Automatic Holter electrocardiogram analysis in ischaemic stroke patients to detect paroxysmal atrial fibrillation: ready to replace physicians?

BACKGROUND AND PURPOSE: The detection of paroxysmal atrial fibrillation (pAF) in patients presenting with ischaemic stroke shifts secondary stroke prevention to oral anticoagulation. In order to deal with the time- and resource-consuming manual analysis of prolonged electrocardiogram (ECG)-monitoring data, we investigated the effectiveness of pAF detection with an automated algorithm (AA) in comparison to a manual analysis with software support within the IDEAS study [study analysis (SA)]. METHODS: We used the dataset of the prospective IDEAS cohort of patients with acute ischaemic stroke/transient ischaemic attack presenting in sinus rhythm undergoing prolonged 72-h Holter ECG with central adjudication of atrial fibrillation (AF). This adjudicated diagnosis of AF was compared with a commercially available AA. Discordant results with respect to the diagnosis of pAF were resolved by an additional cardiological reference confirmation. RESULTS: Paroxysmal AF was finally diagnosed in 62 patients (5.9%) in the cohort (n = 1043). AA more often diagnosed pAF (n = 60, 5.8%) as compared with SA (n = 47, 4.5%). Due to a high sensitivity (96.8%) and negative predictive value (99.8%), AA was able to identify patients without pAF, whereas abnormal findings in AA required manual review (specificity 96%; positive predictive value 60.6%). SA exhibited a lower sensitivity (75.8%) and negative predictive value (98.5%), and showed a specificity and positive predictive value of 100%. Agreement between the two methods classified by kappa coefficient was moderate (0.591). CONCLUSION: Automated determination of 'absence of pAF' could be used to reduce the manual review workload associated with review of prolonged Holter ECG recordings.

[Acute treatment and secondary prophylaxis of ischemic stroke : An excellent example for personalized medicine]. / Akuttherapie und Sekundärprophylaxe des ischämischen Schlaganfalls : Ein Musterbeispiel für personalisierte Medizin.

About a quarter of a million people in Germany suffer a stroke every year. Stroke is the most dreaded cardiovascular disease, even before myocardial infarction and heart failure. In the last two to three years, significant progress has been made in acute treatment, secondary prophylaxis in patients with patent foramen ovale, and the interdisciplinary evaluation of atrial fibrillation as the cause of the stroke. These new findings allow for more precise treatment.

Automatic detection of paroxysmal atrial fibrillation in patients with ischaemic stroke: better than routine diagnostic workup?

BACKGROUND AND PURPOSE: Prolonged electrocardiogram (ECG) monitoring after ischaemic stroke increases the diagnostic yield of paroxysmal atrial fibrillation (pAF). In order to facilitate the additional workload involved in ECG analysis due to prolonged monitoring times, we investigated the effectiveness of pAF detection with an automated software algorithm (SA) in comparison to the routine staff-based analysis (RA) during standard stroke-unit care. Therefore, patients with acute ischaemic stroke or transitory ischaemic attack presenting with sinus rhythmus on the admission ECG and no history of atrial fibrillation were prospectively included. METHODS: A 24-h Holter ECG assessment was performed using either RA based on a computer-aided evaluation and subsequent review by a cardiologist or a commercially available automated SA. In the case of discordant results concerning the occurrence of pAF between the two methods, the data underwent an independent external rating. RESULTS: Of 809 prospectively enrolled patients, 580 patients fulfilled the inclusion criteria. pAF was ultimately diagnosed in 3.3% of the cohort (19 patients). SA and RA correctly diagnosed pAF in 17 patients resulting in a comparable diagnostic effectiveness of the analysis methods (sensitivity: SA 89.5% vs. RA 89.5%; specificity: SA 99.3% vs. RA 99.1%; κ, 0.686; P < 0.001; 95% confidence interval, 0.525-0.847). RA revealed clinically relevant ECG abnormalities in an additional seven patients. CONCLUSIONS: Although it should not completely replace RA, SA-based evaluation of Holter ECG reaches a high diagnostic effectiveness for the detection of pAF and can be used for a rapid and resource-saving analysis of ECG data to deal with prolonged monitoring times.

