The hindbrain and cortico-reticular pathway in adolescent idiopathic scoliosis

AIM

To characterise the corticoreticular pathway (CRP) in a case-control cohort of adolescent idiopathic scoliosis (AIS) patients using high-resolution slice-accelerated readout-segmented echo-planar diffusion tensor imaging (DTI) to enhance the discrimination of small brainstem nuclei in comparison to automated whole-brain volumetry and tractography and their clinical correlates.

MATERIALS AND METHODS

Thirty-four participants (16 AIS patients, 18 healthy controls) underwent clinical and orthopaedic assessments and brain magnetic resonance imaging (MRI) on a 3 T MRI machine. Automated whole-brain volume-based morphometry, tract-based spatial statistics analysis, and manual CRP tractography by two independent raters were performed. Intra-rater and inter-rater agreement of DTI metrics from CRP tractography were assessed by intraclass correlation coefficient. Normalised structural brain volumes and DTI metrics were compared between groups using Student's t-tests. Linear correlation analysis between imaging parameters and clinical scores was also performed.

RESULTS

AIS patients demonstrated a significantly larger pons volume compared to controls (p=0.006). Significant inter-side CRP differences in mean (p=0.02) and axial diffusivity (p=0.01) were found in patients only. Asymmetry in CRP fractional anisotropy significantly correlated with the Cobb angle (p=0.03).

CONCLUSION

Relative pontine hypertrophy and asymmetry in CRP DTI metrics suggest central supranuclear inter-hemispheric imbalance in AIS, and support the role of the CRP in axial muscle tone. Longitudinal evaluation of CRP DTI metrics in the prediction of AIS progression may be clinically relevant.

Predictors and outcomes of withholding and withdrawal of life-sustaining treatments in intensive care units in Singapore: a multicentre observational study

BACKGROUND

Clinical practice guidelines on limitation of life-sustaining treatments (LST) in the intensive care unit (ICU), in the form of withholding or withdrawal of LST, state that there is no ethical difference between the two. Such statements are not uniformly accepted worldwide, and there are few studies on LST limitation in Asia. This study aimed to evaluate the predictors and outcomes of withholding and withdrawal of LST in Singapore, focusing on the similarities and differences between the two approaches.

METHODS

This was a multicentre observational study of patients admitted to 21 adult ICUs across 9 public hospitals in Singapore over an average of three months per year from 2014 to 2019. The primary outcome measures were withholding and withdrawal of LST (cardiopulmonary resuscitation, invasive mechanical ventilation, and vasopressors/inotropes). The secondary outcome measure was hospital mortality. Multivariable generalised mixed model analysis was used to identify independent predictors for withdrawal and withholding of LST and if LST limitation predicts hospital mortality.

RESULTS

There were 8907 patients and 9723 admissions. Of the former, 80.8% had no limitation of LST, 13.0% had LST withheld, and 6.2% had LST withdrawn. Common independent predictors for withholding and withdrawal were increasing age, absence of chronic kidney dialysis, greater dependence in activities of daily living, cardiopulmonary resuscitation before ICU admission, higher Acute Physiology and Chronic Health Evaluation (APACHE) II score, and higher level of care in the first 24 h of ICU admission. Additional predictors for withholding included being of Chinese race, the religions of Hinduism and Islam, malignancy, and chronic liver failure. The additional predictor for withdrawal was lower hospital paying class (with greater government subsidy for hospital bills). Hospital mortality in patients without LST limitation, with LST withholding, and with LST withdrawal was 10.6%, 82.1%, and 91.8%, respectively (p < 0.001). Withholding (odds ratio 13.822, 95% confidence interval 9.987-19.132) and withdrawal (odds ratio 38.319, 95% confidence interval 24.351-60.298) were both found to be independent predictors of hospital mortality on multivariable analysis.

CONCLUSIONS

Differences in the independent predictors of withholding and withdrawal of LST exist. Even after accounting for baseline characteristics, both withholding and withdrawal of LST independently predict hospital mortality. Later mortality in patients who had LST withdrawn compared to withholding suggests that the decision to withdraw may be at the point when medical futility is recognised.

Mechanical circulatory support for cardiogenic shock: a network meta-analysis of randomized controlled trials and propensity score-matched studies

PURPOSE

Cardiogenic shock is associated with high mortality. In refractory shock, it is unclear if mechanical circulatory support (MCS) devices improve survival. We conducted a network meta-analysis to determine which MCS devices confers greatest benefit.

METHODS

We searched MEDLINE, Embase, and Scopus databases through 27 August 2023 for relevant randomized controlled trials (RCTs) and propensity score-matched studies (PSMs). We conducted frequentist network meta-analysis, investigating mortality (either 30 days or in-hospital) as the primary outcome. We assessed risk of bias (Cochrane risk of bias 2.0 tool/Newcastle-Ottawa Scale) and as sensitivity analysis reconstructed survival data from published survival curves for a one-stage unadjusted individual patient data (IPD) meta-analysis using a stratified Cox model.

RESULTS

We included 38 studies (48,749 patients), mostly reporting on patients with Society for Cardiovascular Angiography and Intervention shock stages C-E cardiogenic shock. Compared with no MCS, extracorporeal membrane oxygenation with intra-aortic balloon pump (ECMO-IABP; network odds ratio [OR]: 0.54, 95% confidence interval (CI): 0.33-0.86, moderate certainty) was associated with lower mortality. There were no differences in mortality between ECMO, IABP, microaxial ventricular assist device (mVAD), ECMO-mVAD, centrifugal VAD, or mVAD-IABP and no MCS (all very low certainty). Our one-stage IPD survival meta-analysis based on the stratified Cox model found only ECMO-IABP was associated with lower mortality (hazard ratio, HR, 0.55, 95% CI 0.46-0.66).

CONCLUSION

In patients with cardiogenic shock, ECMO-IABP may reduce mortality, while other MCS devices did not reduce mortality. However, this must be interpreted within the context of inter-study heterogeneity and limited certainty of evidence.

Temporal trends in out-of-hospital cardiac arrest with an initial non-shockable rhythm in Singapore

Aim

Out-of-hospital cardiac arrest (OHCA) with an initial non-shockable rhythm is the predominant form of OHCA in adults. We evaluated its 10-year trends in epidemiology and management in Singapore.

Methods

Using the national OHCA registry we studied the trends of 20,844 Emergency Medical Services-attended adult OHCA from April 2010 to December 2019. Survival to hospital discharge was the primary outcome. Trends and outcomes were analyzed using linear and logistic regression, respectively.

Results

Incidence rates of adult OHCAs increased during the study period, driven by non-shockable OHCA. Compared to shockable OHCA, non-shockable OHCAs were significantly older, had more co-morbidities, unwitnessed and residential arrests, longer no-flow time, and received less bystander cardiopulmonary resuscitation (CPR) and in-hospital interventions (p < 0.001). Amongst non-shockable OHCA, age, co-morbidities, residential arrests, no-flow time, time to patient, bystander CPR and epinephrine administration increased during the study period, while presumed cardiac etiology decreased (p < 0.05). Unlike shockable OHCA, survival for non-shockable OHCA did not improve (p < 0.001 for trend difference). The likelihood of survival for non-shockable OHCA significantly increased with witnessed arrest (adjusted odds ratio (aOR) 2.02) and bystander CPR (aOR 3.25), but decreased with presumed cardiac etiology (aOR 0.65), epinephrine administration (aOR 0.66), time to patient (aOR 0.93) and age (aOR 0.98). Significant two-way interactions were observed for no-flow time and residential arrest with bystander CPR (aOR 0.96 and 0.40 respectively).

Conclusion

The incidence of non-shockable OHCA increased between 2010 and 2019. Despite increased interventions, survival did not improve for non-shockable OHCA, in contrast to the improved survival for shockable OHCA.

Measurement Properties of the 15-Item Singapore Caregiver Quality of Life Scale (SCQOLS-15) in Family Caregivers of Patients with Heart Diseases

PURPOSE

To evaluate the measurement properties of the 15-item Singapore Caregiver Quality of Life Scale (SCQOLS-15) in family caregivers of patients with heart diseases.

METHODS

The SCQOLS-15 survey was self-administered by family caregivers of patients with chronic heart diseases, at baseline and 1 week later. The criterion validity of SCQOLS-15 and its domain scores was assessed by calculating the Spearman correlation coefficient (ρ) with the Brief Assessment Scale for Caregivers (BASC), Caregiver Reaction Assessment (CRA), and their sub-scores. Known-group validity was assessed using the New York Heart Association (NYHA) functional class. Test-retest reliability was evaluated using the intraclass correlation coefficient (ICC).

RESULTS

Of the 327 caregivers included, 65% were adult children and 28% were spouses. The distribution of NYHA classes of the patients was I: 27%, II: 40%, III: 24%, and IV: 9%. There was a positive correlation between the SCQOLS-15 and BASC total scores (ρ = 0.7). SCQOLS-15 domain scores were also correlated with BASC and CRA sub-scores as per a priori hypotheses, with absolute values of ρ ranging from 0.4 to 0.6. The mean values of SCQOLS-15 total and all domain scores were lower among caregivers of patients with NYHA class III/IV compared to those of class I/II patients (each P < 0.05). Among 146 caregivers who completed the follow-up and self-rated a stable quality-of-life, ICCs for test-retest reliability of SCQOLS-15 total and all domain scores were ≥ 0.8.

