Enhanced phylogenetic insights into the microbiome of chronic rhinosinusitis through the novel application of long read 16S rRNA gene amplicon sequencing

INTRODUCTION

16S rRNA next generation sequencing (NGS) has been the de facto standard of microbiome profiling. A limitation of this technology is the inability to accurately assign taxonomy to a species order. Long read 16S sequencing platforms, including Oxford Nanopore Technologies (ONT), have the potential to overcome this limitation. The paranasal sinuses are an ideal niche to apply this technology, being a low biomass environment where bacteria are implicated in disease propagation. Characterising the microbiome to a species order may offer new pathophysiological insights.

METHODOLOGY

Cohort series comparing ONT and NGS biological conclusions. Swabs obtained endoscopically from the middle meatus of 61 CRSwNP patients underwent DNA extraction, amplification and dual sequencing (Illumina Miseq (NGS) and ONT GridION). Agreement, relative abundance, prevalence, and culture correlations were compared.

RESULTS

Mean microbiome agreement between sequencers was 61.4%. Mean abundance correlations were strongest at a familial/genus order and declined at a species order where NGS lacked resolution. The most significant discrepancies applied to Corynebacterium and Cutibacterium, which were estimated in lower abundance by ONT. ONT accurately identified 84.2% of cultured species, which was significantly higher than NGS.

CONCLUSIONS

ONT demonstrated superior resolution and culture correlations to NGS, but underestimated core sinonasal taxa. Future application and optimisation of this technology can advance our understanding of the sinonasal microenvironment.

Predictors of left ventricular mass and coronary artery calcium phenotypes

Funding Acknowledgements

Type of funding sources: Public Institution(s). Main funding source(s): National Medical Research Council, Ministry of Health, Singapore and the Lee Foundation

Background

Left ventricular (LV) mass and coronary artery calcium score (CACS) are both independent predictors of cardiovascular risk. There is paucity of data on the interplay of risk factors on LV mass in the presence or absence of subclinical coronary atherosclerosis.

Purpose

The objective of this present study was to explore the relationship of risk factors to indexed LV mass and CACS in a healthy Southeast-Asian population.

Methods

This study recruited volunteers with no known cardiovascular disease. LV mass, measured by cardiovascular magnetic resonance, was indexed to body surface area (LVMI), and CACS determined by non-contrast CT scanning. Blood pressure (BP) was measured via both office and ambulatory monitoring, and physical activity assessed through wearable devices. Analysis of LVMI was stratified into high, normal and low defined as more than one standard deviation away from the mean for each sex, with inter-group differences evaluated using chi-squared or ANOVA statistical tests. Subjects in each LVMI group were further subdivided by the presence and absence of coronary calcification (total 6 subgroups; LVMI/CACS phenotypes).

Results

A total of 880 subjects were included, including 428 males and 452 females. There was no significant difference in prevalence of coronary calcification across the LVMI groups for males, while females with high LVMI had significantly greater proportion of positive CACS (p = 0.036). Higher LVMI was observed in younger male subjects, but not in females.

In both sexes, body mass index was positively associated with LVMI (p = 0.004 for males, p = 0.037 for females), but not CACS. Waist circumference was associated with higher LVMI in males only.

Greater amounts of weekly self-reported exercise (p = 0.006) and daily calories burned (p = 0.022) were associated with increased LVMI for males only. However, wearable-derived measures of daily physical activity and step counts did not significantly affect LVMI or LVMI/CACS phenotypes in both sexes.

BP was a strong predictor of LVMI in both sexes regardless of office or ambulatory readings, in both day and night-time. The association was also observed with LVMI/CACS phenotypes: higher systolic or diastolic BP was significantly associated with positive CACS across all risk groups. Notably, subjects with low LVMI and positive CACS were normotensive (office BP 129/82 for males, 123/77 for females).

Higher HDL cholesterol levels correlated to absence of coronary calcification in males only (p = 0.010). In females, lower levels of total (p = 0.001) and LDL (p = 0.005) cholesterol were associated with absence of coronary calcification across all LVMI categories.

Conclusion

Only BP was strongly associated with LVMI and LVMI/CACS phenotypes in both sexes. There appears to be no correlation between physical activity and LVMI/CACS phenotypes. There is a need for causative studies to better evaluate the varying influence of risk factors on LVMI and CACS.

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.

