Prognostic usefulness of left ventricular thrombus by echocardiography in dilated cardiomyopathy in predicting stroke, transient ischemic attack, and death

Risk factors and a Bayesian network model to predict ischemic stroke in patients with dilated cardiomyopathy

OBJECTIVE

This study aimed to identify risk factors and create a predictive model for ischemic stroke (IS) in patients with dilated cardiomyopathy (DCM) using the Bayesian network (BN) approach.

MATERIALS AND METHODS

We collected clinical data of 634 patients with DCM treated at three referral management centers in Beijing between 2016 and 2021, including 127 with and 507 without IS. The patients were randomly divided into training (441 cases) and test (193 cases) sets at a ratio of 7:3. A BN model was established using the Tabu search algorithm with the training set data and verified with the test set data. The BN and logistic regression models were compared using the area under the receiver operating characteristic curve (AUC).

RESULTS

Multivariate logistic regression analysis showed that hypertension, hyperlipidemia, atrial fibrillation/flutter, estimated glomerular filtration rate (eGFR), and intracardiac thrombosis were associated with IS. The BN model found that hyperlipidemia, atrial fibrillation (AF) or atrial flutter, eGFR, and intracardiac thrombosis were closely associated with IS. Compared to the logistic regression model, the BN model for IS performed better or equally well in the training and test sets, with respective accuracies of 83.7 and 85.5%, AUC of 0.763 [95% confidence interval (CI), 0.708-0.818] and 0.822 (95% CI, 0.748-0.896), sensitivities of 20.2 and 44.2%, and specificities of 98.3 and 97.3%.

CONCLUSION

Hypertension, hyperlipidemia, AF or atrial flutter, low eGFR, and intracardiac thrombosis were good predictors of IS in patients with DCM. The BN model was superior to the traditional logistic regression model in predicting IS in patients with DCM and is, therefore, more suitable for early IS detection and diagnosis, and could help prevent the occurrence and recurrence of IS in this patient cohort.

Recurrence of LV Thrombus in a Patient with Severe Ischaemic Cardiomyopathy Anticoagulated with Apixaban

Background

Anticoagulation with warfarin remains the mainstay treatment for left ventricular thrombi. Although successful thrombus resolution has been reported with direct oral anticoagulants' (DOACs') recurrence/progression while resuming Apixaban therapy is yet to be reported. Case Presentation. This case report describes left ventricular thrombus progression/recurrence in a patient anticoagulated with Apixaban undergoing implantable cardioverter defibrillator to cardiac resynchronisation therapy with defibrillator upgrade procedure. He was thereafter changed to warfarin. Contrast echocardiogram at 6 months follow-up did not identify the previously demonstrated mural thrombus.

Conclusion

Prospective randomised control trials should be conducted in patients with left ventricular thrombus to compare anticoagulants, assess the efficacy and safety of DOACs, and evaluate uninterrupted DOAC versus transient withdrawal for cardiac device procedures.

How Brain Infarction Links With the Microbiota-Gut-Brain Axis: Hints From Studies Focusing on the Risk Factors for Ischemic Stroke

Ischemic stroke (IS) is among the top prevalent neurologic disorders globally today. Risk factors such as hypertension, diabetes, and aging, contribute to the development of IS, and patients with these risk factors face heavier therapeutic burden and worse prognosis. Microbiota–gut–brain axis describes the crosstalk between the gut flora, intestine, and center nervous system, which conduct homeostatic effects through the bacterial metabolites, the regulation of immune activity, also the contact with enteric nerve ends and vagus nerve. Nowadays, more studies have paid attention to the important roles that microbiota–gut–brain axis played in the risk factors of IS. In the current article, we will review the recent works focusing on the bi-directional impacts of gut dysbiosis and the pathogenic process of IS-related risk factors, for the purpose to summarize some novel findings in this area, and try to understand how probiotics could limit the development of IS via different strategies.