CONCLUSION

The SCQOLS-15 is a valid and reliable instrument for measuring the quality of life in caregivers of heart disease patients.

Blood Pressure Targets for Out-of-Hospital Cardiac Arrest: A Systematic Review and Meta-Analysis

BACKGROUND

With ideal mean arterial pressure (MAP) targets in resuscitated out-of-hospital cardiac arrest (OHCA) patients unknown, we performed a meta-analysis of randomised controlled trials (RCTs) to compare the effects of higher versus lower MAP targets.

METHODS

We searched four databases until 1 May 2023 for RCTs reporting the effects of higher MAP targets (>70 mmHg) in resuscitated OHCA patients and conducted random-effects meta-analyses. The primary outcome was mortality while secondary outcomes were neurological evaluations, arrhythmias, acute kidney injury, and durations of mechanical ventilation and ICU stay. We conducted inverse-variance weighted strata-level meta-regression against a proportion of non-survivors to assess differences between reported MAPs. We also conducted a trial sequential analysis of RCTs.

RESULTS

Four RCTs were included. Higher MAP was not associated with reduced mortality (OR: 1.09, 95%-CI: 0.84 to 1.42, p = 0.51), or improved neurological outcomes (OR: 0.99, 95%-CI: 0.77 to 1.27, p = 0.92). Such findings were consistent despite additional sensitivity analyses. Our robust variance strata-level meta-regression revealed no significant associations between mean MAP and the proportion of non-survivors (B: 0.029, 95%-CI: -0.023 to 0.081, p = 0.162), and trial sequential analysis revealed no meaningful survival benefit for higher MAPs.

CONCLUSIONS

A higher MAP target was not significantly associated with improved mortality and neurological outcomes in resuscitated OHCA patients.

Association between Conversion to Shockable Rhythms and Survival with Favorable Neurological Outcomes for Out-of-Hospital Cardiac Arrests

BACKGROUND

The initial cardiac rhythm in out-of-hospital cardiac arrest (OHCA) portends different prognoses and affects treatment decisions. Initial shockable rhythms are associated with good survival and neurological outcomes but there is conflicting evidence for those who initially present with non-shockable rhythms. The aim of this study is to evaluate if OHCA with conversion from non-shockable (i.e., asystole and pulseless electrical activity) rhythms to shockable rhythms compared to OHCA remaining in non-shockable rhythms is associated with better survival and neurological outcomes.

METHOD

OHCA cases from the Pan-Asian Resuscitation Outcomes Study registry in 13 countries between January 2009 and February 2018 were retrospectively analyzed. Cases with missing initial rhythms, age <18 years, presumed non-medical cause of arrest, and not conveyed by emergency medical services were excluded. Multivariable logistic regression analysis was performed to evaluate the relationship between initial and subsequent shockable rhythm, survival to discharge, and survival with favorable neurological outcomes (cerebral performance category 1 or 2).

RESULTS

Of the 116,387 cases included. 11,153 (9.6%) had initial shockable rhythms and 9,765 (8.4%) subsequently converted to shockable rhythms. Japan had the lowest proportion of OHCA patients with initial shockable rhythms (7.3%). For OHCA with initial shockable rhythm, the adjusted odds ratios (aOR) for survival and good neurological outcomes were 8.11 (95% confidence interval [CI] 7.62-8.63) and 15.4 (95%CI 14.1-16.8) respectively. For OHCA that converted from initial non-shockable to shockable rhythms, the aORs for survival and good neurological outcomes were 1.23 (95%CI 1.10-1.37) and 1.61 (95%CI 1.35-1.91) respectively. The aORs for survival and good neurological outcomes were 1.48 (95%CI 1.22-1.79) and 1.92 (95%CI 1.3 - 2.84) respectively for initial asystole, while the aOR for survival in initial pulseless electrical activity patients was 0.83 (95%CI 0.71-0.98). Prehospital adrenaline administration had the highest aOR (2.05, 95%CI 1.93-2.18) for conversion to shockable rhythm.

CONCLUSION

In this ambidirectional cohort study, conversion from non-shockable to shockable rhythm was associated with improved survival and neurologic outcomes compared to rhythms that continued to be non-shockable. Continued advanced resuscitation may be beneficial for OHCA with subsequent conversion to shockable rhythms.

Determinants of health-related quality of life after out-of-hospital cardiac arrest (OHCA): A systematic review

OBJECTIVE

With a growing number of out-of-hospital cardiac arrest (OHCA) survivors globally, the focus of OHCA management has now broadened to survivorship. An outcome central to survivorship is health-related quality of life (HRQoL). This systematic review aimed to synthesise evidence related to the determinants of HRQoL of OHCA survivors.

METHODS

We systematically searched MEDLINE, Embase, and Scopus from inception to 15 August 2022 to identify studies investigating the association of at least one determinant and HRQoL in adult OHCA survivors. All articles were independently reviewed by two investigators. We abstracted data pertaining to determinants and classified them using a well-established HRQoL theoretical framework - the Wilson and Cleary (revised) model.

RESULTS

31 articles assessing a total of 35 determinants were included. Determinants were classified into the five domains in the HRQoL model. 26 studies assessed determinants related to individual characteristics (n=3), 12 studied biological function (n=7), nine studied symptoms (n=3), 16 studied functioning (n=5), and 35 studied characteristics of the environment (n=17). In studies that included multivariable analyses, most reported that individual characteristics (older age, female sex), symptoms (anxiety, depression), and functioning (impaired neurocognitive function) were significantly associated with poorer HRQoL.

CONCLUSIONS

Individual characteristics, symptoms, and functioning played significant roles in explaining the variability in HRQoL. Significant non-modifiable determinants such as age and sex could be used to identify populations at risk of poorer HRQoL, while significant modifiable determinants such as psychological health and neurocognitive functioning could serve as targets for post-discharge screening and rehabilitation plans. PROSPERO registration number: CRD42022359303.

Did lockdown influence bystanders' willingness to perform cardiopulmonary resuscitation? A worldwide registry-based perspective

AIM

Bystander cardiopulmonary resuscitation (CPR) significantly increases the survival rate after out-of-hospital cardiac arrest. Using population-based registries, we investigated the impact of lockdown due to Covid-19 on the provision of bystander CPR, taking background changes over time into consideration.

METHODS

Using a registry network, we invited all registries capable of delivering data from 1. January 2017 to 31. December 2020 to participate in this study. We used negative binominal regression for the analysis of the overall results. We also calculated the rates for bystander CPR. For every participating registry, we analysed the incidence per 100000 inhabitants of bystander CPR and EMS-treated patients using Poisson regression, including time trends.

RESULTS

Twenty-six established OHCA registries reported 742 923 cardiac arrest patients over a four-year period covering 1.3 billion person-years. We found large variations in the reported incidence between and within continents. There was an increase in the incidence of bystander CPR of almost 5% per year. The lockdown in March/April 2020 did not impact this trend. The increase in the rate of bystander CPR was also seen when analysing data on a continental level. We found large variations in incidence of bystander CPR before and after lockdown when analysing data on a registry level.

CONCLUSION

There was a steady increase in bystander CPR from 2017 to 2020, not associated with an increase in the number of ambulance-treated cardiac arrest patients. We did not find an association between lockdown and bystanders' willingness to start CPR before ambulance arrival, but we found inconsistent patterns of changes between registries.

The Effect of Building-Level Socioeconomic Status on Bystander Cardiopulmonary Resuscitation: A Retrospective Cohort Study

OBJECTIVE

Understanding the social determinants of bystander cardiopulmonary resuscitation (CPR) receipt can inform the design of public health interventions to increase bystander CPR. The association of socioeconomic status with bystander CPR is generally poorly understood. We evaluated the relationship between socioeconomic status and bystander CPR in cases of out-of-hospital cardiac arrest (OHCA).

METHODS

This was a retrospective cohort study based on the Singapore cohort of the Pan-Asian Resuscitation Outcomes Study registry between 2010 and 2018. We categorized patients into low, medium, and high Singapore Housing Index (SHI) levels-a building-level index of socioeconomic status. The primary outcome was receipt of bystander CPR. The secondary outcomes were prehospital return of spontaneous circulation and survival to discharge.

RESULTS

A total of 12,730 OHCA cases were included, the median age was 71 years, and 58.9% were male. The bystander CPR rate was 56.7%. Compared to patients in the low SHI category, those in the medium and high SHI categories were more likely to receive bystander CPR (medium SHI: adjusted odds ratio [aOR] 1.48, 95% CI 1.30-1.69; high SHI: aOR 1.93, 95% CI 1.67-2.24). High SHI patients had higher survival compared to low SHI patients on unadjusted analysis (OR 1.79, 95% CI 1.08-2.96), but not adjusted analysis (adjusted for age, sex, race, witness status, arrest time, past medical history of cancer, and first arrest rhythm). When comparing high with low SHI, females had larger increases in bystander CPR rates than males.

CONCLUSIONS

Lower building-level socioeconomic status was independently associated with lower rate of bystander CPR, and females were more susceptible to the effect of low socioeconomic status on lower rate of bystander CPR.

Pathophysiologic mechanism for MYOcarditis in COVID-19 VAccinations ("MYOVAx" Study)

Funding Acknowledgements

Type of funding sources: Public grant(s) – National budget only. Main funding source(s): NMRC COVID-19 Research Fund

Objective

This is the first prospective cohort study in Singapore to investigate the COVID-19 vaccine-associated myocarditis to understand its pathophysiology.

