Clinical, lifestyle, socioeconomic determinants and rate of asymptomatic intracranial atherosclerosis in stroke free Pakistanis

Physical Activity Is Inversely Associated With Severe Intracranial Stenosis in Stroke-Free Participants of NOMAS

BACKGROUND

Although protective in secondary stroke prevention of intracranial arterial stenosis (ICAS), it is uncertain if the benefits of leisure time physical activity (LTPA) extend to asymptomatic ICAS or extracranial carotid stenosis (ECAS). Therefore, we sought to determine LTPA's relationship with ECAS and ICAS in a stroke-free, race-ethnically diverse cohort.

METHODS

This cross-sectional study included participants from the magnetic resonance imaging substudy of the Northern Manhattan Study, of whom 1274 had LTPA assessments at enrollment. LTPA was represented continuously as metabolic equivalent score (MET-score) and ordinally as model-based cluster analysis (LTPA-cluster), both based on the same LTPA assessments. We evaluated ECAS sonographically using carotid intima-media thickening and number of carotid plaques. ICAS was assessed with time-of-flight magnetic resonance angiograph and defined as ≥50% or ≥70% stenosis. We applied regression analyses to evaluate the association between LTPA with ECAS and ICAS, adjusting for confounders.

RESULTS

Of 1274 included participants (mean age 71±9 years; 60% women; 65% Hispanic), the mean MET-score was 10±16 and 60% were in a LTPA-cluster with any activity. Among those with carotid ultrasound (n=1234), the mean carotid intima-media thickening was 0.97±0.09 mm, and 56% of participants had at least one carotid plaque identified. Among those with magnetic resonance angiograph (n=1211), 8% had ≥50% ICAS and 5% had ≥70% ICAS. For ICAS, MET-score was associated with ≥70% ICAS (adjusted odds ratio per unit increase in MET-score [95% CI, 0.97 [0.94-0.99]) but not with ECAS measures (carotid intima-media thickening, adjusted β-estimate per unit increase in MET-score [95% CI], 0.002 [-0.003 to 0.006] or number of plaques, adjusted β-estimate [95% CI], 0.0001 [-0.0001 to 0.0003]). Substituting MET-score with LTPA-clusters replicated the association between ≥70% ICAS and LTPA (adjusted odds ratio per each increased LTPA-cluster [95% CI], 0.83 [0.70-0.99]).

CONCLUSIONS

In this diverse stroke-free population, we found LTPA most strongly associated with asymptomatic ≥70% ICAS. Given the high-risk nature of ≥70% ICAS, these findings may emphasize the role of LTPA in people at risk for ICAS.

Clinical and Functional Outcomes of Patients Receiving Cerebral Reperfusion Therapy: A Stroke Databank Study in Brazil

Objectives

Cerebral reperfusion therapy is recommended for the treatment of acute ischemic stroke. However, the outcomes of patients receiving this therapy in middle- and low-income countries should be better defined. This study aimed to evaluate the clinical and functional outcomes of cerebral reperfusion therapy in patients with ischemic stroke.

Materials and Methods

This retrospective study included patients with ischemic stroke treated with cerebral reperfusion therapy, including intravenous thrombolysis (IVT), mechanical thrombectomy (MT), and IVT with MT. The primary outcomes were death and disability, assessed using the modified Rankin scale (mRS), and stroke severity, assessed using the National Institutes of Health Stroke Scale (NIHSS), after intervention and 90 days after ictus. The association between the type of treatment and the primary outcome was assessed using binary logistic regression after adjusting for confounding variables. Furthermore, receiver operating characteristic (ROC) curves were generated to identify the cutoff point of the NIHSS score that could best discriminate the mRS score in all types of treatments.

