Timing of procedural stroke and death in asymptomatic patients undergoing carotid endarterectomy: individual patient analysis from four RCTs

BACKGROUND

The effectiveness of carotid endarterectomy (CEA) for stroke prevention depends on low procedural risks. The aim of this study was to assess the frequency and timing of procedural complications after CEA, which may clarify underlying mechanisms and help inform safe discharge policies.

METHODS

Individual-patient data were obtained from four large carotid intervention trials (VACS, ACAS, ACST-1 and GALA; 1983-2007). Patients undergoing CEA for asymptomatic carotid artery stenosis directly after randomization were used for the present analysis. Timing of procedural death and stroke was divided into intraoperative day 0, postoperative day 0, days 1-3 and days 4-30.

RESULTS

Some 3694 patients were included in the analysis. A total of 103 patients (2·8 per cent) had serious procedural complications (18 fatal strokes, 68 non-fatal strokes, 11 fatal myocardial infarctions and 6 deaths from other causes) [Correction added on 20 April, after first online publication: the percentage value has been corrected to 2·8]. Of the 86 strokes, 67 (78 per cent) were ipsilateral, 17 (20 per cent) were contralateral and two (2 per cent) were vertebrobasilar. Forty-five strokes (52 per cent) were ischaemic, nine (10 per cent) haemorrhagic, and stroke subtype was not determined in 32 patients (37 per cent). Half of the strokes happened on the day of CEA. Of all serious complications recorded, 44 (42·7 per cent) occurred on day 0 (20 intraoperative, 17 postoperative, 7 with unclear timing), 23 (22·3 per cent) on days 1-3 and 36 (35·0 per cent) on days 4-30.

CONCLUSION

At least half of the procedural strokes in this study were ischaemic and ipsilateral to the treated artery. Half of all procedural complications occurred on the day of surgery, but one-third after day 3 when many patients had been discharged.

Cells respond to deletion of CAV1 by increasing synthesis of extracellular matrix

A range of cellular functions have been attributed to caveolae, flask-like invaginations of the plasma membrane. Here, we have used RNA-seq to achieve quantitative transcriptional profiling of primary embryonic fibroblasts from caveolin 1 knockout mice (CAV1-/- MEFs), and thereby to gain hypothesis-free insight into how these cells respond to the absence of caveolae. Components of the extracellular matrix were decisively over-represented within the set of genes displaying altered expression in CAV1-/- MEFs when compared to congenic wild-type controls. This was confirmed biochemically and by imaging for selected examples. Up-regulation of components of the extracellular matrix was also observed in a second cell line, NIH-3T3 cells genome edited to delete CAV1. Up-regulation of components of the extracellular matrix was detected in vivo by assessing collagen deposition and compliance of CAV1-/- lungs. We discuss the implications of these findings in terms of the cellular function of caveolae.

Mechanisms and mitigating factors for venous thromboembolism in chronic kidney disease: the REGARDS study

Essentials Chronic kidney disease (CKD) is associated with procoagulant and inflammatory biomarkers. We studied the association of CKD and venous thromboembolism (VTE) in a case-cohort study. Factor VIII, D-dimer and C-reactive protein appeared to explain the association of CKD and VTE. Statin use was protective against VTE in those with and without CKD.

SUMMARY

Background Chronic kidney disease (CKD) is associated with venous thromboembolism (VTE) risk via unknown mechanisms. Whether factors associated with reduced VTE risk in the general population might also be associated with reduced VTE risk in CKD patients is unknown. Objectives To determine whether thrombosis biomarkers attenuate VTE risk, and whether factors associated with reduced VTE risk are similarly effective in CKD patients. Methods Baseline biomarkers were measured in a cohort (294 VTE cases; 939 non-cases) from the Reasons for Geographic and Racial Differences in Stroke (REGARDS) study, a nationwide prospective cohort study of 30 239 persons aged ≥45 years with 4.3 years of follow-up. The hazard ratio (HR) of VTE per 10 mL min-1 1.73 m-2 decrease in estimated glomerular filtration rate (eGFR), and the percentage attenuation of this HR by each biomarker, were calculated. Associations of protective factors (physical activity, lower body mass index [BMI], and aspirin, warfarin and statin use) with VTE were estimated in those with and without CKD. Results The HR for VTE with lower eGFR was 1.13 (95% confidence interval [CI] 1.02-1.25), and VTE risk was attenuated by 23% (95% CI 5-100) by D-dimer, by 100% (95% CI 50-100) by factor VIII, and by 15% (95% CI 2-84) by C-reactive protein. Normal BMI was associated with lower VTE risk in those without CKD (HR 0.47, 95% CI 0.32-0.70), but not in those with CKD (HR 1.07, 95% CI 0.51-2.22). Statin use, physical activity and warfarin use were associated with lower VTE risk in both groups. Conclusions Procoagulant and inflammatory biomarkers mediated the association of eGFR with VTE. Higher physical activity, statin use and warfarin use mitigated VTE risk in those with CKD and those without CKD, but normal BMI did not mitigate VTE risk in CKD patients.