Intra-Left Ventricular Hemodynamics Assessed with 4D Flow Magnetic Resonance Imaging in Patients with Left Ventricular Thrombus

Left ventricular thrombus (LVT) has been identified to be crucial in patients with reduced ejection fraction (EF). Three-dimensional cine phase-contrast magnetic resonance imaging (4D flow MRI) can visualize the intra-LV vortex during diastole and quantify the maximum flow velocity (Vmax) at the apex. In this study, we investigated whether the change in the intra-LV vortex was associated with the presence of LVT in patients with cardiac disease.In total, 36 patients (63.5 ± 11.9 years, 28 men, 12/24 with/without LVT) with diffuse LV dysfunction underwent 4D flow MRI. The relative vortex area using streamline images and Vmax of blood flow toward the apex at the apical left ventricle were evaluated. The correlation between the relative vortex area and Vmax was assessed using Pearson's correlation coefficient. The ability to detect LVT was evaluated using the area under the curve (AUC) of the receiver operating characteristic.The relative vortex area was found to be smaller (27 ± 10% versus 45 ± 11%, P = 0.000026), whereas Vmax at the apical left ventricle was lower (19.1 ± 4.4 cm/second versus 27.4 ± 8.9 cm/second, P = 0.0006) in patients with LVT. Vmax at the apical left ventricle demonstrated significant correlations with the relative vortex area (r = 0.43, P = 0.01) and relative transverse length of the vortex (r = 0.45, P = 0.007). The AUC was 0.91 for the relative vortex area, whereas it was 0.80 for Vmax in the apical left ventricle.A smaller LV vortex and lower flow velocity at the LV apex were associated with LVT in patients with reduced EF.

A novel risk model to predict first-ever ischemic stroke in heart failure with reduced ejection fraction

Patients with heart failure are at increased risk for ischemic stroke. We aim to develop a more accurate stroke risk prediction tools identify high-risk patients with heart failure with reduced ejection fraction (HFrEF). Patient data were extracted retrospectively from the electronic medical database between January 2009 and February 2019. Univariate and multivariate Cox regression analysis were performed to identify independent predictors, which were utilized to construct a nomogram for predicting ischemic stroke. AUROC analysis was used to compare the prognostic value between the new risk score and CHADS₂/CHA₂DS₂-VASc scores. In 6087 patients with HFrEF, the risk of first-ever ischemic stroke was 5.8% events/pts-years (n=468) during 8007.2 person-years follow-up. A nomogram constructed by integrating 6 variables, including age, atrial fibrillation (AF), deep vein thrombosis (DVT), d-dimer, anticoagulant use and spontaneous echocardiographic contrast (SEC)/left ventricular thrombus (LVT), exhibited a greater area under the curve of 0.727, 0.728 and 0.714 than that by CHADS₂ score (0.515, 0.522 and 0.540), and by CHA₂DS₂-VASc score (0.547, 0.553 and 0.562) for predicting first-ever ischemic stroke at hospitalization, 30-day and 6-month follow-up (all p<0.001). This novel stroke risk score performed better than existing CHADS₂/ CHA₂DS₂-VASc scores and showed improvement in predicting first-ever ischemic stroke in HFrEF patients.

Decreased eGFR Is Associated With Ischemic Stroke in Patients With Dilated Cardiomyopathy

