Cost-Effectiveness of Monitoring Patients Post-Stroke With Mobile ECG During the Hospital Stay.

Background The effectiveness of a nurse-led in-hospital monitoring protocol with mobile ECG (iECG) was investigated for detecting atrial fibrillation in patients post-ischemic stroke or post-transient ischemic attack. The study aimed to assess the cost-effectiveness of using iECG during the initial hospital stay compared with standard 24-hour Holter monitoring. Methods and Results A Markov microsimulation model was constructed to simulate the lifetime health outcomes and costs. The rate of atrial fibrillation detection in iECG and Holter monitoring during the in-hospital phase and characteristics of modeled population (ie, age, sex, CHA2DS2-VASc) were informed by patient-level data. Costs related to recurrent stroke, stroke management, medications (new oral anticoagulants), and rehabilitation were included. The cost-effectiveness analysis outcome was calculated as an incremental cost per quality-adjusted life-year gained. As results, monitoring patients with iECG post-stroke during the index hospitalization was associated with marginally higher costs (A$31 196) and greater benefits (6.70 quality-adjusted life-years) compared with 24-hour Holter surveillance (A$31 095 and 6.66 quality-adjusted life-years) over a 20-year time horizon, with an incremental cost-effectiveness ratio of $3013/ quality-adjusted life-years. Monitoring patients with iECG also contributed to lower recurrence of stroke and stroke-related deaths (140 recurrent strokes and 20 deaths avoided per 10 000 patients). The probabilistic sensitivity analyses suggested iECG is highly likely to be a cost-effective intervention (100% probability). Conclusions A nurse-led iECG monitoring protocol during the acute hospital stay was found to improve the rate of atrial fibrillation detection and contributed to slightly increased costs and improved health outcomes. Using iECG to monitor patients post-stroke during initial hospitalization is recommended to complement routine care.

Nurse Led Smartphone Electrographic Monitoring for Atrial Fibrillation after Ischemic Stroke: SPOT-AF.

BACKGROUND AND PURPOSE: Paroxysmal atrial fibrillation (PAF) underlying acute stroke frequently evades detection by standard practice, considered to be a combination of routine electrocardiogram (ECG) monitoring, and 24-hour Holter recordings. We hypothesized that nurse-led in-hospital intermittent monitoring approach would increase PAF detection rate. METHODS: We recruited patients hospitalised for stroke/transient ischemic attack, without history of atrial fibrillation (AF), in a prospective multi-centre observational study. Patients were monitored using a smartphone-enabled handheld ECG (iECG) during routine nursing observations, and underwent 24-hour Holter monitoring according to local practice. The primary outcome was comparison of AF detection by nurse-led iECG versus Holter monitoring in patients who received both tests: secondary outcome was oral anticoagulant commencement at 3-month following PAF detection. RESULTS: One thousand and seventy-nine patients underwent iECG monitoring: 294 had iECG and Holter monitoring. AF was detected in 25/294 (8.5%) by iECG, and 8/294 (2.8%) by 24-hour Holter recordings (P<0.001). Median duration from stroke onset to AF detection for iECG was 3 days (interquartile range [IQR], 2 to 6) compared with 7 days (IQR, 6 to 10) for Holter recordings (P=0.02). Of 25 patients with AF detected by iECG, 11 were commenced on oral anticoagulant, compared to 5/8 for Holter. AF was detected in 8.8% (69/785 patients) who underwent iECG recordings only (P=0.8 vs. those who had both iECG and 24-hour Holter). CONCLUSIONS: Nurse-led in-hospital iECG surveillance after stroke is feasible and effective and detects more PAF earlier and more frequently than routine 24-hour Holter recordings. Screening with iECG could be incorporated into routine post-stroke nursing observations to increase diagnosis of PAF, and facilitate institution of guideline-recommended anticoagulation.

Smartphone electrographic monitoring for atrial fibrillation in acute ischemic stroke and transient ischemic attack.

