Part 9: Acute coronary syndromes: 2010 International Consensus on Cardiopulmonary Resuscitation and Emergency Cardiovascular Care Science With Treatment Recommendations

Accidental hypothermia: direct evidence for consciousness as a marker of cardiac arrest risk in the acute assessment of cold patients

BACKGROUND

Rapid stratification of the risk of cardiac arrest is essential in the assessment of patients with isolated accidental hypothermia. Traditional methods based on measurement of core temperature are unreliable in the field. Behavioural observations have been used as predictors of core temperature and thus indirect predictors of cardiac arrest. This study aims to quantify the direct relationship between observed conscious level and cardiac arrest.

METHODS

Retrospective case report analysis identified 114 cases of isolated accidental hypothermia meeting inclusion criteria. Level of consciousness in the acute assessment and management phase was classified using the AVPU system with an additional category of "Alert with confusion"; statistical analysis then related level of consciousness to incidence of cardiac arrest.

RESULTS

All patients who subsequently suffered cardiac arrest showed some impairment of consciousness (p <  < .0001), and the risk of arrest increased directly with the level of impairment; none of the 33 fully alert patients arrested. In the lowest impairment category, Alert confused, a quarter of the 12 patients went on to arrest, while in the highest Unresponsive category, two thirds of the 43 patients arrested. Where core temperature was available (62 cases), prediction of arrest by consciousness level was at least as good as prediction from core temperature.

CONCLUSIONS

This study provides retrospective analytical evidence that consciousness level is a valid predictor of cardiac arrest risk in isolated accidental hypothermia; the importance of including confusion as a criterion is a new finding. This study suggests the use of consciousness alone may be at least as good as core temperature in cardiac arrest risk prediction. These results are likely to be of particular relevance to the management of accidental hypothermia in the pre-hospital and mass casualty environment, allowing for rapid and accurate triage of hypothermic patients.

A Comparison of Clinical Characteristics and Outcomes Between Indigenous and Non-Indigenous Patients Presenting to Townsville Hospital Emergency Department With Chest Pain

BACKGROUND

Indigenous Australians have a high rate of ischaemic heart disease (IHD). There is a paucity of local data for North Queensland regarding the clinical characteristics of Indigenous people who present to the emergency department (ED) with chest pain. The aim of the study is to compare the cardiovascular risk factors, social characteristics, and the clinical outcomes between Indigenous and non-Indigenous patients who presented with cardiac-related chest pain.

METHODS

This is a retrospective single-centre audit. The data was collected through chart reviews of chest pain presentations to the Townsville University Hospital Emergency Department, Queensland, Australia, from January to December 2017. We categorised the patients into Indigenous and non-Indigenous groups and compared their cardiac risk factors and social characteristics. We further classified the patients into three diagnosis groups and we measured the clinical outcomes in the patients with a diagnosis of cardiac-related chest pain. We used a data linkage to the Registry of Births, Deaths and Marriages for the death outcomes. A multivariable analysis was done to determine the risk of major adverse cardiac event (MACE) for Indigenous vs non-Indigenous patients.

RESULTS

Indigenous patients were over-represented making up 19.1% of the total cohort (compared with 11.1% of the North Queensland Indigenous population) and presented at a younger age (median age: 45 vs 52, p<0.005). Traditional cardiovascular risk factors were significantly higher in Indigenous patients. The incidence of discharge against medical advice was also higher (6.5% vs 2.7%, p<0.005). There was an underutilisation of the local chest pain pathway amongst the Indigenous group (35.8% vs 44.7%, p<0.005). In patients with a diagnosis of cardiac-related chest pain, the rate of receiving invasive coronary angiogram procedures was similar in both cohorts (44.5% vs 43.7%, p=0.836). With regards to outcomes, Indigenous patients suffered from acute coronary syndrome (ACS) at a younger median age (51 vs 64, p<0.005) and were more likely to have severe three vessel disease (17% vs 6%, p<0.005) leading to coronary bypass graft surgery (CABG) (19% vs 6%, p<0.005). When adjusted for age, gender, and comorbidities, Indigenous patients were more likely to have MACE within 1 year of their chest pain presentation, compared with non-Indigenous patients with the same diagnosis (adjusted odds ration [AOR]=2.0, 95% CI [1.1, 3.8], p=0.03).

CONCLUSION

In our study, Indigenous patients carried a heavier burden of cardiovascular risk factors, presented at a younger age, with more severe coronary disease and had a higher rate of CABG. We found an underutilisation of the local chest pain protocol amongst the Indigenous cohort, which suggests a need to improve support structures in the ED. In our multivariable analysis, Indigenous patients suffered from a significantly higher MACE compared to non-Indigenous patients which indicates that more collaborative efforts are needed to improve the cardiovascular health of local Aboriginal and Torres Strait Islander people.

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.

Prospective Study on Plasma MicroRNA-4286 and Incident Acute Coronary Syndrome

Background Mounting evidence suggests that circulating microRNAs (miRNAs) are critical indicators of cardiovascular disease. However, prospective studies linking circulating miRNAs to incident acute coronary syndrome (ACS) are limited, and the underlying effect of associated miRNA on incident ACS remains unknown. Methods and Results Based on a 2-stage prospective nested case-control design within the Dongfeng-Tongji cohort, we profiled plasma miRNAs from 23 pairs of incident ACS cases and controls by microarray and validated the candidate miRNAs in 572 incident ACS case-control pairs using quantitative real-time polymerase chain reaction. We observed that plasma miR-4286 was associated with higher risk of ACS (adjusted odds ratio according to an interquartile range increase, 1.26 [95% CI, 1.07-1.48]). Further association analysis revealed that triglyceride was positively associated with plasma miR-4286, and an interquartile range increase in triglyceride was associated with an 11.04% (95% CI, 3.77%-18.83%) increase in plasma miR-4286. In addition, the Mendelian randomization analysis suggested a potential causal effect of triglyceride on plasma miR-4286 (β coefficients: 0.27 [95% CI, 0.01-0.53] and 0.27 [95% CI, 0.07-0.47] separately by inverse variance-weighted and Mendelian randomization-pleiotropy residual sum and outlier tests). Moreover, the causal mediation analysis indicated that plasma miR-4286 explained 5.5% (95% CI, 0.7%-17.0%) of the association of triglyceride with incident ACS. Conclusions Higher level of plasma miR-4286 was associated with an increased risk of ACS. The upregulated miR-4286 in plasma can be attributed to higher triglyceride level and may mediate the effect of triglyceride on incident ACS.

Profile of copper-associated DNA methylation and its association with incident acute coronary syndrome

Background

Acute coronary syndrome (ACS) is a cardiac emergency with high mortality. Exposure to high copper (Cu) concentration has been linked to ACS. However, whether DNA methylation contributes to the association between Cu and ACS is unclear.

Methods

We measured methylation level at > 485,000 cytosine-phosphoguanine sites (CpGs) of blood leukocytes using Human Methylation 450 Bead Chip and conducted a genome-wide meta-analysis of plasma Cu in a total of 1243 Chinese individuals. For plasma Cu-related CpGs, we evaluated their associations with the expression of nearby genes as well as major cardiovascular risk factors. Furthermore, we examined their longitudinal associations with incident ACS in the nested case-control study.