Dilated cardiomyopathy (DCM) is increasingly indicated as a cause of cardioembolic syndrome, in particular, cardioembolic ischemia stroke. However, the potential risk factors for stroke among DCM patients remain under investigated. DCM patients hospitalized from June 2011 to June 2016 were included. The cases were defined as the group of DCM patients with stroke compared with those without stroke. Clinical characteristic data were collected and compared between the two groups including demographic data, complicated diseases, echocardiography index, and laboratory parameters and estimated glomerular filtration rate (eGFR). A multivariate logistic regression analysis model adjusted by sex and age was used to explore the related risk factors for stroke in DCM patients. A total of 779 hospitalized patients with DCM were included. Of these, 55 (7.1%) had experienced a stroke. Significantly lower eGFR levels (68.03 ± 26.22 vs 79.88 ± 24.25 mL/min/1.73 m², P = .001) and larger left atrial diameters (45.32 ± 7.79 vs 43.25 ± 7.11 mm, P = .04) were found in the group of patients having DCM with stroke compared to those without stroke. When the eGFR was categorized as eGFR >60, 30<eGFR≤ 60 and eGFR ≤ 30, there were more patients with 30<eGFR≤ 60 (30.9% vs 17.7%) and eGFR≤ 30 (9.1% vs 3.3%) in the ischemic stroke group (P = 0.003). A multivariate logistic regression analysis model adjusted by sex and age showed that 30 <eGFR≤60 (odds ratio [OR]: 2.07, 95% confidence interval [CI]: [1.05-4.07], P = .035) and eGFR≤30 (OR: 4.04, 95% CI: [1.41-11.62], P = .009) were statistically associated with ischemic stroke in patients with DCM. It is concluded that decreased eGFR is significantly associated with an increased risk of ischemic stroke in patients with DCM.

D-dimer level and long-term outcome in patients with end-stage heart failure secondary to idiopathic dilated cardiomyopathy

Background

Previous studies had demonstrated hemostatic abnormalities in patients with heart failure (HF) and several studies have shown that abnormal coagulation indices, represented by elevated D-dimer, had prognostic significance in patients with compatible or acute decompensated HF. However, the impact of D-dimer on the outcome in patients with end-stage HF remains unclear.

Methods

A total of 244 consecutive patients with end-stage HF due to idiopathic dilated cardiomyopathy (DCM) were prospectively enrolled from February 2011 to September 2014. D-dimer levels were measured and its prognostic value was assessed. Primary endpoint was all-cause mortality during the follow-up period. Secondary endpoints were stroke, bleeding, occurrence of sustained ventricular tachycardia or ventricular fibrillation, and major adverse cardiovascular events (MACE).

Results

D-dimer was significantly elevated in the non-survivors (median: 0.8 vs. 1.1 mg/L, P < 0.001). Traditional markers including B-type natriuretic peptide, troponin I, left ventricular ejection fraction, and left ventricular end-diastolic dimension provided limited prognostic value; but the addition of D-dimer refined the risk stratification. The optimal cut-off value of D-dimer to predict all-cause mortality was 0.84 mg/L by receiver operator characteristic analysis. Elevated D-dimer level was independently associated with increased risk of long-term all-cause mortality (HR = 2.315, 95% CI: 1.570–3.414, P < 0.001) and MACE (HR = 1.256, 95% CI: 1.058–1.490, P = 0.009), and the predictive value was independent of age, sex, atrial fibrillation and anticoagulation status.

Conclusions

Elevated D-dimer level was independently associated with poor long-term outcome in patients with end-stage HF secondary to idiopathic DCM, and the predictive value was superior to that of traditional prognostic markers.

Left ventricular wall motion abnormality is associated with cryptogenic stroke

BACKGROUND

Left ventricular wall motion abnormality (LVWMA) unrelated to known cardiac risk factors is an uncertain risk for stroke.

AIMS

We evaluated whether LVWMA was associated with cryptogenic stroke.

METHODS

This retrospective, observational study included 4316 acute ischemic stroke patients, and the association between cryptogenic stroke and LVWMA was examined in comparison with other stroke subtypes.

RESULTS

The prevalence of LVWMA was 10.0% in the study population. In a fully adjusted, binary logistic regression, LVWMA was independently associated with cryptogenic stroke compared with stroke from large artery atherosclerosis (odds ratio = 1.627, 95% confidence interval = 1.129-2.345), small vessel occlusion (odds ratio = 1.948, 95% confidence interval = 1.261-3.010), or other causes (odds ratio = 4.950, 95% confidence interval = 1.145-21.412). Meanwhile, the association of LVWMA with cryptogenic stroke was similar to the associations of LVWMA with cardioembolic stroke (odds ratio = 0.758, 95% confidence interval = 0.525-1.094) and stroke with two or more causes (odds ratio = 0.992, 95% confidence interval = 0.609-1.615). In multinomial regression, LVWMA had the strongest association with cardioembolic stroke, followed by cryptogenic stroke and stroke from two or more causes. The strength of the associations with LVWMA then decreased sequentially in patients with large artery atherosclerosis, small vessel occlusion, and other causes.