Rationale Paroxysmal atrial fibrillation is a common and preventable cause of devastating strokes. However, currently available monitoring methods, including Holter monitoring, cardiac telemetry and event loop recorders, have drawbacks that restrict their application in the general stroke population. AliveCor™ heart monitor, a novel device that embeds miniaturized electrocardiography (ECG) in a smartphone case coupled with an application to record and diagnose the ECG, has recently been shown to provide an accurate and sensitive single lead ECG diagnosis of atrial fibrillation. This device could be used by nurses to record a 30-s ECG instead of manual pulse taking and automatically provide a diagnosis of atrial fibrillation. Aims To compare the proportion of patients with paroxysmal atrial fibrillation detected by AliveCor™ ECG monitoring with current standard practice. Sample size 296 Patients. Design Consecutive ischemic stroke and transient ischemic attack patients presenting to participating stroke units without known atrial fibrillation will undergo intermittent AliveCor™ ECG monitoring administered by nursing staff at the same frequency as the vital observations of pulse and blood pressure until discharge, in addition to the standard testing paradigm of each participating stroke unit to detect paroxysmal atrial fibrillation. Study outcome Proportion of patients with paroxysmal atrial fibrillation detected by AliveCor™ ECG monitoring compared to 12-lead ECG, 24-h Holter monitoring and cardiac telemetry. Discussion Use of AliveCor™ heart monitor as part of routine stroke unit nursing observation has the potential to be an inexpensive non-invasive method to increase paroxysmal atrial fibrillation detection, leading to improvement in stroke secondary prevention.

Beyond Neglect: Preliminary Evidence of Retrospective Time Estimation Abnormalities in Non-Neglect Stroke and Transient Ischemic Attack Patients.

Perception of the passage of time is essential for safe planning and navigation of everyday activities. Findings from the literature have demonstrated a gross underestimation of time interval in right-hemisphere damaged neglect patients, but not in non-neglect unilaterally-damaged patients, compared to controls. This study aimed to investigate retrospective estimation of the duration of a target detection task over two occasions, in 30 stroke patients (12 left-side stroke 15 right-side stroke, and 3 right-side stroke with neglect) and 10 transient ischemic attack patients, relative to 31 age-matched controls. Performances on visual short-term and working memory tasks were also examined to investigate the associations between timing abilities with residual cognitive functioning. Initial results revealed evidence of perceptual time underestimation, not just in neglect patients, but also in non-neglect unilaterally-damaged stroke patients and transient ischemic attack patients. Three months later, underestimation of time persisted only in left-side stroke and right-side stroke with neglect patients, who also demonstrated reduced short-term and working memory abilities. Findings from this study suggest a predictive role of residual cognitive impairments in determining the prognosis of perceptual timing abnormalities.

Worse stroke outcome in atrial fibrillation is explained by more severe hypoperfusion, infarct growth, and hemorrhagic transformation.

BACKGROUND: Atrial fibrillation is associated with greater baseline neurological impairment and worse outcomes following ischemic stroke. Previous studies suggest that greater volumes of more severe baseline hypoperfusion in patients with history of atrial fibrillation may explain this association. We further investigated this association by comparing patients with and without atrial fibrillation on initial examination following stroke using pooled multimodal magnetic resonance imaging and clinical data from the Echoplanar Imaging Thrombolytic Evaluation Trial and the Diffusion and Perfusion Imaging Evaluation for Understanding Stroke Evolution studies. METHODS: Echoplanar Imaging Thrombolytic Evaluation Trial was a trial of 101 ischemic stroke patients randomized to intravenous tissue plasminogen activator or placebo, and Diffusion and Perfusion Imaging Evaluation for Understanding Stroke Evolution was a prospective cohort of 74 ischemic stroke patients treated with intravenous tissue plasminogen activator at three to six hours following symptom onset. Patients underwent multimodal magnetic resonance imaging before treatment, at three to five days and three-months after stroke in Echoplanar Imaging Thrombolytic Evaluation Trial; before treatment, three to six hours after treatment and one-month after stroke in Diffusion and Perfusion Imaging Evaluation for Understanding Stroke Evolution. Patients were assessed with the National Institutes of Health Stroke Scale and the modified Rankin scale before treatment and at three-months after stroke. Patients were categorized into definite atrial fibrillation (present on initial examination), probable atrial fibrillation (history but no atrial fibrillation on initial examination), and no atrial fibrillation. Perfusion data were reprocessed with automated magnetic resonance imaging analysis software (RAPID, Stanford University, Stanford, CA, USA). Hypoperfusion volumes were defined using time to maximum delays in two-second increments from >4 to >8 s. Hemorrhagic transformation was classified according to the European Cooperative Acute Stroke Studies criteria. RESULTS: Of the 175 patients, 28 had definite atrial fibrillation, 30 probable atrial fibrillation, 111 no atrial fibrillation, and six were excluded due to insufficient imaging data. At baseline, patients with definite atrial fibrillation had more severe hypoperfusion (median time to maximum >8 s, volume 48 vs. 29 ml, P = 0.02) compared with patients with no atrial fibrillation. At outcome, patients with definite atrial fibrillation had greater infarct growth (median volume 47 vs. 8 ml, P = 0.001), larger infarcts (median volume 75 vs. 23 ml, P = 0.001), more frequent parenchymal hematoma grade hemorrhagic transformation (30% vs. 10%, P = 0.03), worse functional outcomes (median modified Rankin scale score 4 vs. 3, P = 0.03), and higher mortality (36% vs. 16%, P = 0·.3) compared with patients with no atrial fibrillation. Definite atrial fibrillation was independently associated with increased parenchymal hematoma (odds ratio = 6.05, 95% confidence interval 1.60-22.83) but not poor functional outcome (modified Rankin scale 3-6, odds ratio = 0.99, 95% confidence interval 0.35-2.80) or mortality (odds ratio = 2.54, 95% confidence interval 0.86-7.49) three-months following stroke, after adjusting for other baseline imbalances. CONCLUSION: Atrial fibrillation is associated with greater volumes of more severe baseline hypoperfusion, leading to higher infarct growth, more frequent severe hemorrhagic transformation and worse stroke outcomes.