Turn Impossible into I'm Possible: An Interventional Radiographer's Battle Experience Against COVID-19

Introduction

The coronavirus disease 2019 (COVID-19) pandemic presented an unprecedented challenge to the world. Due to its transmissible nature, it is essential for radiographers to have a comprehensive understanding of the epidemiology of COVID-19 to formulate protocols and strategies to ensure the safety of patients and staff. This article aims to present a radiographer's perspective of the impact of COVID-19 on interventional radiology (IR) services in Singapore General Hospital.

Methods

IR is a multidisciplinary centre. In order to prevent cross infection, patients infected with COVID-19 were held in isolated locations. These cases were assessed according to the patient's condition and imaging requirements. Broadly, the workflow is classified into portable ultrasound-guided bedside and fluoroscopy procedures. Additional roles such as duty manager radiographer, controller radiographer and infection prevention liaison officer (IPLO) were introduced to manage the care of COVID-19 patients.

Results

Strategic Management Planning: To avoid total departmental shutdown, a modified working shift system was implemented. Staff were separated to prevent cross-transmission and maintain workplace social distancing. Maintaining Staff Morale and Teamwork: Regular and clear communication with staff is critical to avoid declining morale so as to prevent lapses in infection control and decision making. Infection Prevention and Control: To enhance the efficacy of infection control during this viral outbreak, the IPLO provided a clear and well communicated operational plan for managing the outbreak.Embracing Innovative Technology: A mitigating solution was imposed by the department to ensure that continuing professional development can be achieved easily via video conferencing platforms.

Conclusion

Radiographers must be adaptable to changes in the healthcare climate in order to ensure continuity of care. The COVID-19 pandemic gave rise to various role extensions for radiographers, demonstrating the potential of this specialised group of individuals to contribute to our nation's fight against the virus.

Can cord blood lipid and lipoprotein levels inform LDL targets?

Funding Acknowledgements

Type of funding sources: None.

Introduction

  Current ESC dyslipidemia guidelines recommend lowering LDL targets to 1.4mmol/L (55mg/dL) for very high risk individuals. Lipid levels of newborns may provide insights into physiologic levels at the time of birth. There is limited data on cord blood lipids/lipoprotein levels in Asian populations. This study aims to describe cord blood lipid levels in a multi-ethnic Asian population.

Methods

  We analyzed 563 (F = 275) anonymized residual cord serum samples for the measurement of cholesterol, triglycerides, dLDL and HDL on the Cobas c702 autoanalyzer and cLDL after exclusion of outliers (Tukey). Following tests for Gaussian distribution (Shapiro-Wilk) all data were log transformed. Gender differences were assessed by Mann-Whitney U test. dLDL was compared with cLDL (Passing-Bablok regression, Wilcoxon’s test, Bland-Altman plot). Statistical calculations were performed using MedCalc v20 (MedCalc software, Ostend, Belgium).

Results

There was no gender difference for cord cholesterol (p = 0.1781) and cLDL (p = 0.6186) and their values were: cholesterol (range:0.78-3.09mmol/L; mean:1.486; reference interval:0.92-2.42) and cLDL (range:0.19-1.85mmol/L; mean:0.60 ; reference interval:0.27-1.21). dLDL was higher in females (p = 0.0388) (range:0.17-1.84mmol/L; median:0.54; IQR:0.37,0.71; reference interval:0.22-1.26; 99th percentile 1.42) compared to males (range:0.16-1.19mmol/L; median:0.49; IQR:0.36,0.62; reference interval:0.21-0.98; 99th percentile 1.13). Cord dLDL values were significantly lower (p < 0.001) than cLDL; the difference (Bland-Altman) between dLDL and cLDL ranged from -0.2062-0.0141 mmol/L (mean -0.0960). Passing-Bablok regression analysis showed cLDL = 1.0465dLDL + 0.0695 with a correlation coefficient (Spearman) of 0.963 (p < 0.0001). Female triglycerides were lower (p < 0.0001) [range:0.11-0.82mmol/L; median:0.24; IQR:0.19,0.31; reference interval:0.11-0.64] than males [range:0.11-0.85mmol/L; median:0.28; IQR:0.21,0.38; reference interval:0.13-0.66]. HDL was higher in females [range:0.40-1.62mmol/L; median:0.75; IQR:0.62,0.93; reference interval:0.44-1.34] than males [range:0.33-1.29mmol/L; median:0.69; IQR:0.58,0.86; reference interval:0.43-1.16] (p = 0.005).

Conclusion

  Contemporary cord blood lipid/lipoprotein values have been derived for our local multi-ethnic Asian population. Directly measured LDL, shows ESC guideline LDL targets are not lower than cord dLDL levels at the 99th percentile. However cLDL overestimates cord dLDL in this cohort of subjects.