Results

Patients (n = 291) underwent IVT only (n = 241), MT (n = 21), or IVT with MT (n = 29). In the IVT with MT group, the incidence of death within 90 days increased by five times (OR, 5.192; 95% CI, 2.069-13.027; p = 0.000), prevalence of disability increased by three times (OR, 3.530; 95% CI, 1.376-9.055; p = 0.009) and NIHSS score increased after IVT (from 14.4 ± 6.85 to 17.8 ± 6.36; p = 0.045). There was no significant difference between the initial NIHSS score and that after MT (p = 0.989). Patients' NIHSS score that increased or decreased by 2.5 points had a sensitivity of 0.74 and specificity of 0.65, indicating severe disability or death in these patients.

Conclusion

Altogether, a 2.5-point variation in NIHSS score after reperfusion is an indicator of worse outcomes. In our particular context, patients receiving the combination of IVT and MT had inferior results, which probably reflects challenges to optimize MT in LMIC.

Risk Factors for Asymptomatic and Symptomatic Intracranial Atherosclerosis Determined by Magnetic Resonance Vessel Wall Imaging in Chinese Population: A Case–Control Study

Background and Purpose

The association between risk factors and intracranial atherosclerosis disease (ICAD) determined by magnetic resonance (MR) vessel wall imaging in Chinese population has not been investigated. The aim of this study was to investigate the associations of conventional vascular risk factors with asymptomatic and symptomatic ICAD using MR vessel wall imaging in Chinese population.

Methods

The study population was recruited from two cohort studies of ICASMAP and CAMERA comprised 104 symptomatic ICAD subjects (57.1 ± 11.1 years; 35.6% females), 51 asymptomatic ICAD subjects (70.1 ± 8.4 years; 50.0% females) and 418 controls (58.0 ± 13.3 years; 61.0% females) defined as asymptomatic subjects without ICAD on MR vessel wall imaging. We compared the vascular risk factors between the three groups using a multivariate logistic regression analysis.

Results

Compared with controls, there was a significant positive association between age (OR: 1.07, 95% CI: 1.03–1.10, p < 0.001) and hypertension (OR: 3.03, 95% CI: 1.45–6.36, p = 0.003) and asymptomatic ICAD. There was a positive association of smoking (OR: 3.41, 95% CI: 1.57–7.42, p = 0.001), hypertension (OR: 7.43, 95% CI: 3.81–14.49, p < 0.001) and diabetes (OR: 3.54, 95% CI: 1.93–6.49, p < 0.001) and an inverse association of high-density lipoprotein (HDL) (p < 0.017) with symptomatic ICAD. Compared to asymptomatic ICAD, there was a significant inverse association of age (OR: 0.86, 95% CI: 0.81–0.92, p < 0.001) and HDL (p < 0.001) with symptomatic ICAD.

Conclusion

Old age and hypertension are associated with asymptomatic ICAD and smoking, hypertension, diabetes and lower HDL are associated with an increased risk of symptomatic ICAD in Chinese population.

Clinical Trial Registration

URL: http://www.clinicaltrials.gov. Unique identifier: NCT03417063.

Association of smokeless tobacco and cerebrovascular accident: a systematic review and meta-analysis of global data

BACKGROUND

The association of smokeless tobacco (SLT) with stroke has been dealt with in only a few reviews. The present meta-analysis aims to present the updated comprehensive summary risk of stroke in adult SLT users along with sub group analysis.

METHODS

A systematic literature search for articles evaluating risk of stroke in SLT users was conducted. The study characteristics and risk estimates were extracted independently by two authors (RG and SG). Random-effect model was used to estimate the summary relative risks.

RESULTS

The overall risk of stroke in SLT users was found to be significantly higher (1.17, 95% CI 1.04–1.30) compared to non-users, especially for users in Southeast Asian region. The results remained unchanged even after strict adjustment for smoking (1.18, 95% CI 1.04–1.32). SLT users had 1.34 times or 13.4% higher risk of fatal stroke, though risk of nonfatal stroke was not enhanced. Significantly higher risk of stroke was seen in users of chewing tobacco (1.35, 95% CI 1.20–1.50) in comparison to non-chewers. Gender-based analysis showed enhanced risk of fatal stroke in both male and female users. SLT-attributable fraction of fatal stroke was highest for India at 14.8%.