Pre-stroke CHADS2 and CHA2DS2-VASc scores are useful in stratifying three-month outcomes in patients with and without atrial fibrillation.

BACKGROUND: CHADS2 and CHA2DS2-VASc scores are validated tools for assessing stroke risk in patients with atrial fibrillation (AF). We investigated whether these scores are associated with 3-month stroke outcomes and evaluated the utility of these scores in stratifying 3-month stroke outcomes in both patients with and without AF. METHODS: We analysed 6,612 acute ischaemic stroke patients from the Virtual International Stroke Trials Archive who received either placebo or ineffective active treatments not associated with significant cardiac complications. Outcomes included 3-month mortality, good functional outcomes defined as modified Rankin Scale score ≤1 and serious cardiac adverse events (SCAEs) defined as one of acute coronary syndrome, symptomatic heart failure, cardiopulmonary arrest, life-threatening arrhythmia and cardiac death. The association between the pre-stroke CHADS2 and CHA2DS2-VASc scores and 3-month stroke outcomes was assessed using binary logistic regression. The utility of the two scores in estimating 3-month stroke outcomes was assessed using area under the receiver operator characteristic curves (AUC) and compared using the χ(2) test. RESULTS: In this cohort, 26.5% had AF, 35.3% received IV tissue plasminogen activator (tPA), 17.7% died, 25.1% achieved good functional outcomes and 9.5% had ≥1 SCAE at 3 months. High-risk (≥2) pre-stroke CHADS2 and CHA2DS2-VASc scores are both associated with 3-month mortality (CHADS2: odds ratio, OR, 2.33, 95% confidence interval 1.81-3.00; CHA2DS2-VASc: OR 3.01, 2.00-4.80), good functional outcomes (CHADS2: OR 0.47, 0.39-0.57; CHA2DS2-VASc: OR 0.55, 0.42-0.71) and SCAEs (CHADS2: OR 1.76, 1.28-2.42; CHA2DS2-VASc: OR 2.69, 1.53-4.73) after adjusting for baseline differences in neurological impairment, tPA use and AF. The pre-stroke CHA2DS2-VASc score is better than the CHADS2 score in estimating 3-month stroke outcomes in both patients with and without AF (p ≤ 0.005 in all AUC comparisons). High-risk pre-stroke CHA2DS2-VASc score has high sensitivity for mortality (AF: 0.96, 0.94-0.98; no AF: 0.88, 0.86-0.91) and negative predictive value for SCAE (AF: 0.93, 0.87-0.96; no AF: 0.96, 0.95-0.97) within 3 months. Low risk pre-stroke CHA2DS2-VASc score has high specificity for good functional outcome (AF: 0.99, 0.98-0.994; no AF: 0.94, 0.93-0.95) at 3 months. CONCLUSIONS: The pre-stroke CHA2DS2-VASc score appears to be a simple tool for identifying patients at lower risk of poor outcomes and serious cardiac complications within 3 months following ischaemic stroke in patients with and without AF. © 2013 S. Karger AG, Basel.