CONCLUSIONS

The association of LVWMA with cryptogenic stroke was comparable to that of LVWMA with cardioembolic stroke but stronger than that of LVWMA with non-cardioembolic stroke. LVWMA unrelated to known cardiac risk factors could be considered an independent risk factor for cryptogenic stroke.

Risk of thromboembolic complications in adult congenital heart disease: A literature review

Adult congenital heart disease (ACHD) is a constantly expanding population with challenging issues. Initial medical and surgical treatments are seldom curative, and the majority of patients still experience late sequelae and complications, especially thromboembolic events. These common and potentially life-threating adverse events are probably dramatically underdiagnosed. Better identification and understanding of thromboembolic risk factors are essential to prevent long-term related morbidities. In addition to specific situations associated with a high risk of thromboembolic events (Fontan circulation, cyanotic congenital heart disease), atrial arrhythmia has been recognized as an important risk factor for thromboembolic events in ACHD. Unlike in patients without ACHD, thromboembolic risk stratification scores, such as the CHA₂DS₂-VASc score, may not be applicable in ACHD. Overall, after a review of the scientific data published so far, it is clear that the complexity of the underlying congenital heart disease represents a major risk factor for thromboembolic events. As a consequence, prophylactic anticoagulation is indicated in patients with complex congenital heart disease and atrial arrhythmia, regardless of the other risk factors, as opposed to simple heart defects. The landscape of ACHD is an ongoing evolving process, and specific thromboembolic risk scores are needed, especially in the setting of simple heart defects; these should be coupled with specific trials or long-term follow-up of multicentre cohorts.

Left ventricular wall motion abnormalities are associated with stroke recurrence

Objective:

To investigate the role of left ventricular wall motion abnormalities (LVWMA), unrelated to high-risk cardioembolic conditions, in stroke recurrence.

Methods:

This study included consecutive acute ischemic stroke patients. Transthoracic echocardiography was performed as a routine evaluation for stroke patients. The outcomes were the time to recurrent any stroke and ischemic stroke.

Results:

Among 4,316 acute ischemic stroke patients, 430 had LVWMA without high-risk cardioembolic sources. The median observation periods of patients at risk of any stroke and ischemic stroke were 24.5 and 24.7 months. During the follow-up, any stroke and ischemic stroke recurrence were observed in 310 (7.2%) and 250 (5.8%) patients. LVWMA were associated with outcomes after adjustment for traditional cardiovascular risk factors, laboratory and imaging variables, and therapeutic interventions (hazard ratio [HR] 1.707, 95% confidence interval [CI] 1.262–2.310 for any stroke; HR 1.709, 95% CI 1.222–2.390 for ischemic stroke). Moreover, LVWMA could still be considered as independent risk factors after correction for covariates that were significantly associated with outcomes in univariable regression (HR 1.747, 95% CI 1.292–2.364 for any stroke; HR 1.704, 95% CI 1.219–2.382 for ischemic stroke). There were no significant interactions between LVWMA and outcomes between the subgroups except for the statin treatment subgroup.

Conclusions:

This study suggests that LVWMA, even when unassociated with high-risk cardioembolic sources, could be an independent predictor for stroke recurrence in patients with ischemic stroke.

