Risk of stroke in chronic heart failure patients with preserved ejection fraction, but without atrial fibrillation: analysis of the CHARM-Preserved and I-Preserve trials.

AIMS: The incidence and predictors of stroke in patients with heart failure and preserved ejection fraction (HF-PEF), but without atrial fibrillation (AF), are unknown. We described the incidence of stroke in HF-PEF patients with and without AF and predictors of stroke in those without AF. METHODS AND RESULTS: We pooled data from the CHARM-Preserved and I-Preserve trials. Using Cox regression, we derived a model for stroke in patients without AF in this cohort and compared its performance with a published model in heart failure patients with reduced ejection fraction (HF-REF)-predictive variables: age, body mass index, New York Heart Association class, history of stroke, and insulin-treated diabetes. The two stroke models were compared and Kaplan-Meier curves for stroke estimated. The risk model was validated in a third HF-PEF trial. Of the 6701 patients, 4676 did not have AF. Stroke occurred in 124 (6.1%) with AF and in 171 (3.7%) without AF (rates 1.80 and 1.00 per 100 patient-years, respectively). There was no difference in performance of the stroke model derived in the HF-PEF cohort and the published HF-REF model (c-index 0.71, 95% confidence interval 0.57-0.84 vs. 0.73, 0.59-0.85, respectively) as the predictive variables overlapped. The model performed well in the validation cohort (0.86, 0.62-0.99). The rate of stroke in patients in the upper third of risk approximated to that in patients with AF (1.60 and 1.80 per 100 patient-years, respectively). CONCLUSIONS: A small number of clinical variables identify a subset of patients with HF-PEF, but without AF, at elevated risk of stroke.

Interruption to antiplatelet therapy early after acute ischaemic stroke: a nested case-control study.

AIMS: Antiplatelet drugs are often discontinued early after ischaemic stroke, either because of poor compliance, complications or withdrawal of care. It is unclear whether this places patients at increased risk of recurrence. We explored the association between cardiovascular event rate and persistence with prescribed antiplatelet drugs. METHODS: We used a matched case-control design using the Virtual International Stroke Trials Archive (VISTA). Cases were patients who had an acute coronary syndrome, recurrent stroke or transient ischaemic attack within 90 days post-stroke and were matched for age ± 10 years and sex with up to four controls. Antiplatelet use was categorized as persistent (used for >3 days and continued up to day 90), early cessation (used antiplatelet <3 days) or stopped/interrupted users (used for >3 days but stopped prior to day 90). These categories were compared in cases and controls using a conditional logistic regression model that adjusted for potential confounders. RESULTS: A total of 970 patients were included, of whom 194 were cases and 776 were matched controls. At 90 days, 10 cases (5.2%) and 58 controls (7.5%) stopped/interrupted their antiplatelet. The risk of cardiovascular event was not different in stopped/interrupted users (adjusted odds ratio 0.70, 95% confidence interval 0.33, 1.48; P = 0.352) and early cessations (adjusted odds ratio 1.04, 95% confidence interval 0.62, 1.74; P = 0.876) when compared to persistent users. CONCLUSION: We found no increased risk in patients who stopped and interrupted antiplatelets early after stroke but the study was limited by a small sample size and further research is needed.

Use of a 3-Item Short-Form Version of the Barthel Index for Use in Stroke: Systematic Review and External Validation.

BACKGROUND AND PURPOSE: There may be a potential to reduce the number of items assessed in the Barthel Index (BI), and shortened versions of the BI have been described. We sought to collate all existing short-form BI (SF-BI) and perform a comparative validation using clinical trial data. METHODS: We performed a systematic review across multidisciplinary electronic databases to find all published SF-BI. Our validation used the VISTA (Virtual International Stroke Trials Archive) resource. We describe concurrent validity (agreement of each SF-BI with BI), convergent and divergent validity (agreement of each SF-BI with other outcome measures available in the data set), predictive validity (association of prognostic factors with SF-BI outcomes), and content validity (item correlation and exploratory factor analyses). RESULTS: From 3546 titles, we found 8 articles describing 6 differing SF-BI. Using acute trial data (n=8852), internal reliability suggested redundancy in BI (Cronbach α, 0.96). Each SF-BI demonstrated a strong correlation with BI, modified Rankin Scale, National Institutes of Health Stroke Scale (all ρ≥0.83; P<0.001). Using rehabilitation trial data (n=332), SF-BI demonstrated modest correlation with quality of life measures Stroke Impact Scale and 5 domain EuroQOL (ρ≥0.50, P<0.001). Prespecified prognostic factors were associated with SF-BI outcomes (all P<0.001). Our factor analysis described a 3 factor structure, and item reduction suggested an optimal 3-item SF-BI comprising bladder control, transfer, and mobility items in keeping with 1 of the 3-item SF-BI previously described in the literature. CONCLUSIONS: There is redundancy in the original BI; we have demonstrated internal and external validity of a 3-item SF-BI that should be simple to use.