Introduction

Acute myocarditis and other cardiovascular symptoms have been observed to be associated with the two mRNA-based coronavirus disease 2019 (COVID-19) vaccines—namely Pfizer-BioNTech BNT162b2 and Moderna mRNA-1273)—currently in-use in Singapore. The mechanisms through which myocarditis occurs are unknown, hence our study aims to understand the pathophysiology of myocarditis associated with COVID-19 vaccines.

Methods

Patients with onset of cardiac manifestations were recruited from multiple hospital outpatient clinics between November 2021 and September 2022. Clinical history and physical examination data was collected with blood sample collection, echocardiography, 12-lead electrocardiogram (ECG), coronary angiography and magnetic resonance imaging (MRI) at recruitment and 6-month follow-up. Analysis of biomarkers, genetic, serological and MRI data was conducted.

Results

As of 6 September 2022, a total of 5 patients have been enrolled (4 males, 1 female). The most commonly reported symptoms across all patients were chest pain/discomfort (80%), followed by palpitations (40%). MRI evidence of myocarditis has been detected in 2 (50%) of the male patients, of which both reported two or more symptoms occurring 1-2 days post-vaccination. Both patients have each received at least two doses of either the Pfizer-BioNTech BNT162b2 vaccine or Moderna mRNA-1273 vaccine. Their MRI findings were consistent with myocarditis. On late gadolinium enhancement (LGE) imaging, epicardial enhancement at the basal inferolateral segment and mid-wall enhancement at the apical anterior, lateral and inferior walls were observed in one patient. Patchy, mid-wall LGE in the basal inferior/inferolateral wall was observed in the other patient. No MRI evidence of myocarditis was available for the sole female patient.

Conclusion

While more data is needed to definitively prove the association of the two mRNA-based Pfizer-BioNTech BNT162b2 and Moderna mRNA-1273 COVID-19 vaccines with post-vaccination myocarditis, we believe our findings may support further investigations to enable risk stratification for vaccine-associated myocarditis and identify potential preventative strategies accordingly.

Effects of Carotid Artery Stiffness on Cerebral Small-Vessel Disease and Cognition

Background Carotid artery stiffness is associated with cognitive impairment and dementia, but the underlying mechanisms remain unknown. We examined the associations of carotid artery stiffness with cerebral small-vessel disease markers, cognition, and dementia subtypes in a memory clinic cohort. Methods and Results A total of 272 participants underwent carotid ultrasonography, 3 Tesla brain magnetic resonance imaging, and neuropsychological assessment. Carotid ultrasonography was used to assess β-index, pressure-strain elastic modulus, and pulse-wave velocity-β. Brain magnetic resonance images were graded for cerebral small-vessel disease markers, including white matter hyperintensities, lacunes, and cerebral microbleeds. Participants were classified as having no cognitive impairment, cognitive impairment and no dementia, or dementia subtyped as Alzheimer disease and vascular dementia. Cognition was assessed using National Institute of Neurological Disorders and Stroke-Canadian Stroke Network harmonization battery. After adjusting for age, sex, cardiovascular risk factors, and diseases, multivariable models showed that β-index (β=0.69; P=0.002), elastic modulus (β=0.78; P<0.001), and pulse-wave velocity-β (β=0.80; P<0.001) were associated with white matter hyperintensities, and elastic modulus (odds ratio [OR], 1.39 [95% CI, 1.04-1.85]) and pulse-wave velocity-β (OR, 1.47 [95% CI, 1.10-1.98]) were independently associated with lacunes. Similarly, β-index (OR, 2.04 [95% CI, 1.14-4.13]), elastic modulus (OR, 2.22 [95% CI, 1.25-4.42]), and pulse-wave velocity-β (OR, 2.50 [95% CI, 1.36-5.18]) were independently associated with vascular dementia. Carotid stiffness measures were independently associated with worse performance in global cognition, visuomotor speed, visuospatial function, and executive function. These associations became largely nonsignificant after further adjusting for cerebral small-vessel disease markers. Conclusions In memory clinic patients, carotid artery stiffness was associated with white matter hyperintensities and lacunes, impairment in global and domain-specific cognition, and causative subtypes of dementia, particularly vascular. The effects of carotid stiffness on cognition were not independent of, and were partially mediated by, cerebral small-vessel disease.

Impact of COVID-19 on barriers to dispatcher-assisted cardiopulmonary resuscitation in adult out-of-hospital cardiac arrests in Singapore

OBJECTIVE

Fewer out-of-hospital cardiac arrest (OHCA) patients received bystander cardiopulmonary resuscitation during the COVID-19 pandemic in Singapore. We investigated the impact of COVID-19 on barriers to dispatcher-assisted cardiopulmonary resuscitation (DA-CPR).

METHODS

We reviewed audio recordings of all calls to our national ambulance service call centre during the pandemic (January-June 2020) and pre-pandemic (January-June 2019) periods. Our primary outcome was the presence of barriers to DA-CPR. Multivariable logistic regression was used to assess the effect of COVID-19 on the likelihood of barriers to and performance of DA-CPR, adjusting for patient and event characteristics.

RESULTS

There were 1241 and 1118 OHCA who were eligible for DA-CPR during the pandemic (median age 74 years, 61.6 % males) and pre-pandemic (median age 73 years, 61.1 % males) periods, respectively. Compared to pre-pandemic, there were more residential and witnessed OHCA during the pandemic (87 % vs 84.9 % and 54 % vs 38.1 %, respectively); rates of DA-CPR were unchanged (57.3 % vs 61.1 %). COVID-19 increased the likelihood of barriers to DA-CPR (aOR 1.47, 95 % CI: 1.25-1.74) but not performance of DA-CPR (aOR 0.86, 95 % CI: 0.73 - 1.02). Barriers such as 'patient status changed' and 'caller not with patient' increased during COVID-19 pandemic. 'Afraid to do CPR' markedly decreased during the pandemic; fear of COVID-19 transmission made up 0.5 % of the barriers.

CONCLUSION

Barriers to DA-CPR were encountered more frequently during the COVID-19 pandemic but did not affect callers' willingness to perform DA-CPR. Distancing measures led to more residential arrests with increases in certain barriers, highlighting opportunities for public education and intervention.

Prior Cancer Is Associated with Lower Atherosclerotic Cardiovascular Disease Risk at First Acute Myocardial Infarction

Background: Patients with cancer are at increased risk of acute myocardial infarction (AMI). It is unclear if the Atherosclerotic Cardiovascular Disease (ASCVD) risk score at incident AMI is reflective of this higher risk in patients with prior cancer than those without. Methods: We linked nationwide AMI and cancer registries from 2008 to 2019. A total of 18,200 eligible patients with ASCVD risk score calculated at incident AMI were identified (1086 prior cancer; 17,114 no cancer). Results: At incident AMI, age-standardized mean ASCVD risk was lower in the prior cancer group (18.6%) than no cancer group (20.9%) (p < 0.001). Prior to incident AMI, smoking, hypertension, hyperlipidemia and diabetes mellitus were better controlled in the prior cancer group. However post-AMI, prior cancer was associated with lower guideline-directed medical therapy usage and higher all-cause mortality (adjusted hazard ratio 1.85, 95% confidence interval 1.66−2.07). Conclusions: AMI occurred despite better control of cardiovascular risk factors and lower age-standardized estimated mean 10-year ASCVD risk among patients with prior cancer than no cancer. Prior cancer was associated with lower guideline-directed medical therapy post-AMI and higher mortality.

Microaxial Left Ventricular Assist Device in Cardiogenic Shock: A Systematic Review and Meta-Analysis

Microaxial left ventricular assist devices (LVAD) are increasingly used to support patients with cardiogenic shock; however, outcome results are limited to single-center studies, registry data and select reviews. We conducted a systematic review and meta-analysis, searching three databases for relevant studies reporting on microaxial LVAD use in adults with cardiogenic shock. We conducted a random-effects meta-analysis (DerSimonian and Laird) based on short-term mortality (primary outcome), long-term mortality and device complications (secondary outcomes). We assessed the risk of bias and certainty of evidence using the Joanna Briggs Institute and the GRADE approaches, respectively. A total of 63 observational studies (3896 patients), 6 propensity-score matched (PSM) studies and 2 randomized controlled trials (RCTs) were included (384 patients). The pooled short-term mortality from observational studies was 46.5% (95%-CI: 42.7–50.3%); this was 48.9% (95%-CI: 43.8–54.1%) amongst PSM studies and RCTs. The pooled mortality at 90 days, 6 months and 1 year was 41.8%, 51.1% and 54.3%, respectively. Hemolysis and access-site bleeding were the most common complications, each with a pooled incidence of around 20%. The reported mortality rate of microaxial LVADs was not significantly lower than extracorporeal membrane oxygenation (ECMO) or intra-aortic balloon pumps (IABP). Current evidence does not suggest any mortality benefit when compared to ECMO or IABP.

The effect of building-level socioeconomic status on bystander cardiopulmonary resuscitation: a retrospective cohort study

Background/Introduction

In out-of-hospital cardiac arrest (OHCA), bystander cardiopulmonary resuscitation (BCPR) increases survival [1]. Understanding the social determinants of BCPR receipt can inform the design of public health interventions to increase BCPR. The association of socioeconomic status (SES) with BCPR is generally poorly understood.