Recurrent cerebral ischaemia in a pregnant woman with patent foramen ovale II° and thrombophilia.

This case report concerns a pregnant multipara (age: 27 years) in the 16th gestational week. She developed a sudden onset of paraesthesia in her left lower arm although injecting dalteparin 5000 IU once daily subcutaneously (s. c.) due to a heterozygous factor V Leiden mutation and a prior miscarriage in the first pregnancy and preeclampsia in her third pregnancy. After the miscarriage she delivered two healthy children under prophylactic anticoagulation with low molecular weight heparin (LMWH). Now via magnetic resonance imaging (MRI) she was diagnosed as having multiple cerebral ischaemic lesions. Further workup revealed the presence of a patent foramen ovale (PFO) II° but no venous thrombosis in her legs. She was then treated with dalteparin 5000 IU twice daily by subcutaneous injections. At 19th gestational week she developed paraesthesia in her left lower arm again. The MRI showed a cortical lesion in the territory of the right median cerebral artery. The anticoagulation dose was increased stepwise under surveillance of the anti-FXa-level 3-4 h after subcutaneous injections aiming to achieve the supratherapeutic range of 1.2-1.5 IU/ml anti-Xa-units. No more neurological symptoms appeared under this antithrombotic therapy. The patient delivered by induction of labor at the 38th gestational week.

Clinical predictors to identify paroxysmal atrial fibrillation after ischaemic stroke.

BACKGROUND AND PURPOSE: Detection of paroxysmal atrial fibrillation (pAF) after an ischaemic cerebrovascular event is of imminent interest, because oral anticoagulation as a highly effective secondary preventive treatment is available. Whereas permanent atrial fibrillation (AF) can be detected during routine electrocardiogram (ECG), longer detection duration will detect more pAF but might be resource consuming. The current study tried to identify clinical predictors for pAF detected during long-term Holter ECG and clinical follow-up. METHODS: Patients with acute ischaemic stroke were prospectively investigated with an intensified algorithm to detect pAF (7-day Holter ECG, follow-up investigations after 90 days and 1 year). RESULTS: Two hundred and eighty-one patients were included, 44 of whom had to be excluded since they presented with permanent AF and another 13 patients had to be excluded due to other causes leaving 224 patients (mean age 68.5 years, 58.5% male). Twenty-nine (12.9%) patients could be identified to have pAF during prolonged Holter monitoring, an additional 13 (5.8%) after follow-up investigations. Multivariate analysis identified advanced age [odds ratio (OR) 1.05, 95% confidence interval (CI) 1.01-1.08] as well as clinical symptoms >24 h (OR 5.17, 95% CI 1.73-15.48) and a history of coronary artery disease (OR 3.14, 95% CI 1.35-7.28) to be predictive for the detection of pAF. CONCLUSIONS: In acute stroke patients with advanced age, history of coronary artery disease and clinical symptoms >24 h, a prolonged Holter ECG monitoring and follow-up is warranted to identify pAF. This could increase the detection rate of patients requiring anticoagulation and may be able to reduce the risk of recurrent stroke in the case of successful anticoagulation of these patients.

[Heart or brain? Problem patients at the interface between cardiology and neurology]. / Herz oder Hirn? Problempatienten an der Schnittstelle zwischen Kardiologie und Neurologie.

A large number of patients fall into a category at the interface between heart or brain and are expected to require thorough clinical knowledge from both the cardiological as well as the neurological point of view for further patient-oriented treatment. The current article therefore addresses this important issue and aims to provide important information for clinical decision making for those patients at the interface between heart and brain. Due to the clinical impact, patients with carotid stenosis, a patent foramen ovale or non-valvular atrial fibrillation are described in more detail in this article.

Recanalization of large intracranial vessels using the penumbra system: a single-center experience.

