Persistent or permanent atrial fibrillation is associated with severe cardioembolic stroke in patients with non-valvular atrial fibrillation.

BACKGROUND: Little is known about the difference in the severity of cardioembolic (CE) stroke between patients with paroxysmal atrial fibrillation (PAF) and persistent/permanent AF (PerAF). We assessed stroke severity in patients with CE stroke divided by the type of AF. METHODS: Three hundred and fifty-eight consecutive patients with CE stroke within 48 h of onset and with a modified Rankin Scale (mRS) score ≤ 1 before onset were studied. We compared basic characteristics, stroke severity, and functional outcome between patients with PAF (n = 127) and PerAF (n = 231). RESULTS: Patients with PerAF were more likely to take oral anticoagulants (OACs) than those with PAF (37% vs. 13%, P <  0.0001), even though still underuse of OAC in both patients. Regarding stroke severity on admission, patients with PerAF exhibited a tendency toward a higher score on the National Institutes of Health Stroke Scale (NIHSS) compared with patients with PAF (12 [5-20] vs. 9 [4-18]; P = 0.12). Mortality and mRS score at discharge were higher in the PerAF than in the PAF group (13% vs. 4%; P = 0.005, and 3 [1-5] vs. 2 [1-4]; P = 0.01, respectively). Multivariate analyses confirmed that PerAF was a significant determinant of severe stroke (NIHSS score > 8) on admission (odds ratio [OR] to PAF = 1.80; 95% confidence interval [CI] 1.08-2.98; P = 0.02) and of an mRS score ≥ 3 at discharge (OR = 2.07; 95% CI 1.24-3.46; P = 0.006). Patients with PerAF had three times more internal carotid artery occlusion evaluated by magnetic resonance angiography, which indicated a more severe cerebral embolism compared with patients with PAF. CONCLUSIONS: We found underuse of OAC in high risk AF patients with CE stroke. PerAF is significantly associated with severe stroke on admission and an unfavorable functional outcome at discharge in Japanese patients with CE stroke.

Low Body Mass Index is a Poor Prognosis Factor in Cardioembolic Stroke Patients with NonValvular Atrial Fibrillation.

BACKGROUND: The relationship between body mass index (BMI) and the severity of cardioembolic stroke (CES) remains poorly understood. METHOD: A total of 419 consecutive CES patients with nonvalvular atrial fibrillation (NVAF), and with a modified Rankin Scale (mRS) score of 0 or 1 before onset admitted within 48hours after onset to the Hirosaki Stroke and Rehabilitation Center were studied. The patients were divided into three groups, low BMI (L-BMI; n = 36, BMI < 18.5 kg/m2), normal BMI (N-BMI; n = 284, 18.5 ≤ BMI < 25.0), and high BMI (H-BMI; n = 99, BMI ≥ 25.0). We compared stroke severity and functional outcome among the three groups. RESULTS: Stroke severity on admission, assessed by the National Institutes of Health Stroke Scale (NIHSS) showed that patients with L-BMI had the highest NIHSS score (median, 16 [11-25]), followed by N-BMI and H-BMI (11 [5-19] and 9 [3-19], P = .002). Functional outcome at discharge, assessed by mRS, was most severe in L-BMI patients (5 [3-5]), followed by N-BMI and H-BMI (3 [1-4] and 2 [1-4], P = .001). Multivariate analyses revealed that L-BMI was a significant determinant of severe stroke (NIHSS scores ≥8) at admission (odds ratio [OR] to N-BMI = 2.79, 95% confidence interval [CI], 1.17-7.78, P = .02) and poor functional outcome (mRS scores ≥3) at discharge (OR = 2.53, 95% CI, 1.12-6.31, P = .02). However, H-BMI did not affect stroke severity at admission or functional outcome at discharge. CONCLUSION: Low BMI is a risk factor for severe stroke on admission and unfavorable functional outcome at discharge in Japanese CES patients with NVAF.