External validation of the PRECISE-DAPT score in an Asian cohort of patients with acute coronary syndrome post-percutaneous coronary intervention

Background

Dual antiplatelet therapy (DAPT) is a key treatment in acute coronary syndrome (ACS) patients after percutaneous coronary intervention (PCI), and the PRECISE-DAPT score is one of the risk assessment tools developed to guide its optimal duration. However, the PRECISE-DAPT derivation cohorts were largely based on Western populations and it remains unclear whether the score is able to demonstrate good predictive value in Asian populations.

Objective

To validate the performance of the PRECISE-DAPT score in a nationwide Asian cohort of ACS patients who underwent PCI and with subsequent DAPT.

Methods

Patients admitted with ACS between January 2012 and December 2014 were extracted from the Singapore Cardiac Longitudinal Outcomes Database (SingCLOUD). The primary outcome was major adverse cardiovascular events (MACE), a composite of deaths, ischemic and hemorrhagic strokes, and recurrent myocardial infarction. The PRECISE-DAPT score was calculated for each patient and was used to stratify patients into low bleeding risk (LBR) (score <25) and high bleeding risk (HBR) (score ≥25) groups (Figure 1). The PRECISE-DAPT guidelines propose that patients with LBR follow a DAPT regimen of 12 months, while patients with HBR follow a DAPT regimen of 3 months followed by aspirin or clopidogrel monotherapy for the rest of the year. Medication adherence to the PRECISE-DAPT guidelines with a proportion of days covered (PDC) of 80% over the 1-year period post-PCI was taken as the cutoff to define adherence, i.e. patients with at least 80% of days covered were defined as adherent. Multivariate Cox regression analysis adjusted for age, gender, ethnicity, smoking status, prior MI, prior PCI and diabetes mellitus was applied to examine the association between the PRECISE-DAPT adherence and MACE. Score discrimination using c-statistic were calculated and calibration curves were visually assessed.

Results

A total of 1135 patients were analyzed. The PRECISE-DAPT score of the adherent group (n=486) was lower compared to the non-adherent group, that made up the majority (n=649) [16.8 (± 9.63) vs 30.37 (± 18.4), p<0.001]. The overall incidence rate of MACE in this cohort was 14.3% and bleeding rate was 1.5%. Non-adherence to PRECISE-DAPT guidelines was independently associated with MACE at 1 year [OR 1.48, 95% CI 1.03 – 2.13, p=0.033] (Figure 1). Receiver-operating characteristic (ROC) analysis demonstrated that the PRECISE-DAPT score in predicting MACE has an area under curve (AUC) of 0.644 [95% CI 0.603, 0.685] (Figure 2) with a sensitivity of 42.8% and specificity of 80.2%.

Conclusion

The PRECISE-DAPT score is able to predict MACE in Asian patients with ACS treated with PCI with high specificity but is not sensitive. The lower AUC value derived suggests that other important factors potentially contribute to the development of MACE in this cohort. Further research is warranted to identify factors that may improve its discriminative performance.

Funding Acknowledgement

Type of funding sources: Public grant(s) – National budget only. Main funding source(s): National Medical Research Council (NMRC) Figure 1. Cox regression for MACEFigure 2. Histogram and AUC Curve

Clinical characteristics and outcomes of myocardial infarction with nonobstructive coronary arteries

Background

Myocardial infarction with nonobstructive coronary arteries (MINOCA) is caused by a heterogenous group of conditions with clinically significant sequelae.

Purpose

This study aims to compare the clinical characteristics and prognosis of MINOCA with myocardial infarction with obstructive coronary artery disease (MICAD).

Methods

Data was obtained from the Singapore Cardiac Longitudinal Outcomes Database (SingCLOUD), a national multicenter registry of patients with cardiovascular disease. Patients with a first presentation of acute myocardial infarction who underwent coronary angiography between 1 January 2011 and 31 December 2014 were extracted from the database. Follow up was conducted until 31 December 2017. Subjects were classified as having either MICAD or MINOCA based on angiographic findings. The primary outcomes were all-cause mortality and major adverse cardiac events (MACE) defined as a composite of all-cause mortality, recurrent myocardial infarction, hospitalization for heart failure and ischemic stroke.

