Accuracy of cuff blood pressure and systolic blood pressure amplification

Automated cuff measured blood pressure (BP) is the global standard used for diagnosing hypertension, but there are concerns regarding the accuracy of the method. Individual variability in systolic BP (SBP) amplification from central (aorta) to peripheral (brachial) arteries could be related to the accuracy of cuff BP, but this has never been determined and was the aim of this study. Automated cuff BP and invasive brachial BP were recorded in 795 participants (74% male, aged 64 ± 11 years) receiving coronary angiography at five independent research sites (using seven different automated cuff BP devices). SBP amplification was recorded invasively by catheter and defined as brachial SBP minus aortic SBP. Compared with invasive brachial SBP, cuff SBP was significantly underestimated (130 ± 18 mmHg vs. 138 ± 22 mmHg, p < 0.001). The level of SBP amplification varied significantly among individuals (mean ± SD, 7.3 ± 9.1 mmHg) and was similar to level of difference between cuff and invasive brachial SBP (mean difference -7.6 ± 11.9 mmHg). SBP amplification explained most of the variance in accuracy of cuff SBP (R2 = 19%). The accuracy of cuff SBP was greatest among participants with the lowest SBP amplification (ptrend < 0.001). After cuff BP values were corrected for SBP amplification, there was a significant improvement in the mean difference from the intra-arterial standard (p < 0.0001) and in the accuracy of hypertension classification according to 2017 ACC/AHA guideline thresholds (p = 0.005). The level of SBP amplification is a critical factor associated with the accuracy of conventional automated cuff measured BP.

Aortic stenosis and transcatheter aortic valve implantation in the elderly

BACKGROUND

Severe aortic stenosis (AS) is a condition that commonly affects elderly Australians. Once symptomatic, severe AS has a poor prognosis if untreated. Transcatheter aortic valve implantation (TAVI) is a percutaneous procedure that is now the recommended treatment for elderly patients with severe AS who are suitable for intervention.

OBJECTIVE

This article provides a contemporary review of the diagnosis and management of severe AS in the elderly.

DISCUSSION

Management options for severe AS include TAVI, surgical aortic valve replacement (SAVR), or medical/palliative therapy. In elderly adults, TAVI improves mortality, symptoms and quality of life compared with medical therapy, and is superior to SAVR. The decision regarding which management option is most appropriate for an individual patient is made using a collaborative multidisciplinary approach. General practitioners play key roles in providing information to risk stratify patients when considering intervention, caring for patients after the procedure and/or providing medical and palliative treatment for those deemed unsuitable for intervention.

[89Zr]-immuno-PET prediction of response to rituximab treatment in patients with therapy refractory interstitial pneumonitis: a phase 2 trial

INTRODUCTION

Immune-mediated interstitial pneumonitis may be treated with anti-CD20 therapy after failure of conventional therapies. However, clinical response is variable. It was hypothesized that autoreactive CD20-positive cells may play an important role in this variability. This prospective study aims to elucidate if imaging of CD20-positive cells in the lungs allows prediction of the response to anti-CD20 treatment.

METHODS

Twenty-one patients with immune-mediated interstitial lung disease (ILD) with deteriorated pulmonary function received a dose of 1000 mg rituximab on day 1 and day 14 spiked with a tracer dose of radiolabeled [89Zr]-rituximab. PET/CT was performed on days 3 and 6. Standardized uptake values (SUV) were calculated as a measure for pulmonary CD20 expression. Based on pulmonary function tests (PFT), forced vital capacity (FVC), and diffusing capacity for carbon monoxide (DLCO), prior to and 6 months after treatment, patients were classified as responder (stable disease or improvement) or non-responder.

RESULTS

Fifteen patients (71%) were classified as responder. Pulmonary [89Zr]-rituximab PET SUVmean was significantly correlated with the change in FVC and DLCO (K = 0.49 and 0.56, respectively) when using target-to-background ratios, but not when using SUVmean alone. [89Zr]-rituximab SUVmean was significantly higher in responders than in non-responders (0.35 SD 0.09 vs. 0.23 SD 0.06; P = 0.02).