Purpose

We aimed to evaluate the effect of SES on BCPR in OHCA using a building-level SES marker.

Methods

This was a retrospective cohort study based on the Singapore cohort of the Pan-Asian Resuscitation Outcomes Study registry, an ongoing long-term prospective registry for OHCA in the Asia-Pacific region, between 2010 to 2018. We categorized patients into low, medium and high Singapore Housing Index (SHI) levels. The SHI, which appraises a residential property value on an ordinal scale of 1 to 7 (low to high), is a building-level marker that has a robust association with income and residence value [2]. The primary outcome was receipt of BCPR. The secondary outcomes were pre-hospital return of spontaneous circulation (ROSC) and survival – defined as survival to 30 days or hospital discharge, whichever occurred first.

Results

A total of 12,730 OHCA cases were included (Figure 1), the median age was 71 years and 58.9% were male. BCPR rate was 56.7%. OHCA patients in the low SHI tier were the youngest, most likely male, and least likely to have any medical co-morbidities (Table 1). Compared the low SHI category, those in the medium and high SHI categories were more likely to receive BCPR (medium SHI: adjusted odds ratio [aOR] 1.483, 95% CI 1.301–1.691, p&lt;0.01; high SHI: aOR 1.933, 95% CI 1.669–2.240, p&lt;0.01). As a continuous variable, every unit increase in SHI was associated with increased BCPR (aOR 1.142, 95% CI 1.110–1.174, p&lt;0.001). High SHI patients had higher survival compared to low SHI patients on unadjusted analysis (OR 1.789, 95% CI 1.080–2.964) but not adjusted analysis (adjusted for age, sex, race, witness status, arrest time, past medical history of cancer, and first arrest rhythm). There were no significant differences in the proportion of ROSC across three categories of SHI (p=0.426). When comparing high with low SHI, females had larger increases in BCPR rates compared to males (ratio of OR 1.370, 95% CI 1.012–1.853). There were no significant associations between SHI and BCPR in the subgroups age ≥65 years, witnessed arrest, daytime arrest, and arrests after 2014, and no interaction effects were observed.

Conclusions

Lower building-level SES was independently associated with lower rate of BCPR. Higher SES was associated with higher 30-day survival on unadjusted analysis but not adjusted analysis, and this study may be under-powered for this outcome. Females were more susceptible to the effect of low SES on lower rate of BCPR, and community CPR training should focus on recognizing OHCA and performing BCPR in women in low SES communities.

Funding Acknowledgement

Type of funding sources: Public grant(s) – National budget only. Main funding source(s): National Medical Research Council, Clinician Scientist Awards, Singapore (NMRC/CSA/024/2010, NMRC/CSA/0049/2013 and NMRC/CSA-SI/0014/2017) and Ministry of Health, Health Services Research Grant, Singapore (HSRG/0021/2012).

Immunoassay-Compatible Inactivation of SARS-CoV-2 in Plasma Samples for Enhanced Handling Safety

Severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) inactivation is an important step toward enhanced biosafety in testing facilities and affords a reduction in the biocontainment level necessary for handling virus-positive biological specimens. Virus inactivation methods commonly employ heat, detergents, or combinations thereof. In this work, we address the dearth of information on the efficacy of SARS-CoV-2 inactivation procedures in plasma and their downstream impact on immunoassays. We evaluated the effects of heat (56 °C for 30 min), detergent (1-5% Triton X-100), and solvent-detergent (SD) combinations [0.3-1% tri-n-butyl phosphate (TNBP) and 1-2% Triton X-100] on 19 immunoassays across different assay formats. Treatments are deemed immunoassay-compatible when the average and range of percentage recovery (treated concentration relative to untreated concentration) lie between 90-110 and 80-120%, respectively. We show that SD treatment (0.3% TNBP/1% Triton-X100) is compatible with more than half of the downstream immunoassays tested and is effective in reducing SARS-CoV-2 infectivity in plasma to below detectable levels in plaque assays. This facile method offers enhanced safety for laboratory workers handling biological specimens in clinical and research settings.

Clustering of Environmental Parameters and the Risk of Acute Myocardial Infarction

The association between days with similar environmental parameters and cardiovascular events is unknown. We investigate the association between clusters of environmental parameters and acute myocardial infarction (AMI) risk in Singapore. Using k-means clustering and conditional Poisson models, we grouped calendar days from 2010 to 2015 based on rainfall, temperature, wind speed and the Pollutant Standards Index (PSI) and compared the incidence rate ratios (IRR) of AMI across the clusters using a time-stratified case-crossover design. Three distinct clusters were formed with Cluster 1 having high wind speed, Cluster 2 high rainfall, and Cluster 3 high temperature and PSI. Compared to Cluster 1, Cluster 3 had a higher AMI incidence with IRR 1.04 (95% confidence interval 1.01–1.07), but no significant difference was found between Cluster 1 and Cluster 2. Subgroup analyses showed that increased AMI incidence was significant only among those with age ≥65, male, non-smokers, non-ST elevation AMI (NSTEMI), history of hyperlipidemia and no history of ischemic heart disease, diabetes or hypertension. In conclusion, we found that AMI incidence, especially NSTEMI, is likely to be higher on days with high temperature and PSI. These findings have public health implications for AMI prevention and emergency health services delivery during the seasonal Southeast Asian transboundary haze.

Association of High-Volume Centers With Survival Outcomes Among Patients With Nontraumatic Out-of-Hospital Cardiac Arrest: A Systematic Review and Meta-Analysis

Importance

Although high volume of cases of out-of-hospital cardiac arrest (OHCA) is a key feature of cardiac arrest centers, which have proven survival benefit, the role of center volume as an independent variable associated with improved outcomes is unclear.

Objective

To assess the association of high-volume centers with survival and neurological outcomes in nontraumatic OHCA.

Data Sources

Medline, Embase, and the Cochrane Central Register of Controlled Trials were searched from inception to October 11, 2021, for studies including adult patients with nontraumatic OHCA who were treated at high-volume vs non-high-volume centers.

Study Selection

Randomized clinical trials, nonrandomized studies of interventions, prospective cohort studies, and retrospective cohort studies were selected that met the following criteria: (1) adult patients with OHCA of nontraumatic etiology, (2) comparison of high-volume with low-volume centers, (3) report of a volume-outcome association, and (4) report of outcomes of interest. At least 2 authors independently reviewed each article, blinded to each other's decision.

Data Extraction and Synthesis

Data abstraction and quality assessment were independently conducted by 2 authors. Meta-analyses were performed for adjusted odds ratios (aORs) and crude ORs using a random-effects model. This study followed the Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) reporting guideline.

Main Outcomes and Measures

Survival and good neurological outcomes according to the Cerebral Performance Categories Scale at hospital discharge or 30 days.

Results

A total of 16 studies involving 82 769 patients were included. Five studies defined high volume as 40 or more cases of OHCA per year; 3 studies defined high volume as greater than 100 cases of OHCA per year. All other studies differed in definitions. Survival to discharge or 30 days improved with treatment at high-volume centers, regardless of whether aORs (1.28 [95% CI, 1.00-1.64]) or crude ORs (1.43 [95% CI, 1.09-1.87]) were pooled. There was no association between center volume and good neurological outcomes at 30 days or hospital discharge in patients with OHCA (aOR, 0.96 [95% CI, 0.77-1.20]).

Conclusions and Relevance

In this meta-analysis and systematic review, care at high-volume centers was associated with improved survival outcomes, even after adjustment for potential confounders, but was not associated with improved neurological outcomes for patients with nontraumatic OHCA. More studies evaluating the relative importance of center volume compared with other variables (eg, the availability of treatment modalities) associated with survival outcomes in patients with OHCA are required.

Investigating 5-Level EQ-5D (EQ-5D-5L) Values Based on Preferences of Patients With Heart Disease

OBJECTIVES

Several studies have shown that patients with heart disease value hypothetical health states differently from the general population. We aimed to investigate the health preferences of patients with heart disease and develop a value set for the 5-level EQ-5D (EQ-5D-5L) based on these patient preferences.

METHODS

Patients with confirmed heart disease were recruited from 2 hospitals in Singapore. A total of 86 EQ-5D-5L health states (10 per patient) were valued using a composite time trade-off method according to the international valuation protocol for EQ-5D-5L; 20-parameter linear models and 8-parameter cross-attribute level effects models with and without an N45 term (indicating whether any health state dimension at level 4 or 5 existed) were estimated. Each model included patient-specific random intercepts. Model performance was evaluated for out-of-sample and in-sample predictive accuracy in terms of root mean square error. The discriminative ability of the utility values was assessed using heart disease-related functional classes.

RESULTS

A total of 576 patients were included in the analysis. The preferred model, with the lowest out-of-sample root mean square error, was a 20-parameter linear model including N45. Predicted utility values ranged from -0.727 for the worst state to 1 for full health; the value for the second-best state was 0.981. Utility values demonstrated good discriminative ability in differentiating among patients of varied functional classes.

CONCLUSIONS

An EQ-5D-5L value set representing the preferences of patients with heart disease was developed. The value set could be used for patient-centric economic evaluation and health-related quality of life assessment for patients with heart disease.