BACKGROUND AND PURPOSE: The PS is an innovative mechanical device designed to recanalize large-vessel occlusions by thrombus aspiration. The purpose of this study was to evaluate the effectiveness and neurologic outcome of patients treated with the PS in the setting of acute ischemic stroke. MATERIALS AND METHODS: A total of 91 patients with acute ischemic stroke due to large-vessel occlusion were treated with the PS and were included in our retrospective study. In 14 patients, only the PS was used for treatment; in 77 patients, mechanical recanalization was combined with IA and/or IV thrombolysis. Outcome was measured by using the mRS; recanalization was assessed with the TICI score. RESULTS: Mean patient age was 62 ± 19.4 years; the average NIHSS score at hospital admission was 17. Successful recanalization was achieved in 77% of patients. Median time from arterial puncture to recanalization was 49 minutes (quartiles, 31-86 minutes). At follow-up, 36% of the patients showed an NIHSS improvement of ≥10%, and 34% of the patients with an anterior circulation occlusion had an mRS score of ≤2, whereas only 7% of the patients with a posterior occlusion had a favorable outcome at follow-up. In total, 20 patients died during hospitalization; none of these deaths were device-related. CONCLUSIONS: In this study, the PS was an effective device for mechanical recanalization. Successful recanalization with the PS was associated with significant improvement of functional outcome in patients experiencing ischemic stroke secondary to anterior circulation occlusions.

Angiographic CT after intravenous contrast agent application: A noninvasive follow-up tool after intracranial angioplasty and stenting.

BACKGROUND AND PURPOSE: ICAS is one of the therapeutic options in symptomatic cerebral artery stenosis. iaDSA is the current criterion standard examination after ICAS for the detection of ISR. In this study, we evaluated ivACT as a potential noninvasive follow-up alternative. MATERIALS AND METHODS: In 17 cases, ivACT and iaDSA were performed after ICAS. Both procedures were carried out on a flat-panel-detector-equipped angiography system. Postprocessing of ivACT acquisitions was performed on a dedicated workstation producing multiplanar reformations of the stent region and other intracranial arteries. Restenotic lesions were compared with iaDSA measurements. All studies were independently evaluated by 2 experienced neuroradiologists blinded to patients data. RESULTS: In 5 cases, ISR was diagnosed on iaDSA images. All restenotic lesions were reliably detected (sensitivity, 100%; 95%CI, 48%-100%) and could be correctly quantified on ivACT images in comparison with iaDSA. The neuroradiologists correctly excluded ISR in 11 of 12 lesions after viewing the ivACT examinations (specificity, 92%; 95%CI, 62%-100%). Measurements of ISR on ivACT were highly correlated to iaDSA (Pearson r = 0.94, P < .01). CONCLUSIONS: IvACT is a promising noninvasive follow-up examination after ICAS. With its high spatial resolution, it can reliably detect or exclude ISR. Contrary to iaDSA, there is no need for a recovery period after ivACT and the risk of neurologic complications is practically lowered to zero.

Aortic calcification on plain chest radiography predicts embolic complications during carotid artery stenting.

BACKGROUND AND PURPOSE: Aortic arch calcification (AC) on conventional angiograms has recently been shown to be associated with embolic complications during carotid artery stenting (CAS). Because conventional angiography is not routinely carried out in patients prior to CAS, a less invasive, commonly available diagnostic modality is warranted to identify AC. METHODS: We investigated the occurrence of AC on routinely acquired chest radiographs and its influence on diffusion-weighted imaging (DWI) lesions as surrogate markers for stroke. RESULTS: A total of 152 patients (mean age: 67.5 +/- 8.9 years, 112 men) underwent CAS and completed pre- and post-procedural DWI. AC larger than 1 cm in length was classified as relevant and could be detected in 63 patients (41.4%) on plain chest radiographs. In patients with AC, significantly more new DWI-lesions were found than in patients without AC [median 2; interquartile range (IQR): 0-7 vs. median 1, IQR: 0-2; P < 0.05]. After multivariate regression analysis, AC was independently associated with new post-procedural DWI lesions. DISCUSSION: AC is a common finding in patients with a high-grade carotid stenosis and predicts embolic complications during CAS. Since AC can be detected on plain chest radiography, this diagnostic tool is useful to identify high-risk patients for CAS.