Results

All 4124 patients who met the inclusion criteria were included in this study, of which 159 (3.9%) were diagnosed with MINOCA. Patients with MINOCA were more likely to be female, present with a non-ST elevation myocardial infarction (NSTEMI), have a higher left ventricular ejection fraction and less likely to have diabetes mellitus, previous ischemic stroke or smoking history. Over a mean follow-up duration of 4.5 years, MINOCA patients had a lower incidence of all-cause mortality (10.1% vs. 16.5%, p=0.030) and MACE (20.8% vs. 35.5%, p<0.0001) compared to patients with MICAD. On multivariable analysis, patients with MINOCA had a significantly lower risk of all-cause mortality (HR 0.42; 95% CI 0.21–0.82; p=0.011), MACE (HR 0.42; 95% CI 0.26–0.69; p=0.001) and recurrent myocardial infarction (HR 0.35; 95% CI 0.15–0.85; p=0.021). Within the MINOCA group, older age, higher creatinine, a STEMI presentation and the absence of antiplatelet use predicted all-cause mortality and MACE.

Conclusions

While patients with MINOCA had better clinical outcomes compared to MICAD patients, MINOCA is not a benign entity with about one in five patients experiencing a major adverse cardiovascular event in the mid-term.

Funding Acknowledgement

Type of funding sources: Public grant(s) – National budget only. Main funding source(s): National Medical Research Council Project Grant

Adverse events in acute myocardial infarction patients: the DAPT Score for risk stratification in an Asian population

Background

Dual antiplatelet therapy (DAPT) is essential in mitigating adverse ischemic events after myocardial infarction (MI), and current guidelines have recommended the therapy to be administered for at least 1 year. Though prolonged DAPT helps to reduce ischemic events in high-risk patients, it can also increase the risk of significant bleeding. Risk stratification tools, such as the DAPT Score, can help to identify patients who are most or least likely to benefit from prolonged DAPT.

Purpose

To evaluate the performance of the DAPT Score as a predictor of major adverse cardiovascular events (MACE) in an Asian cohort who underwent percutaneous coronary intervention (PCI) for MI.

Methods

The analysis cohort consisted of 2086 MI patients (86% of primary PCI patients) who were admitted to Singaporean hospitals between 2012 and 2014. Demographic, clinical and therapeutic data regarding the index hospitalisation and 12-month follow-up period were collected. Patients were grouped according to their DAPT Score (high ischemic vs high bleeding risk) and DAPT duration (12 vs <12 months; Figure 1). The primary endpoint was MACE (all-cause mortality, recurrent MI and stroke). MACE as an outcome was evaluated using multivariable Cox regression adjusted for age, gender, ethnicity, smoking status, prior MI, PCI or coronary artery bypass graft, hypertension, dyslipidaemia, cerebrovascular disease, diabetes mellitus, family history of coronary artery disease, vein graft stent and type of MI at presentation.

Results

The overall incidence rate of MACE in this cohort was 12.3%. There was a significantly higher MACE rate in Group 2 patients compared to Group 1 patients (high ischemic risk and <12-month DAPT vs high ischemic risk and 12-month DAPT; hazard ratio: 1.37, 95% confidence interval: 1.02–1.83, P=0.038). No other significant differences in MACE rates were observed among the rest of the groups (Group 3: 1.44 [0.89–2.34]; Group 4: 1.15 [0.61–2.16], P>0.050). Furthermore, MACE was independently associated with diabetes, hypertension, prior MI and cerebrovascular disease (1.49 [1.10–2.02], 1.43 [1.00–2.05], 1.41 [1.01–1.98], 3.06 [2.15–4.37], respectively, P<0.050). Patients <65 years and males were found to be protected against MACE (0.71 [0.51–0.99], 0.72 [0.52–0.99], respectively, P<0.050). The overall bleeding rate was 2.2% (Group 1: 2.0%; Group 2: 1.7%; Group 3: 6.0%; Group 4: 0.7%).

Conclusions

The DAPT Score predicted MACE up to 12 months after PCI in MI patients with high ischemic risk and <12 months of DAPT. This highlights the importance of adequate duration of DAPT in high ischemic risk MI patients. Moreover, the elderly, female, diabetic, hypertensive and those with prior cerebrovascular disease or MI were at increased risk for MACE.

Funding Acknowledgement

Type of funding sources: Public grant(s) – National budget only. Main funding source(s): National Medical Research Council - Health Services Research Grants (Ministry of Health, Singapore) CohortsCox regression for MACE

1048Characteristics of ST-Elevation Myocardial Infarction (STEMI) patients in Asia Pacific: findings from the ASPECT collaboration

Background

The Asia Pacific Evaluation of Cardiovascular Therapies (ASPECT) Collaboration was established to better understand the characteristics of patients undergoing PCI and cardiac interventions across the Asia Pacific region, including STEMI. The aim of this study was to compare STEMI patient characteristics across Asia Pacific (AP) countries in order to understand regional differences.