Impact of Atrial Natriuretic Peptide Value for Predicting Paroxysmal Atrial Fibrillation in Ischemic Stroke Patients.

INTRODUCTION: The impact of atrial natriuretic peptide (ANP) value for predicting paroxysmal atrial fibrillation (pAF) in ischemic stroke patients remains uncertain. METHODS: The consecutive 222 ischemic stroke patients (median 77 [IQR 68-83] years old, 93 females) within 48 hours after onset were retrospectively studied. Plasma ANP and brain natriuretic peptide (BNP) levels were simultaneously measured at admission. Of all, 158 patients had no evidence of atrial fibrillation (AF) (sinus rhythm [SR] group), 25 patients had pAF (pAF group), and the other 39 patients had chronic AF (cAF group). We investigated predicting factors for pAF, with focus on ANP, BNP, and ANP/BNP ratio. RESULTS: ANP value was significantly higher in the pAF than in the SR group (97 [50-157] mg/dL versus 42 [26-72] mg/dL, P < .05) and further increased in the cAF group (228 [120-392], P < .05 versus pAF and SR groups). Similarly, the BNP value was higher in the pAF than in the SR group (116 [70-238] mg/dL versus 34 [14-72] mg/dL, P < .05) and further increased in the cAF group (269 [199-423], P < .05 versus pAF and SR groups). ANP/BNP ratio was lower in the pAF and cAF groups than in the SR group (.6 [.5-1.2] and .7 [.5-1.0] versus 1.3 [.8-2.4], both P < .05]. Multivariate analysis in the SR and pAF groups (n = 183) demonstrated that age, congestive heart failure, ANP, and BNP, but not ANP/BNP ratio, were independent predictors for detecting pAF. Receiver operating characteristic curve analysis further showed that area under the curve was similar between ANP and BNP (.76 and .80). CONCLUSIONS: ANPmay be clinically useful for detecting pAF in ischemic stroke patients as well as BNP.

Impact of Sex Difference on Severity and Functional Outcome in Patients with Cardioembolic Stroke.

INTRODUCTION: Female sex is a risk factor for thromboembolic events in Caucasian, but not in Japanese, patients with nonvalvular atrial fibrillation. However, it remains unclear whether the female sex is also a risk factor for severe stroke and unfavorable functional outcome in patients with cardioembolic (CE) stroke. METHODS: Three hundred fifty-five consecutive patients with CE stroke within 48 hours after onset and with a modified Rankin Scale (mRS) score of 1 or lower before onset were studied. We compared basic characteristics, stroke severity, and functional outcome between female (n = 157) and male (n = 198) patients. RESULTS: The mean age was higher in female than in male patients (80 ± 8 versus 75 ± 9 years, P < .00001). The congestive heart failure, hypertension, age [≥ 75 years], diabetes, stroke/transient ischemic attack [TIA] (CHADS2) score before onset was similar between the two groups (median, 3 [2-4] in both groups). Stroke severity on admission, assessed by the National Institutes of Health Stroke Scale (NIHSS), was higher in female than in male patients (13 [5-20] versus 8 [3-16], P = .0009). Functional outcome at discharge, assessed by mRS, was unfavorable in female than in male patients (3 [1-5] versus 2 [1-4], P = .005). An mRS score of 3 or higher at discharge was found more in female than in male patients (59% versus 39%, P = .0001). Multivariate analyses confirmed that female sex was a significant determinant of severe stroke (NIHSS ≥ 8) on admission (odds ratio [OR] to male = 1.97; 95% confidence interval [CI]; 1.24-3.15, P = .004) and for the mRS score of 3 or higher at discharge (OR = 1.83; 95% CI, 1.16-2.89; P = .01). Similar results were obtained by propensity-score matching analysis. CONCLUSIONS: Female sex is a risk factor for severe stroke on admission and unfavorable functional outcome at discharge in Japanese patients with CE stroke.