Results

We identified four novel Cu-associated CpGs (cg20995564, cg18608055, cg26470501 and cg05825244) within a 5% false discovery rate (FDR). DNA methylation level of cg18608055, cg26470501, and cg05825244 also showed significant correlations with expressions of SBNO2, BCL3, and EBF4 gene, respectively. Higher DNA methylation level at cg05825244 locus was associated with lower high-density lipoprotein cholesterol level and higher C-reactive protein level. Furthermore, we demonstrated that higher cg05825244 methylation level was associated with increased risk of ACS (odds ratio [OR], 1.23; 95% CI 1.02–1.48; P = 0.03).

Conclusions

We identified novel DNA methylation alterations associated with plasma Cu in Chinese populations and linked these loci to risk of ACS, providing new insights into the regulation of gene expression by Cu-related DNA methylation and suggesting a role for DNA methylation in the association between copper and ACS.

Role of Dedicated Cardiac Emergency Unit in Early Identification and Management of Acute Myocardial Infarction in a Developing Country of South Asia

Background The care of patients presenting with chest pain to multidisciplinary services hospital gets compromised due to the busy triage system. A separate and specialized equipped cardiac emergency unit (CAR-ERU) can improve patient's outcomes. Objectives To enhance early recognition and treatment of acute myocardial infarction (AMI) patients. To sustain key performance quality indicators (KPIs) for AMI. Methods In October 2016, a separate CAR-ERU was established inside the multidisciplinary emergency department (MED). A dedicated specialized heart-lung and vascular teams were hired under the supervision of service line leadership. The KPIs that were identified benchmark with international practice guidelines. Data were collected and stored for analysis. Exemption from the ethical review committee was obtained. Results A total of 2914 patients visited CAR-ERU from October 2016 to September 2017 for a period of one year. Out of which 30% were diagnosed with acute coronary syndrome (ACS) and this included 8% diagnosis with ST-segment elevation myocardial infarction (STEMI). Over 98.8% of the electrocardiogram (ECG) was done within 10 minutes of arrival while aspirin was given to 96.5% of patients within one hour. The door to balloon time (DBT) of <90 min was achieved in 70% of patients. A significant reduction in length of stay in the emergency department and financial burden was noted. Sustainability of major KPI was observed over the subsequent years.  Conclusion The introduction of a dedicated CAR-EU improved clinical outcomes, reduced length of stay and financial burden in AMI patients managed in CAR-EU. Our tertiary care hospital is the first one of its kind to take this quality initiative in a lower-middle-income country (LMIC) Pakistan.

Do patients with non-ST-elevation myocardial infarction without chest pain suffer a poor prognosis?

OBJECTIVE

Previous studies have discussed acute myocardial infarction (AMI) patients without chest pain, but have not focused on non-ST-elevation myocardial infarction (NSTEMI).

MATERIALS AND METHODS

This 1-year study investigated whether chest pain presence relates to demographics, risk factors, and outcomes in NSTEMI patients. We retrospectively reviewed 194 patients, 73 without chest pain vs. 121 with chest pain, and compared the differences between clinical presentations, risk factors, medical management, and outcomes of these two groups.

RESULTS

Compared to patients with chest pain, patients without chest pain were significantly older, had lower SBP, higher HR, more cerebrovascular disease, less ischemic heart disease, higher delay to ED (emergency department) visit, lower ED medication prescriptions, lower percutaneous cardiac intervention, and higher in-hospital and one-year mortality rate. In a multivariate logistic regression, the adjusted odds ratios (OR) of patients without chest pain were 4.38 for the elderly, 0.99 for every 1 mmHg increase in SBP, 1.02 for every beat/min HR increase, 0.37 for those with ischemic heart disease, and 5.09 for those with cerebrovascular disease. The adjusted OR of in-hospital mortality were 3.09 for patients without chest pain, 0.32 for those with hypertension, 0.32 for smokers, 3.98 for those with shock, and 0.16 for those with percutaneous cardiac intervention. Finally, the only significantly adjusted OR of one-year mortality was 5.37 for patients without chest pain.

CONCLUSION

NSTEMI patients without chest pain were significantly older, had lower SBP, more tachycardia, more cerebrovascular disease, but less ischemic heart disease. They also experienced higher in-hospital and one-year mortality rates.

A multi-stage association study of plasma cytokines identifies osteopontin as a biomarker for acute coronary syndrome risk and severity

Cytokines play a critical role in the pathogenesis and development of cardiovascular diseases. However, data linking cytokines to risk and severity of acute coronary syndrome (ACS) are still limited. We measured plasma profile of 280 cytokines using a quantitative protein microarray in 12 ACS patients and 16 healthy controls, and identified 15 differentially expressed cytokines for ACS. Osteopontin, chemokine ligand 23, brain derived neurotrophic factor and C-reactive protein (CRP) were further validated using immunoassay in two independent case-control studies with a total of 210 ACS patients and 210 controls. We further examined their relations with incident ACS among 318 case-control pairs nested within the Dongfeng-Tongji cohort, and found plasma osteopontin and CRP concentrations were associated with incident ACS, and the multivariable-adjusted odds ratio (95% confidence interval) was 1.29 (1.06-1.57) per 1-SD increase for osteopontin and 1.30 (1.02-1.66) for CRP, respectively. Higher levels of circulating osteopontin were also correlated with higher severity of ACS, and earlier ACS onset time. Adding osteopontin alone or in combination with CRP modestly improved the predictive ability of ACS beyond the Framingham risk scores. Our findings suggested that osteopontin might be a biomarker for incident ACS, using osteopontin adds moderately to traditional cardiovascular risk factors.

The HEART Pathway Randomized Controlled Trial One-year Outcomes

OBJECTIVE

The objective was to determine the impact of the HEART Pathway on health care utilization and safety outcomes at 1 year in patients with acute chest pain.

METHODS

Adult emergency department (ED) patients with chest pain (N = 282) were randomized to the HEART Pathway or usual care. In the HEART Pathway arm, ED providers used the HEART score and troponin measures (0 and 3 hours) to risk stratify patients. Usual care was based on American College of Cardiology/American Heart Association guidelines. Major adverse cardiac events (MACE-cardiac death, myocardial infarction [MI], or coronary revascularization), objective testing (stress testing or coronary angiography), and cardiac hospitalizations and ED visits were assessed at 1 year. Randomization arm outcomes were compared using Fisher's exact tests.

RESULTS

A total of 282 patients were enrolled, with 141 randomized to each arm. MACE at 1 year occurred in 10.6% (30/282): 9.9% in the HEART Pathway arm (14/141; 10 MIs, four revascularizations without MI) versus 11.3% in usual care (16/141; one cardiac death, 13 MIs, two revascularizations without MI; p = 0.85). Among low-risk HEART Pathway patients, 0% (0/66) had MACE, with a negative predictive value (NPV) of 100% (95% confidence interval = 93%-100%). Objective testing through 1 year occurred in 63.1% (89/141) of HEART Pathway patients compared to 71.6% (101/141) in usual care (p = 0.16). Nonindex cardiac-related hospitalizations and ED visits occurred in 14.9% (21/141) and 21.3% (30/141) of patients in the HEART Pathway versus 10.6% (15/141) and 16.3% (23/141) in usual care (p = 0.37, p = 0.36).

CONCLUSIONS

The HEART Pathway had a 100% NPV for 1-year safety outcomes (MACE) without increasing downstream hospitalizations or ED visits. Reduction in 1-year objective testing was not significant.