Methods

Each site across Australia, Singapore, Malaysia, Vietnam and Hong Kong provided de-identified individual patient data. Comparison of characteristics by sites were performed using one-way ANOVA, Kruskal-Wallis or Chi-squared tests, using Stata 14.2.

Results

Of the 12,620 cases, there were more males (p < 0.001) and the average of patients’ age ranged from 55 (Malaysia) to 68 (Vietnam) years old. Family history of coronary artery disease was not common amongst Hong Kong (1%) and Singaporean (12%) patients, and most patients did not have history of congestive heart failure, peripheral vascular disease or coronary artery bypass grafting. History of dyslipidaemia varied significantly among patients in Malaysia (98%) and Vietnam (12%) (p < 0.001). About 37% of the Malaysian patients had previous myocardial infarction, which is greater than twice of other cohorts (p < 0.001). Most cohort had either normal or mild ejection fraction (EF) but 40% of the Singaporean patients had severely reduced EF (p < 0.001).

Conclusions

Patient characteristics varied significantly across AP countries. On-going analyses will focus on the impact of varying patient characteristics on clinical outcomes.

Key messages

As characteristics varied, prevention and procedural strategies need to be adapted carefully. Additional input from other AP countries will better inform these strategies.

Impact of age and sex on subclinical coronary atherosclerosis in a healthy asian population

Funding Acknowledgements

Type of funding sources: None.

Background and Aims

The influence of age and gender on clinical atherosclerotic cardiovascular disease is well reported, but literature remains sparse on whether these extend to the disease in its preclinical stage. We aim to report the prevalence, risk-factors and impact of age and gender on the burden of subclinical coronary atherosclerosis in a healthy Asian population.

Methods

Healthy subjects aged 30-69 years old, with no history of cardiovascular disease or diabetes were recruited from the general population. Subclinical coronary atherosclerosis was quantified via the Coronary Artery Calcium Score (CACS) with CACS of 0 indicating the absence of calcified plaque, 1 to 10 minimal plaque, 11 to 100 mild plaque, and >100 moderate to severe plaque.

Results

A total of 663 individuals (mean age 49.4 ± 9.2 years, 44.8% male) were included. The prevalence of any CAC was 29.3% with 9% having CAC > 100.  The prevalence was significantly higher in males than females (43.1 vs 18.0%, p < 0.001). These gender differences became increasingly pronounced with increasing age, especially in those with moderate-severe CAC. Multivariable analysis revealed significant associations between increasing age, male, higher blood pressure, increased glucose levels and higher LDL cholesterol levels with the presence of any CAC. LDL cholesterol was more significantly associated with CAC in females compared to males (Pinteraction = 0.022).

Conclusions

The prevalence of preclinical atherosclerosis increased with age, and was higher in males than females, with gender-specific differences in associated risk factors. These results will better inform individualised future risk management strategies to prevent the development and progression of coronary artery disease within healthy individuals.

P205 Effectiveness of a portable patient education video prior to coronary angiography and angioplasty

Introduction

 Coronary angiography and angioplasty is widely used in the diagnosis and treatment of coronary artery disease. Limited time to explain the procedure to patients in busy clinical settings may lead to increased adverse outcomes. 

Purpose

To evaluate the effectiveness of a portable patient education video in improving knowledge and allaying patient"s anxiety prior to coronary angiography and angioplasty.

Methods

 Consecutive patients undergoing coronary angiography and angioplasty were prospectively recruited over 1 year from June 2016 to May 2017 from a tertiary cardiac institution. We developed a 3 minute animated patient education video on the procedure. Patients were randomised 1:3 into a control group (receiving routine standard of care) and intervention group (watched video plus routine standard of care). Before the procedure, a self-administered written survey was conducted in the control group, pre-video in the intervention group, and post-video in the intervention group. Demographic data, knowledge and State Trait Anxiety Inventory (STAI) scores were gathered. Figure 1 shows excerpts of the video.