Pericarditis and myocarditis after COVID-19 mRNA vaccination in a nationwide setting

Introduction: Despite reports suggesting an association between COVID-19 mRNA vaccination and pericarditis and myocarditis, detailed nationwide population-based data are sparsely available. We describe the incidence of pericarditis and myocarditis by age categories and sex after COVID-19 mRNA vaccination from a nationwide mass vaccination programme in Singapore. Methods: The incidence of adjudicated cases of pericarditis and myocarditis following COVID-19 mRNA vaccination that were reported to the vaccine safety committee between January to July 2021 was compared with the background incidence of myocarditis in Singapore. Results: As of end July 2021, a total of 34 cases were reported (9 pericarditis only, 14 myocarditis only, and 11 concomitant pericarditis and myocarditis) with 7,183,889 doses of COVID-19 mRNA vaccine administered. Of the 9 cases of pericarditis only, all were male except one. The highest incidence of pericarditis was in males aged 12–19 years with an incidence of 1.11 cases per 100,000 doses. Of the 25 cases of myocarditis, 80% (20 cases) were male and the median age was 23 years (range 12–55 years) with 16 cases after the second dose. A higher-than-expected number of cases were seen in males aged 12–19 and 20–29 years, with incidence rates of 3.72 and 0.98 case per 100,000 doses, respectively. Conclusion: Data from the national registry in Singapore indicate an increased incidence of pericarditis and myocarditis in younger men after COVID-19 mRNA vaccination. Keywords: COVID-19 vaccine, myocarditis, pericarditis

Pericarditis and myocarditis after COVID-19 mRNA vaccination in a nationwide setting

INTRODUCTION

Despite reports suggesting an association between COVID-19 mRNA vaccination and pericarditis and myocarditis, detailed nationwide population-based data are sparsely available. We describe the incidence of pericarditis and myocarditis by age categories and sex after COVID-19 mRNA vaccination from a nationwide mass vaccination programme in Singapore.

METHODS

The incidence of adjudicated cases of pericarditis and myocarditis following COVID-19 mRNA vaccination that were reported to the vaccine safety committee between January to July 2021 was compared with the background incidence of myocarditis in Singapore.

RESULTS

As of end July 2021, a total of 34 cases were reported (9 pericarditis only, 14 myocarditis only, and 11 concomitant pericarditis and myocarditis) with 7,183,889 doses of COVID-19 mRNA vaccine administered. Of the 9 cases of pericarditis only, all were male except one. The highest incidence of pericarditis was in males aged 12-19 years with an incidence of 1.11 cases per 100,000 doses. Of the 25 cases of myocarditis, 80% (20 cases) were male and the median age was 23 years (range 12-55 years) with 16 cases after the second dose. A higher-than-expected number of cases were seen in males aged 12-19 and 20-29 years, with incidence rates of 3.72 and 0.98 case per 100,000 doses, respectively.

CONCLUSION

Data from the national registry in Singapore indicate an increased incidence of pericarditis and myocarditis in younger men after COVID-19 mRNA vaccination.

Gender disparities among adult recipients of layperson bystander cardiopulmonary resuscitation by location of cardiac arrest in Pan-Asian communities: A registry-based study

BACKGROUND

Bystander cardiopulmonary resuscitation (BCPR) is a critical component of the 'chain of survival' in reducing mortality among out-of-hospital cardiac arrest (OHCA) victims. Inconsistent findings on gender disparities among adult recipients of layperson BCPR have been reported in the literature. We aimed to fill this knowledge gap by investigating the extent of gender disparities in a cross-national setting within Pan-Asian communities.

METHODS

We utilised data collected from the Pan-Asian Resuscitation Outcomes Study (PAROS), an international, multicentre, prospective study conducted between 2009 and 2018. We included all OHCA cases with non-traumatic arrest aetiology transported by emergency medical services and excluded study sites that did not consistently collect information about the location of cardiac arrest. Logistic regression was used to analyse the association between gender and BCPR, stratified by location.

FINDINGS

We analysed a cohort of 56,192 OHCA cases with an overall BCPR rate of 36.2% (20,329/56,192). At public locations, the BCPR rate was 31.2% (631/2022) for female and 36.4% (3235/8892) for male OHCA victims; while at home, the rate was 38.3% (6838/17,842) for females and 35.1% (9625/27,436) for males. Controlling for site differences and several factors in multivariable logistic regression, we found females less likely to receive BCPR than males in public locations (odds ratio [OR]=0.89, 95% confidence interval [CI]: 0.70-0.99), but more likely to receive BCPR at home (OR=1.16, 95% CI: 1.11-1.21).

INTERPRETATION

In Pan-Asian communities, gender differences exist in adult recipients of BCPR and differ between home and public locations. Future studies should account for additional information on bystanders and societal factors to identify targets for interventions.

FUNDING

The study was supported by grants from the National Medical Research Council (NMRC/CSA/0049/2013) and Laerdal Foundation (20040).

Early Coronary Angiography Is Associated with Improved 30-Day Outcomes among Patients with Out-of-Hospital Cardiac Arrest

We evaluated the association between early coronary angiography (CAG) and outcomes in resuscitated out-of-hospital cardiac arrest (OHCA) patients, by linking data from the Singapore Pan-Asian Resuscitation Outcomes Study, with a national registry of cardiac procedures. The 30-day survival and neurological outcome were compared between patients undergoing early CAG (within 1-calender day), versus patients not undergoing early CAG. Inverse probability weighted estimates (IPWE) adjusted for non-randomized CAG. Of 976 resuscitated OHCA patients of cardiac etiology between 2011–2015 (mean(SD) age 64(13) years, 73.7% males), 337 (34.5%) underwent early CAG, of whom, 230 (68.2%) underwent PCI. Those who underwent early CAG were significantly younger (60(12) vs. 66(14) years old), healthier (42% vs. 59% with heart disease; 29% vs. 44% with diabetes), more likely males (86% vs. 67%), and presented with shockable rhythms (69% vs. 36%), compared with those who did not. Early CAG with PCI was associated with better survival and neurological outcome (adjusted odds ratio 1.91 and 1.82 respectively), findings robust to IPWE adjustment. The rates of bleeding and stroke were similar. CAG with PCI within 24 h was associated with improved clinical outcomes after OHCA, without increasing complications. Further studies are required to identify the characteristics of patients who would benefit most from this invasive strategy.

High prevalence of central hypothyroidism among patients with transfusion dependent thalassemia in Hospital Pulau Pinang: A cross sectional study

INTRODUCTION

Thalassemia is the most common heritable haematological disorder in Malaysia. Hypothyroidism is one of the complications of the transfusion dependent thalassemia (TDT) patients as a result of iron overload.

MATERIALS AND METHODS

All registered TDT patients attending Haematology day care, Hospital Pulau Pinang from January 2019 to January 2020 were included in the study. Hypothyroidism was defined according to TSH and FT4, or based on the history of treatment for diagnosed hypothyroidism.

RESULTS

There were 51 TDT patients, with 24 (47%) males and 27 (53%) females. Most of the patients were Malays (27, 53%) followed with Chinese (23, 45%) and Indonesian (1, 2%). Beta thalassemia major and HbE beta thalassaemia accounted for 35 (68.8%) and 14 (27.5%) TDT patients respectively, while two (3.9%) were HbH Constant Spring. Eleven (21.6%) had hypothyroidism; of which seven (63.6%) had central hypothyroidism, three (27.3%) had subclinical hypothyroidism, the remaining one (9.1%) had primary hypothyroidism. Three (27.3%) had concomitant hypogonadism, one (9.1%) had hypocortisolism and another (9.1%) had both diabetes mellitus and hypogonadism. There was no statistical relationship between the prevalence of hypothyroidism and age, serum ferritin, splenectomy history and iron chelation therapy.

CONCLUSION

High prevalence of central hypothyroidism is reported. Measurement of both TSH and FT4 is recommended as initial screening for thyroid dysfunction among patient with TDT.

Incidence, characteristics and complications of dispatcher-assisted cardiopulmonary resuscitation initiated in patients not in cardiac arrest

AIM

Dispatcher-assisted cardiopulmonary resuscitation (DA-CPR) can increase bystander CPR rates and improve outcomes in out-of-hospital cardiac arrest (OHCA). Despite the use of protocols, dispatchers may falsely recognise some cases to be in cardiac arrest. Hence, this study aimed to find the incidence of DA-CPR initiated for non-OHCA cases, its characteristics and clinical outcomes in the Singapore population.

METHODS

This was a multi-centre, observational study of all dispatcher-recognised cardiac arrests cases between January to December 2017 involving three tertiary hospitals in Singapore. Data was obtained from the Pan-Asian Resuscitation Outcomes Study cohort. Audio review of dispatch calls from the national emergency ambulance service were conducted and information about patients' clinical outcomes were prospectively collected from health records. Univariate analysis was performed to determine factors associated with in-hospital mortality among non-OHCA patients who received DA-CPR.

RESULTS

Of the 821 patients recognised as having OHCA 328 (40.0%) were not in cardiac arrest and 173 (52.7%) of these received DA-CPR. No complications from chest compressions were found from hospital records. The top diagnoses of non-OHCA patients were cerebrovascular accidents (CVA), syncope and infection. Only final diagnoses of CVA (aOR 20.68), infection (aOR 17.34) and myocardial infarction (aOR 32.19) were significantly associated with in-hospital mortality.

CONCLUSION

In this study, chest compressions initiated on patients not in cardiac arrest by dispatchers did not result in any reported complications and was not associated with in-hospital mortality. This provides reassurance for the continued implementation of DA-CPR.

