Stroke: the bare essentials

Clinical Relevance of Orthostatic Hypotension in Patients with Atrial Fibrillation and Suspected Transient Ischemic Attack

INTRODUCTION

Orthostatic hypotension (OH) and atrial fibrillation (AF) are both regarded as independent risk factors for transient ischemic attack (TIA). However, the clinical implication of OH in the presence of AF is unclear. This study investigates, for the first time, the association between blood pressure (BP), OH and mortality in a cohort of patients with AF and TIA symptoms.

AIM

To investigate the incidence of the association between OH, AF and TIA.

METHODS

This retrospective observational study utilised the Leicester one-stop transient TIA clinic patient database to consider the initial systolic and diastolic BP of 688 patients with a diagnosis of AF. The primary outcome was time until death. Covariant measures included status of AF diagnosis (known or new AF), cardiovascular risk factors, and primary clinic diagnosis [cerebrovascular (CV) versus non-cerebrovascular (non-CV)]. Statistical models adjusted for sex, age, previous AF diagnosis.

RESULTS

Mortality rate was higher in the over 85 age group [191.5 deaths per 1000 person years (py) (95% CI 154.0-238.1)] and lower in the aged 75 and younger age group [40.0 deaths per 1000 py (95% CI 27.0-59.2)] compared to intermediate groups. A 10 mmHg increase in supine diastolic BP was associated with a significant reduction in the hazard of mortality for patients suspected of TIA with AF [adjusted HR 0.79 (95% CI 0.68-0.92), p < 0.001]. The mortality rate for patients with OH was 119.0 deaths per 1000 py compared with a rate of 98.0 for patients without OH (rate ratio 1.2, p = 0.275).

CONCLUSION

Higher diastolic BP may be a marker for reduced mortality risk in patients with a previous AF diagnosis and non-CV diagnosis. Lower diastolic BP and the presence of AF pertain to a higher mortality risk. This study raises the importance of opportunistic screening for both OH and AF in patients presenting to TIA clinic.

HIV infection and stroke

The landscape of human immunodeficiency virus (HIV) infection is changing with the increasing coverage of antiretroviral therapy (ART). Patients are living longer but continually exposed to a virologically suppressed HIV infection. This has resulted in a decrease in acquired immune deficiency syndrome (AIDS)-related complications such as opportunistic infections, and an increase in non-AIDS complications such as stroke. In this era, stroke is perhaps the most important neurologic complication of HIV infection. Furthermore, stroke is more of a heterogeneous disease in people living with HIV infection and therefore needs to be approached systematically. Many of the etiologies are treatable. HIV-associated vasculopathy is perhaps the most common etiology in this population and our understanding of this is still evolving. Moreover, the treatment of HIV infection may contribute to an excess risk of stroke and interact with stroke therapies.

Acute Stroke and Transient Ischemic Attack in the Outpatient Clinic

Ischemic stroke is cause of substantial death and disability in the United States. Transient ischemic attack, a precursor to ischemic stroke, conveys a high risk of recurrent stroke within 90 days from event. These conditions are highly preventable and treatable. The cause is heterogenous and includes atherothrombosis, cardioembolism, lacunar disease, or cryptogenic, and some uncommon causes, such as arterial dissection and prothrombotic states. The emergent evaluation includes establishing time of onset, vital signs, glucose level, and severity of the deficit.

Management of acute cerebral ischaemia

Stroke is a major public health issue. Many are treatable in the acute stage, provided patients are admitted soon enough. The overall incidence of stroke in Western countries is approximately 2400 per year per million inhabitants, and 80% are due to cerebral ischaemia. The prevalence is approximately 12,000 per million inhabitants. Stroke is associated with increased long-term mortality, handicap, cognitive and behavioural impairments, recurrence, and an increased risk of other types of vascular events. There is strong evidence that stroke patients should be treated in dedicated stroke units; each time 24 patients are treated in a stroke unit, instead of a conventional ward, one death and one dependence are prevented. This effect does not depend on age, severity, and the stroke subtype. For this reason, stroke unit care is the cornerstone of the treatment of stroke, aiming at the detection and management of life-threatening emergencies, stabilization of most physiological parameters, and prevention of early complications. In cerebral ischaemia, besides this general management, specific therapies include intravenous recombinant tissue plasminogen activator, given as soon as possible and before 4.5hours, mechanical thrombectomy on top of rt-PA or alone in case of contra-indication to rt-PA, in patients with proximal large-vessel occlusion, aspirin 300mg, immediately or after 24hours in case of thrombolysis, and, in a few patients, decompressive surgery.

Towards the identification of blood biomarkers for acute stroke in humans: a comprehensive systematic review

AIMS

Identification of biomarkers for stroke will aid our understanding of its aetiology, provide diagnostic and prognostic indicators for patient selection and stratification, and play a significant role in developing personalized medicine. We undertook the largest systematic review conducted to date in an attempt to characterize diagnostic and prognostic biomarkers in acute ischaemic and haemorrhagic stroke and those likely to predict complications following thrombolysis.

METHODS

A comprehensive literature search was carried out to identify diagnostic and prognostic stroke blood biomarkers. Mean differences (MDs) and 95% confidence intervals (CIs) were calculated for each biomarker.

RESULTS

We identified a total of 141 relevant studies, interrogating 136 different biomarkers. Three biomarkers (C-reactive protein, P-selectin and homocysteine) significantly differentiated between ischaemic stroke and healthy control subjects. Furthermore, glial fibrillary acidic protein levels were significantly different between haemorrhagic stroke and ischaemic stroke patients (MD 224.58 ng l⁻¹; 95% CI 25.84, 423.32; P= 0.03), high levels of admission glucose were a strong predictor of poor prognosis after ischaemic stroke and symptomatic intracerebral haemorrhage post-thrombolysis, glutamate was found to be an indicator of progressive (unstable) stroke (MD 172.65 µmol l⁻¹, 95% CI 130.54, 214.75; P= 0.00001), D-dimer predicted in-hospital death (MD 0.67 µg ml⁻¹, 95% CI 0.35, 1.00; P= 0.0001), and high fibrinogen levels were associated with poor outcome at 3 months (MD 47.90 mg l⁻¹, 95% CI 14.88, 80.93; P= 0.004) following ischaemic stroke.

CONCLUSIONS

Few biomarkers currently investigated have meaningful clinical value. Admission glucose may be a strong marker of poor prognosis following acute thrombolytic treatment. However, molecules released in the bloodstream before, during or after stroke may have potential to be translated into sensitive blood-based tests.