The International Liaison Committee on Resuscitation-Review of the last 25 years and vision for the future

2017 marks the 25th anniversary of the International Liaison Committee on Resuscitation (ILCOR). ILCOR was formed in 1992 to create a forum for collaboration among principal resuscitation councils worldwide. Since then, ILCOR has established and distinguished itself for its pioneering vision and leadership in resuscitation science. By systematically assessing the evidence for resuscitation standards and guidelines and by identifying national and regional differences, ILCOR reached consensus on international resuscitation guidelines in 2000, and on international science and treatment recommendations in 2005, 2010 and 2015. However, local variation and contextualization of guidelines are evident by subtle differences in regional and national resuscitation guidelines. ILCOR's efforts to date have enhanced international cooperation, and progressively more transparent and systematic collection and analysis of pertinent scientific evidence. Going forward, this sets the stage for ILCOR to pursue its vision to save more lives globally through resuscitation.

Genome-Wide Analysis of DNA Methylation and Acute Coronary Syndrome

Rationale:

Acute coronary syndrome (ACS) is a leading cause of death worldwide. Immune functions play a vital role in ACS development; however, whether epigenetic modulation contributes to the regulation of blood immune cells in this disease has not been investigated.

Objective:

We conducted an epigenome-wide analysis with circulating immune cells to identify differentially methylated genes in ACS.

Methods and Results:

We examined genome-wide methylation of whole blood in 102 ACS patients and 101 controls using HumanMethylation450 array, and externally replicated significant discoveries in 100 patients and 102 controls. For the replicated loci, we further analyzed their association with ACS in 6 purified leukocyte subsets, their correlation with the expressions of annotated genes, and their association with cardiovascular traits/risk factors. We found novel and reproducible association of ACS with blood methylation at 47 cytosine-phosphoguanine sites (discovery: false discovery rate <0.005; replication: Bonferroni corrected P <0.05). The association of methylation levels at these cytosine-phosphoguanine sites with ACS was further validated in at least 1 of the 6 leukocyte subsets, with predominant contributions from CD8 + T cells, CD4 + T cells, and B cells. Blood methylation of 26 replicated cytosine-phosphoguanine sites showed significant correlation with expressions of annotated genes (including IL6R , FASLG , and CCL18 ; P <5.9×10 −4 ), and differential gene expression in case versus controls corroborated the observed differential methylation. The replicated loci suggested a role in ACS-relevant functions including chemotaxis, coronary thrombosis, and T-cell–mediated cytotoxicity. Functional analysis using the top ACS-associated methylation loci in purified T and B cells revealed vital pathways related to atherogenic signaling and adaptive immune response. Furthermore, we observed a significant enrichment of the replicated cytosine-phosphoguanine sites associated with smoking and low-density lipoprotein cholesterol ( P enrichment ≤1×10 −5 ).

Conclusions:

Our study identified novel blood methylation alterations associated with ACS and provided potential clinical biomarkers and therapeutic targets. Our results may suggest that immune signaling and cellular functions might be regulated at an epigenetic level in ACS.

Do elderly females have a higher risk of acute myocardial infarction? A retrospective analysis of 329 cases at an emergency department

OBJECTIVE

Acute myocardial infarction (AMI) is a medical emergency; a missed or delayed diagnosis of this disease may contribute to a poor outcome and even death. Several studies have found elderly patients with AMI have atypical presentations for diagnosis, therefore we undertook this study to determine the risks among the elderly population, especially in female patients.

MATERIALS AND METHODS

In this one-year retrospective study, we reviewed the cases of AMI patients who had visited the emergency department at Mackay Memorial Hospital, Taiwan, and who had either been discharged or had died following a diagnosis of AMI (ICD code 410). We compared the differences between the clinical presentations of these two groups as well as the risk factors, medical management, and outcomes.

RESULTS

In our study, only 329 patients (164 elderly; 165 adults) met the defined criteria. The most common symptom of AMI was chest pain, and this was more common in adult patients than in elderly patients (81.8% vs. 60.4%, p < 0.001). In comparison with patients in the adult group, the patients in the elderly group had a significantly higher proportion of females (46.3% vs. 12.7%), non-ST-elevation myocardial infarction (NSTEMI) (71.3% vs. 46.7%), presenting with no chest pain (39.6% vs. 18.2%), shortness of breath (17.7% vs. 8.8%), nausea/vomiting/dizziness (7.9% vs. 2.4%), abdominal pain (4.3% vs. 0.6%), diabetes mellitus (45.1% vs. 26.1%), cerebrovascular disease (22.6% vs. 6.1%), longer hospital stays (18.2 ± 31.0 days vs. 9.8 ± 8.2 days), and increased in-hospital mortality rates (15.9% vs. 6.7%).

CONCLUSION

Compared with the adult AMI group, the elderly AMI group had a higher proportion of females, electrocardiography with NSTEMI and no chest-pain complaints, and a larger proportion of elderly patients with diabetes, ischemic heart disease, heart attacks at home and cardiac shock, which had longer hospital stays, and higher mortality rates.

The HEART score with high-sensitive troponin T at presentation: ruling out patients with chest pain in the emergency room

The HEART score is a simple scoring system, ranging from 0 to 10, specifically developed for risk stratification of patients with undifferentiated chest pain. It has been validated for the conventional troponin, but not for high-sensitive troponin. We assess a modified version of the HEART score using a single high-sensitivity troponin T dosage at presentation, regardless of symptom duration, and with different ECG criteria to evaluate if the patients with a low HEART score could be safely discharged early. The secondary aim was to confirm a statistically significant difference in each HEART score group (low 0-3, intermediate 4-6, high 7-10) in the occurrence of major adverse cardiac events at 30 and 180 days. We retrospectively analyzed the HEART score of 1597 consecutive patients admitted to the Emergency Department of our Hospital for chest pain between January 1 and June 30, 2014. Of these, 190 did not meet the inclusion criteria and 29 were lost to follow-up. None of the 512 (37.2 %) patients with a low HEART score had an event within 180 days. The difference between the cumulative incidences of events in the three HEART score groups was statistically significant (P < 0.0001). We demonstrate that it might be possible to safely discharge Emergency Department chest pain patients with a low modified HEART score after an initial determination of high-sensitive troponin T, without a prolonged observation period or an additional cardiac testing.

Out-of-hospital cardiac arrest survivors sent for emergency angiography: a clinical score for predicting acute myocardial infarction

BACKGROUND

Out-of-hospital cardiac arrest (OHCA) remains a major public health issue. Emergency coronary angiography and percutaneous coronary intervention might improve survival, especially when cardiac arrest is caused by acute myocardial infarction (AMI). However, identifying patients with AMI after OHCA remains challenging. The aim of this study was to determine the clinical and ECG criteria in OHCA that may help to identify better the patients with AMI.

METHODS

Consecutive OHCA patients who underwent emergency coronary angiography in our centre between 2009 and 2013 were included in this retrospective single-centre observational study.

RESULTS

A total of 177 patients with complete datasets were included. Significant coronary artery disease was found in 71% of the patients, and 43% presented with AMI. The independent predictors of AMI were ST elevation in any lead including aVR (odds ratio (OR) 18.06; 95% confidence interval (CI) 6.6-49.38), chest pain before cardiac arrest (OR 4.05; 95% CI 1.55-10.54) and an initial shockable rhythm (OR 2.99; 95% CI 1.34-6.45). An additive score that included these three predictors yielded a sensitivity and a specificity for detecting AMI of 93% and 63%, respectively.

CONCLUSIONS

These data suggest that fewer than half of patients with OHCA undergoing emergency coronary angiography present with AMI. The identification of OHCA patients with AMI might be improved by a simple score using post-resuscitation ECG and simple clinical criteria.