Beyond return of spontaneous circulation: update on post-cardiac arrest management in the intensive care unit

A well-functioning chain of survival is critical for good outcomes following out-of-hospital cardiac arrest, a major public health concern in Singapore. While the percentage of survivors to hospital admission has increased over the years, the percentage of survivors to hospital discharge and the number of patients with good neurological recovery can be greatly improved. This underscores the urgent need to focus on 'post-cardiac arrest care', the fifth link in the chain of survival, to improve the outcomes of patients who are admitted to the intensive care unit (ICU) after return of spontaneous circulation. This review builds on earlier recommendations of the Singapore National Targeted Temperature Management Workgroup in 2017 to provide a focused update on post-cardiac arrest management and a practical guide for physicians managing resuscitated patients with cardiac arrest in the ICU.

Assessing unrealised potential for organ donation after out-of-hospital cardiac arrest

Background

Organ donation after brain death is the standard practice in many countries. Rates are low globally. This study explores the potential national number of candidates for uncontrolled donations after cardiac death (uDCD) amongst out-of-hospital cardiac arrest (OHCA) patients and the influence of extracorporeal cardiopulmonary resuscitation (ECPR) on the candidacy of these potential organ donors using Singapore as a case study.

Methods

Using Singapore data from the Pan-Asian Resuscitation Outcomes Study, we identified all non-traumatic OHCA cases from 2010 to 2016. Four established criteria for identifying uDCD candidates (Madrid, San Carlos Madrid, Maastricht and Paris) were retrospectively applied onto the population. Within these four groups, a condensed ECPR eligibility criteria was employed and thereafter, an estimated ECPR survival rate was applied, extrapolating for possible neurologically intact survivors had ECPR been administered.

Results

12,546 OHCA cases (64.8% male, mean age 65.2 years old) qualified for analysis. The estimated number of OHCA patients who were eligible for uDCD ranged from 4.3 to 19.6%. The final projected percentage of potential uDCD donors readjusted for ECPR survivors was 4.2% (Paris criteria worst-case scenario, n = 532) to 19.4% of all OHCA cases (Maastricht criteria best-case scenario, n = 2428), for an estimated 14.3 to 65.4 uDCD donors per million population per year (pmp/year).

Conclusions

In Singapore case study, we demonstrated the potential numbers of candidates for uDCD among resuscitated OHCA cases. This sizeable pool of potential donors demonstrates the potential for an uDCD program to expand the organ donor pool. A small proportion of these patients might however survive had they been administered ECPR. Further research into the factors influencing local organ and patient outcomes following uDCD and ECPR is indicated.

Subclinical vasculopathy and skeletal muscle metrics in the singapore longitudinal ageing study

Frailty is associated with future cardiovascular events in older adults. This cross-sectional study examined the relationship between subclinical vasculopathy with measures of skeletal muscle mass and function. Asymptomatic community-dwelling Asians ≥55 years underwent assessments for subclinical vasculopathy (carotid intima-media thickness (cIMT), aortic and carotid stiffness, and endothelial function), muscle mass (calf circumference adjusted for body mass index) and function (knee extension strength, 6-meter fast gait speed). Multivariable regression analyses for associates of muscle mass/function controlled for demographics and cardiometabolic risk factors. Among 336 participants (median age 62 years, 55.1% male, 3.6% sarcopenia), cIMT, aortic and carotid stiffness inversely correlated with muscle mass, strength and gait speed; cIMT remained independently associated with gait speed (β=-0.26) in multivariable analyses. Age and sex significantly modified the relationship between subclinical vasculopathy and muscle mass/function. Associations, only found in those aged ≥70, included cIMT with gait speed (β=-0.48) and knee strength (β=-9.33), and aortic augmentation index and aortic stiffness composite z-score with gait speed (β=-0.11 and β=-0.19 respectively). Among males, cIMT correlated with gait speed (β=-0.31). The association of subclinical vasculopathy with skeletal muscle mass and function in asymptomatic adults ≥55 years is best reflected by cIMT. The roles of mediating pathways deserve further evaluation.

Cost-effectiveness of prenatal screening methods for congenital heart defects in pregnancies conceived by in-vitro fertilization

OBJECTIVES

To determine if a policy of universal fetal echocardiography (echo) in pregnancies conceived by in-vitro fertilization (IVF) is cost-effective as a screening strategy for congenital heart defects (CHDs) and to examine the cost-effectiveness of various other CHD screening strategies in IVF pregnancies.

METHODS

A decision-analysis model was designed from a societal perspective with respect to the obstetric patient, to compare the cost-effectiveness of three screening strategies: (1) anatomic ultrasound (US): selective fetal echo following abnormal cardiac findings on detailed anatomic survey; (2) intracytoplasmic sperm injection (ICSI) only: fetal echo for all pregnancies following IVF with ICSI; (3) all IVF: fetal echo for all IVF pregnancies. The model initiated at conception and had a time horizon of 1 year post-delivery. The sensitivities and specificities for each strategy, the probabilities of major and minor CHDs and all other clinical estimates were derived from the literature. Costs, including imaging, consults, surgeries and caregiver productivity losses, were derived from the literature and Medicare databases, and are expressed in USA dollars ($). Effectiveness was quantified as quality-adjusted life years (QALYs), based on how the strategies would affect the quality of life of the obstetric patient. Secondary effectiveness was quantified as number of cases of CHD and, specifically, cases of major CHD, detected.

RESULTS

The average base-case cost of each strategy was as follows: anatomic US, $8119; ICSI only, $8408; and all IVF, $8560. The effectiveness of each strategy was as follows: anatomic US, 1.74487 QALYs; ICSI only, 1.74497 QALYs; and all IVF, 1.74499 QALYs. The ICSI-only strategy had an incremental cost-effectiveness ratio (ICER) of $2 840 494 per additional QALY gained when compared to the anatomic-US strategy, and the all-IVF strategy had an ICER of $5 692 457 per additional QALY when compared with the ICSI-only strategy. Both ICERs exceeded considerably the standard willingness-to-pay threshold of $50 000-$100 000 per QALY. In a secondary analysis, the ICSI-only strategy had an ICER of $527 562 per additional case of major CHD detected when compared to the anatomic-US strategy. All IVF had an ICER of $790 510 per case of major CHD detected when compared with ICSI only. It was determined that it would cost society five times more to detect one additional major CHD through intensive screening of all IVF pregnancies than it would cost to pay for the neonate's first year of care.

CONCLUSION

The most cost-effective method of screening for CHDs in pregnancies following IVF, either with or without ICSI, is to perform a fetal echo only when abnormal cardiac findings are noted on the detailed anatomy scan. Performing routine fetal echo for all IVF pregnancies is not cost-effective. © 2020 International Society of Ultrasound in Obstetrics and Gynecology.

Artificial Intelligence Applications for COVID-19 in Intensive Care and Emergency Settings: A Systematic Review

Background: Little is known about the role of artificial intelligence (AI) as a decisive technology in the clinical management of COVID-19 patients. We aimed to systematically review and critically appraise the current evidence on AI applications for COVID-19 in intensive care and emergency settings. Methods: We systematically searched PubMed, Embase, Scopus, CINAHL, IEEE Xplore, and ACM Digital Library databases from inception to 1 October 2020, without language restrictions. We included peer-reviewed original studies that applied AI for COVID-19 patients, healthcare workers, or health systems in intensive care, emergency, or prehospital settings. We assessed predictive modelling studies and critically appraised the methodology and key findings of all other studies. Results: Of fourteen eligible studies, eleven developed prognostic or diagnostic AI predictive models, all of which were assessed to be at high risk of bias. Common pitfalls included inadequate sample sizes, poor handling of missing data, failure to account for censored participants, and weak validation of models. Conclusions: Current AI applications for COVID-19 are not ready for deployment in acute care settings, given their limited scope and poor quality. Our findings underscore the need for improvements to facilitate safe and effective clinical adoption of AI applications, for and beyond the COVID-19 pandemic.

Impact of COVID-19 on Out-of-Hospital Cardiac Arrest in Singapore

This study aimed to evaluate the impact of the Coronavirus Disease 2019 (COVID-19) pandemic on out-of-hospital cardiac arrest (OHCA) in Singapore. We used data from the Singapore Civil Defence Force to compare the incidence, characteristics and outcomes of all Emergency Medical Services (EMS)-attended adult OHCA during the pandemic (January-May 2020) and pre-pandemic (January-May 2018 and 2019) periods. Pre-hospital return of spontaneous circulation (ROSC) was the primary outcome. Binary logistic regression was used to calculate the adjusted odds ratios (aOR) for the characteristics of OHCA. Of the 3893 OHCA patients (median age 72 years, 63.7% males), 1400 occurred during the pandemic period and 2493 during the pre-pandemic period. Compared with the pre-pandemic period, OHCAs during the pandemic period more likely occurred at home (aOR: 1.48; 95% CI: 1.24-1.75) and were witnessed (aOR: 1.71; 95% CI: 1.49-1.97). They received less bystander CPR (aOR: 0.70; 95% CI: 0.61-0.81) despite 65% of witnessed arrests by a family member, and waited longer for EMS (OR ≥ 10 min: 1.71, 95% CI 1.46-2.00). Pre-hospital ROSC was less likely during the pandemic period (aOR: 0.67; 95% CI: 0.53-0.84). The pandemic saw increased OHCA incidence and worse outcomes in Singapore, likely indirect effects of COVID-19.