Associations of coagulation factors IX and XI levels with incident coronary heart disease and ischemic stroke: the REGARDS study

Essentials Coagulation factors (F) IX and XI have been implicated in cardiovascular disease (CVD) risk. We studied associations of FIX and FXI with incident coronary heart disease (CHD) and stroke. Higher FIX antigen was associated with incident CHD risk in blacks but not whites. Higher levels of FIX antigen may be a CHD risk factor among blacks.

SUMMARY

Background Recent studies have suggested the importance of coagulation factor IX and FXI in cardiovascular disease (CVD) risk. Objectives To determine whether basal levels of FIX or FXI antigen were associated with the risk of incident coronary heart disease (CHD) or ischemic stroke. Patients/Methods The REasons for Geographic And Racial Differences in Stroke (REGARDS) study recruited 30 239 participants across the contiguous USA between 2003 and 2007. In a case-cohort study within REGARDS, FIX and FXI antigen were measured in participants with incident CHD (n = 609), in participants with incident ischemic stroke (n = 538), and in a cohort random sample (n = 1038). Hazard ratios (HRs) for CHD and ischemic stroke risk were estimated with Cox models per standard deviation higher FIX or FXI level, adjusted for CVD risk factors. Results In models adjusting for CHD risk factors, higher FIX levels were associated with incident CHD risk (HR 1.19; 95% confidence interval [CI] 1.01-1.40) and the relationship of higher FXI levels was slightly weaker (HR 1.15; 95% CI 0.97-1.36). When stratified by race, the HR of FIX was higher in blacks (HR 1.39; 95% CI 1.10-1.75) than in whites (HR 1.06; 95% CI 0.86-1.31). After adjustment for stroke risk factors, there was no longer an association of FIX levels with ischemic stroke, whereas the association of FXI levels with ischemic stroke was slightly attenuated. Conclusions Higher FIX antigen levels were associated with incident CHD in blacks but not in whites. FIX levels may increase CHD risk among blacks.

Association of stroke risk biomarkers with stroke symptoms: the Reasons for Geographic and Racial Differences in Stroke cohort

Essentials Stroke symptom history predicts future stroke and may indicate prior unrecognized stroke. We studied associations of stroke symptoms with stroke risk biomarkers. Several stroke risk biomarkers were independently associated with stroke symptom history. Findings support a hypothesis that stroke symptoms may represent unrecognized stroke.

SUMMARY

Background History of stroke symptoms in the absence of prior diagnosed stroke or transient ischemic attack (TIA) is associated with future stroke risk, as are biomarkers of inflammation, cardiac function and hemostasis. Objective To better elucidate the pathobiology of stroke symptoms, we studied associations of these biomarkers with history of stroke symptoms. Methods The Reasons for Geographic and Racial Differences in Stroke (REGARDS) cohort enrolled 30 239 black and white Americans age 45 years and older in 2003-7. In cross-sectional analyses in a random sample of 960 participants without prior stroke or TIA, levels of N-terminal pro-B-type natriuretic peptide (NT-proBNP), fibrinogen, factor VIII (FVIII), factor XI (FXI), C-reactive protein (CRP) and D-dimer were studied in relation to self-reported history of six sudden onset stroke symptoms. Results There were 190 participants with at least one stroke symptom and 770 without. Adjusting for age, race, sex and stroke risk factors, NT-proBNP, FXI, CRP and D-dimer in the top vs. bottom quartile were associated with prevalent stroke symptoms with odds ratios 2.69 (95% confidence interval [CI], 1.45-4.98), 1.65 (95% CI, 1.00-2.73), 2.21 (95% CI, 1.32-3.71) and 2.14 (95% CI, 1.22-3.75), respectively. Conclusions Strong associations of stroke risk biomarkers with stroke symptoms in persons without a clinical history of cerebrovascular disease support a hypothesis that some of these stroke symptoms represent unrecognized cerebrovascular disease. Future work is needed to determine whether these biomarkers identify persons with stroke symptoms who have a particularly high stroke risk.