Incidence of coronary intervention in cardiac arrest survivors with non-shockable initial rhythms and no evidence of ST-elevation MI (STEMI)

OBJECTIVE

With the demonstrated benefit of an early-invasive strategy for STEMI and VF/VT arrest patients, there is interest in assessing the potential benefit of early angiography for non-shockable (PEA/Asystole) arrest patients. We hypothesized that in cardiac arrest patients who obtain return of spontaneous circulation (ROSC) after a non-shockable initial rhythm and do not have STEMI the incidence of coronary intervention would be clinically insignificant (<5%).

METHODS

Retrospective multicenter US clinical registry study of post-cardiac arrest patients at 18 hospitals between 1/00 and 5/14. The incidence of significant coronary artery disease (CAD) as defined by documented coronary intervention (i.e. PCI, angioplasty, stent or CABG) was assessed.

RESULTS

There were 1396 arrest patients with ROSC and known initial rhythms (517/1396=37% shockable; 879/1396=63% nonshockable). 440 (299/440=58% shockable; 141/440=32% nonshockable) of these patients received angiography. In the 141 non-shockable patients that received angiography, 97 patients did not have STEMI listed as an indication for catheterization and 24 (25%) of those had a coronary intervention documented yielding an observed incidence of coronary intervention in non-shockable post-arrest patients without STEMI who received angiography of 24.7% (24/97). Of note, the overall incidence of coronary intervention in all ROSC patients with non-shockable initial rhythms was 5.5% (48/879).

CONCLUSIONS

In this large multi-center retrospective analysis there is a high incidence of coronary intervention in post-arrest patients with initially non-shockable rhythms and without STEMI on ECG who are taken for angiography.

Prognostic value of CT-derived left atrial and left ventricular measures in patients with acute chest pain

PURPOSE

To determine which left atrial (LA) and left ventricular (LV) parameters are associated with future major adverse cardiac event (MACE) and whether these measurements have independent prognostic value beyond risk factors and computed tomography (CT)-derived coronary artery disease measures.

MATERIALS AND METHODS

This retrospective analysis was performed under an IRB waiver and in HIPAA compliance. Subjects underwent coronary CT angiography (CCTA) using a dual-source CT system for acute chest pain evaluation. LV mass, LV ejection fraction (EF), LV end-systolic volume (ESV) and LV end-diastolic volume (EDV), LA ESV and LA diameter, septal wall thickness and cardiac chamber diameters were measured. MACE was defined as cardiac death, non-fatal myocardial infarction, unstable angina, or late revascularization. The association between cardiac CT measures and the occurrence of MACE was quantified using Cox proportional hazard analysis.

RESULTS

225 subjects (age, 56.2±11.2; 140 males) were analyzed, of whom 42 (18.7%) experienced a MACE during a median follow-up of 13 months. LA diameter (HR:1.07, 95%CI:1.01-1.13permm) and LV mass (HR:1.05, 95%CI:1.00-1.10perg) remained significant prognostic factor of MACE after controlling for Framingham risk score. LA diameter and LV mass were also found to have prognostic value independent of each other. The other morphologic and functional cardiac measures were no significant prognostic factors for MACE.

CONCLUSION

CT-derived LA diameter and LV mass are associated with future MACE in patients undergoing evaluation for chest pain, and portend independent prognostic value beyond traditional risk factors, coronary calcium score, and obstructive coronary artery disease.

[Budget impact analysis of antiplatelet therapy with ticagrelor and clopidogrel in patients with acute coronary syndrome after coronary artery bypass surgery]

AIM

Clinical and economic examinations were made to study whether it is appropriate to use antiplatelet therapy (APT) with ticagrelor in combination with acetylsalicylic acid (ASA) versus a combination of clopidogrel and ASA in patients with acute coronary syndrome (ACS) following coronary artery bypass surgery (CABS).

MATERIAL AND METHODS

A budget impact analysis was used. Data on the efficiency and safety of APT were taken from a relevant analysis in the subgroups of the randomized controlled trial PLATO. Direct medical cost due to APT and expenses on therapy for acute myocardial infarction, stroke, and massive bleeding, and those on medical care for patients dying from cardiovascular events and other causes, as well as indirect cost - gross domestic product (GDP) losses due to untimely death, were taken into account. The findings were assessed from the perspectives of society.

RESULTS

The analysis indicated that direct medical costs per patient following CABS, both in case of calculation based on the recorded price for ticagrelor and on the median registered prices for clopidogrel generics, and based on the auction prices for comparison agents proved to be lower when clopidogrel was administered because of the higher cost of ticagrelor-based APT. At the same time GDP losses due to untimely death, as calculated per patient with ACS during post-CABS therapy with clopidogrel + ASA, were more than twice above average losses per patient taking ticagrelor in combination with ACA (107,122 and 221,645 rubles, respectively). From the registered price for ticagrelor and the median registered prices for clopidogrel generics, the total costs per patient with ACS following CABS were lower if Brilinta was used in combination with ASA versus therapy with clopidogrel in combination with ASA (210,092 and 273,257 rubles per year, respectively; the cost savings were 63,165 rubles per patient per year when ticagrelor was administered). On the basis of the auction prices for comparison drugs, the total costs per patient with ACS after CABS proved to be lower if Brilinta was used in combination with ASA versus therapy with brand name clopidogrel in combination with ASA (201,018 and 293,982 rubles per patients year, respectively; the cost savings were 92,963 rubles per patient per year when ticagrelor was used).

CONCLUSION

The use of ticagrelor in combination with ASA ensures resource savings to treat ACS patients undergoing CABS as compared with a regiment including a combination of clopidogrel and ASA.

Cost analysis of the History, ECG, Age, Risk factors, and initial Troponin (HEART) Pathway randomized control trial

INTRODUCTION

The HEART Pathway is a diagnostic protocol designed to identify low-risk patients presenting to the emergency department with chest pain that are safe for early discharge. This protocol has been shown to significantly decrease health care resource utilization compared with usual care. However, the impact of the HEART Pathway on the cost of care has yet to be reported.

METHODS AND RESULTS

We performed a cost analysis of patients enrolled in the HEART Pathway trial, which randomized participants to either usual care or the HEART Pathway protocol. For low-risk patients, the HEART Pathway recommended early discharge from the emergency department without further testing. We compared index visit cost, cost at 30 days, and cardiac-related health care cost at 30 days between the 2 treatment arms. Costs for each patient included facility and professional costs. Cost at 30 days included total inpatient and outpatient costs, including the index encounter, regardless of etiology. Cardiac-related health care cost at 30 days included the index encounter and costs adjudicated to be cardiac-related within that period. Two hundred seventy of the 282 patients enrolled in the trial had cost data available for analysis. There was a significant reduction in cost for the HEART Pathway group at 30 days (median cost savings of $216 per individual), which was most evident in low-risk (Thrombolysis In Myocardial Infarction score of 0-1) patients (median savings of $253 per patient) and driven primarily by lower cardiac diagnostic costs in the HEART Pathway group.

CONCLUSIONS

Using the HEART Pathway as a decision aid for patients with undifferentiated chest pain resulted in significant cost savings.

Effectiveness of a multidisciplinary critical pathway based on a computerised physician order entry system for ST-segment elevation myocardial infarction management in the emergency department: a retrospective observational study

OBJECTIVES

The purpose of this study was to investigate whether a multidisciplinary organised critical pathway (CP) for ST-segment elevation myocardial infarction (STEMI) management can significantly attenuate differences in the duration from emergency department (ED) arrival to evaluation and treatment, regardless of the arrival time, by eliminating off-hour and weekend effects.