Multiplexed Single-Cell Leukocyte Enzymatic Secretion Profiling from Whole Blood Reveals Patient-Specific Immune Signature

Enzymatic secretion of immune cells (leukocytes) plays a dominant role in host immune responses to a myriad of biological triggers, including infections, cancers, and cardiovascular diseases. Current tools to probe these leukocytes inadequately profile these vital biomarkers; the need for sample preprocessing steps of cell lysis, labeling, washing, and pipetting inevitably triggers the cells, changes its basal state, and dilutes the individual cell secretion in bulk assays. Using a fully integrated system for multiplexed profiling of native immune single-cell enzyme secretion from 50 μL of undiluted blood, we eliminate sample handling. With a total analysis time of 60 min, the integrated platform performs six tasks of leukocyte extraction, cell washing, fluorescent enzyme substrate mixing, single-cell droplet making, droplet incubation, and real-time readout for leukocyte secretion profiling of neutrophil elastase, granzyme B, and metalloproteinase. We calibrated the device, optimized the protocols, and tested the leukocyte secretion of acute heart failure (AHF) patients at admission and predischarge. This paper highlights the presence of single-cell enzymatic immune phenotypes independent of CD marker labeling, which could potentially elucidate the innate immune response states. We found that patients recovering from AHF showed a corresponding reduction in immune-cell enzymatic secretion levels and donor-specific enzymatic signatures were observed, which suggests patient-to-patient heterogeneous immune response. This platform presents opportunities to elucidate the complexities of the immune response from a single drop of blood and bridge the current technological, biological, and medical gap in understanding immune response and biological triggers.

Crash Landing of Thyroid Storm: A Case Report and Review of the Role of Extra-Corporeal Systems

Thyroid storm is a rare but life-threatening endocrinological emergency with significant mortality ranging from 10-30% with multi-organ involvement and failure. In view of the rarity of this condition and efficacy of established first line medical treatment, use of extra-corporeal treatments are uncommon, not well-studied, and its available evidence exists only from case reports and case series. We describe a 28-year-old man who presented with an out-of-hospital cardiac arrest secondary to thyroid storm. Despite conventional first-line pharmacotherapy, he developed cardiogenic shock and circulatory collapse with intravenous esmolol infusion, as well as multi-organ failure. He required therapeutic plasma exchange, concurrent renal replacement therapy, and veno-arterial extra-corporeal membrane oxygenation, one of the few reported cases in the literature. While there was clinical stabilization and improvement in tri-iodothyronine levels on three extra-corporeal systems, he suffered irreversible hypoxic-ischemic brain injury. We reviewed the use of early therapeutic plasma exchange and extra-corporeal membrane oxygenation, as well as the development of other novel extra-corporeal modalities when conventional pharmacotherapy is unsuccessful or contraindicated. This case also highlights the complexities in the management of thyroid storm, calling for caution with beta-blockade use in thyrocardiac disease, with close monitoring and prompt organ support.

Impact of COVID-19 on health-related quality of life in patients with cardiovascular disease: a multi-ethnic Asian study

Background

Little is known about the impact of the global coronavirus disease-2019 (COVID-19) pandemic on patients with cardiovascular disease (CVD), the biggest global killer and major risk factor for severe COVID-19 infections. We aim to explore the indirect consequences of COVID-19 on health-related quality of life (HRQoL) of patients with CVD.

Methods

Eighty-one adult outpatients with CVD were assessed using the EQ-5D, a generic health status instrument with five dimensions (mobility, self-care, usual activities, pain/discomfort, anxiety/depression), before and during the pandemic. Changes in the EQ-5D dimensional responses were compared categorically as well as using the dimension-specific sum-score (range 1–3, with a higher score indicating worse health). The responses and sum-score were compared using the exact test of symmetry and the paired t-test, respectively.

Results

These patients [mean age (SD) 59.8 (10.5); 92.6% males; 56% New York Heart Association (NYHA) functional class I] had coronary artery disease (69%), heart failure (28%), or arrhythmias (15%). None experienced change in NYHA class between assessments. About 30% and 38% of patients reported problems with at least one of the EQ-5D dimensions pre-pandemic and during the pandemic, respectively. The highest increase in health problems was reported for anxiety/depression (12.5% pre-pandemic vs 23.5% during pandemic; p = 0.035) with mean domain-specific score from 1.12 (SD 0.33) to 1.25 (SD 0.46) (standardized effect size = 0.373, p = 0.012). There was no meaningful change in other dimensions as well as overall HRQoL.

Conclusion

The COVID-19 pandemic is associated with a significant worsening of the mental health of patients with CVD.

Nitrates in combination with hydralazine in cardiorenal syndrome: a randomized controlled proof-of-concept study

AIMS

Cardiorenal syndrome (CRS) is a common problem of great morbidity and mortality. Hydralazine-isosorbide dinitrate (H-ISDN) may be used in renal failure and may improve exercise capacity in heart failure (HF). Our proof-of-concept study aimed to evaluate early evidence of efficacy, safety, and feasibility of H-ISDN compared with standard of care in CRS.

METHODS AND RESULTS

This multi-centre, single-blind, randomized trial in Singapore enrolled CRS patients, defined as chronic HF with concomitant renal failure [estimated glomerular filtration rate (eGFR) < 60 ml/min/1.73 m² ]. The primary outcome was 6 min walk test (6MWT) distance measured at 6 months. Secondary outcomes included study feasibility; efficacy outcomes which included renal, cardiac, and endothelial functions, health-related quality of life using Short Form-36, clinical outcomes; and adverse events. Forty-four patients [71 ± 10 years; 75% male; median (inter-quartile range) N-terminal prohormone brain natriuretic peptide 1346 (481-2272) pg/mL] with CRS (left ventricular ejection fraction 42 ± 12% and eGFR 46 ± 15 ml/min/1.73 m² ) were randomized into two equal groups. Of these, 39 (89%) had hypertension, 27 (61%) had diabetes mellitus, and 17 (39%) had atrial fibrillation. Six (27%) discontinued H-ISDN owing to intolerance and poor compliance. There was a trend towards improved 6MWT distance with H-ISDN compared with standard of care at 6 months (mean difference 27 m; 95% CI, -12 to 66), with little differences in secondary efficacy outcomes. Giddiness and hypotension occurred more frequently with H-ISDN, but HF hospitalizations and mortality were less.

CONCLUSIONS

Our pilot study does not support the addition of H-ISDN on top of standard medical therapy to improve exercise capacity in patients with CRS.

Incidence and Outcomes of Out-of-Hospital Cardiac Arrest in Singapore and Victoria: A Collaborative Study

Background

Incidence and outcomes of out‐of‐hospital cardiac arrest (OHCA) vary between communities. We aimed to examine differences in patient characteristics, prehospital care, and outcomes in Singapore and Victoria.

Methods and Results

Using the prospective Singapore Pan‐Asian Resuscitation Outcomes Study and Victorian Ambulance Cardiac Arrest Registry, we identified 11 061 and 32 003 emergency medical services‐attended adult OHCAs between 2011 and 2016 respectively. Incidence and survival rates were directly age adjusted using the World Health Organization population. Survival was analyzed with logistic regression, with model selection via backward elimination. Of the 11 061 and 14 834 emergency medical services‐treated OHCAs (overall mean age±SD 65.5±17.2; 67.4% males) in Singapore and Victoria respectively, 11 054 (99.9%) and 5595 (37.7%) were transported, and 440 (4.0%) and 2009 (13.6%) survived. Compared with Victoria, people with OHCA in Singapore were older (66.7±16.5 versus 64.6±17.7), had less shockable rhythms (17.7% versus 30.3%), and received less bystander cardiopulmonary resuscitation (45.7% versus 58.5%) and defibrillation (1.3% versus 2.5%) (all P<0.001). Age‐adjusted OHCA incidence and survival rates increased in Singapore between 2011 and 2016 (P<0.01 for trend), but remained stable, though higher, in Victoria. Likelihood of survival increased significantly (P<0.001) with arrest in public locations (adjusted odds ratio [aOR] 1.81), witnessed arrest (aOR 2.14), bystander cardiopulmonary resuscitation (aOR 1.72), initial shockable rhythm (aOR 9.82), and bystander defibrillation (aOR 2.04) but decreased with increasing age (aOR 0.98) and emergency medical services response time (aOR 0.91).

Conclusions

Singapore reported increasing OHCA incidence and survival rates between 2011 and 2016, compared with stable, albeit higher, rates in Victoria. Survival differences might be related to different emergency medical services practices including patient selection for resuscitation and transport.

Prevalence of endocrine complications in transfusion dependent thalassemia in Hospital Pulau Pinang: A pilot study

INTRODUCTION

Frequent blood transfusions results in iron overload and lead to multiple endocrine complications. In spite of improvements in iron chelation therapy, a significant number of transfusion dependent thalassaemia (TDT) patients still develop endocrine complications. The aim of this study is to evaluate the prevalence of various endocrine complications in our adult TDT patients and to study the correlation with serum ferritin and liver iron concentration (LIC).

METHODS

A retrospective review of all TDT patients treated in Haematology Unit, Hospital Pulau Pinang (HPP) was conducted.