CONCLUSION

Rituximab treatment was effective in the majority of patients. As a higher pulmonary uptake of [89Zr]-rituximab correlated with improvement of PFT and treatment outcome, [89Zr]-rituximab PET imaging may serve as a potential predictive biomarker for anti-CD20 therapy.

TRIAL REGISTRATION

Clinicaltrials.gov identifier NCT02251964.

Dedicated Next Day Discharge Post Minimalist TAVI: The Tasmanian Experience

OBJECTIVES

To assess the safety, feasibility and independent predictors of next day discharge (NDD) in patients undergoing minimalist transcatheter aortic valve implantation (TAVI) for severe aortic stenosis (AS) in a real-world Australian population.

METHODS

This single centre study reviewed 135 consecutive patients who underwent minimalist transfemoral TAVI from June 2020 to February 2022. Baseline demographics, procedural characteristic and outcomes were obtained. All patients were assessed by the local protocol for NDD. Patients were then divided into two groups: those who achieved next day discharge (NDD) and those requiring >1 overnight hospital stay. Univariate, bivariate and stepwise multivariate logistic regression modelling was used to identify the predictors of successful next day discharge.

RESULTS

The mean age of the cohort was 82.9±5.7 years with 62.3% patients male, the average STS score was 4.1±2.4. All 135 patients underwent a successful transfemoral TAVI procedure, with 131 (97%) receiving a balloon-expandable valve. Ninety-seven (97) (71.9%) patients achieved NDD. Thirty (30)-day outcomes were excellent with a 30-day mortality of 0.7%, transient ischaemic attack/cardiovascular accident (TIA/CVA) 1.5%, major vascular complication 1.5% and 11.4% need for permanent pacemaker (PPM). In patients not achieving NDD, the average length of stay (LOS) was 3.0 days. Baseline characteristics demonstrated pre-existing first degree atrioventricular (AV) block and right bundle branch block (RBBB) as statistically significant negative predictors of NDD on univariate analysis. Next day discharge was achievable in only 50% of patients who suffered any minor or major procedural complication (15/30). Stepwise multivariate logistic regression modelling demonstrated female gender (OR 3.094, 95% CI 1.141-8.391, p=0.026), smaller aortic valve area (AVA) (OR 48.265, 95% CI 2.269-102.6, p=0.013), the presence of diabetes mellitus (OR 0.594, 95% CI 0.356-0.991, p=0.046) and a longer procedure time (OR 0.960, 95% CI 0.935-0.986, p=0.002) as statistically significant negative predictors of NDD. In addition, there was no difference in 30-day readmission rates between the NDD and non-NDD cohort (7.2% vs 10.5%, p=0.386).

CONCLUSION

Next day discharge is safe and feasible in almost three quarters of patients undergoing minimalist TAVI for severe AS in a predominantly balloon expandable valve cohort, with a very low rate of 30-day readmission. NDD provides advantages for hospital efficiency and improved cost-effectiveness. Female gender, smaller AVA, the presence of diabetes mellitus and a longer procedure time were independent negative predictors of successful NDD.

Comparison between cuff-based and invasive systolic blood pressure amplification

OBJECTIVE

Accurate measurement of central blood pressure (BP) using upper arm cuff-based methods is associated with several factors, including determining the level of systolic BP (SBP) amplification. This study aimed to determine the agreement between cuff-based and invasively measured SBP amplification.

METHODS

Patients undergoing coronary angiography had invasive SBP amplification (brachial SBP - central SBP) measured simultaneously with cuff-based SBP amplification using a commercially available central BP device (device 1: Sphygmocor Xcel; n = 171, 70% men, 60 ± 10 years) and a now superseded model of a central BP device (device 2: Uscom BP+; n = 52, 83% men, 62 ± 10 years).

