Acute Coronary Syndrome Subgroup Research Articles

Unstable Angina and Other Acute Coronary Syndromes

Patients with coronary artery disease (CAD) present clinically when their disease enters an unstable phase known as an acute coronary syndrome (ACS), in which the cap of a previously stable atheromatous coronary plaque ruptures or erodes, which in turn activates a thrombotic cascade that may lead to coronary artery occlusion, myocardial infarction (MI), cardiogenic shock, and patient death. There are nearly 2 million episodes of ACS in the United States annually; it is the most common reason for hospitalization with CAD and is the leading cause of death in the developed world. ACS patients include those with unstable angina (UA), non–ST segment elevation myocardial infarction (non-STEMI), and ST segment elevation myocardial infarction (STEMI) and patients who die suddenly of an arrhythmia precipitated by coronary occlusion. The distinction among various ACS subgroups reflects varying characteristics of clinical presentation (presence or absence of elevated cardiac biomarkers) and the type of electrocardiographic (ECG) changes manifested on the initial ECG at the time of hospitalization. This chapter focuses on UA and non-STEMI. A graph outlines mortality risks faced by patients with varying degrees of renal insufficiency. An algorithm describes the suggested management of patients admitted with UA or non-STEMI. Tables describe the risk stratification of the patient with chest pain, categories of Killip class, examination findings of a patient with high-risk ACS, diagnosis of MI, causes of troponin elevation other than ischemic heart disease, initial risk stratification of ACS patients, and long-term medical therapies and goals in ACS patients. This review contains 2 highly rendered figures, 11 tables, and 76 references.

Levels of BNP and Stress Blood Glucose in Acute Coronary Syndrome Patients and Their Relationships with the Severity of Coronary Artery Lesion

This study aims to analyze the clinical significance of the measuring B-type natriuretic peptide (BNP) and stress glycemia in patients with acute coronary syndrome (ACS), and to investigate the relationships between the two biomarkers and the severity of coronary artery lesions. One hundred and five consecutive patients with ACS admitted for coronary artery angiography were divided into three clinical subgroups. These patients were then further assigned into either of three subgroups according to their Gensini score. Moreover, a group of patients with stable angina (SA) and those with no history of coronary disease served as controls. The patients' BNP levels were analyzed on admission and their fasting blood glucose was measured the next morning. BNP and fasting blood glucose concentrations were highly elevated in patients with ACS irrespective of their subgroups compared to SA and control patients. This observation was statistically significant (P < 0.001). Further, the concentrations of BNP and fasting blood glucose between the three ACS subgroups were significantly different (P < 0.001) depending on the severity of the coronary artery disease. There is a positive correlation between levels of BNP and blood glucose concentration and Gensini score in ACS patients (r = 0.782, P < 0.05, r = 0.732, P < 0.05). BNP level and stress glycemia were significantly higher in ACS patients than those in SA and control groups. There is a correlation between BNP level and stress blood glucose concentration and the severity of coronary artery lesions. Combined analysis of BNP and stress blood glucose can be helpful and effective for risk stratification of patients with ACS after admission.

GW24-e3065 Risk Factors for Recurrence of Cardiovascular Events Following Acute Coronary Syndrome: Longitudinal Analysis from 2006 to 2011

ObjectivesCardiovascular (CV) disease is the leading cause of mortality in the US and worldwide; thus, it is important to understand the disease sequelae and prognostic predictors to help improve patient...

Abstract 360: A Simplified Post-Discharge Telephone Intervention To Reduce Hospital Readmission for Patients with Cardiovascular Disease.