Clinical Selection Strategies to Identify Ischemic Stroke Patients With Large Anterior Vessel Occlusion: Results From SITS-ISTR (Safe Implementation of Thrombolysis in Stroke International Stroke Thrombolysis Registry).

BACKGROUND AND PURPOSE: The National Institutes of Health Stroke Scale (NIHSS) correlates with presence of large anterior vessel occlusion (LAVO). However, the application of the full NIHSS in the prehospital setting to select patients eligible for treatment with thrombectomy is limited. Therefore, we aimed to evaluate the prognostic value of simple clinical selection strategies. METHODS: Data from the Safe Implementation of Thrombolysis in Stroke International Stroke Thrombolysis Registry (January 2012-May 2014) were analyzed retrospectively. Patients with complete breakdown of NIHSS scores and documented vessel status were included. We assessed the association of prehospital stroke scales and NIHSS symptom profiles with LAVO (internal carotid artery, carotid-terminus or M1-segment of the middle cerebral artery). RESULTS: Among 3505 patients, 23.6% (n=827) had LAVO. Pathological finding on the NIHSS item best gaze was strongly associated with LAVO (adjusted odds ratio 4.5, 95% confidence interval 3.8-5.3). All 3 face-arm-speech-time test (FAST) items identified LAVO with high sensitivity. Addition of the item gaze to the original FAST score (G-FAST) or high scores on other simplified stroke scales increased specificity. The NIHSS symptom profiles representing total anterior syndromes showed a 10-fold increased likelihood for LAVO compared with a nonspecific clinical profile. If compared with an NIHSS threshold of ≥6, the prehospital stroke scales performed similarly or even better without losing sensitivity. CONCLUSIONS: Simple modification of the face-arm-speech-time score or evaluating the NIHSS symptom profile may help to stratify patients' risk of LAVO and to identify individuals who deserve rapid transfer to comprehensive stroke centers. Prospective validation in the prehospital setting is required.

Antiplatelet therapy following ischaemic stroke - Continue or change pre-existing therapy?

INTRODUCTION: Antiplatelet therapy is routinely prescribed early after ischaemic stroke. Many patients will already be taking antiplatelet therapy and it is unknown whether these patients should continue the same antiplatelet treatment or switch to a different regimen. METHODS: We selected patients with ischaemic stroke from the Virtual International Stroke Trials Archive database who were prescribed antiplatelets both before and after their stroke and who had detailed records of adverse events after stroke. We compared patients who changed to a new antiplatelet regimen after their stroke to those who continued the same regimen. The primary outcome was recurrent ischaemic stroke within 90 days after their index stroke and the secondary outcome was intracranial haemorrhage (ICH) or extracranial haemorrhage (ECH). We used logistic regression analysis and adjusted for age and baseline NIHSS. RESULTS: A total of 1129 participants were included. Of these, 538 subjects changed antiplatelet regimen post stroke and 591 continued the same regimen. A recurrent ischaemic event occurred in 4.1% of subjects who changed regimen and 4.3% who continued unchanged (adjusted OR = 0.93; 95% CI 0.54-1.75, p = 0.929). The incidence of ICH and ECH within the first 90 days was similar in both groups (2.4% vs. 2.6% (adjusted OR = 1.02; 95% CI 0.48-2.18, p = 0.955) and 4.7% vs. 2.9% (adjusted OR = 1.82; 95% CI 0.96-3.43, p = 0.065), respectively). DISCUSSION: The analysis was performed using a non-randomised registry data. CONCLUSION: In patients who suffer ischaemic stroke whilst taking antiplatelets, a change in antiplatelet regimen was not associated with an altered risk of early recurrent ischaemic stroke rate or bleeding. However, the results must be interpreted in view of the low event rates.

Sex and Stroke in Thrombolyzed Patients and Controls.

