High-sensitivity troponin T and long-term adverse cardiac events among patients presenting with suspected acute coronary syndrome in Singapore

INTRODUCTION@#Prognostic thresholds for 30-day major adverse cardiac events (MACE) have been studied for high-sensitivity troponin T (hsTnT) in patients with suspected acute coronary syndrome (ACS), but there is limited data on the prognostic performance of hsTnT for one-year MACE.@*METHODS@#We prospectively measured hsTnT (in ng/mL up to two decimal places) at 0, 2 and 7 hours for patients presenting with symptoms suggestive of ACS to our emergency department from March 2010 to April 2013. We assessed the prognostic performance of hsTnT cut-offs for 30-day and one-year MACE, and the utility of delta-hsTnT in predicting MACE.@*RESULTS@#Among 2,444 patients studied, 273 (11.2%) developed MACE (including index MACE) by 30 days and 359 (14.7%) patients developed MACE at one year. The suggested hsTnT cut-off for 30-day MACE was ≥ 10 ng/L at 0 hour (positive predictive value [PPV] 33.5%, negative predictive value [NPV] 94.5%) and 7 hours (PPV 37.3%, NPV 94.5%), and ≥ 20 ng/L at 2 hours (PPV 36.9%, NPV 96.9%). For one-year MACE, the suggested cut-off was also ≥ 10 ng/L at all readings. Plasma hsTnT ≥ 30 ng/L at any reading gave PPV > 54% and NPV > 93% for 30-day MACE. Absolute 0-2 hour and 2-7 hour delta-hsTnT ≥ 10 ng/L gave PPV > 50% for 30-day and one-year MACE.@*CONCLUSION@#Patients with 0-, 2- or 7-hour hsTnT ≥ 30 ng/L and 0-2 hour delta-hsTnT ≥ 10 ng/L had PPV > 50% for 30-day and one-year MACE, and should be investigated thoroughly.

Easy-to-learn cardiopulmonary resuscitation training programme: a randomised controlled trial on laypeople's resuscitation performance

<p><b>INTRODUCTION</b>Simplifying the learning of cardiopulmonary resuscitation (CPR) is advocated to improve skill acquisition and retention. A simplified CPR training programme focusing on continuous chest compression, with a simple landmark tracing technique, was introduced to laypeople. The study aimed to examine the effectiveness of the simplified CPR training in improving lay rescuers' CPR performance as compared to standard CPR.</p><p><b>METHODS</b>A total of 85 laypeople (aged 21-60 years) were recruited and randomly assigned to undertake either a two-hour simplified or standard CPR training session. They were tested two months after the training on a simulated cardiac arrest scenario. Participants' performance on the sequence of CPR steps was observed and evaluated using a validated CPR algorithm checklist. The quality of chest compression and ventilation was assessed from the recording manikins.</p><p><b>RESULTS</b>The simplified CPR group performed significantly better on the CPR algorithm when compared to the standard CPR group (p < 0.01). No significant difference was found between the groups in time taken to initiate CPR. However, a significantly higher number of compressions and proportion of adequate compressions was demonstrated by the simplified group than the standard group (p < 0.01). Hands-off time was significantly shorter in the simplified CPR group than in the standard CPR group (p < 0.001).</p><p><b>CONCLUSION</b>Simplifying the learning of CPR by focusing on continuous chest compressions, with simple hand placement for chest compression, could lead to better acquisition and retention of CPR algorithms, and better quality of chest compressions than standard CPR.</p>

Basic Cardiac Life Support: 2016 Singapore Guidelines

Basic Cardiac Life Support (BCLS) or cardiopulmonary resuscitation (CPR) refers to the skills required (without use of equipment) in the resuscitation of cardiac arrest individuals. On recognising cardiac arrest, chest compressions should be initiated. Good quality compressions are with arms extended, elbows locked, shoulders directly over the casualty's chest and heel of the palm on the lower half of the sternum. The rescuer pushes hard and fast, compressing 4-6 cm deep for adults at 100-120 compressions per minute with complete chest recoil. Two quick mouth-to-mouth ventilations (each 400-600 mL tidal volume) should be delivered after every 30 chest compressions. Chest compression-only CPR is recommended for lay rescuers, dispatcher-assisted CPR and those unable or unwilling to give ventilations. CPR should be stopped when the casualty wakes up, an emergency team takes over casualty care or if an automated external defibrillator prompts for analysis of heart rhythm or delivery of shock.