RESULTS

Mean difference (±2SD, limits of agreement) between cuff-based and invasive SBP amplification was 4 mmHg (-12, +20 mmHg, P < 0.001) for device 1 and -2 mmHg (-14, +10 mmHg, P = 0.10) for device 2. Both devices systematically overestimated SBP amplification at lower levels and underestimated at higher levels of invasive SBP amplification, but with stronger bias for device 1 (r = -0.68 vs. r = -0.52; Z = 2.72; P = 0.008). Concordance of cuff-based and invasive SBP amplification across quartiles of invasive SBP amplification was low, particularly in the lowest and highest quartiles. The root mean square errors from regression between cuff-based central SBP and brachial SBP were significantly lower (indicating less variability) than from invasive regression models (P < 0.001).

CONCLUSIONS

Irrespective of the difference from invasive measurements, cuff-based estimates of SBP amplification showed evidence of proportional systematic bias and had less individual variability. These observations could provide insights on how to improve the performance of cuff-based central BP.

Colchicine and quality of life in patients with acute coronary syndromes: Results from the COPS randomized trial

BACKGROUND

Recent data suggest that colchicine may reduce cardiovascular events among patients presenting with acute coronary syndromes. This sub-study of the Australian COPS trial aimed to assess whether colchicine affects health status outcomes.

METHODS

Health status was assessed at baseline and 12-months using the EuroQol-5 Dimension 5-level (EQ-5D-5L) score and the full 19-question Seattle Angina Questionnaire (SAQ). Data were available for 786 patients (388 randomized to colchicine, 398 to placebo).

RESULTS

Baseline characteristics were well matched between groups; mean age was 60.1 (SD 14.8) years, and 20 % were female. Baseline health status scores were impaired, and most parameters demonstrated significant improvement from baseline to 12-months (EQ-5D-5L Visual Analogue Score [VAS] 69.3 to 77.7; SAQ angina frequency score 83.0 to 95.3, both p < 0.001). No significant differences in adjusted mean score change among any of the EQ-5D-5L or SAQ dimensions were observed between treatment groups in either intention-to-treat or per-protocol analysis. There were borderline interactions in EQ-5D-5L scores for those with previous MI vs not, and in SAQ scores for those with obesity vs not. In categorical analysis using observed data, patients treated with colchicine were more likely to have clinically significant improvement in physical limitation score over the period (36 % improved vs. 28 %, p < 0.05). Baseline health status scores were not associated with the primary endpoint at 12 months.

CONCLUSIONS

Treatment with colchicine did not appear to affect change in measures of health status following acute coronary syndromes, but it did lead to a greater likelihood of improvement in physical limitation scores.

TRIAL REGISTRATION

ACTRN, ACTRN12615000861550. Registered 18/08/2015, https://www.anzctr.org.au/Trial/Registration/TrialReview.aspx?id=368973.

Colchicine and quality of life in patients with acute coronary syndromes: results from the COPS randomized trial

Background

Recent data suggest that colchicine may reduce cardiovascular events among patients presenting with acute coronary syndromes. This sub-study of the Australian COPS trial aimed to assess whether colchicine affects health status outcomes.

Methods

Health status was assessed at baseline and 12-months using the EuroQol-5 Dimension 5-level (EQ-5D-5L) score and the full 19-question Seattle Angina Questionnaire (SAQ). Data were available for 786 patients (388 randomized to colchicine, 398 to placebo).

Results

Baseline characteristics were well matched between groups; mean age was 60.1 (SD 14.8) years, and 20% were female. Baseline health status scores were impaired, and most parameters demonstrated significant improvement from baseline to 12-months (EQ-5D-5L Visual Analogue Score [VAS] 69.3 to 77.7; SAQ angina frequency score 83.0 to 95.3, both p&lt;0.001). No significant differences in adjusted mean score change among any of the EQ-5D-5L or SAQ dimensions were observed between treatment groups in either intention-to-treat or per-protocol analysis. There were borderline interactions in EQ-5D-5L scores for those with previous MI vs not, and in SAQ scores for those with obesity vs not. In categorical analysis using observed data, patients treated with colchicine were more likely to have clinically significant improvement in physical limitation score over the period (36% improved vs. 28%, P&lt;0.05). Baseline health status scores were not associated with the primary endpoint at 12 months.