Results

We recruited 332 patients- 80 controls (80% males, mean age 59.6 ± 11.5, 51% previous procedures) and 252 intervention group (86% males, mean age 59.0 ± 9.4, 52% previous procedure). Compared to the control group, the intervention group had lower overall baseline knowledge scores (7.6vs8.5, p = 0.022) and similar anxiety scores (94vs92, p = 0.323); but significantly higher overall knowledge scores (10.3vs8.5, p= <0.001) and lower anxiety scores (75vs92, p= <0.001) after watching the video. Within the intervention group, there was a significant increase in overall knowledge scores (7.6vs10.3, p= <0.001) and reduction in anxiety scores (94vs 75, p= <0.001) before versus after watching the video. See Table 1. Subjectively, after watching the video, 98% of the patients reported benefit, 96% were more prepared and 85% less worried. There was significant improvement in knowledge scores and reduction in anxiety scores (p < 0.001) in the subset of patients who had previously underwent a similar procedure (n = 131).

Conclusion

The video improved knowledge and reduced anxiety in patients undergoing coronary angiography and angioplasty. This is a useful adjunct to incorporate into existing workflows to improve patient care.

Table 1 Total scores* Procedural events - Sedation Procedural events - Access site Procedural events-Contrast Procedural events-Stent Complications-General risk Complications-Bleeding Complications-Myocardial infarction Complications-Stroke Complications-Re-stenosis Anxiety-STAI# P-value comparing pre and post amongst cases (n = 252) <0.001 <0.001 <0.001 <0.001 <0.001 0.094 <0.001 <0.001 <0.001 <0.001 <0.001 P-value comparing cases (post) and controls (n = 80) <0.001 0.042 0.005 0.006 0.131 0.021 <0.001 <0.001 <0.001 <0.001 <0.001 * Range from 0-12 # State-Trait Anxiety Inventory (STAI), 40 questions, score range from 40-160

Abstract P205 Figure 1

P259 Adherence to optimal medical therapy in Asian patients with acute myocardial infarction treated with PCI

On Behalf

SingCLOUD collaborators

Background

 Notable regional differences have been observed worldwide in clinical characteristics and outcomes in patients experiencing acute myocardial infarction (AMI). Asian patients present younger and report higher adverse outcomes rates compared to Western cohorts. The reasons are multifactorial, but adherence to medication prescription guidelines is one of the modifiable factors.

Purpose

 Our aim was to study the effect of physician adherence to Optimal Medical Therapy (OMT) prescription guidelines on a MACE outcome in a high-risk group of Asian AMI patients over 1 year following percutaneous coronary intervention (PCI).

Method

 Data for this retrospective study was from the Singapore Cardiac Longitudinal Outcomes Database (SingCLOUD) pilot study involving AMI patients surviving primary PCI at two tertiary centers from 2012 to 2013. Guideline-directed OMT adherence was defined as concurrent prescription of at least one statin plus dual antiplatelet therapy (DAPT – aspirin plus P2Y12-I). Prescription of β-blockers and ACE-i/ARBs was also recorded. Prescription status and MACE (repeat MI, stroke, death) was recorded at discharge, 3, 6 and 9 months, and 1 year following the index discharge. The cumulative effect of OMT adherence at 3, 6, 9 months and 1 year post-discharge was studied by comparing risk of first MACE among patient groups with complete, partial and non-adherence to OMT prescription guidelines.

Results

 2,478 patients, 80.3% males, mean age 60.3 ± 11.7 years were studied. 1094 (44.1%) underwent primary PCI for STEMI. Single drug prescription at discharge for aspirin, P2Y12-I, and statins was 95, 97 and 95.8%, while prescription of β -blockers and ACE-inhibitors was 86.5 and 75.7%. Prescription of statins and aspirin declined gradually while P2Y12-I fell to 67.9% at 6mo and 47.6% at 1 year. Adherence to OMT declined from 92.3% at discharge to 82.1, 58.5, 56.1 and 40.3% at 3, 6, 9 months and 1 year, respectively. Of 342 (13.8%) occurrences of first MACE, 48.5% occurred within 3mo post-discharge. Complete adherence to OMT upon discharge significantly decreased risk of MACE at 3mo (OR = 0.066; 95% CI: 0.054-0.080; p < 0.001) and 12mo (OR = 0.017; 95% CI: 0.010-0.028; p < 0.001) relative to non-adherence.

Conclusion

 Over the course of a year in this high-risk group of PCI-treated AMI patients, there was a reduction in prescription adherence to the minimally essential OMT. Complete OMT adherence is beneficial in reducing MACE. Interventions targeting reasons for non-adherence are important in improving patient outcomes.