Clinical predictors and outcomes of patients with left ventricular thrombus following ST-segment elevation myocardial infarction

We aimed to characterize the independent predictors of LVT following STEMI and the association with outcomes. The clinical predictors of left ventricular thrombus (LVT) formation after ST-segment elevation myocardial infarction (STEMI) are not well-defined in the contemporary era. We performed a retrospective analysis of STEMI patients at Duke from 2000 to 2011 who had a transthoracic echocardiogram within 90 days post-STEMI and compared patients with and without LVT (LVT+ vs. LVT-). Univariate Cox proportional hazards regression models of baseline characteristics were examined and significant variables were used in a multivariable model to assess adjusted relationships with LVT. A multivariable Cox PH survival model with covariate adjustments was used for assessment of LVT and long-term mortality. Of all eligible patients, 1734 patients met inclusion criteria and 4.3 % (N = 74) had a LVT. LVT+ patients tended to have a history of heart failure (HF) and higher initial troponin compared to LVT- patients. After adjustment, higher heart rate, non-white race, HF severity, and presence of left anterior descending artery (LAD) disease were independent predictors of LVT. There was a trend toward an association between LVT and increased all-cause mortality (HR 1.36; 95 % CI 0.84-2.21, P = 0.22), however this was not statistically significant. LVT was seen in over 4 % of this contemporary post-STEMI population. Several baseline characteristics were independently associated with LVT: Heart rate, HF severity, LAD disease, and non-white race. Prospective studies are warranted to determine whether anticoagulation in patients at increased risk for LVT improves outcomes.

Risk assessment in patients with an acute ST-elevation myocardial infarction

ST-elevation myocardial infarction (STEMI) is one of the leading causes of mortality and morbidity worldwide. While the survival after acute STEMI has considerably improved, mortality rate still remains high, especially in high-risk patients. Survival after acute STEMI is influenced by clinical characteristics such as age as well as the presence of comorbidities. However, during emergency care increasing access to tools such as the electrocardiogram, chest x-ray and echocardiography can provide additional information helping to further risk stratify patients. In the invasive setting, this can also include coronary angiography, invasive hemodynamic recordings and angiographic assessments of coronary flow and myocardial perfusion. We outline the common investigations used in STEMI and their role in risk assessment of patients with an acute STEMI.

A review of stroke and pregnancy: incidence, management and prevention

Stroke, defined as a focal or global disturbance of cerebral function lasting over 24h resulting from disruption of its blood supply, is a devastating event for a pregnant woman. This can result in long-term disability or death, and impact on her family and unborn child. In addition to pre-existing patient risk factors, the hypercoagulable state and pre-eclampsia need to be taken into account. The patterns and types of stroke affect pregnant women differ from the non-pregnant female population of child-bearing age. Like other thrombo-embolic diseases in pregnancy, stroke is essentially a disease of the puerperium. Population studies have estimated the risk of stroke at between 21.2 and 46.2 per 100,000. The US Nationwide Inpatient Sample, identified 2850 pregnancies complicated by stroke in the United States in 2000-2001, for a rate of 34.2 per 100,000 deliveries. There were 117 deaths, a mortality rate of 1.4 per 100,000. Both the mortality and disability rates were higher than previously reported, with 10-13% of women dying. With the increasing prevalence of obesity, hypertension and cardiac disease amongst women of child-bearing age, so is the incidence of stroke during pregnancy and the puerperium. In the United States, an alarming trend toward higher numbers of stroke hospitalizations during the last decade was demonstrated in studies from 1995 to 1996 and 2006 to 2007. The rate of all types of stroke increased by 47% among antenatal hospitalizations, and by 83% among post-partum hospitalizations. Hypertensive disorders, obesity and heart disease complicated 32% of antenatal admissions and 53% of post-partum admissions. In addition to pre-existing patient risk factors, the hypercoagulable state and pre-eclampsia need to be taken into account. The patterns and types of stroke affect pregnant women differ from the non-pregnant female population of child-bearing age. Like other thrombo-embolic diseases in pregnancy, stroke is essentially a disease of the puerperium.