Effects of age and symptom status on silent ischemic lesions after carotid stenting with and without the use of distal filter devices.

BACKGROUND AND PURPOSE: The routine use of distal filter devices during carotid angioplasty and stent placement (CAS) is controversial. The aim of this study was to analyze their effects on the incidence of new diffusion-weighted imaging (DWI) lesions as surrogate markers for stroke in important subgroups. MATERIALS AND METHODS: DWI was performed immediately before and after CAS in 68 patients with and 175 without protection, and patients were further subdivided according to their age or symptom status. RESULTS: The proportion of patients with new ipsilateral DWI lesion(s) was significantly lower after protected versus unprotected CAS (52% versus 68%), as well as in symptomatic patients (56% versus 74%) or those at or younger than 75 years of age (46% versus 67%; all P < .05). Similarly, the total number of lesions was significantly lower after protected versus unprotected CAS (median, 1; interquartile range [IQR], 0-2; versus median, 1; IQR 0-4.75) and in symptomatic patients (median, 1; IQR, 0-3; versus median, 2; IQR, 0-6) or those at or younger than 75 years of age (median, 0; IQR, 0-2; versus median, 1; IQR, 0-4; all P < .05). In contrast, for asymptomatic patients (48% versus 52%; P = .8; median, 0; IQR, 0-2; versus median, 1; IQR, 0-2.5; P = .6) or those older than 75 years of age (73% versus 69%; P = .7; median, 1; IQR, 0-4; versus median, 1.5; IQR, 0-5.75; P = .6), the proportion of patients with new lesion(s) and the total number of these lesions were not significantly different between protected and unprotected CAS. CONCLUSIONS: The use of distal filter devices generally reduces the incidence of new DWI lesions; however, this beneficial effect might not necessarily pertain to older and asymptomatic patients.

Early treatment after a symptomatic event is not associated with an increased risk of stroke in patients undergoing carotid stenting.

A recently symptomatic carotid artery stenosis carries a high risk of subsequent ischaemic events and thus requires rapid treatment. We investigated the influence of the time delay between the last symptomatic event of a carotid stenosis and subsequent carotid artery stenting (CAS) with respect to the combined 30-day outcome of stroke and death. In a group of 320 patients undergoing CAS the median delay before the intervention was 19 days (interquartile range 10-36) and the combined 30-day complication rate was 8.4%. Time delay was not significantly associated with peri-procedural complications, regardless of whether this variable was dichotomized (<14 days and > or =14 days), separated into interquartile ranges or analysed as a continuous variable. Our results indicate that early CAS is not associated with an increased complication rate in patients with a recently symptomatic carotid stenosis. Thus, if CAS has been selected as the treatment modality for a patient, it should be performed as soon as possible to maximize the benefit of the intervention in reducing the risk of stroke.

Preprocedural C-reactive protein levels predict stroke and death in patients undergoing carotid stenting.