Background: Readmission rates are high for patients with cardiovascular disease, particularly heart failure (HF) and acute coronary syndrome (ACS). Telephone calls by clinical staff have had mixed effects. We aim to evaluate the degree of implementation and the effect of a quality improvement initiative using a simplified post-discharge phone call by administrative assistants. Methods: Clinical data were retrospectively reviewed at a single urban public hospital. From January through October 2012 all patient discharged home from inpatient cardiology services (intervention group, n=1034 discharges) were identified. Within 7 days, administrative assistants contacted patients via telephone and queried regarding (1) medication compliance, (2) awareness of follow-up appointments and (3) if clinician contact is requested. Outcome events were defined as readmissions (for any cause) within 30 days to the same hospital and are reported as patients experiencing readmission, and total readmissions. A comparison group of all patients discharged home from inpatient cardiology services from January through October 2010 (n=746) were selected as controls (no phone calls). Categorical data were compared in a univariate fashion using the Chi Square test. Statistical significance is defined as p&lt;.05. Results: Of the 1034 discharge events in the intervention group, 620 (60.0%) had phone calls attempted. Of those, 419 (67.6%) were directly contacted. Patients were statistically different with respect to language, ethnicity and insurance status. Of the patients called, 48 (7.7%) reported medication abnormalities, 13 (2.1%) did not understand their follow-up and 38 (6.1%) had a question for a clinician. The rates of patients experiencing events was not statistically different (132 [17.7%] vs. 156 [15.1%], OR 0.85, p=.14). Total readmissions were significantly reduced (157[21.0%] vs. 179 [17.3%], OR 0.82, p=.047). Pre-specified subgroups of ACS and HF patients showed a trend towards decreased re-admissions but were not statistically significant. Conclusion: A simplified post-discharge telephone call strategy is associated with a trend towards reduced hospital readmissions for cardiology patients. Further refinements are needed to improve program implementation.

Abstract 251: Risk Factors for Recurrence of Cardiovascular Events Following Acute Coronary Syndrome: Longitudinal Analysis from 2006-2011

Background: Cardiovascular (CV) disease is the leading cause of mortality in the US and worldwide; thus, it is important to understand the disease sequelae and prognostic predictors to help improve patient outcomes and reduce healthcare costs. Methods: Patients with an ICD-9 code for acute myocardial infarction (MI) or unstable angina (UA) during acute coronary syndrome (ACS) hospitalization were identified from the HealthCore Integrated Research Database (HIRD SM ) between Jan 2006 and Sep 2011. A multivariable Cox proportional hazards model was used to evaluate the effect of risk factors on time to first subsequent CV event (defined as stroke, MI or CHD-related mortality), adjusting for baseline demographic characteristics, comorbidities, treatment utilization and index ACS characteristics. Results: Of 140,903 ACS patients identified, mean age was 66.8 years, 58.6% were male, and mean follow-up was 1.9 years. Baseline comorbidities include 41.9% with type 1 or 2 diabetes mellitus (DM), 60.4% hypertension (HTN), 10.7% renal dysfunction and 3.3% prior CABG/PCI. During the index ACS hospitalization, 42.7% had UA, 40.3% CABG and/or PCI and 3.6% of patients died. A total of 22.0% of patients had a recurrent CV event following index ACS, with an increased adjusted hazard of a recurrent event if the patient was older (hazard ratio=1.48 in &gt; 65 vs &lt;65 years), had a history of heart failure (HR=1.41), renal dysfunction (HR=1.36), HTN (HR= 1.14) or DM (HR=1.10), all P &lt; 0.001. Additionally, patients had a decreased adjusted hazard of a recurrent CV event with pre-admission single or fixed-dose combination statin use (HR=0.96 and 0.87, respectively) or a CABG prior to admission (HR=0.89), all P &lt;0.001. Conclusion: Following an ACS event, patients with pre-admission statin use or a prior CABG had decreased risk, while older patients or those with baseline comorbidities had increased risk of an adverse CV event occurring sooner. Ultimately, identifying high-risk ACS subgroups may facilitate tailored and more aggressive treatment to improve outcomes.