CONCLUSION

The significant higher risk of stroke with SLT use, even after adjustment for smoking, emphasizes the imperative need to include SLT cessation advice for control and prevention of stroke.

Intracranial atherosclerotic disease

Intracranial atherosclerosis (ICAS) is a progressive pathological process that causes progressive stenosis and cerebral hypoperfusion and is a major cause of stroke occurrence and recurrence around the world. Multiple factors contribute to the development of ICAS. Angiography imaging techniques can improve the diagnosis of and the selection of appropriate treatment regimens for ICAS. Neither aggressive medication nor endovascular interventions can eradicate stroke recurrence in patients with ICAS. Non-pharmacological therapies such as remote ischemic conditioning and hypothermia are emerging. Comprehensive therapy with medication in combination with endovascular intervention and/or non-pharmacological treatment may be a potential strategy for ICAS treatment in the future. We summarized the epidemiology, pathophysiological mechanisms, risk factors, biomarkers, imaging and management of ICAS.

Strategies to Improve Stroke Care Services in Low- and Middle-Income Countries: A Systematic Review

Background: The burden of stroke in low- and middle-income countries (LMICs) is large and increasing, challenging the already stretched health-care services. Aims and Objectives: To determine the quality of existing stroke-care services in LMICs and to highlight indigenous, inexpensive, evidence-based implementable strategies being used in stroke-care. Methods: A detailed literature search was undertaken using PubMed and Google scholar from January 1966 to October 2015 using a range of search terms. Of 921 publications, 373 papers were shortlisted and 31 articles on existing stroke-services were included. Results: We identified efficient models of ambulance transport and pre-notification. Stroke Units (SU) are available in some countries, but are relatively sparse and mostly provided by the private sector. Very few patients were thrombolysed; this could be increased with telemedicine and governmental subsidies. Adherence to secondary preventive drugs is affected by limited availability and affordability, emphasizing the importance of primary prevention. Training of paramedics, care-givers and nurses in post-stroke care is feasible. Conclusion: In this systematic review, we found several reports on evidence-based implementable stroke services in LMICs. Some strategies are economic, feasible and reproducible but remain untested. Data on their outcomes and sustainability is limited. Further research on implementation of locally and regionally adapted stroke-services and cost-effective secondary prevention programs should be a priority.

An Examination of Stroke Risk and Burden in South Asians

BACKGROUND

South Asians (India, Pakistan, Sri Lanka, Bangladesh, Nepal, and Bhutan) are at a disproportionately higher risk of stroke and heart disease due to their cardiometabolic profile. Despite evidence for a strong association between diabetes and stroke, and growing stroke risk in this ethnic minority-notwithstanding reports of higher stroke mortality irrespective of country of residence-the explanation for the excess risk of stroke remains unknown.

METHODS

We have used extensive literature review, epidemiologic studies, morbidity and mortality records, and expert opinions to examine the burden of stroke among South Asians, and the risk factors identified thus far.

RESULTS

We summarize existing evidence and indicate gaps in current knowledge of stroke epidemiology among South Asian natives and immigrants.

CONCLUSIONS

This research focuses attention on a looming epidemic of stroke mainly due to modifiable risk factors, but also new determinants that might aggravate the effect of vascular risk factors in South Asians causing more disabling strokes and death.

Quality of life after stroke in Pakistan

Background

There is very little information about the quality of life (QOL) of stroke survivors in LMIC countries with underdeveloped non communicable health infrastructures, who bear two thirds of the global stroke burden.

Methodology

We used a sequential mix methods approach. First, a quantitative analytical cross-sectional study was conducted on 700 participants, who constituted 350 stroke survivor and their caregiver dyads. QOL of stroke survivor was assessed via Stroke Specific Quality of Life Scale (SSQOLS) whereas QOL of caregivers was assessed through RAND-36. In addition; we assessed complications, psychosocial and functional disability of stroke survivors. Following this quantitative survey, caregivers were qualitatively interviewed to uncover contextually relevant themes that would evade quantitative surveys. Multiple linear regression technique was applied to report adjusted β-coefficients with 95% C.I.