Healthcare professional requirements for the care of adult diabetes patients managed with insulin pumps in Australia

BACKGROUND

Healthcare professional (HCP) time supporting insulin pump therapy (IPT) has not been documented, yet it is important in planning and allocating resources for effective care.

AIM

This study aims to determine HCP time spent in IPT patient care to inform resource planning for optimal IPT delivery.

METHODS

Twenty-four Australian adult IPT-experienced institutions (14 government funded, seven private, three both) collected data between April 2012 and January 2013 prospectively, including: patient demographics, HCP classification, purpose of HCP-patient interaction, interaction mode and HCP time with the patient. A subset of patients was tracked from pre-pump education until stable on IPT.

RESULTS

Data on 2577 HCP-adult patient interactions (62% face-to-face, 29% remote, 9% administrative) were collected over 12.2 ± 6.4 weeks for 895 patients; age 35.4 ± 14.2 years; 67% female; 99% type 1 diabetes, representing 25% of all IPT patients of the institutions. Time (hours) spent on IPT interactions per centre per week were: nurses 5.4 ± 2.8, dietitians 0.4 ± 0.2 and doctors 1.0 ± 0.5. IPT starts accounted for 48% of IPT interaction time. The percentage of available diabetes clinic time spent on outpatient IPT interactions was 20.4%, 4.6% and 2.7% for nurses, dietitians and doctors respectively. Fifteen patients tracked from pre-pump to stabilisation over 11.8 ± 4.5 weeks, required a median (range) of 9.2 (3.0-20.9), 2.4 (0.5-6.0) and 1.8 (0.5-5.4) hours per patient from nurses, dietitians and doctors respectively.

CONCLUSIONS

IPT patient care represents a substantial investment in HCP time, particularly for nurses. Funding models for IPT care need urgent review to ensure this now mainstream therapy integrates well into healthcare resources.

NeuroThera® Efficacy and Safety Trial-3 (NEST-3): a double-blind, randomized, sham-controlled, parallel group, multicenter, pivotal study to assess the safety and efficacy of transcranial laser therapy with the NeuroThera® Laser System for the treatment of acute ischemic stroke within 24 h of stroke onset

RATIONALE

Transcranial laser therapy is undergoing clinical trials in patients with acute ischemic stroke. The NeuroThera® Efficacy and Safety Trial-1 was strongly positive for 90-day functional benefit with transcranial laser therapy, and post hoc analyses of the subsequent NeuroThera® Efficacy and Safety Trial-2 trial suggested a meaningful beneficial effect in patients with moderate to moderately severe ischemic stroke within 24 h of onset. These served as the basis for the NeuroThera® Efficacy and Safety Trial-3 randomized controlled trial.

AIM

The purpose of this pivotal study was to demonstrate safety and efficacy of transcranial laser therapy with the NeuroThera® Laser System in the treatment of subjects diagnosed with acute ischemic stroke.

DESIGN

NeuroThera® Efficacy and Safety Trial-3 is a double-blind, randomized, sham-controlled, parallel group, multicenter, pivotal study that will enroll 1000 subjects at up to 50 sites. All subjects will receive standard medical management based on the American Stroke Association and European Stroke Organization Guidelines. In addition to standard medical management, both groups will undergo the transcranial laser therapy procedure between 4·5 and 24 h of stroke onset. The study population will be randomized into two arms: the sham control group will receive a sham transcranial laser therapy procedure and the transcranial laser therapy group will receive an active transcranial laser therapy procedure. The randomization ratio will be 1:1 and will be stratified to ensure a balanced subject distribution between study arms.

STUDY OUTCOMES

The primary efficacy end point is disability at 90 days (or the last rating), as assessed on the modified Rankin Scale, dichotomized as a success (a score of 0-2) or a failure (a score of 3 to 6).

Estimating insulin demand for protein-containing foods using the food insulin index

BACKGROUND/OBJECTIVE

The Food Insulin Index (FII) is a novel algorithm for ranking foods on the basis of insulin responses in healthy subjects relative to an isoenergetic reference food. Our aim was to compare postprandial glycemic responses in adults with type 1 diabetes who used both carbohydrate counting and the FII algorithm to estimate the insulin dosage for a variety of protein-containing foods.