Conclusions

Treatment with colchicine did not appear to affect change in measures of health status following acute coronary syndromes, but it did lead to a greater likelihood of improvement in physical limitation scores.

Funding Acknowledgement

Type of funding sources: Public hospital(s). Main funding source(s): Peninsula Health, Monash University

Migration towards Bangladesh coastlines projected to increase with sea-level rise through 2100

To date, projections of human migration induced by sea-level change (SLC) largely suggest large-scale displacement away from vulnerable coastlines. However, results from our model of Bangladesh suggest counterintuitively that people will continue to migrate toward the vulnerable coastline irrespective of the flooding amplified by future SLC under all emissions scenarios until the end of this century. We developed an empirically calibrated agent-based model of household migration decision-making that captures the multi-faceted push, pull and mooring influences on migration at a household scale. We then exposed ~4800 000 simulated migrants to 871 scenarios of projected 21st-century coastal flooding under future emissions pathways. Our model does not predict flooding impacts great enough to drive populations away from coastlines in any of the scenarios. One reason is that while flooding does accelerate a transition from agricultural to non-agricultural income opportunities, livelihood alternatives are most abundant in coastal cities. At the same time, some coastal populations are unable to migrate, as flood losses accumulate and reduce the set of livelihood alternatives (so-called 'trapped' populations). However, even when we increased access to credit, a commonly-proposed policy lever for incentivizing migration in the face of climate risk, we found that the number of immobile agents actually rose. These findings imply that instead of a straightforward relationship between displacement and migration, projections need to consider the multiple constraints on, and preferences for, mobility. Our model demonstrates that decision-makers seeking to affect migration outcomes around SLC would do well to consider individual-level adaptive behaviors and motivations that evolve through time, as well as the potential for unintended behavioral responses.

Colchicine in Patients With Acute Coronary Syndrome

Background:

Inflammation plays a crucial role in clinical manifestations and complications of acute coronary syndromes (ACS). Colchicine, a commonly used treatment for gout, has recently emerged as a novel therapeutic option in cardiovascular medicine owing to its anti-inflammatory properties. We sought to determine the potential usefulness of colchicine treatment in patients with ACS.

Methods:

This was a multicenter, randomized, double-blind, placebo-controlled trial involving 17 hospitals in Australia that provide acute cardiac care service. Eligible participants were adults (18–85 years) who presented with ACS and had evidence of coronary artery disease on coronary angiography managed with either percutaneous coronary intervention or medical therapy. Patients were assigned to receive either colchicine (0.5 mg twice daily for the first month, then 0.5 mg daily for 11 months) or placebo, in addition to standard secondary prevention pharmacotherapy, and were followed up for a minimum of 12 months. The primary outcome was a composite of all-cause mortality, ACS, ischemia-driven (unplanned) urgent revascularization, and noncardioembolic ischemic stroke in a time to event analysis.

Results:

A total of 795 patients were recruited between December 2015 and September 2018 (mean age, 59.8±10.3 years; 21% female), with 396 assigned to the colchicine group and 399 to the placebo group. Over the 12-month follow-up, there were 24 events in the colchicine group compared with 38 events in the placebo group ( P =0.09, log-rank). There was a higher rate of total death (8 versus 1; P =0.017, log-rank) and, in particular, noncardiovascular death in the colchicine group (5 versus 0; P =0.024, log-rank). The rates of reported adverse effects were not different (colchicine 23.0% versus placebo 24.3%), and they were predominantly gastrointestinal symptoms (colchicine, 23.0% versus placebo, 20.8%).

