absence of MRI-detected wall motion abnormalities and/or late gadolinium enhancement in 5 stroke patients corresponded with the exclusion of culprit lesions or significant coronary artery disease by coronary angiography. Four patients had abnormal MRI findings, whereof 2 showed evidence of myocardial infarction and in whom coronary angiography demonstrated a >70% stenosis of a coronary artery. CONCLUSIONS: The TRELAS sub-study indicates that noninvasive cardiac MRI may provide helpful information to identify stroke patients with or without acute coronary syndrome. Our findings might help to select stroke patients in urgent need of coronary angiography.

Neuropsychological effects of MRI-detected brain lesions after left atrial catheter ablation for atrial fibrillation: long-term results of the MACPAF study.

BACKGROUND: MRI-detected brain lesions are common after left atrial catheter ablation for symptomatic atrial fibrillation. The clinical relevance of these acute ischemic lesions is not fully understood, but ablation-related cerebral injury could contribute to cognitive dysfunction. METHODS AND RESULTS: In the prospective Mesh Ablator versus Cryoballoon Pulmonary Vein Ablation of Symptomatic Paroxysmal Atrial Fibrillation (MACPAF) study, serial 3-T brain MRIs and neuropsychological assessment were performed to analyze the rate of ablation-related brain lesions and their effect on cognitive function. Thirty-seven patients with paroxysmal atrial fibrillation (median age, 63.0 [interquartile range, 57-68] years; 41% female; median CHA2DS2VASc score 2 [interquartile range, 1-3]) underwent 41 ablation procedures according to study criteria. None of these patients had overt neurological deficits after ablation. High-resolution diffusion-weighted imaging, performed within 48 hours after ablation, showed that new brain lesions (range, 1-17) were present in 16 (43.2%) patients after 18 (43.9%) left atrial catheter ablation procedures. Follow-up MRI at 6 months (median, 6.5; interquartile range, 6-7) revealed that 7 (12.5%) of the 56 total acute brain lesions after ablation formed a persistent glial scar in 5 (31.3%) patients. Large diffusion-weighted imaging lesions and a corresponding fluid-attenuated inversion recovery lesion 48 hours after ablation predicted lesion persistence on 6-month follow-up. Neither persistent brain lesions nor the ablation procedure itself had a significant effect on attention or executive functions, short-term memory, or verbal and nonverbal learning after 6 months. CONCLUSIONS: Ablation-related acute ischemic brain lesions persist to some extent but do not cause cognitive impairment 6 months after the ablation procedure. CLINICAL TRIAL REGISTRATION: URL: http://www.clinicaltrials.gov. Unique identifier: NCT01061931.

High prevalence and significance of hepatitis D virus infection among treatment-naïve HBsAg-positive patients in Northern Vietnam.

BACKGROUND: Hepatitis D virus (HDV) infection is considered to cause more severe hepatitis than hepatitis B virus (HBV) monoinfection. With more than 9.5 million HBV-infected people, Vietnam will face an enormous health burden. The prevalence of HDV in Vietnamese HBsAg-positive patients is speculative. Therefore, we assessed the prevalence of HDV in Vietnamese patients, determined the HDV-genotype distribution and compared the findings with the clinical outcome. METHODS: 266 sera of well-characterized HBsAg-positive patients in Northern Vietnam were analysed for the presence of HDV using newly developed HDV-specific RT-PCRs. Sequencing and phylogenetic analysis were performed for HDV-genotyping. RESULTS: The HDV-genome prevalence observed in the Vietnamese HBsAg-positive patients was high with 15.4% while patients with acute hepatitis showed 43.3%. Phylogenetic analysis demonstrated a predominance of HDV-genotype 1 clustering in an Asian clade while HDV-genotype 2 could be also detected. The serum aminotransferase levels (AST, ALT) as well as total and direct bilirubin were significantly elevated in HDV-positive individuals (p<0.05). HDV loads were mainly low (<300 to 4.108 HDV-copies/ml). Of note, higher HDV loads were mainly found in HBV-genotype mix samples in contrast to single HBV-infections. In HBV/HDV-coinfections, HBV loads were significantly higher in HBV-genotype C in comparison to HBV-genotype A samples (p<0.05). CONCLUSION: HDV prevalence is high in Vietnamese individuals, especially in patients with acute hepatitis B. HDV replication activity showed a HBV-genotype dependency and could be associated with elevated liver parameters. Besides serological assays molecular tests are recommended for diagnosis of HDV. Finally, the high prevalence of HBV and HDV prompts the urgent need for HBV-vaccination coverage.