Unstable angina/non-ST-segment Elevation Myocardial Infarction Research Articles

The management of non-culprit vessel(s) in patients with unstable angina/non-ST elevation myocardial infarction and chronic kidney dysfunction.

The clinical effects of multivessel interventions in patients with unstable angina/non-ST-segment elevation myocardial infarction (UA/NSTEMI), multivessel disease (MVD) and chronic kidney disease (CKD) remain uncertain. This study aimed to investigate the safety and effectiveness of intervention in non-culprit lession(s) among this cohort. We consecutively included patients diagnosed with UA/NSTEMI, MVD and CKD between January 2008 and December 2018 at our centre. After successful percutaneous coronary intervention (PCI), we compared 48-month overall mortality between those undergoing multivessel PCI (MV-PCI) through a single-procedure or staged-procedure approach and culprit vessel-only PCI (CV-PCI) after 1:1 propensity score matching. We conducted stratified analyses and tests for interaction to investigate the modifying effects of critical covariates. Additionally, we recorded the incidence of contrast-induced nephropathy (CIN) to assess the perioperative safety of the two treatment strategies. Of the 749 eligible patients, 271 pairs were successfully matched. Those undergoing MV-PCI had reduced all-cause mortality (hazard ratio (HR): 0.67, 95% confidence interval (CI): 0.48-0.67). Subgroup analysis showed that those with advanced CKD (estimated glomerular filtration rate (eGFR) ≤ 30 mL/min/1.73 m2 ) could not benefit from MV-PCI (P = 0.250), and the survival advantage also tended to diminish in diabetes (P interaction < 0.01; HR = 0.95, 95% CI = 0.65-1.45). Although the staged-procedure approach (N = 157) failed to bring additional survival benefits compared to single-procedure MV-PCI (N = 290) (P = 0.460), it showed a tendency to decrease the death risk. CIN risks in MV-PCI and CV-PCI groups were not significantly different (risk ratio = 1.60, 95% CI = 0.94-2.73). Among patients with UA/NSTEMI and non-diabetic CKD and an eGFR > 30 mL/min/1.73 m2 , MV-PCI was associated with a reduced risk of long-term death but did not increase the incidence of CIN during the management of MVD compared to CV-PCI. And staged procedures might be a preferable option over single-procedure MV-PCI.

Management of acute coronary syndrome in emergency departments: a cross sectional multicenter study (Tunisia)

BackgroundWe aimed to describe diagnosed acute coronary syndrome (ACS) and its care management and outcomes in emergency departments (EDs) and to determine related cardiovascular risk factors (CVRFs).MethodsWe conducted a cross sectional multicenter study that included 1173 adults admitted to EDs for acute chest pain (ACP) in 2015 at 14 sites in Tunisia. Data included patients’ baseline characteristics, diagnosis, treatment and output.ResultsACS represented 49.7% of non-traumatic chest pain [95% CI: 46.7–52.6]; 74.2% of ACS cases were unstable angina/non-ST-segment-elevation myocardial infarction (UA/NSTEMI). Males represented 67.4% of patients with ACS (p < 0.001). The median age was 60 years (IQR 52–70). Emergency medical service transportation was used in 11.9% of cases. The median duration between chest pain onset and ED arrival was two hours (Inter quartile ranges (IQR) 2–4 h). The age-standardized prevalence rate was 69.9/100,000 PY; the rate was 96.24 in men and 43.7 in women. In the multivariable analysis, CVRFs related to ST segment elevation myocardial infarction were age correlated to sex and active smoking. CVRFs related to UA/NSTEMI were age correlated to sex, familial and personal vascular history and type 2 diabetes. We reported 27 cases of major adverse cardiovascular events (20.0%) in patients with STEMI and 36 in patients with UA/NSTEMI (9.1%).ConclusionHalf of the patients consulting EDs with ACP had ACS. Emergency medical service transportation calls were rare. Management delays were acceptable. The risk of developing an UA/NSTEMI was equal to the number of CVRFs + 1. To improve patient outcomes, it is necessary to increase adherence to international management guidelines.

Competing Risks of Cardiovascular Versus Noncardiovascular Death During Long-Term Follow-Up After Acute Coronary Syndromes.

BackgroundUnderstanding the relative risk of cardiovascular versus noncardiovascular death is important for designing clinical trials. These risks may differ depending on patient age, sex, and type of acute coronary syndrome (ACS).Methods and Results IMPROVE‐IT (Improved Reduction of Outcomes: Vytorin Efficacy International Trial) was a randomized controlled trial of simvastatin plus either ezetimibe or placebo following stabilized ACS. Cause of death was adjudicated by an independent committee. We compared the cumulative incidence of cardiovascular and noncardiovascular death for patients with unstable angina/non‐ST‐segment elevation myocardial infarction (UA/NSTEMI) and ST‐segment elevation myocardial infarction (STEMI), in those <65 and ≥65 years old, and males and females, over 7 years of follow‐up. Of 18 131 patients, the presenting event was STEMI for 5190 (29%) and UA/NSTEMI for 12 941 (71%); 10 173 (56%) patients were <65 years old and 7971 (44%) were ≥65 years old at presentation. UA/NSTEMI patients were older than STEMI patients, with more cardiovascular and noncardiovascular risk factors. In STEMI patients, the cumulative incidence of cardiovascular death was higher for ∼4 years following the index event, after which noncardiovascular death predominated. In UA/NSTEMI patients, the cumulative incidence of cardiovascular death remained higher than noncardiovascular death over the full follow‐up period. Patients ≥65 years old and <65 years old had a higher incidence of cardiovascular death than noncardiovascular death over the entirety of follow‐up. Female patients had a higher incidence of cardiovascular death than noncardiovascular death for ∼6 years following the index event; male patients had a higher incidence of cardiovascular death than noncardiovascular death over the entirety of follow‐up.ConclusionsAmong post‐ACS patients enrolled in a long‐term clinical trial, the relative incidence of cardiovascular and noncardiovascular death differed based on type of ACS presentation and sex, but not age. These findings further delineate long‐term prognosis after ACS and should inform the design of future cardiovascular outcomes trials.