Advanced Cardiac Life Support: 2016 Singapore Guidelines

The main areas of emphasis in the Advanced Cardiac Life Support (ACLS) guidelines are: early recognition of cardiac arrest and call for help; good-quality chest compressions; early defibrillation when applicable; early administration of drugs; appropriate airway management ensuring normoventilation; and delivery of appropriate post-resuscitation care to enhance survival. Of note, it is important to monitor the quality of the various care procedures. The resuscitation team needs to reduce unnecessary interruptions to chest compressions in order to maintain adequate coronary perfusion pressure during the ACLS drill. In addition, the team needs to continually look out for reversible causes of the cardiac arrest.

Singapore Defibrillation Guidelines 2016

The most common initial rhythm in a sudden cardiac arrest is ventricular fibrillation or pulseless ventricular tachycardia. This is potentially treatable with defibrillation, especially if provided early. However, any delay in defibrillation will result in a decline in survival. Defibrillation requires coordination with the cardiopulmonary resuscitation component for effective resuscitation. These two components, which form the key links in the chain of survival, have to be brought to the cardiac victim in a timely fashion. An effective chain of survival is needed in both the institution and community settings.

Role of peak current in conversion of patients with ventricular fibrillation

<p><b>INTRODUCTION</b>Peak currents are the final arbiter of defibrillation in patients with ventricular fibrillation (VF). However, biphasic defibrillators continue to use energy in joules for electrical conversion in hopes that their impedance compensation properties will address transthoracic impedance (TTI), which must be overcome when a fixed amount of energy is delivered. However, optimal peak currents for conversion of VF remain unclear. We aimed to determine the role of peak current and optimal peak levels for conversion in collapsed VF patients.</p><p><b>METHODS</b>Adult, non-pregnant patients presenting with non-traumatic VF were included in the study. All defibrillations that occurred were included. Impedance values during defibrillation were used to calculate peak current values. The endpoint was return of spontaneous circulation (ROSC).</p><p><b>RESULTS</b>Of the 197 patients analysed, 105 had ROSC. Characteristics of patients with and without ROSC were comparable. Short duration of collapse < 10 minutes correlated positively with ROSC. Generally, patients with average or high TTI converted at lower peak currents. 25% of patients with high TTI converted at 13.3 ± 2.3 A, 22.7% with average TTI at 18.2 ± 2.5 A and 18.6% with low TTI at 27.0 ± 4.7 A (p = 0.729). Highest peak current conversions were at < 15 A and 15-20 A. Of the 44 patients who achieved first-shock ROSC, 33 (75.0%) received < 20 A peak current vs. > 20 A for the remaining 11 (25%) patients (p = 0.002).</p><p><b>CONCLUSION</b>For best effect, priming biphasic defibrillators to deliver specific peak currents should be considered.</p>

Prevalence, Presentation, and Outcome of Heart Failure with Preserved Ejection Fraction among Patients Presenting with Undifferentiated Dyspnoea to the Emergency Room: A 10-year Analysis from a Tertiary Centre