Characteristics of intracerebral hemorrhage during rivaroxaban treatment: comparison with those during warfarin.

BACKGROUND AND PURPOSE: Neuroradiological characteristics and functional outcomes of patients with intracerebral hemorrhage (ICH) during novel oral anticoagulant treatment were not well defined. We examined these in comparison with those during warfarin treatment. METHODS: The consecutive 585 patients with ICH admitted from April 2011 through October 2013 were retrospectively studied. Of all, 5 patients (1%) had ICH during rivaroxaban treatment, 56 (10%) during warfarin, and the other 524 (89%) during no anticoagulants. We focused on ICH during rivaroxaban and warfarin treatments and compared the clinical characteristics, neuroradiological findings, and functional outcomes. RESULTS: Patients in the rivaroxaban group were all at high risk for major bleeding with hypertension, abnormal renal/liver function, stroke, bleeding history or predisposition, labile international normalized ratio, elderly, drugs/alcohol concomitantly (HAS-BLED) score of 3 and higher rate of past history of ICH. Moreover, multiple cerebral microbleeds (≥4) were detected more frequently in rivaroxaban group than in warfarin (80% versus 29%; P=0.04). Hematoma volume in rivaroxaban group was markedly smaller than that in warfarin (median: 4 versus 11 mL; P=0.03). No patient in the rivaroxaban group had expansion of hematoma and surgical treatment. Rivaroxaban group showed lower modified Rankin Scale at discharge relative to warfarin, and the difference between modified Rankin Scale before admission and at discharge was smaller in rivaroxaban than in warfarin (median: 1 versus 3; P=0.047). No patient in the rivaroxaban group died during hospitalization, whereas 10 (18%) warfarin patients died. CONCLUSIONS: Rivaroxaban-associated ICH occurs in patients at high risk for major bleeding. However, they had a relatively small hematoma, no expansion of hematoma, and favorable functional and vital outcomes compared with warfarin-associated ICH.

Minute changes of cerebral parenchymal non-contrast computed tomography attenuation reflect cerebral volume alterations of blood.

AIMS: Non-infarcted acute cerebral ischaemic areas appear hypo-attenuated on non-contrast narrow-window computed tomography images. We aimed to determine the mechanism underlying minute computed tomography hypo-attenuation and visualise these attenuation changes on non-contrast computed tomography images. METHODS: The cerebral parenchyma was defined by pixels with attenuation of 20-50 Hounsfield units. We calculated the mean cerebral parenchymal attenuation in non-contrast computed tomography images. We analysed the correlation of complete blood counts with corresponding mean cerebral parenchymal attenuation values using linear regression analysis. Moreover, we developed an image processing method that involved pixel colorisation based on the noise-reduced attenuation value for minute cerebral parenchymal attenuation visualisation. RESULTS: Haemoglobin, haematocrit and red blood cell counts positively correlated with mean cerebral parenchymal attenuation values. The cerebral haematocrit is correlated with the blood haematocrit; therefore, cerebral parenchymal attenuation correlated linearly with cerebral haemoglobin concentration. Haemoglobin contents in a pixel partially determine the X-ray absorption dose and attenuation value. Pixel haemoglobin contents are determined by the cerebral volume of blood in a pixel. Image processed computed tomography images reflected cerebral volume of blood and showed the same alterations with regional cerebral blood volume maps of perfusion computed tomography. CONCLUSIONS: Cerebral parenchymal attenuation correlated with cerebral haemoglobin concentration and cerebral volume of blood. Infarcted cerebral parenchyma shows about 5 Hounsfield units gray matter attenuation decrease. Attenuation decrease by less than 5 Hounsfield units means decreased cerebral volume of blood, indicating a reversible functional change. One cannot recognise minute hypo-attenuation (<5 Hounsfield units) in routine computed tomography images. However, it can be visualised through an image processing method on non-contrast computed tomography images. It may detect pre-infarction cerebral volume of blood and regional cerebral blood volume alterations.