DESIGN

Retrospective observational cohort study.

SETTING

2 tertiary academic hospitals.

PARTICIPANTS

Consecutive patients in the Fast Interrogation Rule for STEMI (FIRST) program.

INTERVENTIONS

A study was conducted on patients in the FIRST program, which uses a computerised physician order entry (CPOE) system. The patient demographics, time intervals and clinical outcomes were analysed based on the arrival time at the ED: group 1, normal working hours on weekdays; group 2, off-hours on weekdays; group 3, normal working hours on weekends; and group 4, off-hours on weekends.

PRIMARY AND SECONDARY OUTCOME MEASURES

Clinical outcomes categorised according to 30-day mortality, in-hospital mortality and the length of stay.

RESULTS

The duration from door-to-data or FIRST activation did not differ significantly among the 4 groups. The median duration between arrival and balloon placement during percutaneous coronary intervention did not significantly exceed 90 min, and the proportions (89.6-95.1%) of patients with door-to-balloon times within 90 min did not significantly differ among the 4 groups, regardless of the ED arrival time (p=0.147). Moreover, no differences in the 30-day (p=0.8173) and in-hospital mortality (p=0.9107) were observed in patients with STEMI.

CONCLUSIONS

A multidisciplinary CP for STEMI based on a CPOE system can effectively decrease disparities in the door-to-data duration and proportions of patients with door-to-balloon times within 90 min, regardless of the ED arrival time. The application of a multidisciplinary CP may also help attenuate off-hour and weekend effects in STEMI clinical outcomes.

Adherence to an Accelerated Diagnostic Protocol for Chest Pain: Secondary Analysis of the HEART Pathway Randomized Trial

OBJECTIVES

Accelerated diagnostic protocols (ADPs), such as the HEART Pathway, are gaining popularity in emergency departments (EDs) as tools used to risk stratify patients with acute chest pain. However, provider nonadherence may threaten the safety and effectiveness of ADPs. The objective of this study was to determine the frequency and impact of ADP nonadherence.

METHODS

A secondary analysis of participants enrolled in the HEART Pathway RCT was conducted. This trial enrolled 282 adult ED patients with symptoms concerning for acute coronary syndrome without ST-elevation on electrocardiogram. Patients randomized to the HEART Pathway (N = 141) were included in this analysis. Outcomes included index visit disposition, nonadherence, and major adverse cardiac events (MACEs) at 30 days. MACE was defined as death, myocardial infarction, or revascularization. Nonadherence was defined as: 1) undertesting-discharging a high-risk patient from the ED without objective testing (stress testing or coronary angiography) or 2) overtesting-admitting or obtaining objective testing on a low-risk patient.

RESULTS

Nonadherence to the HEART Pathway occurred in 28 of 141 patients (20%, 95% confidence interval [CI] = 14% to 27%). Overtesting occurred in 19 of 141 patients (13.5%, 95% CI = 8% to 19%) and undertesting in nine of 141 patients (6%, 95% CI = 3% to 12%). None of these 28 patients suffered MACE. The net effect of nonadherence was 10 additional admissions among patients identified as low-risk and appropriate for early discharge (absolute decrease in discharge rate of 7%, 95% CI = 3% to 13%).

CONCLUSIONS

Real-time use of the HEART Pathway resulted in a nonadherence rate of 20%, mostly due to overtesting. None of these patients had MACE within 30 days. Nonadherence decreased the discharge rate, attenuating the HEART Pathway's impact on health care use.

Chest Pain of Suspected Cardiac Origin: Current Evidence-based Recommendations for Prehospital Care

Introduction

In the United States, emergency medical services (EMS) protocols vary widely across jurisdictions. We sought to develop evidence-based recommendations for the prehospital evaluation and treatment of chest pain of suspected cardiac origin and to compare these recommendations against the current protocols used by the 33 EMS agencies in the state of California.

Methods

We performed a literature review of the current evidence in the prehospital treatment of chest pain and augmented this review with guidelines from various national and international societies to create our evidence-based recommendations. We then compared the chest pain protocols of each of the 33 EMS agencies for consistency with these recommendations. The specific protocol components that we analyzed were use of supplemental oxygen, aspirin, nitrates, opiates, 12-lead electrocardiogram (ECG), ST segment elevation myocardial infarction (STEMI) regionalization systems, prehospital fibrinolysis and β-blockers.

Results

The protocols varied widely in terms of medication and dosing choices, as well as listed contraindications to treatments. Every agency uses oxygen with 54% recommending titrated dosing. All agencies use aspirin (64% recommending 325mg, 24% recommending 162mg and 15% recommending either), as well as nitroglycerin and opiates (58% choosing morphine). Prehospital 12-Lead ECGs are used in 97% of agencies, and all but one agency has some form of regionalized care for their STEMI patients. No agency is currently employing prehospital fibrinolysis or β-blocker use.

Conclusion

Protocols for chest pain of suspected cardiac origin vary widely across California. The evidence-based recommendations that we present for the prehospital diagnosis and treatment of this condition may be useful for EMS medical directors tasked with creating and revising these protocols.

Comparing an Unstructured Risk Stratification to Published Guidelines in Acute Coronary Syndromes

Introduction

Guidelines are designed to encompass the needs of the majority of patients with a particular condition. The American Heart Association (AHA) in conjunction with the American College of Cardiology (ACC) and the American College of Emergency Physicians (ACEP) developed risk stratification guidelines to aid physicians with accurate and efficient diagnosis and management of patients with acute coronary syndrome (ACS). While useful in a primary care setting, in the unique environment of an emergency department (ED), the feasibility of incorporating guidelines into clinical workflow remains in question. We aim to compare emergency physicians’ (EP) clinical risk stratification ability to AHA/ACC/ACEP guidelines for ACS, and assessed each for accuracy in predicting ACS.

Methods

We conducted a prospective observational cohort study in an urban teaching hospital ED. All patients presenting to the ED with chest pain who were evaluated for ACS had two risk stratification scores assigned: one by the treating physician based on clinical evaluation and the other by the AHA/ACC/ACEP guideline aforementioned. The patient’s ACS risk stratification classified by the EP was compared to AHA/ACC/ACEP guidelines. Patients were contacted at 30 days following the index ED visit to determine all cause mortality, unscheduled hospital/ED revisits, and objective cardiac testing performed.

Results

We enrolled 641 patients presenting for evaluation by 21 different EPs. There was a difference between the physician’s clinical assessment used in the ED, and the AHA/ACC/ACEP task force guidelines. EPs were more likely to assess patients as low risk (40%), while AHA/ACC/ACEP guidelines were more likely to classify patients as intermediate (45%) or high (45%) risk. Of the 119 (19%) patients deemed high risk by EP evaluation, 38 (32%) were diagnosed with ACS. AHA/ACC/ACEP guidelines classified only 57 (9%) patients low risk with 56 (98%) of those patients diagnosed with no ACS.

Conclusion

In the ED, physicians are more efficient at correctly placing patients with underlying ACS into a high-risk category. A small percentage of patients were considered low risk when applying AHA/ACC/ACEP guidelines, which demonstrates how clinical insight is often required to make an efficient assessment of cardiac risk and established criteria may be overly conservative when applied to an acute care population.

Single vs double antiplatelet therapy in acute coronary syndrome: Predictors of bleeding after coronary artery bypass grafting

AIM: To investigate the contribution of anti-platelet therapy and derangements of pre-operative classical coagulation and thromboelastometry parameters to major bleeding post-coronary artery bypass grafting (CABG).