Akut koroner sendromlu hastalarda endotelyal progenitör hücre sayımı

Aim. Endothelial progenitor cells repair related region by removal of damaged endothelial cells mechanically or replacing endothelial cells via migration from bone marrow to peripheric blood pool with stimulus of cytokines. Previously, it has been shown that number of these cells decrease in chronic stage of stable coronary heart disease, whereas they increase in number in acute coronary syndromes. The aim of this study is to investigate the difference in the number of endothelial progenitor cells among subgroups of acute coronary syndrome (ST elevation myocardial infarction, non-ST elevation myocardial infarction and unstable angina pectoris ) in patients hospitalized in coronary intensive care unit. Method. The study data were analysed in two steps. In the first step, it has been investigated whether there were any differences regarding endothelial progenitor cell count among three subgroups of acute coronary syndrome (n=112). In the second step, a further 13 patients who were hospitalized with a prediagnosis of unstabil angina pectoris and subsequently reported to have normal echocardiography and coronary angiography were also enrolled. The patients were divided into two groups; the patients with unstabil angina pectoris of whom no increase in cardiac enzymes detected indicating the absence of any cardiac damage and patients with normal coronary angiography findings constituted the first group (Grup A, n=41) and the patients with ST elevation myocardial infarction and non-ST elevation myocardial infarction of whom an increase in cardiac enzymes detected indicating a documented cardiac damage constituted the second group (Grup B, n=84). We investigated whether there were any differences regarding endothelial progenitor cell count between these two groups. Results. Our results indicate that the number of endothelial progenitor cells did not differ significantly among these three groups in the first step (3.87 ± 2.74, 5.46 ± 6.38 and 3.95 ± 2.94, respectively; p=0.232). The results of the statistical analysis also revealed no differences between Grup A and Grup B regarding EPC counts (3.89 ± 2.81 vs 4.80 ± 5.22; p=0.302). Conclusion. In the light of these data, in coronary heart disease in which resistance to treatment is a topical problem despite improvements in therapeutic modalities, further clinical studies are needed about the number and the functions of these cells in the bone marrow and peripheric blood, their effects on target tissues and the factors regulating them, for theurapeutic use of these cells.

INCREASED MONOCYTIC EXPRESSION OF UROKINASE RECEPTOR IN ACUTE CORONARY SYNDROME: A POTENTIAL MARKER OF CLINICAL INSTABILITY

ObjectivesUrokinase receptor (uPAR) is highly expressed in atheromatous plaques and plays a crucial role in inflammation by modulating cell migration and matrix degradation. We hypothesise that uPAR is also increased...

Prevalence and non-invasive predictors of left main or three-vessel coronary disease: evidence from a collaborative international meta-analysis including 22 740 patients

BackgroundLeft main disease (LMD) and three-vessel disease (3VD) have important prognostic value in patients with coronary artery disease. However, uncertainties still exist about their prevalence and predictors in patients with...

Study on the levels of BNP, hs-CRP and stress blood glucose in ACS patients and its relationship with the extent of the coronary artery lesion

ObjectiveTo study the diversity of levels of B-type natriuretic peptide (BNP), high sensitivity C-reactive protein (hs-CRP) and stress blood glucose in patients of acute coronary syndrome (ACS), meanwhile, to investigate...