Abstract P259 Figure 1 - Medication over 1 year

Evaluation of WRF model seasonal forecasts for tropical region of Singapore

Abstract. The Weather and Research Forecast (WRF) model is evaluated for the monsoon and inter-monsoon seasons over the tropical region of Singapore. The model configuration, physical parameterizations and performance results are described in this paper. In addition to the ready-to-use data available with the WRF model, the model configuration includes high resolution MODIS land use (500 m horizontal resolution) and JPL-NASA sea surface temperature (1 km horizontal resolution) data. The model evaluation is performed against near surface observations for temperature, relative humidity, wind speed and direction, available from a dense network of weather monitoring stations across Singapore. It is found that the high resolution data sets bring significant improvement in the model forecasts. The results also indicate that the model forecasts are more accurate in the monsoon seasons compared to the inter-monsoon seasons.

The role of stent-grafts for prevention and treatment of restenosis

Restenosis rates in the superficial femoral artery remain high in patients treated with balloon angioplasty or bare metal stents. Stent-grafts represent an alternative endovascular treatment modality for these patients. In the US, the only FDA-approved stent-graft for femoral use is the Viabahn endoprosthesis (W.L. Gore, Flagstaff, AZ). The Viabahn is constructed of nitinol and ePTFE and has a proprietary heparin bioactive surface. Stent-grafts have the potential to reduce restenosis by impeding intimal hyperplasia and reducing tissue in-growth; however, the problem of edge restenosis has not been eliminated. Graft thrombosis remains an important mode of stent-graft failure. The Viabahn has been shown in observational studies and randomized trials to be an effective and safe treatment strategy compared to bare self-expanding stents and surgical prosthetic bypass grafts. Patient and appropriate lesion selection remain important in achieving long term patency. In this paper, we review the data surrounding the use of stent-grafts in the SFA to prevent and treat restenosis. Important technical considerations specific to the use of the Viabahn are also discussed.

Excimer laser assisted angioplasty for complex infrainguinal peripheral artery disease: a 2008 update

Conventional percutaneous transluminal angioplasty (PTA) for complex or long segment infrainguinal occlusive arterial disease is limited by elastic recoil, dissection and restenosis, with high rates of intermediate and long term restenosis . Debulking with excimer laser has been advocated as a useful adjunctive strategy to improve procedural success and long term patency. This paper reviews the technological development of excimer laser, the studies supporting its use in infrainguinal arterial disease, effective and safe lasing techniques, its advantages, limitations and disadvantages. Case examples will be presented to illustrate its use in infrainguinal arterial disease. Although randomized controlled trials are lacking, existing registry and case series studies suggest efficacy of the excimer laser-assisted PTA for complex infrainguinal arterial disease, including patients with critical limb ischemia.

Ethnicity modifies the association between diabetes mellitus and ischaemic heart disease in Chinese, Malays and Asian Indians living in Singapore

AIMS/HYPOTHESIS

The aim of the study was to determine whether the risk of ischaemic heart disease (IHD) associated with diabetes mellitus differs between ethnic groups.

METHODS

Registry linkage was used to identify IHD events in 5707 Chinese, Malay and Asian Indian participants from three cross-sectional studies conducted in Singapore between the years 1984 and 1995. The study provided a median of 10.2 years of follow-up with 240 IHD events experienced. We assessed the interaction between diabetes mellitus and ethnicity in relation to the risk of IHD events using Cox proportional hazards regression.

RESULTS

Diabetes mellitus was more common in Asian Indians. Furthermore, diabetes mellitus was associated with a greater risk of IHD in Asian Indians. The hazard ratio when comparing diabetes mellitus with non-diabetes mellitus was 6.41 (95% CI 5.77-7.12) in Asian Indians and 3.07 (95% CI 1.86-5.06) in Chinese (p = 0.009 for interaction). Differences in the levels of established IHD risk factors among diabetics from the three ethnic groups did not appear to explain the differences in IHD risk.

CONCLUSIONS/INTERPRETATION

Asian Indians are more susceptible to the development of diabetes mellitus than Chinese and Malays. When Asian Indians do develop diabetes mellitus, the risk of IHD is higher than for Chinese and Malays. Consequently, the prevention of diabetes mellitus amongst this ethnic group is particularly important for the prevention of IHD in Asia, especially given the size of the population at risk. Elucidation of the reasons for these ethnic differences may help us understand the pathogenesis of IHD in those with diabetes mellitus.

Smoking enhances absorption of insulin but reduces glucodynamic effects in individuals using the Lilly-Dura inhaled insulin system

AIM

To quantify the pharmacokinetic (PK) and glucodynamic (GD) impact of smoking on inhaled and subcutaneous (SC) insulin administration in healthy subjects.