METHODS: Two groups of CABG patients were studied: Group A, treated with aspirin alone (n = 50), and Group B treated with aspirin and clopidogrel (n = 50). Both had similar preoperative, clinical, biologic characteristics and operative management. Classic coagulation parameters and rotational thromboelastometry (ROTEM) profiles were determined preoperatively for both groups and the same heparin treatment was administered. ROTEM profiles (INTEM and EXTEM assays) were analyzed, both for traditional parameters, and thrombin generation potential, expressed by area-under-curve (AUC).

RESULTS: There was no significant difference between rates of major bleeding between patients treated with aspirin alone, compared with those treated with aspirin and clopidogrel (12% vs 16%, P = 0.77). In the 14 cases of major bleeding, pre-operative classic coagulation and traditional ROTEM parameters were comparable. Conversely we observed that the AUC in the EXTEM test was significantly lower in bleeders (5030 ± 1115 Ohm*min) than non-bleeders (6568 ± 548 Ohm*min) (P < 0.0001).

CONCLUSION: We observed that patients with a low AUC value were at a significantly higher risk of bleeding compared to patients with higher AUC, regardless of antiplatelet treatment. This suggests that thrombin generation potential, irrespective of the degree of platelet inhibition, correlates with surgical bleeding.

Cardiac Arrest: A Treatment Algorithm for Emergent Invasive Cardiac Procedures in the Resuscitated Comatose Patient

Patients who are comatose after cardiac arrest continue to be a challenge, with high mortality. Although there is an American College of Cardiology Foundation/American Heart Association Class I recommendation for performing immediate angiography and percutaneous coronary intervention (when indicated) in patients with ST-segment elevation myocardial infarction, no guidelines exist for patients without ST-segment elevation. Early introduction of mild therapeutic hypothermia is an established treatment goal. However, there are no established guidelines for risk stratification of patients for cardiac catheterization and possible percutaneous coronary intervention, particularly in patients who have unfavorable clinical features in whom procedures may be futile and affect public reporting of mortality. An algorithm is presented to improve the risk stratification of these severely ill patients with an emphasis on consultation and evaluation of patients prior to activation of the cardiac catheterization laboratory.

The HEART Pathway randomized trial: identifying emergency department patients with acute chest pain for early discharge

BACKGROUND

The HEART Pathway is a decision aid designed to identify emergency department patients with acute chest pain for early discharge. No randomized trials have compared the HEART Pathway with usual care.

METHODS AND RESULTS

Adult emergency department patients with symptoms related to acute coronary syndrome without ST-elevation on ECG (n=282) were randomized to the HEART Pathway or usual care. In the HEART Pathway arm, emergency department providers used the HEART score, a validated decision aid, and troponin measures at 0 and 3 hours to identify patients for early discharge. Usual care was based on American College of Cardiology/American Heart Association guidelines. The primary outcome, objective cardiac testing (stress testing or angiography), and secondary outcomes, index length of stay, early discharge, and major adverse cardiac events (death, myocardial infarction, or coronary revascularization), were assessed at 30 days by phone interview and record review. Participants had a mean age of 53 years, 16% had previous myocardial infarction, and 6% (95% confidence interval, 3.6%-9.5%) had major adverse cardiac events within 30 days of randomization. Compared with usual care, use of the HEART Pathway decreased objective cardiac testing at 30 days by 12.1% (68.8% versus 56.7%; P=0.048) and length of stay by 12 hours (9.9 versus 21.9 hours; P=0.013) and increased early discharges by 21.3% (39.7% versus 18.4%; P<0.001). No patients identified for early discharge had major adverse cardiac events within 30 days.

CONCLUSIONS

The HEART Pathway reduces objective cardiac testing during 30 days, shortens length of stay, and increases early discharges. These important efficiency gains occurred without any patients identified for early discharge suffering MACE at 30 days.

CLINICAL TRIAL REGISTRATION

URL: http://www.clinicaltrials.gov. Unique Identifier: NCT01665521.

From door to recovery: a collaborative approach to the development of a post-cardiac arrest center

Out-of-hospital cardiac arrest remains common and, despite advances in resuscitation practices, continues to carry a high mortality that may be influenced by several factors, including where a patient is cared for after the cardiac arrest. Implementing a post-cardiac arrest care guideline for survivors of out-of-hospital and in-hospital cardiac arrest involves a multidisciplinary approach with short-term and long-term strategies. Physician and nursing leaders must work in synergy to guide the implementation of an evidence-based plan of care. A collaborative approach was used at a hospital to develop processes, build consensus for protocols, and provide support to staff and teams. A joint approach has allowed the hospital to move from traditional silos of individual departmental care to a continuum of patient-focused management after cardiac arrest. This care coordination is initiated in the emergency department and follows the patient through to discharge.

Emergency medical services management of ST-segment elevation myocardial infarction in the United States--a report from the American Heart Association Mission: Lifeline Program

OBJECTIVE

ST-segment elevation myocardial infarction (STEMI) is a major cause of morbidity and mortality in the United States. Emergency medical services (EMS) agencies play a critical role in its initial identification and treatment. We conducted this study to assess EMS management of STEMI care in the United States.

METHODS

A structured questionnaire was administered to leaders of EMS agencies to define the elements of STEMI care related to 4 core measures: (1) electrocardiogram (ECG) capability at the scene, (2) destination protocols, (3) catheterization laboratory activation before hospital arrival, and (4) 12-lead ECG quality review. Geographic areas were grouped into large metropolitan, small metropolitan, micropolitan, and noncore (or rural) by using Urban Influence Codes, with a stratified analysis.

RESULTS

Data were included based on responses from 5296 EMS agencies (36% of those in the United States) serving 91% of the US population, with at least 1 valid response from each of the 50 states and the District of Columbia. Approximately 63% of agencies obtained ECGs at the scene using providers trained in ECG acquisition and interpretation. A total of 46% of EMS systems used protocols to determine hospital destination, cardiac catheterization laboratory activation, and communications with the receiving hospital. More than 75% of EMS systems used their own agency funds to purchase equipment, train personnel, and provide administrative oversight. A total of 49% of agencies have quality review programs in place. In general, EMS systems covering higher population densities had easier access to resources needed to maintain STEMI systems of care. Emergency medical services systems that have adopted all 4 core elements cover 14% of the US population.

CONCLUSIONS

There are large differences in EMS systems of STEMI care in the United States. Most EMS agencies have implemented at least 1 of the 4 core elements of STEMI care, with many having implemented multiple elements.

Routine angiography in survivors of out of hospital cardiac arrest with return of spontaneous circulation: a single site registry

BACKGROUND

Coronary revascularization in resuscitated out of hospital cardiac arrest (OOHCA) patients has been associated with improved survival.

METHODS

This was a retrospective review of patients with OOHCA between 01/07/2007 and 31/03/2009 surviving to hospital admission. Cardiac risk factors, demographics, treatment times, electrocardiogram (ECG), angiographic findings and in-hospital outcomes were recorded.

RESULTS

Of the 78 patients, 63 underwent coronary angiography. Traditional cardiac risk factors were common in this group. Chest pain occurred in 33.3% pre-arrest, 59.0% were initially treated at a peripheral hospital, 83.3% had documented ventricular tachycardia or ventricular fibrillation, 55.1% had specific ECG changes, 65.4% had acute myocardial infarction (AMI) as the cause of OOHCA and the majority had multi-vessel disease. ST elevation strongly predicted AMI. The in-hospital survival was 67.9% with neurological deficit in 13.2% of survivors. The group of patients who had an angiogram were more likely to have AMI as a cause of cardiac arrest (71.4% vs 40.0%, p = 0.01) and more likely to have survived to discharge (74.6% vs 40.0%, p < 0.01). Poor outcome was associated with older age, cardiogenic shock, longer transfer times, diabetes, renal impairment and a long duration to return of spontaneous circulation.