CT perfusion improves diagnostic accuracy and confidence in acute ischaemic stroke.

BACKGROUND AND OBJECTIVE: CT perfusion (CTP) is rapid and accessible for emergency ischaemic stroke diagnosis. The feasibility of introducing CTP and diagnostic accuracy versus non-contrast CT (NCCT) in a tertiary hospital were assessed. METHODS: All patients presenting <9 h from stroke onset or with wake-up stroke were eligible for CTP (Siemens 16-slice scanner, 2×24 mm slabs) unless they had estimated glomerular filtration rate (eGFR)<50 ml/min or diabetes with unknown eGFR. NCCT was assessed by a radiologist and stroke neurologist for early ischaemic change and hyperdense arteries. CTP was assessed for prolonged time to peak and reduced cerebral blood flow. Technical adequacy was defined as 2 CTP slabs of sufficient quality to diagnose stroke. RESULTS: Between January 2009 and September 2011, 1152 ischaemic stroke patients were admitted, 475 (41%) were <9 h/wake-up onset. Of these, 276 (58%) had CTP. Reasons for not performing CTP were diabetes with unknown eGFR (48 (10%)), known kidney disease (36 (8%)), established infarct on NCCT (27 (6%)), posterior circulation syndrome (25 (5%)) and patient motion/instability (16 (3%)). Clinician discretion excluded a further 47 (10%). CTP was more frequently diagnostic than NCCT (80% vs 50%, p<0.001). Non-diagnostic CTP was due to lacunar infarction (28 (10%)), infarct outside slab coverage (21 (8%)), technical failure (4 (1%)) and reperfusion (2 (0.7%)). Normal CTP in 86/87 patients with stroke mimics supported withholding tissue plasminogen activator. CTP technical adequacy improved from 56% to 86% (p<0.001) after the first 6 months. Median time for NCCT/CTP/arch-vertex CT angiogram (including processing and interpretation) was 12 min. No clinically significant contrast nephropathy occurred. CONCLUSIONS: CTP in suspected stroke is widely applicable, rapid and increases diagnostic confidence.

Assessing response to stroke thrombolysis: validation of 24-hour multimodal magnetic resonance imaging.

BACKGROUND: Imaging is used as a surrogate for clinical outcome in early-phase stroke trials. Assessment of infarct growth earlier than the standard 90 days used for clinical end points may be equally accurate and more practical. OBJECTIVE: To compare assessment of the effect of reperfusion therapies using 24-hour vs day 90 magnetic resonance imaging. DESIGN: Infarct volume was assessed on diffusion-weighted imaging (DWI) at baseline and 24 hours after stroke onset and on fluid-attenuated inversion recovery images at day 90. The DWI and fluid-attenuated inversion recovery lesions were manually outlined by 2 independent raters, and the volumes were averaged. Interrater consistency was assessed using the median difference in lesion volume between raters. SETTING: Referral center. Patients  Imaging data were available for 83 patients; 77 of these patients received thrombolysis. MAIN OUTCOME MEASURES: Infarct volume at 24 hours and 90 days. RESULTS: The 24-hour DWI infarct volume had a strong linear correlation with day 90 fluid-attenuated inversion recovery infarct volume (r = 0.98, 95% confidence interval, 0.97-0.99). Recanalization had a significant effect on infarct evolution between baseline and 24 hours but not between 24 hours and day 90. Infarct growth from baseline was significantly reduced by recanalization, whether assessed at 24 hours or day 90. Infarct volume at either time point predicted functional outcome independent of age and baseline stroke severity. Interrater agreement was better for DWI than fluid-attenuated inversion recovery (1.4 mL [8%] vs 1.8 mL [17%]; P = .002). CONCLUSIONS: Assessment of final infarct volume using DWI at 24 hours captures the effect of reperfusion therapies on infarct growth and predicts functional outcome similarly to imaging at day 90. This has the potential to reduce loss to follow-up in trials and may add early prognostic information in clinical practice.

Frequent early cardiac complications contribute to worse stroke outcome in atrial fibrillation.