METHODS

This study employed the euglycemic clamp procedure in a four-period, four-way randomized crossover design. Eight smoking and eight non-smoking healthy males were given SC insulin on two occasions and human insulin inhalation powder (HIIP) on two other occasions.

RESULTS

Smokers exhibited greater insulin exposure (AUC(0-t')) than non-smokers, following both routes of insulin administration (HIIP, P = 0.003, 58% increase; SC, P = 0.006, 24% increase). The maximum insulin concentration (C(max)) following HIIP was greater in smokers by 172% (P = 0.001) compared with non-smokers. The glucodynamic effects were greater in smokers following HIIP, consistent with the insulin concentration difference observed. However, maximum glucose response (R(max)) following SC was decreased by 36% (P = 0.001) and obtained later [time of maximum glucose response (TR(max)); P < 0.001] in smokers than in non-smokers. Smokers appeared less sensitive to insulin [total glucose infused during the clamp procedure normalised by total insulin exposure (G(tot))/AUC(0-t')] than non-smokers following both SC (P = 0.001) and inhaled (P = 0.011) routes of administration.

CONCLUSION

Smokers had substantially increased peak HIIP insulin concentration, but the glucodynamic effect was partially offset, most likely because of increased insulin resistance.

Anisotropy of acceleration in turbulent flows

Third-order Lagrangian stochastic models for the evolution of fluid-particle hyperaccelerations (material derivatives of Lagrangian accelerations) are shown to account naturally for the anisotropy of acceleration variances in low-Reynolds-number turbulent flows and for their dependency upon the energy-containing scales of motion. Model predictions are shown to be in close accord with the results of direct numerical simulations for a turbulent channel flow and with previously acquired simulation data for a homogeneous turbulent shear flow.

Stereotactic brain biopsies in AIDS patients--early local experience

AIM

To assess the usefulness of stereotactic brain biopsies in AIDS patients with cerebral lesions in Singapore.

METHODS

A total of 10 patients with AIDS and cerebral lesions underwent stereotactic brain biopsies in the Department of Neurosurgery, Tan Tock Seng Hospital (TTSH) between September 1997 and September 1998. The patients were referred from the Communicable Diseases Centre (CDC), TTSH. These patients either failed a trial of therapy for toxoplasmosis encephalitis (TE) or had CT/MRI scans which did not suggest TE. Four were CT-guided and six were MRI-guided stereotactic biopsies. The Radionics Cosman-Robert-Wells (CRW) stereotactic apparatus was used for all cases.

RESULTS

The male to female ratio was 9:1. Histological diagnosis from biopsy was lymphoma (5), metastatic adenocarcinoma (1), TE (1), abscess (1), encephalitis (1) and granulomatous tissue (1-presumed tuberculosis).

CONCLUSION

The early experience is that stereotactic brain biopsy is useful in patients with AIDS and cerebral lesions. The etiology is confirmed in the majority of cases and impacts on management decisions and prognostication.

Hypoxia augments cytokine (transforming growth factor-beta (TGF-beta) and IL-1)-induced vascular endothelial growth factor secretion by human synovial fibroblasts

Vascular endothelial growth factor (VEGF) is abundant in synovium and synovial fluids, where it probably contributes to vascular permeability and angiogenesis in arthritic joints. To investigate the probable sources of VEGF in synovium, we compared the ability of several cytokines (TGF-beta, platelet-derived growth factor (PDGF), IL-1, tumour necrosis factor (TNF), basic fibroblast growth factor (bFGF) that are associated with arthritis and angiogenesis, to stimulate secretion of VEGF protein by human synovial fibroblasts. TGF-beta was the strongest inducer of VEGF secretion; six times more VEGF was secreted when cells were stimulated by TGF-beta than when stimulated by PDGF or IL-1 for 24 h. TNF-alpha and bFGF did not stimulate any secretion of VEGF. The stimulatory effects of TGF-beta and IL-1 on VEGF secretion were additive. Hypoxic culture alone also stimulated VEGF secretion, but more importantly, hypoxic culture conditions doubled the rate of VEGF secretion stimulated by the cytokines TGF-beta and IL-1. When dermal and synovial fibroblasts were stimulated identically by hypoxia and cytokines (TGF-beta and IL-1), synovial fibroblasts secreted four times more VEGF than did dermal fibroblasts. Thus in rheumatoid arthritis, the capacity of synovial fibroblasts in the hypoxic environment to secrete large amounts of VEGF in response to cytokines such as TGF-beta probably contributes significantly to angiogenesis in the synovium.

Radiologic case. Lung mass and hemoptysis in a patient with tuberculosis

Images