CONCLUSIONS

Acute myocardial infarction was the commonest cause of OOHCA and a high rate of survival to discharge was seen with a strategy of routine angiography and revascularization.

Root cause analysis of delays to discharge for patients held for serial cardiac troponin levels

OBJECTIVE

Emergency department (ED) patients with symptoms of cardiac ischemia often require a second cardiac troponin (cTn) measurement to rule out non-ST elevation myocardial infarction. We measured the total turnaround time and the component event times following the ordering of the second cTn level to ED discharge to identify root causes of delays.

METHODS

We reviewed a random sample of ED discharges following a second normal cTn measurement and recorded associated event times. The central tendency of time intervals is reported as median and mean number of minutes with interquartile ranges (IQRs) and 95% confidence intervals, respectively.

RESULTS

From 9,656 eligible cases, we randomly selected 226 for data collection. The median number of minutes for each event are as follows: from ordering the second cTn measurement to the time of ED discharge was 90 minutes (IQR 65-120); for blood collection from the time the collection was ordered for was 0 minutes (IQR -12-0); from blood collection to the time the blood was transported to the laboratory was 9 minutes (IQR 2-19); laboratory process duration was 44 minutes (IQR 39-52); from when the results were available to the time the patient was discharged was 30 minutes (IQR 15-52).

CONCLUSIONS

For ED patients discharged following two normal cTn levels, the laboratory processing time and time from the result being available to the time of ED discharge represent the longest modifiable time periods to reduce ED length of stay.

STEMI mortality in community hospitals versus PCI-capable hospitals: results from a nationwide STEMI network programme

AIMS

Reports examining local ST elevation myocardial infarction (STEMI) networks focused mainly on percutaneous coronary intervention (PCI)-related time issues and outcomes. To validate the concept of STEMI networks in a real-world context, more data are needed on management and outcome of an unselected community based STEMI population.

METHODS AND RESULTS

The current study evaluated reperfusion strategies and in-hospital mortality in 8500 unselected STEMI patients admitted to 47 community hospitals (n=3053) and 25 PCI-capable hospitals (n=5447) in the context of a nationwide STEMI network programme that started in 2007 in Belgium. The distance between the hub and spoke hospitals ranged from 2.2 to 47 km (median 15 km). A propensity score was used to adjust for differences in baseline characteristics. Reperfusion strategy was significantly different with a predominant use of primary PCI (pPCI) in PCI-capable hospitals (93%), compared to a mixed use of pPCI (71%) and thrombolysis (20%) in community hospitals. A door-to-balloon time <120 min was achieved in 83% of community hospitals and in 91% of PCI-capable hospitals (p<0.0001). In-hospital mortality was 7.0% in community hospitals versus 6.7% in PCI-capable hospitals with an adjusted odds ratio of 1.1 (95% confidence interval: 0.8-1.4). Between the periods 2007-2008 and 2009-2010, the pPCI rate in community hospitals increased from 60% to 80%, whereas the proportion of conservatively managed patients decreased from 11.1% to 7.9%.

CONCLUSION

In a STEMI network with >70% use of pPCI, in-hospital mortality was comparable between community hospitals and PCI-capable hospitals. Participation in the STEMI network programme was associated with an increased adherence to reperfusion guidelines over time.

Monocytes in coronary artery disease and atherosclerosis: where are we now?

Despite improvements in interventional and pharmacological therapy of atherosclerotic disease, it is still the leading cause of death in the developed world. Hence, there is a need for further development of effective therapeutic approaches. This requires better understanding of the molecular mechanisms and pathophysiology of the disease. Atherosclerosis has long been identified as having an inflammatory component contributing to its pathogenesis, whereas the available therapy primarily targets hyperlipidemia and prevention of thrombosis. Notwithstanding a pleotropic anti-inflammatory effect to some therapies, such as acetyl salicylic acid and the statins, none of the currently approved medicines for management of either stable or complicated atherosclerosis has inflammation as a primary target. Monocytes, as representatives of the innate immune system, play a major role in the initiation, propagation, and progression of atherosclerosis from a stable to an unstable state. Experimental data support a role of monocytes in acute coronary syndromes and in outcome post-infarction; however, limited research has been done in humans. Analysis of expression of various cell surface receptors allows characterization of the different monocyte subsets phenotypically, whereas downstream assessment of inflammatory pathways provides an insight into their activity. In this review we discuss the functional role of monocytes and their different subpopulations in atherosclerosis, acute coronary syndromes, cardiac healing, and recovery with an aim of critical evaluation of potential future therapeutic targets in atherosclerosis and its complications. We will also discuss technical difficulties of delineating different monocyte subpopulations, understanding their differentiation potential and function.

Clinical outcomes, health resource use, and cost in patients with early versus late dual or triple anti-platelet treatment for acute coronary syndrome

BACKGROUND

Acute coronary syndrome (ACS) guidelines recommend early dual anti-platelet therapy (thienopyridines + acetylsalicylic acid [aspirin]). However, triple therapy (thienopyridines + aspirin + glycoprotein IIb/IIIa receptor inhibitors [GRIs]) has shown benefit in clinical trials.

OBJECTIVE

This study assessed real-world ACS treatment patterns and outcomes in the acute care setting.

STUDY DESIGN

A retrospective analysis of patients admitted to hospital with ACS (index event) from January 2007 to December 2009 was conducted (Thomson's MarketScan Hospital Drug Database).

PATIENTS

Eligible patients were ≥18 years of age, of either sex, and had primary admission and discharge diagnoses of ACS.

OUTCOME MEASURES

Cohorts were defined by anti-platelet treatment and then by the timing of treatment initiation (early initiation: within ≤2 days of admission; late initiation: ≥2 days post-admission). Patient characteristics, clinical outcomes, resource utilization, and costs were assessed using descriptive statistics.

RESULTS

A total of 249,907 eligible patients were placed into four treatment cohorts (aspirin assumed for all patients): aspirin only; clopidogrel only (dual therapy); GRI only (dual therapy); and clopidogrel + GRI (triple therapy). Patients in the 'clopidogrel-only' cohort were more likely to be older, female, and have more co-morbidities than those in other cohorts; stroke (6.2 %) and re-hospitalization (15.4 %) rates were higher than in the 'GRI-only' and 'triple therapy' cohorts. The GRI-only cohort had higher major bleeding rates (3.3 %), mortality (7.6 %), and costs ($US21,975 [year 2010 values]) than the clopidogrel-only and triple-therapy cohorts. Late initiation cohorts were more likely to be older, female, and have more co-morbidities than early initiation cohorts. Major bleeding was more likely with GRI-only patients (regardless of initiation timing) than with other cohorts. Late-treated clopidogrel-only patients had higher rates of stroke (6.9 %), ACS-related re-admissions (6.1 %), and all-cause re-admissions (15.9 %) than other cohorts. Late treatment was associated with longer length of stay and significantly higher costs.

CONCLUSIONS

Real-world anti-platelet treatment patterns are consistent with ACS guidelines recommending early initiation and selective GRI use. In contrast to recommendations, some outcomes were improved with triple therapy compared with dual therapy.