<p><b>INTRODUCTION</b>We assessed the local prevalence, characteristics and 10-year outcomes in a heart failure (HF) cohort from the emergency room (ER).</p><p><b>MATERIALS AND METHODS</b>Patients presenting with acute dyspnoea to ER were prospectively enrolled from December 2003 to December 2004. HF was diagnosed by physicians' adjudication based on clinical assessment and echocardiogram within 12 hours, blinded to N-terminal-pro brain natriuretic peptide (NT-proBNP) results. They were stratified into heart failure with preserved (HFPEF) and reduced ejection fraction (HFREF) by left ventricular ejection fraction (LVEF).</p><p><b>RESULTS</b>At different cutoffs of LVEF of ≥50%, ≥45%, ≥40%, and >50% plus excluding LVEF 40% to 50%, HFPEF prevalence ranged from 38% to 51%. Using LVEF ≥50% as the final cutoff point, at baseline, HFPEF (n = 35), compared to HFREF (n = 55), had lower admission NT- proBNP (1502 vs 5953 pg/mL, P <0.001), heart rate (86 ± 22 vs 98 ± 22 bpm, P = 0.014), and diastolic blood pressure (DBP) (75 ± 14 vs 84 ± 20 mmHg, P = 0.024). On echocardiogram, compared to HFREF, HFPEF had more LV concentric remodelling (20% vs 2%, P = 0.003), less eccentric hypertrophy (11% vs 53%, P <0.001) and less mitral regurgitation from functional mitral regurgitation (60% vs 95%, P = 0.027). At 10 years, compared to HFREF, HFPEF had similar primary endpoints of a composite of cardiovascular death, non-fatal myocardial infarction, non-fatal stroke, and rehospitalisation for congestive heart failure (CHF) (HR 0.886; 95% CI, 0.561 to 1.399; P = 0.605), all-cause mortality (HR 0.663; 95% CI, 0.400 to 1.100; P = 0.112), but lower cardiovascular mortality (HR 0.307; 95% CI, 0.111 to 0.850; P = 0.023).</p><p><b>CONCLUSION</b>In the long term, HFPEF had higher non-cardiovascular mortality, but lower cardiovascular mortality compared to HFREF.</p>

Impact of Direct Cardiovascular Laboratory Activation by Emergency Physicians on False-Positive Activation Rates

<p><b>INTRODUCTION</b>Door-to-balloon (DTB) time is critical to ST elevation myocardial infarction (STEMI) patients' survival. Although DTB time is reduced with direct cardiovascular laboratory (CVL) activation by emergency physicians, concerns regarding false-positive activation remain. We evaluate false-positive rates before and after direct CVL activation and factors associated with false-positive activations.</p><p><b>MATERIALS AND METHODS</b>This is a retrospective single centre study of all emergency CVL activation 3 years before and after introduction of direct activation in July 2007. False-positive activation is defined as either: 1) absence of culprit vessel with coronary artery thrombus or ulceration, or 2) presence of chronic total occlusion of culprit vessel, with no cardiac biomarker elevations and no regional wall abnormalities. All false-positive cases were verified by reviewing their coronary angiograms and patient records.</p><p><b>RESULTS</b>A total of 1809 subjects were recruited; 84 (4.64%) identified as false-positives. Incidence of false-positive before and after direct activation was 4.1% and 5.1% respectively, which was not significant (P = 0.315). In multivariate logistic regression analysis, factors associated with false-positive were: female (odds ratio (OR): 2.104 [1.247-3.548], P = 0.005), absence of chest pain (OR: 5.369 [3.024-9.531], P <0.0001) and presence of only left bundle branch block (LBBB) as indication for activation (OR: 65.691 [19.870-217.179], P <0.0001).</p><p><b>CONCLUSION</b>Improvement in DTB time with direct CVL activation by emergency physicians is not associated with increased false-positive activations. Factors associated with false-positive, especially lack of chest pain or LBBB, can be taken into account to optimise STEMI management.</p>

Recognition and treatment of out-of-hospital cardiac arrests by non-emergency ambulance services in Singapore