Results

The QOL study was conducted from January 2014 till June 2014, in two large private and public centers. At each center, 175 dyads were interviewed to ensure representativeness. Median age of stroke survivors was 59(17) years, 68% were male, 60% reported depression and 70% suffered post-stroke complications. The mean SSQOLS score was 164.18 ± 32.30. In the final model severe functional disability [adjβ -33.77(-52.44, -15.22)], depression [adjβ-23.74(-30.61,-16.82)], hospital admissions [adjβ-5.51(-9.23,-1.92)] and severe neurologic pain [adjβ -12.41(-20.10,-4.77)] negatively impacted QOL of stroke survivors (P < 0.01).

For caregivers, mean age was 39.18 ± 13.44 years, 51% were female and 34% reported high stress levels. Complementary qualitative study revealed that primary caregivers were depressed, frustrated, isolated and also disappointed by health services.

Conclusion

The QOL of Stroke survivors as reported by SSQOLS score was better than compared to those reported from other LMIC settings. However, Qualitative triangulation revealed that younger caregivers felt isolated, depressed, overwhelmed and were providing care at great personal cost. There is a need to develop cost effective holistic home support interventions to improve lives of the survivor dyad as a unit.

Trial registration

NCT02351778 (Registered as Observational Study).

Electronic supplementary material

The online version of this article (doi:10.1186/s12883-016-0774-1) contains supplementary material, which is available to authorized users.

Rationale for ischemic conditioning to prevent stroke in patients with intracranial arterial stenosis

Intracranial atherosclerotic arterial stenosis (ICAS) is one of the most common causes of stroke worldwide and is associated with particularly a high risk of recurrent stroke. Although aggressive medical management, consisting of dual antiplatelet therapy and intensive control of vascular risk factors, has improved the prognosis of patients with ICAS, subgroups of patients remain at very high risk of stroke. More effective therapies for these high-risk patients are urgently needed. One promising treatment is remote limb ischemic conditioning, which involves producing repetitive, transient ischemia of a limb by inflating a blood pressure cuff with the intention of protecting the brain from subsequent ischemia. In this study, we review the limitations of currently available treatments, discuss the potential mechanisms of action of ischemic conditioning, describe the preclinical and clinical data suggesting a possible role of ischemic conditioning in treating patients with ICAS, and outline the questions that still need to be answered in future studies of ischemic conditioning in subjects with ICAS.

The association between ankle-brachial index and asymptomatic cranial-carotid stenosis: a population-based, cross-sectional study of 5440 Han Chinese

BACKGROUND AND PURPOSE

Routine screening for asymptomatic cranial-carotid stenosis (ACCS) is controversial and recommendation in clinical practice is vague. The ankle-brachial index (ABI) is reported as a predictor for cardiovascular disease. However, there is a scarcity of data about the association between abnormal ABI and ACCS. A population-based cross-sectional study was conducted to explore the relationship between ABI and ACCS.

METHODS

A sample of 5440 Chinese adults aged 40-94 years old was recruited from 2010 to 2011. The ABI was measured using a portable Doppler device and ACCS was evaluated by bilateral carotid duplex ultrasound and portable examination devices. A logistic regression model was used to analyse the association between ABI and ACCS after adjusting for potential confounding factors.

RESULTS

A low ABI was associated with ACCS [odds ratio (OR) 1.95, 95% confidence interval (CI) 1.42-2.67] after adjusting for potential confounders. When the data were stratified by age and sex, the correlation remained statistically significant in the male (OR 2.32, 95% CI 1.60-3.37) and elderly (OR 3.07, 95% CI 1.97-4.78) subgroups compared to the female (OR 1.26, 95% CI 0.67-2.39) and middle-aged groups (OR 1.27, 95% CI 0.77-2.12), respectively.

CONCLUSION

This study demonstrated that low ABI is a significant risk factor for ACCS in male and elderly Chinese adults.