RESULTS

Of the 45 adult TDT patients, 22 were males and 23 were females with mean age of 28.8±6.9 years old. Majority of TDT in HPP were beta thalassemia major (71.1%), followed by E-Beta thalassemia (24.4%) and HbH-Constant Spring (4.4%). Frequency of transfusion was 3-4 weekly. 40.0% of adult TDT suffered from at least one endocrine complication. Among the adult TDT patients with endocrine complication, 50% have one endocrinopathy, 38.9% with two types of endocrinopathies and 11.1% of them have three or more types of endocrinopathies. Hypogonadism (22.2%) was the commonest endocrine complication, followed by osteoporosis (20%), hypothyroidism (13.3%), diabetes mellitus (6.7%) and hypocortisolism (4.4%). Patients with endocrine complications were significantly older. Mean serum ferritin level and LIC was higher among patients with endocrine complications but both were not statistically significant.

CONCLUSION

Endocrinopathy is still prevalent in 40% of adult TDT patients. This leads to higher health-care resource utilization, cost and significant morbidities among patients with TDT. Therefore, regular monitoring and early detection with intensification of chelation therapy is essential.

Microvascular Disease in Patients With Diabetes With Heart Failure and Reduced Ejection Versus Preserved Ejection Fraction

OBJECTIVE

Microvascular complications are common among patients with diabetes mellitus (DM). The presence of heart failure (HF) is presumed to be due to macrovascular disease (typically HF with reduced ejection fraction [HFrEF] following myocardial infarction). We hypothesized that HF with preserved ejection fraction (HFpEF) in patients with DM may be a manifestation of microvascular disease compared with HFrEF. The objective of this study was to examine the prevalence and association with clinical outcome of microvascular complications in patients with HF and DM.

RESEARCH DESIGN AND METHODS

We investigated the prevalence, association with clinical outcome, and cardiac structure and function of microvascular (neuropathy, nephropathy, and retinopathy) complications of DM in 2,800 prospectively enrolled participants with HF and DM (561 with HFpEF) from the Asian Sudden Cardiac Death In Heart Failure (ASIAN-HF) registry.

RESULTS

A total of 601 (21.5%) participants with DM had microvascular complications. Participants with DM and any (one or more) microvascular complications were more likely to have HFpEF (odds ratio 1.70 [95% CI 1.15-2.50]; P = 0.008). Furthermore, the likelihood of having HFpEF increased with an increasing number of microvascular complications (P _trend < 0.001). Microvascular complications were associated with more left ventricular (LV) hypertrophy and a greater reduction in quality of life in HFpEF than HFrEF (P _interaction < 0.001 for all). Compared with participants with DM and without microvascular complications, the adjusted hazard ratio for the composite outcome of all-cause death or HF hospitalization was 1.35 (95% CI 1.04-1.76) for participants with DM and microvascular complications regardless of HF type (P _interaction = 0.112).

CONCLUSIONS

Diabetic microvascular disease is more common, and related to greater LV remodeling, more impairment of quality in life, and similar adverse outcomes, in participants with HFpEF compared with HFrEF. HFpEF may be a clinical manifestation of microvascular disease in DM.

Therapeutic temperature management (TTM): post-resuscitation care for adult cardiac arrest, with recommendations from the National TTM Workgroup

Therapeutic temperature management (TTM) was strongly recommended by the 2015 International Liaison Committee on Resuscitation as a component of post-resuscitation care. It has been known to be effective in improving the survival rate and neurologic functional outcome of patients after cardiac arrest. In an effort to increase local adoption of TTM as a standard of post-resuscitation care, this paper discusses and makes recommendations on the treatment for local providers.

Single-dose intravenous iron in Southeast Asian heart failure patients: A pilot randomized placebo-controlled study (PRACTICE-ASIA-HF)

AIMS

Iron deficiency is highly prevalent in Southeast Asians with heart failure (HF) and associated with worse outcomes. This trial aimed to assess the effect of intravenous iron in Southeast Asians hospitalized with decompensated HF.

METHODS AND RESULTS

Fifty patients hospitalized for acute decompensated HF, regardless of ejection fraction, with iron deficiency (defined as serum ferritin <300 ng/mL if transferrin saturation is <20%) were randomized to receive either one dose of intravenous ferric carboxymaltose (FCM) 1000 mg or placebo (0.9% saline) following HF stabilization and before discharge in two Singapore tertiary centres. The primary endpoint was difference in 6-min walk test (6MWT) distance over 12 weeks, while secondary endpoints were quality of life assessed using validated Kansas City Cardiomyopathy Questionnaire (KCCQ) and Visual Analogue Scale (VAS). Improvement in 6MWT distance at Week 12 was observed in both FCM and placebo groups (from 252 ± 123 to 334 ± 128 m and from 243 ± 67 to 301 ± 83 m, respectively). Unadjusted analysis showed 6MWT distance for FCM exceeded that for placebo, but adjustment for baseline covariates and time attenuated this effect {adjusted mean difference between groups: 0.88 m [95% confidence interval (CI) -30.2 to 32.0, P = 0.956]}. KCCQ overall summary and VAS were similar in both groups [adjusted mean difference: KCCQ -1.48 (95% CI -8.27 to 5.31, P = 0.670) and VAS 0.26 (95% CI -0.33 to 0.86, P = 0.386)]. FCM was well tolerated with no serious treatment-related adverse events.

CONCLUSIONS

Intravenous FCM administered pre-discharge in Southeast Asians hospitalized with decompensated HF is clinically feasible. Changes in 6MWT distance should be measured beyond Week 12 to account for background therapy effects.

An East-West comparison of self-care barriers in heart failure

BACKGROUND

Barriers in heart failure self-care contribute to heart failure hospitalizations, but geographic differences have not been well-studied. We aimed to compare self-care barriers in heart failure patients managed at tertiary centers in an Eastern (Singapore) versus a Western (USA) nation.

METHODS

Acute heart failure patients were prospectively assessed with a standardized instrument comprising of 47 distinct self-care barriers. The multi-equation generalized structural equation model was used to evaluate for geographic differences in barriers experienced, and association of barriers with outcomes.

RESULTS

Patient-related factors accounted for six out of 10 most prevalent self-care barriers among the 90 patients, with a median number of 11 barriers reported per patient. The Western patients reported a higher level of barriers when compared with their Eastern counterparts (median (interquartile range) 15 (9-24) versus 9 (4-16), p=0.001), after adjusting for demographics and co-morbidities. Many of these differences could be explained by geographic differences between the countries. There was no significant difference identified in all-cause mortality (19.4% versus 10.2%) and heart failure re-hospitalization (41.9% versus 45.8%) at six months between the groups.

CONCLUSIONS

Self-care barriers are highly prevalent among acute heart failure patients, and differ substantially between East and West, but were not associated with geographic differences in outcomes.

Rare presentation of idiopathic duodenoduodenal intussusception

Enteroenteric intussusception is a condition in which the full-thickness bowel wall becomes telescoped into the lumen of distal bowel. Intussusception in adult occurs infrequently and varies from childhood intussusception, particularly in its presentation, aetiology and treatment. Duodenoduodenal intussusception is rare because the duodenum is fixed in the retroperitoneal position. It usually occurs secondary to tumour, lipoma, Brunner's gland hamartomatous polyp or adenoma. The diagnosis in adults is usually made at laparotomy, where presentation is with intestinal obstruction. In non-emergency presentation, it may be difficult to arrive at an accurate diagnosis as symptoms may be vague, self-limiting intermittent abdominal pain. Clinical examinations and investigations may not be conclusive and another working diagnosis such as irritable bowel syndrome would be made. We describe a case where a patient initially presented with symptoms mimicking pancreatitis but his symptoms persisted over the course of 2 weeks. When a laparotomy was performed, duodenoduodenal intussusception was discovered and confirmed with histopathology. In this case, a discernible leading point could not be identified.

Expression patterns of HENMT1 and PIWIL1 in human testis: implications for transposon expression

This study aimed to define the expression patterns of HENMT1 and PIWI proteins in human testis and investigate their association with transposon expression, infertility sub-type or development of testicular germ cell tumours (TGCTs). Testis biopsies showing normal spermatogenesis were used to identify normal localisation patterns of HENMT1 and PIWIL1 by immunolocalisation and RT-PCR after laser microdissection. 222 testis biopsies representing normal spermatogenesis, hypospermatogenesis, spermatogenic arrests, Sertoli cell-only (SCO) tumours and TGCTs were analysed by RT-qPCR for expression of HENMT1/PIWIL1/PIWIL2/PIWIL3/PIWIL4 and LINE-1 Additionally, HENMT1-overexpressing TCam2 seminoma cell lines were analysed for the same parameters by RT-qPCR. We found that HENMT1 and PIWIL1 are coexpressed in pachytene spermatocytes and spermatids. Expression of HENMT1, PIWIL1 and PIWIL2 was mainly dependent on germ cell content but low levels of expression were also detected in some SCO samples. Levels of HENMT1, PIWIL1 and PIWIL2 expression were low in TGCT. Samples with HENMT1, PIWIL2 and PIWIL4 expression showed significantly (P < 0.05) lower transposon expression compared to samples without expression in the same histological group. HENMT1-overexpressing TCam2 cells showed lower LINE-1 expression than empty vector-transfected control lines. Our findings support that the transposon-regulating function of the piRNA pathway found in the mouse is conserved in adult human testis. HENMT1 and PIWI proteins are expressed in a germ-cell-specific manner and required for transposon control.