LV thrombus detection by routine echocardiography: insights into performance characteristics using delayed enhancement CMR

OBJECTIVES

This study sought to evaluate performance characteristics of routine echo for left ventricular thrombus (LVT).

BACKGROUND

Although the utility of dedicated echocardiography (echo) for LVT is established, echo is widely used as a general test for which LVT is rarely the primary indication. We used delayed-enhancement cardiac magnetic resonance (DE-CMR) as a reference to evaluate LVT detection by routine echo.

METHODS

Dedicated LVT assessment using DE-CMR was prospectively performed in patients with left ventricular systolic dysfunction. Echoes were done as part of routine clinical care. Echo and CMR were independently read for LVT and related indexes of LVT size, shape, and image quality/diagnostic confidence. Follow-up was done for embolic events and pathology validation of LVT.

RESULTS

In this study, 243 patients had routine clinical echo and dedicated CMR within 1 week without intervening events. Follow-up supported DE-CMR as a reference standard, with >5-fold difference in endpoints between patients with versus without LVT by DE-CMR (p = 0.02). LVT prevalence was 10% by DE-CMR. Echo contrast was used in 4% of patients. Echo sensitivity and specificity were 33% and 91%, with positive and negative predictive values of 29% and 93%. Among patients with possible LVT as the clinical indication for echo, sensitivity and positive predictive value were markedly higher (60%, 75%). Regarding sensitivity, echo performance related to LVT morphology and mirrored cine-CMR, with protuberant thrombus typically missed when small (p ≤ 0.02). There was also a strong trend to miss mural thrombus irrespective of size (p = 0.06). Concerning positive predictive value, echo performance related to image quality, with lower diagnostic confidence scores for echoes read positive for LVT in discordance with DE-CMR compared with echoes concordant with DE-CMR (p < 0.02).

CONCLUSIONS

Routine echo with rare contrast use can yield misleading results concerning LVT. Echo performance is improved when large protuberant thrombus is present and when the clinical indication is specifically for LVT assessment.

MDCT features of cardiothoracic sources of stroke

Multidetector computed tomography (MDCT) is widely used in the assessment of cardiothoracic disease and provides high-resolution images of the heart, great vessels, and lungs. A range of cardiothoracic conditions can precipitate stroke, including intracardiac thrombus, right-to-left shunts, and diseases of the thoracic aorta. Many of these conditions may be identified on non-electrocardiogram (ECG)-gated studies, but the advent of high temporal resolution ECG-gated MDCT provides superior anatomical delineation. Radiologists should be familiar with the pathogenesis and CT features of cardiothoracic conditions that can precipitate stroke as their early identification to enables appropriate management and prognostic decisions.

Aspirin and clopidogrel with or without phenprocoumon after drug eluting coronary stent placement in patients on chronic oral anticoagulation

OBJECTIVES

Optimal antithrombotic/anticoagulation therapy in patients on chronic oral anticoagulation (OAC) undergoing drug-eluting stent (DES) implantation is unknown. We investigated the efficacy and safety of two regimens of antithrombotic/anticoagulation therapy in patients who present for DES implantation whilst on OAC.

METHODS

We included a series of 515 patients on OAC who underwent DES implantation between 2002 and 2007. Based on predefined clinical and echocardiographic criteria, 306 patients continued OAC (triple therapy) and 209 patients discontinued OAC (dual therapy) for the time they received antiplatelet therapy with clopidogrel and aspirin [stent-related antithrombotic treatment (SRAT)]. The primary end point was a composite of death, myocardial infarction, stent thrombosis or stroke.

RESULTS

During SRAT the primary endpoint was observed in 13 patients in the group with triple therapy versus 15 patients in the group with dual therapy [Kaplan-Meier estimates 4.2% and 7.2%, odds ratio (OR) = 0.61, 95% confidence interval (CI) 0.29-1.28; P = 0.19]. At 2 years of follow-up, the primary endpoint was observed in 35 patients in the group with triple therapy versus 36 patients in the group with dual therapy (Kaplan-Meier estimates 14.1% and 18.0%, OR = 0.76, 95% CI: 0.48-1.21; P = 0.25). Two-year incidence of major bleeding was 1.4% (n = 4, triple therapy) versus 3.1% (n = 6, dual therapy) (P = 0.34).