BACKGROUND: Atrial fibrillation (AF) is associated with worse outcomes following ischemic stroke and more frequent cardiac complications in the general population. We aimed to establish whether early cardiac complications contribute to the poorer ischemic stroke outcomes in patients with AF, independent of baseline differences in age, stroke severity and cardiovascular risk factors. This might have important implications for acute stroke management in patients with AF. METHODS: We searched VISTA-Acute, an academic database containing standardized data for 28,131 patients from 30 randomized-controlled acute stroke trials and 1 stroke registry, for imaging-confirmed placebo-treated patients with complete documentation of baseline demographics, cardiovascular risk factors, presence or absence of AF, neurologic impairment [National Institutes of Health Stroke Scale (NIHSS)], cardiac complications and 3-month outcome (modified Rankin Scale). A total of 2,865 patients from 6 randomized-controlled trials met the selection criteria, of whom 819 had AF. Binary logistic regression modeling was used to determine the independent effect of AF on stroke outcome and serious cardiac adverse events (SCAE), a composite end point including acute coronary syndrome, symptomatic heart failure, cardiopulmonary arrest, ventricular tachycardia, ventricular fibrillation and cardiac mortality. RESULTS: All patients were enrolled into the source trials within 24 h of stroke onset. At baseline, patients with AF were older (mean 75 vs. 67 years, p < 0.001) and had greater neurologic impairment (median NIHSS 15 vs. 13, p < 0.001). The median time to first cardiac adverse event was 3 days [median difference 0, 95% confidence interval (CI) 0-1, p = 0.06] for both patients with and without AF. SCAE occurred more frequently [14.2 vs. 6%, odds ratio (OR) = 2.58, 95% CI 1.97-3.37] in patients with AF, particularly cardiac mortality (4.9 vs. 2.6%, OR = 1.89, 95% CI 1.25-2.88), symptomatic heart failure (6.5 vs. 2.2%, OR = 3.01, 95% CI 2.01-4.50), and ventricular tachycardia and/or fibrillation (2.4 vs. 0.8%, OR = 3.18, 95% CI 1.64-6.16). At 3 months, AF was independently associated with SCAE (OR = 2.14, 95% CI 1.61-2.86) and early mortality (OR = 1.44, 95% CI 1.14-1.81) after adjusting for all baseline imbalances. CONCLUSION: Early SCAE are common after stroke and are independently associated with the presence of AF. Given that many cardiac complications are potentially remediable, these results highlight the need for more rigorous surveillance for cardiac complications in acute ischemic stroke patients with AF.

Pathophysiological determinants of worse stroke outcome in atrial fibrillation.

BACKGROUND: The reasons for worse outcome following ischemic stroke in patients with atrial fibrillation (AF) remain unclear. We aimed to elucidate the pathophysiological determinants of poorer stroke outcome in patients with AF using systematic MRI data from the Echoplanar Imaging Thrombolytic Evaluation Trial (EPITHET). METHODS: Comparisons of infarct size, hypoperfusion volume, infarct growth, arterial occlusion, recanalization, reperfusion, hemorrhagic transformation and stroke severity were made between patients with and without AF enrolled in the EPITHET study. RESULTS: AF was present in 42 of 101 patients. At baseline, AF patients were older (79 vs. 73 years, p = 0.02), had more severe neurological impairment (National Institutes of Health Stroke Scale score 16 vs. 11, p = 0.006), larger infarcts (29 vs. 15 ml, p = 0.04) and greater volumes of more severe hypoperfusion (T(max) > or =8 s, perfusion-weighted imaging volume 70 vs. 43 ml, p = 0.01) compared to patients without AF. There were no significant differences in arterial occlusion site, infarct growth, recanalization or reperfusion. At outcome, AF patients had larger infarcts (52 vs. 16 ml, p = 0.05), more severe hemorrhagic transformation (29 vs. 5%, p = 0.002 for parenchymal hematomas), greater disability (modified Rankin Scale score 4 vs. 3, p = 0.03) and higher mortality rates (31 vs. 12%, p = 0.04). AF was an independent predictor of parenchymal hematoma (OR = 6.90, 95% CI = 1.57-30.25), but not mortality (OR = 2.56, 95% CI = 0.83-7.85). CONCLUSIONS: Patients with AF have worse clinical and imaging outcomes following ischemic stroke. This study suggests that the adverse effect of AF is due to greater volumes of more severely hypoperfused tissue, leading to larger infarct size and greater risk of severe hemorrhagic transformation.