SUBJECTS/METHODS

A total of 11 adults on insulin pump therapy consumed six individual foods (steak, battered fish, poached eggs, low-fat yoghurt, baked beans and peanuts) on two occasions in random order, with the insulin dose determined once by the FII algorithm and once with carbohydrate counting. Postprandial glycemia was measured in capillary blood glucose samples at 15-30  min intervals over 3 h. Researchers and participants were blinded to treatment.

RESULTS

Compared with carbohydrate counting, the FII algorithm significantly reduced the mean blood glucose level (5.7±0.2  vs 6.5±0.2 mmol/l, P=0.003) and the mean change in blood glucose level (-0.7±0.2 vs 0.1±0.2 mmol/l, P=0.001). Peak blood glucose was reached earlier using the FII algorithm than using carbohydrate counting (34±5 vs 56±7 min, P=0.007). The risk of hypoglycemia was similar in both treatments (48% vs 33% for FII vs carbohydrate counting, respectively, P=0.155).

CONCLUSIONS

In adults with type 1 diabetes, compared with carbohydrate counting, the novel FII algorithm improved postprandial hyperglycemia after consumption of protein-containing foods.

Can breathing circuit filters help prevent the spread of influenza A (H1N1) virus from intubated patients?

INTRODUCTION

In March 2010, more than 213 countries worldwide reported laboratory confirmed cases of influenza H1N1 infections with at least 16,813 deaths. In some countries, roughly 10 to 30% of the hospitalized patients were admitted to the ICU and up to 70% of those required mechanical ventilation. The question now arises whether breathing system filters can prevent virus particles from an infected patient from entering the breathing system and passing through the ventilator into the ambient air. We tested the filters routinely used in our institution for their removal efficacy and efficiency for the influenza virus A H1N1 (A/PR/8/34).

METHODS

Laboratory investigation of three filters (PALL Ultipor(®) 25, Ultipor(®) 100 and Pall BB50T Breathing Circuit Filter, manufactured by Pall Life Sciences) using a monodispersed aerosol of human influenza A (H1N1) virus in an air stream model with virus particles quantified as cytopathic effects in cultured canine kidney cells (MDCK).

RESULTS

The initial viral load of 7.74±0.27 log10 was reduced to a viral load of ≤2.43 log10, behind the filter. This represents a viral filtration efficiency of ≥99.9995%.

CONCLUSION

The three tested filters retained the virus input, indicating that their use in the breathing systems of intubated and mechanically ventilated patients can reduce the risk of spreading the virus to the breathing system and the ambient air.

NeuroThera® Efficacy and Safety Trial-3 (NEST-3): a double-blind, randomized, sham-controlled, parallel group, multicenter, pivotal study to assess the safety and efficacy of transcranial laser therapy with the NeuroThera® Laser System for the treatment of acute ischemic stroke within 24 h of stroke onset

RATIONALE

Transcranial laser therapy is undergoing clinical trials in patients with acute ischemic stroke. The NeuroThera® Efficacy and Safety Trial-1 was strongly positive for 90-day functional benefit with transcranial laser therapy, and post hoc analyses of the subsequent NeuroThera® Efficacy and Safety Trial-2 trial suggested a meaningful beneficial effect in patients with moderate to moderately severe ischemic stroke within 24 h of onset. These served as the basis for the NeuroThera® Efficacy and Safety Trial-3 randomized controlled trial.

AIM

The purpose of this pivotal study was to demonstrate safety and efficacy of transcranial laser therapy with the NeuroThera® Laser System in the treatment of subjects diagnosed with acute ischemic stroke.

DESIGN

NeuroThera® Efficacy and Safety Trial-3 is a double-blind, randomized, sham-controlled, parallel group, multicenter, pivotal study that will enroll 1000 subjects at up to 50 sites. All subjects will receive standard medical management based on the American Stroke Association and European Stroke Organization Guidelines. In addition to standard medical management, both groups will undergo the transcranial laser therapy procedure between 4·5 and 24 h of stroke onset. The study population will be randomized into two arms: the sham control group will receive a sham transcranial laser therapy procedure and the transcranial laser therapy group will receive an active transcranial laser therapy procedure. The randomization ratio will be 1:1 and will be stratified to ensure a balanced subject distribution between study arms.

STUDY OUTCOMES

The primary efficacy end point is disability at 90 days (or the last rating), as assessed on the modified Rankin Scale, dichotomized as a success (a score of 0-2) or a failure (a score of 3 to 6).