Increasing rates of angioplasty versus bypass surgery in Canada, 1994-2005

Percutaneous coronary intervention (PCI) is increasingly being offered to patients with coronary artery disease. The purpose of this study was to determine the impact of this change in coronary revascularization strategy on PCI and coronary artery bypass grafting (CABG) utilization across Canada. All cases of PCI and isolated CABG between years 1994 and 2005 were identified through the Canadian Institute for Health Information. Age- and sex-standardized rates of PCI and CABG per 100,000 population as well as PCI-to-CABG ratios were calculated by year and province and across age, sex, income, diabetes, and recent acute coronary syndrome subgroups. In addition, risk-adjusted rates of in-hospital mortality after PCI and CABG were reported by year. Between 1994 and 2005, PCI rates increased from 85.6/100,000 to 186.7/100,000 (P < .001), whereas CABG rates remained stable (75.6/100,000-70.8/100,000; P = .43), resulting in an increase in PCI-to-CABG ratio (1.13-2.64; P < .001). Significant increases in PCI-to-CABG ratios were seen across all provinces (except Newfoundland and Alberta), as well as across all age, sex, income, diabetes, and recent acute coronary syndrome categories. Decline in risk-adjusted in-hospital mortality was seen after both CABG (3.9%-2.2%; P < .001) and PCI (1.6%-1.3%; P < .001) but appeared larger after CABG. Since 1994, rates of PCI have increased significantly as compared to CABG. During the same period, greater declines in risk-adjusted rates of in-hospital mortality were seen among CABG versus PCI patients. Further study is needed to determine the appropriateness of PCI and CABG rates in terms of clinical outcomes and resource utilization.

Utility of rapid D-dimer measurement for screening of acute cardiovascular disease in the emergency setting

Rapid and accurate methods for screening are necessary for the diagnosis of acute cardiovascular diseases (ACVD), including acute coronary syndrome (ACS), pulmonary thromboembolism, and acute aortic dissection. In this study, the utility of rapid D-dimer measurement for the screening of ACVD was evaluated. Consecutive 279 emergent patients in whom ACVD was suspected or not ruled out were enrolled. The median D-dimer concentration of ACVD group (1.10 μg/ml) was significantly higher than that in the non-ACVD group (0.69 μg/ml, p<0.05). Sensitivity, specificity, positive predictive value, and negative predictive value of D-dimer (with cut-off level of 0.75 μg/ml) for the discrimination of ACVD from non-ACVD was 75%, 55%, 38%, and 85%, respectively. In ACVD group, the level of D-dimer in the large vessel disease subgroup was significantly higher than that in the ACS subgroup (6.99 μg/ml and 0.89 μg/ml, respectively; p<0.05). The well-balanced cut-off point for discriminating the two subgroups was D-dimer level of 5.0 μg/ml. D-dimer (with cut-off level of 0.75 μg/ml) showed significantly higher positive test rate for the detection of ACS in very early phase (within 2 h from the onset) compared with troponin T (p<0.05). Rapid measurement of D-dimer is useful for the screening of ACVD in the emergency setting.

Increased plasma osteoprotegerin levels are associated with the presence and severity of acute coronary syndrome

Objective — The objective of this study was to explore the relationship between increased plasma osteoprotegerin (OPG) levels and acute coronary syndrome (ACS).Methods — Plasma OPG levels from 85 subjects undergoing coronary artery angiography in three different groups, including ACS (n = 45), stable angia pectoris (SAP) (n = 20) and normal coronary artery (NCA) (n = 20), were detected by ELISA.Twenty-two ascending aorta specimens were surgically taken from 8 ACS, 7 SAP and 7 NCA patients, and OPG mRNA expression in the specimens was detected by RT-PCR. In addition, 10 coronary artery sections each were selected from autopsy archives for the presence of vulnerable atherosclerosis plaques (VP), stable plaques (SP) or no plaques (NP) and OPG protein expression in the sections was detected by immunohistochemistry.Results — Plasma OPG concentrations in the ACS group were significantly higher than those in the SAP or NCA group. The levels of plasma OPG in the 1-, 2- and 3-vessel disease subgroups of ACS were increasingly higher (P< 0.05 or 0.01). Multiple logistic regression analyses revealed a significant independent relation between plasma OPG concentration and the presence of ACS (P= 0.032, odd ratio = 1.006). Ascending aorta specimens from the ACS group had a greater OPG mRNA expression than those from the NCA or SAP group (P < 0.01). Sections with VP had a markedly higher OPG expression than sections with SP or NP (P < 0.05 and P< 0.01, respectively).Conclusions — Increased plasma osteoprotegerin levels are associated with the presence and severity of acute coronary syndrome.