Conclusions:

The addition of colchicine to standard medical therapy did not significantly affect cardiovascular outcomes at 12 months in patients with ACS and was associated with a higher rate of mortality.

Registration:

URL: https://www.anzctr.org.au ; Unique identifier: ACTRN12615000861550.

Clinical outcomes of self-expandable vs. balloon-expandable TAVI for severe aortic stenosis

Background: Transcatheter aortic valve implantation (TAVI) is an established therapy for patients with severe aortic stenosis (AS). There is limited data exploring differences in outcomes post-TAVI SEV vs. BEV. This study compared procedural success and 30-d clinical outcomes self-expandable valves (SEV), vs. balloon-expandable valves (BEV) for patients with severe AS.Methods: Retrospective analysis was undertaken of patients receiving TAVI at St Vincent's Hospital, Melbourne between August 2009 and May 2018. The primary endpoints included procedural success, clinical outcomes and complication rates at 30-d.Results: Out of 151 patients undergoing TAVI, 70 received (46.3%) SEV (Medtronic CoreValve & Evolut-R) and 81 (53.6%) BEV (Edwards SAPIEN-XT & S3). The mean Society of Thoracic Surgery (STS) risk score did not differ between the groups, SEV (83.6 ± 4.9 years, STS 4.4 ± 3.8) compared to BEV (82.3 ± 5.8 years, STS 4.9 ± 4.9). Procedural success was similar SEV 67 (95.7%) vs. BEV 78 (96.3%). Rates of ≥ moderate paravalvular aortic regurgitation (PAR) at 30-d were significantly higher in SEV compared to BEV (6.7 vs. 0.0%; p = .02). SEV patients had higher rates of pacemaker insertion (36.4 vs. 9.5%; p = .001) and stroke rates (12.4 vs. 1.4%; p = .04) compared to BEV patients. The difference in 30-d mortality between the two groups was similar (SEV 4.6% vs. BEV 1.3%; p = .23).Conclusions: This real-world retrospective analysis demonstrates higher rates of ≥ moderate PAR, stroke and pacemaker insertion with SEV compared to BEV at 30 d post-TAVI for severe symptomatic AS.

Transcatheter Aortic Valve-in-Valve Implantation Complicated by Aorto-Right Ventricular Fistula

We describe the case of a degenerative, sutureless bioprosthetic valve (BPV) with deformation and stent infolding in a patient with elevated surgical risk. Following discussion among the heart team, balloon valve fracture was performed to facilitate deployment of an aortic valve-in-valve transcatheter heart valve. Post-procedural imaging demonstrated BPV frame protrusion and contained annular rupture, which required operative intervention. (Level of Difficulty: Intermediate.).

Indirect Annuloplasty to Treat Functional Mitral Regurgitation: Current Results and Future Perspectives

The incidence of mitral regurgitation (MR) is approximately 1.7% in the developed world, and this increases to more than 10% in patients aged over 75 years. Functional (or secondary) mitral regurgitation (FMR) is defined as poor leaflet coaptation and tethering secondary to either ischemic or non-ischemic left ventricular (LV) dysfunction and dilatation. FMR is more common than degenerative (or primary) MR and is associated with significantly worse outcomes in patients with heart failure, post myocardial infarction and following coronary artery bypass graft surgery. Patients with severe degenerative MR have excellent outcomes with surgical repair, however the benefits of surgery in FMR are less clear. Although annuloplasty is associated with a lower operative mortality compared to replacement, the recurrence rate of mitral regurgitation is high in patients with FMR and neither surgical repair or replacement have been shown to reduce hospitalisation or death in FMR. Furthermore, nearly half of patients are deemed too high risk for surgery and therefore most patients are managed conservatively and there remains an unmet clinical need. Transcatheter mitral valve interventions are an emerging alternative for those at high surgical risk. This mini review focuses on indirect mitral annuloplasty: anatomical considerations, patient selection, current devices, implantation techniques and the associated clinical outcome data.