<p><b>INTRODUCTION</b>Prompt recognition of cardiac arrest and initiation of cardiopulmonary resuscitation (CPR) and defibrillation is necessary for good outcomes from out-of-hospital cardiac arrest (OHCA). This study aims to describe the recognition and treatment of OHCA in patients conveyed by non-emergency ambulance services (EAS) in Singapore.</p><p><b>MATERIALS AND METHODS</b>This is a multi-centre, retrospective chart review, of cases presenting to public emergency departments (EDs), conveyed by non-EAS and found to be in cardiac arrest upon ED arrival. The study was from October 2002 to August 2009. The following variables were examined: ability to recognise cardiac arrest, whether CPR was carried out by the ambulance crew and whether an automated external defibrillator (AED) was applied.</p><p><b>RESULTS</b>Eighty-six patients were conveyed by non-EAS and found to be in cardiac arrest upon ED arrival. Mean age was 63 years (SD 21.8), 70.9% were males. A total of 53.5% of arrests occurred in the ambulance while 70.9% were found to be asystolic upon ED arrival. Seven patients had a known terminal illness. Survival to discharge was 3.5%. Cardiac arrest went unrecognised by the ambulance crew in 38 patients (44.2%). CPR was performed in 35 patients (40.7%) of the 86 patients and AED was applied in only 10 patients (11.6%).</p><p><b>CONCLUSION</b>We found inadequate recognition and delayed initiation of treatment for OHCA. Possible reasons include a lack of training in patient monitoring and detection of cardiac arrest, lack of CPR training, lack of confidence in performing CPR, lack of AEDs on ambulances and lack of training in their use.</p>

Geographic-time distribution of ambulance calls in Singapore: utility of geographic information system in ambulance deployment (CARE 3)

<p><b>INTRODUCTION</b>Pre-hospital ambulance calls are not random events, but occur in patterns and trends that are related to movement patterns of people, as well as the geographical epidemiology of the population. This study describes the geographic-time epidemiology of ambulance calls in a large urban city and conducts a time demand analysis. This will facilitate a Systems Status Plan for the deployment of ambulances based on the most cost effective deployment strategy.</p><p><b>MATERIALS AND METHODS</b>An observational prospective study looking at the geographic-time epidemiology of all ambulance calls in Singapore. Locations of ambulance calls were spot mapped using Geographic Information Systems (GIS) technology. Ambulance response times were mapped and a demand analysis conducted by postal districts.</p><p><b>RESULTS</b>Between 1 January 2006 and 31 May 2006, 31,896 patients were enrolled into the study. Mean age of patients was 51.6 years (S.D. 23.0) with 60.0% male. Race distribution was 62.5% Chinese, 19.4% Malay, 12.9% Indian and 5.2% others. Trauma consisted 31.2% of calls and medical 68.8%. 9.7% of cases were priority 1 (most severe) and 70.1% priority 2 (moderate severity). Mean call receipt to arrival at scene was 8.0 min (S.D. 4.8). Call volumes in the day were almost twice those at night, with the most calls on Mondays. We found a definite geographical distribution pattern with heavier call volumes in the suburban town centres in the Eastern and Southern part of the country. We characterised the top 35 districts with the highest call volumes by time periods, which will form the basis for ambulance deployment plans.</p><p><b>CONCLUSION</b>We found a definite geographical distribution pattern of ambulance calls. This study demonstrates the utility of GIS with despatch demand analysis and has implications for maximising the effectiveness of ambulance deployment.</p>

Improving door-to-balloon times in primary percutaneous coronary intervention for acute ST-elevation myocardial infarction: the value of an audit-driven quality initiative

<p><b>INTRODUCTION</b>The study was designed to reduce door-to-balloon times in primary percutaneous coronary intervention for patients presenting to the Emergency Department with acute ST-elevation myocardial infarction, using an audit as a quality initiative.</p><p><b>MATERIALS AND METHODS</b>A multidisciplinary work group performed a pilot study over 3 months, then implemented various process and work-flow strategies to improve overall door-to-balloon times.</p><p><b>RESULTS AND CONCLUSION</b>We developed a guideline-based, institution-specific written protocol for triaging and managing patients who present to the Emergency Department with symptoms suggestive of STEMI, resulting in shortened median door-to-balloon times from 130.5 to 109.5 minutes (P<0.001).</p>