BACKGROUND AND PURPOSE: We hypothesized that any sex-related difference in outcome poststroke is explained by other prognostic factors and that the response to intravenous recombinant tissue-type plasminogen activator (r-tPA) is equal in males and females after adjustment for such factors. METHODS: We accessed an independent collection of randomized clinical trials-the VISTA (Virtual International Stroke Trials Archive). Data were preprocessed by selecting complete cases (n=8028) and matching females to males (coarsened exact matching, n=4575, 24.3% r-tPA). Outcome was assessed by the 7-point modified Rankin Scale (mRS) measured at 90 days after ischemic stroke. Relationship among variables was estimated by adjusted regression analysis. RESULTS: In nonthrombolyzed patients, ordinal analysis of mRS adjusting for stroke- and sex-related prognostic factors suggested comparable outcomes for females and males (odds ratio, 0.96; 95% confidence interval, 0.85-1.06). Females responded comparably to r-tPA as did males, irrespective of the outcome definition of mRS (ordinal: PInteraction=0.46, relative excess risk because of interaction=0). The number needed to treat was 6.8 and 11.2 for 1 female to achieve mRS score of 0 to 2 and 0 to 1, which was highly congruent with males. Analysis for a nonlinear variation of age-by-sex revealed a good outcome for females <45 years with significant disadvantage thereafter (mRS score of 0-2: PInteraction=0.004). No relationship between sex, r-tPA, and bleeding complications was evident. CONCLUSIONS: Functional outcome (mRS) without r-tPA was overall similar between the sexes, as was the response to r-tPA. Nonlinear sex-by-age interaction improved estimates of functional independence; this should be considered in sex-related studies in stroke.

Statins and risk of poststroke hemorrhagic complications.

OBJECTIVE: To assess whether statin treatment before or after acute ischemic stroke (AIS) affects the risk of acute intracerebral hemorrhage (ICH), postacute ICH, and mortality within 90 days. METHODS: Data were sought from the Virtual International Stroke Trials Archive, an international repository of clinical trials data. Using propensity score matching, we retrospectively compared patients with prior statin treatment and newly initiated statin within 3 days after AIS to patients without statin exposure. Outcomes of interest were acute symptomatic ICH (sICH), any acute ICH, postacute ICH, and mortality during follow-up of 3 months. RESULTS: A total of 8,535 patients (mean age 70 years, 54% male, median baseline NIH Stroke Scale score 13) were analyzed. After propensity score matching, prior statin use was not strongly associated with sICH (adjusted odds ratio [OR] 1.33, 95% confidence interval [CI] 0.83-2.14) or any ICH (adjusted OR 1.35, 95% CI 0.92-1.98). There was no evidence of an interaction between prior statin use and thrombolysis. New initiation of statins was not associated with postacute ICH (adjusted hazard ratio [HR] 1.60, 95% CI 0.70-3.65). There was a signal towards lower 90-day mortality in patients with prior statin use (adjusted HR 0.84, 95% CI 0.70-1.00) and especially early initiation of statins (adjusted HR 0.67, 95% CI 0.46-0.97). CONCLUSIONS: Statin use prior to AIS was not associated with early hemorrhagic complications, irrespective of treatment with thrombolysis. New initiation of statin treatment early after AIS did not affect risk of postacute ICH, but might be associated with reduced mortality.

Efficacy and safety of digoxin in patients with heart failure and reduced ejection fraction according to diabetes status: An analysis of the Digitalis Investigation Group (DIG) trial.

BACKGROUND: Digoxin is recommended in symptomatic heart failure patients with reduced ejection fraction (HF-REF) in sinus rhythm and refractory to other evidence-based therapy. Although HF-REF patients with diabetes have worse functional status than those without, the effects of digoxin have not been specifically evaluated according to diabetes status. METHODS: We examined the efficacy and safety of digoxin in HF-REF patients with and without diabetes in the Digitalis Investigation Group trial. Mortality from all-cause, cardiovascular (CV) causes and heart failure (HF), along with HF hospitalisation and suspected digoxin toxicity were analyzed according to diabetes status and randomised treatment assignment. RESULTS: Of the 6800 patients, those with diabetes (n=1933) were older, more often women, had worse clinical status and more co-morbidity than those without diabetes. All-cause and CV mortality were higher in patients with diabetes than in those without and digoxin did not reduce mortality in either sub-group. The rate of HF hospitalization (per 100 person-years) in patients with diabetes was higher than in those without and was reduced by digoxin in both patient groups: diabetes - placebo 20.5 and digoxin 16.0 (HR 0.79, 95% CI: 0.68-0.91); no diabetes - placebo 12.7 and digoxin 8.7 (HR 0.69, 0.62-0.77); interaction p=0.14. Suspected digoxin toxicity in patients randomised to digoxin was more common among patients with diabetes than without (6.5% versus 5.8%), as was hospitalisation for digoxin toxicity (1.4% versus 0.8%). CONCLUSION: Added to an ACE inhibitor, digoxin reduced HF hospitalisation in HF-REF patients with and without diabetes without a substantial risk of toxicity.

Allopurinol and Cardiovascular Outcomes in Adults With Hypertension.