Impact of the Cox-Maze IV Procedure on Left Atrial Mechanical Function

BACKGROUND

The Cox-Maze IV procedure is a proven surgical treatment for atrial fibrillation (AF). Previous studies on the procedure and its effect on left atrial mechanical function have yielded mixed results.

METHODS

Sixty-four (64) patients underwent Cox-Maze IV at St Vincent's Hospital, Melbourne between March 2010 and May 2016. Baseline characteristics were collected and outcomes assessed including rhythm analysis. Preoperative and postoperative transthoracic echocardiograms were reviewed.

RESULTS

Fifty-seven (57) patients had complete follow-up with all clinical measures collected. The mean age was 71.1±10.2years, 63% being male. Fifty-eight per cent (58%) (33/57) of patients were in AF and 42% (24/57) in sinus rhythm (SR) at preoperative transthoracic echocardiography. Follow-up postoperative transthoracic echocardiography was performed at a mean of 2.3±1.9years. Nineteen (19) patients with a history of paroxysmal AF were in SR both preoperatively and postoperatively. In these patients, there was a significant decrease in Mitral A wave 0.63±0.28m/s (pre-op) vs 0.47±0.29m/s (post-op), p=0.044. There was a significant decrease in left ventricular ejection fraction (LVEF) postoperatively 64.2±9.7% vs 55.0±12.9%, p=0.005. At follow-up, 28% (16/57) were in AF, 61% (35/57) in SR, and 11% (6/57) in a paced rhythm. In a multivariate analysis, predictors of AF recurrence included higher LA volumes (p=0.042) and younger age at surgery p=0.030. Preoperative AF, sex and LVEF had no impact on AF recurrence.

CONCLUSIONS

The Cox-Maze IV procedure, while effective in converting patients to sinus rhythm, may reduce left atrial mechanical function in patients with paroxysmal AF.

Risk perception of hepatitis B infection and uptake of hepatitis B vaccine among students of tertiary institution in Jos

Background:

Hepatitis B virus (HBV) Infection is endemic in Nigeria. Healthcare students are more vulnerable because of direct contact with patients’ body fluids and blood. Risk perception of HBV and HB vaccine uptake are also poor. The aim of this study was to assess the level of risk perception of hepatitis B infection, and uptake of the HBV vaccine, between medical and other students of the University of Jos.

Methods:

A comparative cross sectional study was conducted among 1,200 students of the departments of Medicine, Nursing sciences and Public Administration, University of Jos (400 from each arm) using a pretested self-administered questionnaire. A five point Likert scoring system was used to assess risk perception. Data was analyzed using SPSS version 20. A P -value of <0.05 was considered significant.

Results:

Awareness on HB vaccine prevention was high (88.4%) among University of Jos students. Awareness was similar among medical and nursing students (36.2% and 36.0% respectively) but lower among public administration student (27.8%), P < 0.001. The overall risk perception was 76.8%. This was also similar for medical and nursing students (40.7% and 40.1% respectively), but lower for public administration students (9.1%), P < 0.001. Risk perception is 5x higher among medical students compared to public administration students (OR = 5.22, 95% CI = 2.19 – 12.93; P < 0.001). The uptake of full dose HB vaccine was 60.2%, 20.6% and 15.1% for medical, nursing and public administration students respectively. Medical students are 4x more likely to go for HB vaccination compared with public administration students (OR=3.62; 95% CI=2.39 – 5.48; P < 0.001).

Conclusions:

Awareness and risk perception on HBV infection are high among University of Jos students, but uptake of HB vaccine is low. Findings are worst for non-health students.

Radiation Therapy Induced Cardiovascular Disease

Contemporary treatment modalities for malignancy including radiation therapy have led to improved survival. However treatment related complications manifesting later in life including cardiovascular disease has led to survivors exhibiting a lower long term survival rate, when compared to age matched controls. This narrative review will discuss the pathophysiology, risk factors, clinical presentation, management and preventative techniques related to radiotherapy-induced cardiotoxicity.