Comparing percutaneous coronary intervention and thrombolysis in patients with return of spontaneous circulation after cardiac arrest

OBJECTIVE

To evaluate the effects of percutaneous coronary intervention and thrombolysis after restoration of spontaneous circulation in cardiac arrest patients with ST-elevation myocardial infarction using meta-analysis.

METHODS

We performed a meta-analysis of clinical studies indexed in the PUBMED, MEDLINE and EMBASE databases and published between January 1995 and October 2012. In addition, we compared the hospital discharge and neurological recovery rates between the patients who received percutaneous coronary intervention and those who received thrombolysis.

RESULTS

Twenty-four studies evaluating the effects of percutaneous coronary intervention or thrombolysis after restoration of spontaneous circulation in cardiac arrest patients with ST-elevation myocardial infarction were included. Seventeen of the 24 studies were used in this meta-analysis. All studies were used to compare percutaneous coronary intervention and thrombolysis. The meta-analysis showed that the rate of hospital discharge improved with both percutaneous coronary intervention (p<0.001) and thrombolysis (p<0.001). We also found that cardiac arrest patients with ST-elevation myocardial infarction who received thrombolysis after restoration of spontaneous circulation did not have decreased hospital discharge (p = 0.543) or neurological recovery rates (p = 0.165) compared with those who received percutaneous coronary intervention.

CONCLUSION

In cardiac arrest patients with ST-elevation myocardial infarction who achieved restoration of spontaneous circulation, both percutaneous coronary intervention and thrombolysis improved the hospital discharge rate. Furthermore, there were no significant differences in the hospital discharge and neurological recovery rates between the percutaneous coronary intervention-treated group and the thrombolysis-treated group.

Serum extracellular vesicle protein levels are associated with acute coronary syndrome

AIMS

Biomarkers are essential in the early detection of acute coronary syndromes (ACS). Serum extracellular vesicles are small vesicles in the plasma containing protein and RNA and have been shown to be involved in ACS-related processes like apoptosis and coagulation. Therefore, we hypothesized that serum extracellular vesicle protein levels are associated with ACS.

METHODS AND RESULTS

Three serum extracellular vesicle proteins potentially associated with ACS were identified with differential Q-proteomics and were evaluated in 471 frozen serum samples of ACS-suspected patients presenting to the emergency department (30% of whom had an ACS). Protein levels were measured after vesicle isolation using ExoQuick. Mean serum extracellular vesicle concentration of the different proteins was compared between ACS and non-ACS patients. Selected proteins were tested in a univariate logistic regression model, as well as in a multivariate model to adjust for cardiovascular risk factors. A separate analysis was performed in men and women. In the multivariate logistic regression analysis, polygenic immunoglobulin receptor, (pIgR; OR 1.630, p=0.026), cystatin C (OR 1.641, p=0.021), and complement factor C5a (C5a, OR 1.495, p=0.025) were significantly associated with ACS, while total vesicle protein concentration was borderline significant. The association of the individual proteins with ACS was markedly stronger in men.

CONCLUSIONS

These data show that serum extracellular vesicle pIgR, cystatin C, and C5a concentrations are independently associated with ACS and that there are pronounced gender differences. These observations should be validated in a large, prospective study to assess the potential role of vesicle content in the evaluation of patients suspected of having an ACS.

Reduction in observation unit length of stay with coronary computed tomography angiography depends on time of emergency department presentation

OBJECTIVES

Prior studies demonstrating shorter length of stay (LOS) from coronary computed tomography angiography (CCTA) relative to stress testing in emergency department (ED) patients have not considered time of patient presentation. The objectives of this study were to determine whether low-risk chest pain patients receiving stress testing or CCTA have differences in ED plus observation unit (OU) LOS and if there are disparities in testing modality use, based on the time of patient presentation to the ED.

METHODS

The authors examined a cohort of low-risk chest pain patients evaluated in an ED-based OU using prospective and retrospective OU registry data. During the study period, stress testing and CCTA were both available from 08:00 to 17:00 hours. CCTA was not available on weekends, and therefore only subjects presenting on weekdays were included. Cox regression analysis was used to model the effect of testing modality (stress testing vs. CCTA) on OU LOS. Separate models were fit based on time of patient presentation to the ED using 4-hour blocks beginning at midnight. The primary independent variable was testing modality: stress testing or CCTA. Age, sex, and race were included as covariates. Logistic regression was used to model testing modality choice by time period adjusted for age, sex, and race.

RESULTS

Over the study period, 841 subjects presented Monday through Friday. Median LOS was 18.0 hours (interquartile range [IQR] = 11.7 to 22.9 hours). Objective cardiac testing was completed in 788 of 841 (94%) patients, with 496 (63%) receiving stress testing and 292 (37%) receiving CCTA. After age, race, and sex were adjusted for, patients presenting between 08:00 and 11:59 hours not only had a shorter LOS associated with CCTA (p < 0.0001), but also had a greater likelihood of being tested by CCTA (p = 0.001). None of the other time periods had significant differences in LOS or testing modality choice for CCTA relative to stress testing.

CONCLUSIONS

In an OU setting with weekday and standard business hours CCTA availability, CCTA testing was associated with shorter LOS among low-risk chest pain patients only in patients presenting to the ED between 08:00 and 11:59 hours. That time period was also associated with a greater likelihood of being tested by CCTA, suggesting that ED providers may have intuited the inability of CCTA to shorten LOS during other times.

Information on myocardial ischemia and arrhythmias added by prehospital electrocardiograms

BACKGROUND

The prehospital electrocardiogram (ECG) allows earlier identification of acute ST-segment elevation myocardial infarction (STEMI). Its utility for detection of other acute cardiac events, as well as for transient ST-segment abnormalities no longer present when the first hospital ECG is performed, is not well characterized.

OBJECTIVE

We sought to examine whether the prehospital ECG adds supplemental information to the first ECG obtained in hospital, by comparing data on possible cardiac ischemia and arrhythmias provided by the two ECGs, in ambulance patients later diagnosed as having cardiac disorders, including STEMI.

METHODS

Ambulance personnel acquired 12-lead ECGs for patients suspected of having an acute ischemic event, prior to transport to hospital. The first emergency department 12-lead ECG was provided by medical records at the receiving hospital, and the principal hospital diagnosis for the event was extracted from chart data. Two cardiologists, blinded to the hospital diagnosis, provided their consensus interpretation of 1,209 pairs of ECGs, noting the presence or absence of specific abnormalities on each tracing.

RESULTS

Among the 82 patients who had an eventual hospital diagnosis of STEMI, the study cardiologists identified 71 with ST-segment elevations on the ECGs they examined. The vast majority of these (97%) were observed on both ECGs, but the prehospital ECG showed ST-segment elevation for two additional patients (3%). No additional instances were seen only on the hospital ECG. Among the 116 patients with a hospital diagnosis of non-ST-segment elevation myocardial infarction (NSTEMI), the cardiologists identified 36 with ST-segment depressions: 28 (78%) of these were present on both ECGs, seven (19%) only on the prehospital ECG, and one (3%) only on the hospital ECG. Among the 567 patients with any cardiac hospital diagnosis, the cardiologists identified 87 with arrhythmias: 73 (84%) on both ECGs, 12 (14%) only on the prehospital ECG, and two (2%) only on the hospital ECG.

CONCLUSIONS

Beyond identifying ST-segment elevation earlier, prehospital ECGs detect important transient abnormalities, information not otherwise available from the first emergency department ECG. These data can expedite diagnosis and clinical management decisions among patients suspected of having an acute cardiac event. The prehospital ECG should be fully integrated into emergency medicine practice.