Allopurinol lowers blood pressure in adolescents and has other vasoprotective effects. Whether similar benefits occur in older individuals remains unclear. We hypothesized that allopurinol is associated with improved cardiovascular outcomes in older adults with hypertension. Data from the United Kingdom Clinical Research Practice Datalink were used. Multivariate Cox-proportional hazard models were applied to estimate hazard ratios for stroke and cardiac events (defined as myocardial infarction or acute coronary syndrome) associated with allopurinol use over a 10-year period in adults aged >65 years with hypertension. A propensity-matched design was used to reduce potential for confounding. Allopurinol exposure was a time-dependent variable and was defined as any exposure and then as high (≥300 mg daily) or low-dose exposure. A total of 2032 allopurinol-exposed patients and 2032 matched nonexposed patients were studied. Allopurinol use was associated with a significantly lower risk of both stroke (hazard ratio, 0.50; 95% confidence interval, 0.32-0.80) and cardiac events (hazard ratio, 0.61; 95% confidence interval, 0.43-0.87) than nonexposed control patients. In exposed patients, high-dose treatment with allopurinol (n=1052) was associated with a significantly lower risk of both stroke (hazard ratio, 0.58; 95% confidence interval, 0.36-0.94) and cardiac events (hazard ratio, 0.65; 95% confidence interval, 0.46-0.93) than low-dose treatment (n=980). Allopurinol use is associated with lower rates of stroke and cardiac events in older adults with hypertension, particularly at higher doses. Prospective clinical trials are needed to evaluate whether allopurinol improves cardiovascular outcomes in adults with hypertension.

Online Tool to Improve Stratification of Adverse Events in Stroke Clinical Trials.

BACKGROUND AND PURPOSE: Knowing characteristic adverse events (AEs) and their incidence among patients participating in acute stroke trials may assist interpretation of future studies. We aimed to develop an online tool to inform stroke trial safety. METHODS: We identified relevant AEs from patients within the Virtual International Stroke Trials Archive (VISTA), using receiver operating characteristic principles. We modeled their incidence on patient age, baseline National Institutes of Health Stroke Scale, and comorbidities using binary logistic regression. Models with an R(2) >5% were deemed powerful enough to predict expected AE incidences and were included. The calculator was developed using programs R and Visual Studios. RESULTS: Forty-eight of the most common AEs were identified and incorporated into the IschAEmic Stroke Calculator. The calculator, publicly available at http://www.vistacollaboration.org calculates the expected incidence of AEs or groups of AEs in a trial cohort and where possible compares them with the observed incidence. CONCLUSIONS: The IschAEmic Stroke Calculator is an open access resource to support safety interpretation within acute stroke trials. Prediction of AEs with higher likelihood of occurrence may direct preventive clinical measures.

A collaborative sequential meta-analysis of individual patient data from randomized trials of endovascular therapy and tPA vs. tPA alone for acute ischemic stroke: ThRombEctomy And tPA (TREAT) analysis: statistical analysis plan for a sequential meta-analysis performed within the VISTA-Endovascular collaboration.

RATIONALE: Endovascular treatment has been shown to restore blood flow effectively. Second-generation medical devices such as stent retrievers are now showing overwhelming efficacy in clinical trials, particularly in conjunction with intravenous recombinant tissue plasminogen activator. AIMS AND DESIGN: This statistical analysis plan utilizing a novel, sequential approach describes a prospective, individual patient data analysis of endovascular therapy in conjunction with intravenous recombinant tissue plasminogen activator agreed upon by the Thrombectomy and Tissue Plasminogen Activator Collaborative Group. STUDY OUTCOMES: This protocol will specify the primary outcome for efficacy, as 'favorable' outcome defined by the ordinal distribution of the modified Rankin Scale measured at three-months poststroke, but with modified Rankin Scales 5 and 6 collapsed into a single category. The primary analysis will aim to answer the questions: 'what is the treatment effect of endovascular therapy with intravenous recombinant tissue plasminogen activator compared to intravenous tissue plasminogen activator alone on full scale modified Rankin Scale at 3 months?' and 'to what extent do key patient characteristics influence the treatment effect of endovascular therapy?'. Key secondary outcomes include effect of endovascular therapy on death within 90 days; analyses of modified Rankin Scale using dichotomized methods; and effects of endovascular therapy on symptomatic intracranial hemorrhage. Several secondary analyses will be considered as well as expanding patient cohorts to intravenous recombinant tissue plasminogen activator-ineligible patients, should data allow. DISCUSSION: This collaborative meta-analysis of individual participant data from randomized trials of endovascular therapy vs. control in conjunction with intravenous thrombolysis will demonstrate the efficacy and generalizability of endovascular therapy with intravenous thrombolysis as a concomitant medication.