Different patients, different outcomes: A case-control study of spontaneous coronary artery dissection versus acute coronary syndrome

INTRODUCTION

There is progressive interest worldwide in spontaneous coronary artery dissection (SCAD). To identify a SCAD cohort and compare risk factors, presentation, and management outcomes compared to acute coronary syndrome (ACS) matched controls.

METHODS

Retrospective analysis was performed from 2000 to 2015. Clinical data included a neuropsychiatric history, with management and clinical outcomes assessed at 12 months. Patients were matched on a 1:3 case-control basis according to type of ACS. Twenty-two SCAD patients were matched to 66 controls by ACS type (ST-elevation myocardial infarction 45%, Non-ST-elevation myocardial infarction 41%, unstable angina 14%).

RESULTS

The SCAD group were more likely female (77.3% vs 19.7%, P < 0.0001), of younger age (48.7 ± 10.7 years vs 61.3 ± 10.6 years, P < 0.0001) with no cases of diabetes (0% vs 33.3%, P = 0.002), compared to controls. SCAD patients had a high prevalence of anxiety, depression or previous neuropsychiatric history (52.4% SCAD vs 1.5% ACS, P < 0.0001). A conservative revascularization strategy with stenting was performed in a minority of SCAD patients (13.6% SCAD vs 83.3% ACS, P < 0.0001), with no significant difference in cumulative major adverse cardiac or cerebrovascular events (MACCE) of death, stroke, re-admission, or repeat angiography rates between both groups (13.6% SCAD vs 27.3% ACS P = NS).

CONCLUSION

SCAD affects young females with a paucity of cardiovascular risk factors. The major risk factor for SCAD was a history of anxiety, depression, or neuropsychiatric illness. A conservative approach to SCAD revascularization led to similar MACCE when compared to ACS controls undergoing guideline revascularization at 12 months.

Expectancies mediate the relationship between perceived injustice and return to work following whiplash injury: A 1-year prospective study

BACKGROUND

Emerging evidence suggests that perceived injustice is a risk factor for work disability in individuals with whiplash injury. At present, however, little is known about the processes by which perceived injustice impacts on return to work. The purpose of this study was to examine whether expectancies mediated the relationship between perceived injustice and return to work in patients with whiplash injury.

METHOD

One hundred and fifty-two individuals (81 men, 71 women) with a primary diagnosis of whiplash injury completed self-report measures of pain intensity, perceived injustice and return-to-work expectancies following admission to a rehabilitation programme. Work status was assessed 1 year after discharge.

RESULTS

Consistent with previous research, high scores on a measure of perceived injustice were associated with prolonged work disability. Results indicated that high perceptions of injustice were associated with low return-to-work expectancies. Causal mediation analyses revealed that expectancies fully mediated the relationship between perceived injustice and return to work.

CONCLUSION

The findings suggest that intervention techniques designed to target expectancies could improve return-to-work outcomes in patients with whiplash injury. Discussion addresses the processes by which expectancies might impact on return-to-work outcomes and the manner in which negative return-to-work expectancies might be modified through intervention.

SIGNIFICANCE

The study confirms that expectancies are the mechanism through which perceived injustice impacts return to work following whiplash injury. The findings suggest that interventions designed to specifically target return-to-work expectancies might improve rehabilitation outcomes in patients with whiplash injury.

Mechanistic investigations of the asymmetric hydrosilylation of ketimines with trichlorosilane reveals a dual activation model and an organocatalyst with enhanced efficiency

Mechanistic investigations of a catalyst used for the asymmetric hydrosilylation have revealed a ‘dual activation’ model and catalyst that maintains its performance at 0.01 mol% loading.