CONCLUSIONS

In patients on chronic OAC undergoing DES implantation, clinical and echocardiographic criteria help to define postprocedural antithrombotic/anticoagulation therapy. Based on these criteria, both a double antiplatelet therapy (clopidogrel plus aspirin) and a triple therapy (OAC plus clopidogrel plus aspirin) are associated with favourable safety and efficacy.

The incidence of ischemic stroke in chronic heart failure: a meta-analysis

BACKGROUND

There is marked variability in the reported stroke rates among persons with heart failure (HF). We performed a meta-analysis to provide summary estimates of the stroke rate in HF and to explain heterogeneity in the existing literature. We will summarize the ischemic stroke rate at various time points during follow-up among adults with chronic heart failure.

METHODS AND RESULTS

A systematic review of the electronic literature in Medline and PubMed as well as hand searching of the reference lists of identified articles and of the meeting abstracts for the 1995-2004 American College of Cardiology and American Heart Association scientific sessions was performed to identify qualifying studies. Articles were included if they included a population with chronic HF and reported the number (or percent) of persons with HF who experienced an ischemic stroke during follow-up. Studies were excluded if the study population included > or = 50% of persons with acute (postmyocardial infarction) HF, or if > or = 50% of the study population required artificial support with a ventricular assist device or parenteral inotropic medications. Case reports, case series, and nonoriginal research articles were not included. Determination of study eligibility and data extraction were conducted by 2 independent reviewers using standardized forms. Results are reported as stroke rate per 1000 cases of HF, with 95% Poisson confidence intervals. Pooled estimates of the stroke rate were calculated with fixed and random effects models. Heterogeneity was explored according to a priori specified subgroup analyses. Overall, 26 studies met inclusion criteria. Eighteen of every 1000 persons suffered a stroke during the first year after the diagnosis of HF. The stroke rate increased to a maximum of 47.4 per 1000 at 5 years. Studies with fewer women, those conducted in 1990 or earlier, and cohort studies reported higher stroke rates than studies with more women, those conducted after 1990, and clinical trials.

CONCLUSIONS

Stroke is an important complication among persons with HF. Variability among reported stroke rates can be explained in part by differences in study design, patient population, and HF standards of care at the time of the study. Despite the heterogeneity in reported stroke rates, this meta-analysis shows that stroke prevention in HF represents an opportunity to prevent morbidity and save many lives in this highly fatal disease.

An evidence-based causative classification system for acute ischemic stroke

Regular, evidence-based assignment of patients to etiologic stroke categories is essential to enable valid comparison among studies. We designed an algorithm (SSS-TOAST) that incorporated recent advances in stroke imaging and epidemiology to identify the most probable TOAST category in the presence of evidence for multiple mechanisms. Based on the weight of evidence, each TOAST subtype was subdivided into 3 subcategories as "evident", "probable", or "possible". Classification into the subcategories was determined via predefined specific clinical and imaging criteria. These criteria included published risks of ischemic stroke from various mechanisms and published reports of the strength of associations between clinical and imaging features and particular stroke mechanisms. Two neurologists independently assessed 50 consecutively admitted patients with acute ischemic stroke through reviews of abstracted data from medical records. The number of patients classified as "undetermined-unclassified" per the original TOAST system decreased from 38-40% to 4% using the SSS-TOAST system. The kappa value for inter-examiner reliability was 0.78 and 0.90 for the original TOAST and SSS-TOAST respectively. The SSS-TOAST system successfully classifies patients with acute ischemic stroke into determined etiologic categories without sacrificing reliability. The SSS-TOAST is a dynamic algorithm that can accommodate modifications as new epidemiological data accumulate and diagnostic techniques advance.