BACKGROUND AND PURPOSE: Elevated baseline levels of C-reactive protein (CRP) are associated with an adverse outcome during coronary stent placement. The aim of this study was to evaluate whether preprocedural CRP levels also are predictive of stroke and death in patients undergoing carotid stent placement (CAS). MATERIALS AND METHODS: We reviewed data prospectively collected from 130 patients (97 men, 33 women; mean age, 68.5 +/- 10.1 years; range, 43-89 years) who underwent CAS for symptomatic carotid stenosis and from whom preprocedural CRP values had been obtained. A CRP value of >5 mg/L was considered to be elevated. The frequency of stroke and death within 30 days was compared between patients with and without elevated baseline CRP levels using chi(2) and multivariate logistic regression analysis. RESULTS: Baseline CRP values were normal in 94 (72.3%) patients but were elevated in 36 (27.7%) patients. The demographic and clinical characteristics were similar in both treatment groups. The 30-day stroke and death rate was significantly higher in patients with elevated CRP values (8/36; 22.2%) than in those without (3/94; 3.2%; P < .01). After adjusting for demographic characteristics, degree of carotid stenosis, and use of cerebral protection devices and/or statin therapy, an elevated CRP value before CAS remained a significant and independent predictor of stroke and death within 30 days after CAS (odds ratio, 7.7; 95% confidence interval: 1.8-32.8, P = .006). CONCLUSIONS: Baseline CRP is a powerful predictor of outcome in patients undergoing CAS, which underscores the role of inflammation in the pathogenesis of embolic complications during this procedure.

Carotid endarterectomy versus carotid stenting: an updated review of randomized trials and subgroup analyses.

Atherosclerotic disease of the carotid arteries is responsible for a significant portion of ischemic strokes. Carotid endarterectomy (CEA) is currently the accepted standard of treatment for patients with severe symptomatic carotid stenosis. In the past few years, however, carotid angioplasty and stenting (CAS) has emerged as a potential alternative endovascular treatment strategy for this disorder. In fact, spurred by the positive results of single center studies and small, pivotal randomized trials, some even consider CAS as the treatment modality of choice, especially in presumably surgical high-risk patients. Yet, randomized trials directly comparing CAS with CEA are sparse and have produced conflicting results. The aim of this article is to review the current trial data on this issue and to define the role of these techniques for the management of two important subgroups of patients. An updated meta-analysis of seven randomized trials comparing CEA with CAS demonstrates that CAS is associated with a significantly increased risk of any stroke or death within 30 days (OR. 1.41, 95% CI 1.07-1.87, p < 0.05). Focusing on patients with a symptomatic carotid stenosis, there was also a significant difference in the odds of treatment-related stroke and death between CAS and CEA (OR, 1.41 ; CI 1.05 to 1.88, p < 0.05). Data on all disabling strokes and deaths within 30 days was available from five trials. The odds of disabling stroke or death at 30 days were similar in the endovascular and surgical group (OR, 1.33, 95% CI 0.89 to 1.98). Overall, these data do not justify a blind enthusiasm for CAS and a widespread use of this procedure for the treatment of carotid artery stenosis. On the other hand, a closer inspection of the current literature on elderly patients and those with a contralateral carotid occlusion clearly indicates that CAS and CEA already now have a complementary role. While elderly patients should preferentially be treated with CEA, CAS appears to be the treatment of choice in patients with a symptomatic carotid artery stenosis and a contralateral carotid occlusion in experienced centers.

Effects of physiological aging and cerebrovascular risk factors on the hemodynamic response to brain activation: a functional transcranial Doppler study.

The influence of the vascular system on the coupling of cerebral blood flow (CBF) to focal brain activation during aging is incompletely understood. Using functional transcranial Doppler sonography and a hypercapnic challenge as a marker of intact cerebral vasoreactivity, we determined CBF velocity (CBFV) changes in response to a language and arithmetic task in a group of 43 healthy young subjects (mean age 32 +/- 8.6 years), 18 healthy old subjects (mean age 64 +/- 9.8 years) and 29 old subjects with risk factors for an atherosclerosis (mean age 69 +/- 8.4 years). Despite a similar performance during the cognitive tasks the CBFV changes were significantly lower in the group of old subjects with vascular risk factors compared with the healthy young and old subjects. Similarly, the CBFV changes during hypercapnia were significantly lower in the group of old subjects with vascular risk factors compared with the healthy young and old subjects. In contrast, both cognitive tasks and hypercapnia produced comparable CBFV changes in the group of healthy young and old subjects. These results suggest that the hemodynamic response to neuronal activation is unaffected by aging alone, whereas the presence of cardiovascular risk factors significantly diminishes the capability of cerebral vessels to react to vasodilating stimuli.