Ethnic Differences and Trends in ST-Segment Elevation Myocardial Infarction Incidence and Mortality in a Multi-Ethnic Population

INTRODUCTION@#This study aimed to compare the incidence and mortality of ST-segment elevation myocardial infarction (STEMI) across the 3 main ethnic groups in Singapore, determine if there is any improvement in trends over the years and postulate the reasons underlying the ethnic disparity.@*MATERIALS AND METHODS@#This study consisted of 16,983 consecutive STEMI patients who sought treatment from all public hospitals in Singapore from 2007 to 2014.@*RESULTS@#Compared to the Chinese (58 per 100,000 population in 2014), higher STEMI incidence rate was consistently observed in the Malays (114 per 100,000 population) and Indians (126 per 100,000 population). While the incidence rate for the Chinese and Indians remained relatively stable over the years, the incidence rate for the Malays rose slightly. Relative to the Indians (30-day and 1-year all-cause mortality at 9% and 13%, respectively, in 2014), higher 30-day and 1-year all-cause mortality rates were observed in the Chinese (15% and 21%) and Malays (13% and 18%). Besides the Malays having higher adjusted 1-year all-cause mortality, all other ethnic disparities in 30-day and 1-year mortality risk were attenuated after adjusting for demographics, comorbidities and primary percutaneous coronary intervention.@*CONCLUSION@#It is important to continuously evaluate the effectiveness of existing programmes and practices as the aetiology of STEMI evolves with time, and to strike a balance between prevention and management efforts as well as between improving the outcome of "poorer" and "better" STEMI survivors with finite resources.

Triaging Primary Care Patients Referred for Chest Pain to Specialist Cardiology Centres: Efficacy of an Optimised Protocol

INTRODUCTION@#Patients referred for chest pain from primary care have increased, along with demand for outpatient cardiology consultations. We evaluated 'Triage Protocol' that implements standardised diagnostic testing prior to patients' first cardiology consultation.@*MATERIALS AND METHODS@#Under the 'Triage Protocol', patients referred for chest pain were pretriaged using a standardised algorithm and subsequently referred for relevant functional diagnostic cardiology tests before their initial cardiology consultation. At the initial cardiology consultation scheduled by the primary care provider, test results were reviewed. A total of 522 triage patients (mean age 55 ± 13, male 53%) were frequency-matched by age, gender and risk cohort to 289 control patients (mean age: 56 ± 11, male: 52%). Pretest risk of coronary artery disease was defined according to a Modified Duke Clinical Score (MDCS) as low (20). The primary outcome was time from referral to diagnosis (days). Secondary outcomes were total visits, discharge rate at first consultation, patient cost and adverse cardiac outcomes.@*RESULTS@#The 'Triage Protocol' resulted in shorter times from referral to diagnosis (46 vs 131 days; <0.0001) and fewer total visits (2.4 vs 3.0; <0.0001). However, triage patients in low-risk groups experienced higher costs due to increased testing (S$421 vs S$357, = 0.003). Adverse cardiac event rates under the 'Triage Protocol' indicated no compromise to patient safety (triage vs control: 0.57% vs 0.35%; = 1.000).@*CONCLUSION@#By implementing diagnostic cardiac testing prior to patients' first specialist consultation, the 'Triage Protocol' expedited diagnosis and reduced subsequent visits across all risk groups in ambulatory chest pain patients.

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>