Chemokine SR-PSOX/CXCL16 expression in peripheral blood of patients with acute coronary syndrome

Scavenger receptor that binds phosphatidylserine and oxidized lipoprotein/CXC chemokine ligand 16 (SR-PSOX/CXCL16) promotes foam cell formation through the tumor necrosis factor (TNF)-alpha mediated mechanism. Because chemokine CXCL16 could be expressed in atherosclerotic lesions and induce smooth muscle cell (SMC) proliferation, we presume that the monocyte SR-PSOX/CXCL16 detection in the patients' peripheral blood will be important for early diagnosis and prognosis of atherosclerosis (AS). Enrolled in this study were 40 patients with acute coronary syndrome (ACS), including 20 patients with acute myocardial infarction (AMI) and 20 patients with unstable angina pectoris (UAP), and 20 normal controls. Monocytes in the peripheral blood were isolated, and the changes of expression of CXCL16/SR-PSOX mRNA were compared using reverse transcription-polymerase chain reaction (RT-PCR), with beta-actin as internal control. We compared the expression of CXCL16/SR-PSOX in the ACS subgroups, using Western-blot to analyze protein expression levels. Tissue sections were made from biopsy specimens taken from patients with infective endocarditis, liver cirrhosis, and lung cancer as well as normal controls. And the expression of CXCL16/SR-PSOX was analyzed with a confocal microscope. The expression of CXCL16/SR-PSOX mRNA and protein in the monocytes of peripheral blood was significantly higher in ACS patients than in normal controls (P < 0.05); however, there was no significant difference in CXCL16/SR-PSOX expression between UAP group and AMI group (P > 0.05). Immunofluorescence showed that there were low expression of SR-PSOX in normal vascular endothelial cells and enhanced expression in every layer of the infected vessels, while spreading from endothelial cells to surrounding tissues as infection worsens. Confocal microscopy showed that the expression of SR-PSOX was enhanced in the infiltrated lymphocytes in liver cirrhosis, and that the expression level was proportionate to the degree of inflammation in the portal hepatis and folia. The expression of CXCL16/SR-PSOX in the monocytes of peripheral blood was significantly higher in ACS patients than in the controls. CXCL16/SR-PSOX-mediated inflammation may contribute to the pathogenesis of ACS, and CXCL16 may play an important role in the pathogenesis and development of AS in humans.

Impact of Prior Peripheral Arterial Disease and Stroke on Outcomes of Acute Coronary Syndromes and Effect of Evidence-Based Therapies (from the Global Registry of Acute Coronary Events)

We assessed the effect of previous peripheral arterial disease (PAD) and stroke on clinical outcomes in patients with acute coronary syndrome (ACS) and sought to ascertain the effectiveness of evidence-based therapies in these patients. We used data from the multinational Global Registry of Acute Coronary Events. Patients were enrolled at 102 hospitals in 13 countries between April 1999 and September 2005. Patients presenting with ACS were stratified according to the presence of previous PAD, stroke, PAD and stroke, or neither. In-hospital analysis included 48,418 patients and 6-month analysis included 32,735 patients. The primary end point was all-cause mortality and major adverse cardiac events during 6-month follow-up. Adverse in-hospital and 6-month events were lowest in patients with neither PAD nor stroke and highest in patients with PAD and stroke after adjustment for baseline demographics and co-morbidities. In-hospital mortality for the 4 groups (neither, PAD, stroke, PAD and stroke) was 4.5% versus 7.2% versus 8.9% versus 9.4% (p <0.001) and that for 6-month mortality was 3.9% versus 8.8% versus 9.3% versus 12%, and these differences persisted after accounting for differences in baseline characteristics. Use of evidence-based therapies was associated with significantly less morbidity and mortality in all ACS subgroups. In conclusion, outcomes after ACS are worse in patients with PAD or stroke, with the highest risk in patients with the 2 conditions and the use of evidence-based therapies are associated with improved outcomes in all ACS subgroups.