Evaluating hydrogen bonding control in the diastereoselective Diels-Alder reactions of 9-(2-aminoethyl)-anthracene derivatives

Several 9-(2-aminoethyl)anthracene derivatives were prepared with different nitrogen substitutents including alkyl, acetamide, trifluoroacaeamide and t-butyl carbamate. The selectivity in Diels-Alder cyclodaddition reaction with N-methyl maleimide was evaluated through single crystal X-ray analysis of the products. Models for the change in selectivity with hydrogen bond acceptor are proposed, supported by DFT level calculations.

Methane sources in arctic thermokarst lake sediments on the North Slope of Alaska

The permafrost on the North Slope of Alaska is densely populated by shallow lakes that result from thermokarst erosion. These lakes release methane (CH4 ) derived from a combination of ancient thermogenic pools and contemporary biogenic production. Despite the potential importance of CH4 as a greenhouse gas, the contribution of biogenic CH4 production in arctic thermokarst lakes in Alaska is not currently well understood. To further advance our knowledge of CH4 dynamics in these lakes, we focused our study on (i) the potential for microbial CH4 production in lake sediments, (ii) the role of sediment geochemistry in controlling biogenic CH4 production, and (iii) the temperature dependence of this process. Sediment cores were collected from one site in Siqlukaq Lake and two sites in Sukok Lake in late October to early November. Analyses of pore water geochemistry, sedimentary organic matter and lipid biomarkers, stable carbon isotopes, results from CH4 production experiments, and copy number of a methanogenic pathway-specific gene (mcrA) indicated the existence of different sources of CH4 in each of the lakes chosen for the study. Analysis of this integrated data set revealed that there is biological CH4 production in Siqlukaq at moderate levels, while the very low levels of CH4 detected in Sukok had a mixed origin, with little to no biological CH4 production. Furthermore, methanogenic archaea exhibited temperature-dependent use of in situ substrates for methanogenesis, and the amount of CH4 produced was directly related to the amount of labile organic matter in the sediments. This study constitutes an important first step in better understanding the actual contribution of biogenic CH4 from thermokarst lakes on the coastal plain of Alaska to the current CH4 budgets.

Genetic contributions to variation in general cognitive function: a meta-analysis of genome-wide association studies in the CHARGE consortium (N=53949)

General cognitive function is substantially heritable across the human life course from adolescence to old age. We investigated the genetic contribution to variation in this important, health- and well-being-related trait in middle-aged and older adults. We conducted a meta-analysis of genome-wide association studies of 31 cohorts (N=53,949) in which the participants had undertaken multiple, diverse cognitive tests. A general cognitive function phenotype was tested for, and created in each cohort by principal component analysis. We report 13 genome-wide significant single-nucleotide polymorphism (SNP) associations in three genomic regions, 6q16.1, 14q12 and 19q13.32 (best SNP and closest gene, respectively: rs10457441, P=3.93 × 10(-9), MIR2113; rs17522122, P=2.55 × 10(-8), AKAP6; rs10119, P=5.67 × 10(-9), APOE/TOMM40). We report one gene-based significant association with the HMGN1 gene located on chromosome 21 (P=1 × 10(-6)). These genes have previously been associated with neuropsychiatric phenotypes. Meta-analysis results are consistent with a polygenic model of inheritance. To estimate SNP-based heritability, the genome-wide complex trait analysis procedure was applied to two large cohorts, the Atherosclerosis Risk in Communities Study (N=6617) and the Health and Retirement Study (N=5976). The proportion of phenotypic variation accounted for by all genotyped common SNPs was 29% (s.e.=5%) and 28% (s.e.=7%), respectively. Using polygenic prediction analysis, ~1.2% of the variance in general cognitive function was predicted in the Generation Scotland cohort (N=5487; P=1.5 × 10(-17)). In hypothesis-driven tests, there was significant association between general cognitive function and four genes previously associated with Alzheimer's disease: TOMM40, APOE, ABCG1 and MEF2C.