An analysis of TRITON-TIMI 38, based on the 12 month recommended length of therapy in the European label for prasugrel

Background:In TRITON-TIMI 38, patients with acute coronary syndromes were treated with prasugrel or clopidogrel, with aspirin, for a median of 14.5 (maximum of 15) months. Based on this trial, the EU label for prasugrel recommends treatment for up to 12 months and excludes patients with prior stroke/transient ischemic attack (TIA). Furthermore, the EU label recommends the 10 mg maintenance dose (MD) for patients with body weight ≥60 kg and age <75 years. A lower MD of 5 mg is recommended for those with body weight <60 kg; although generally not recommended, 5 mg can be prescribed to patients ≥75 years after individual risk–benefit evaluation. This paper presents the one-year outcome data for this ‘10 mg indicated cohort’.Methods and results:From the overall cohort of 13,608 patients in TRITON-TIMI 38, 10,804 fulfilled inclusion criteria for the 10 mg indicated cohort, of whom 22% had a history of diabetes, 73% an index diagnosis of unstable angina/non-ST-segment-elevation myocardial infarction (UA/NSTEMI), and 27% an index diagnosis of ST-segment-elevation myocardial infarction (STEMI). In this cohort at 12 months, those given prasugrel experienced significantly fewer ischemic events (cardiovascular death, non-fatal myocardial infarction, or non-fatal stroke, 7.8% vs 10.5%, hazard ratio (HR) = 0.73, p < 0.001, than those given clopidogrel, with a non-significant increase in non-coronary artery bypass graft (CABG) TIMI major bleeding, 1.7% vs 1.5%, HR = 1.15, p = 0.40; similarly, in the overall cohort these frequencies were 9.4% vs 11.4%, HR = 0.81, p < 0.001, for cardiovascular death, non-fatal myocardial infarction, or non-fatal stroke, and 2.2% vs 1.8%, HR = 1.24, p = 0.10, for non-CABG TIMI major bleeding. There was a significant reduction in stent thrombosis in the prasugrel group, with similar mortality rates and no excess of strokes.Conclusions:Treatment with prasugrel according to EU label recommendations results in a significant 27% and 57% relative risk reduction (absolute risk reductions of 2.7% and 1.2%) in ischemic events and stent thromboses respectively compared with clopidogrel, with a 15% relative risk increase (absolute risk increase of 0.2%) for major bleeds (p = 0.40), and no excess of strokes.Limitations:Although restricted to 365 days of follow-up, this analysis encapsulates 1366 of 1424 (95.9%) of all primary endpoint events and 244 of 257 (94.9%) of all first non-CABG TIMI major bleeds reported in the pivotal manuscript. Furthermore, the 10 mg indicated cohort was not a pre-specified subgroup in the study protocol, but due to European labeling restrictions, results for all outcomes in this cohort are presented through 12 months.

Treatment patterns in acute coronary syndrome patients in the United Kingdom undergoing PCI

To evaluate practice patterns in acute coronary syndrome (ACS) patients undergoing percutaneous coronary intervention (PCI), focusing on the United Kingdom (UK). The Antiplatelet Therapy Observational Registry (APTOR) is a prospective observational study of consecutive ACS patients undergoing PCI (N=1525) from January-August 2007 in the UK, France, and Spain. In the UK, median time from hospital admission to PCI was one day post-admission (IQR 0,4) among STEMI patients and five days (IQR 2,9) among unstable angina/non-ST-segment elevation myocardial infarction (UA/NSTEMI) patients. Patients in the UK most frequently received a 300 mg aspirin loading dose (85%), 300 mg clopidogrel loading dose (70%), and 75 mg clopidogrel maintenance dose (99%). Loading dose was given on the day of hospitalisation to 80% of STEMI patients and 68% of UA/NSTEMI patients. Clopidogrel was discontinued by 12 months in 30% of UK patients. Length of hospitalisation was similar between the three countries. Despite established consensus guidelines for ACS patient management, APTOR data show disparity in management practices for ACS patients undergoing PCI in the UK and two other European countries. These data can help provide focus for areas of ACS management requiring improvements to meet guideline therapy, including reducing time from hospitalisation to PCI and maintaining 12 months of dual antiplatelet therapy for all ACS patients undergoing stenting.

A prospective observational study of treatment practice patterns in acute coronary syndrome patients undergoing percutaneous coronary intervention in Europe

The AntiPlatelet Therapy Observational Registry (APTOR) was a prospective observational study of acute coronary syndrome (ACS) patients undergoing percutaneous coronary intervention (PCI) in France, Spain, and the UK. To evaluate patterns of ACS healthcare use, focusing on APTOR results from France. Consecutive presenting ACS patients requiring PCI were recruited between January and August 2007. Treatments and outcomes were recorded from the qualifying ACS event to 12 months follow-up. In France, qualifying diagnosis was unstable angina/non-ST-segment elevation myocardial infarction (UA/NSTEMI) in 255(53%) patients and ST-segment elevation myocardial infarction (STEMI) in 228(47%)patients. Ninety-six percent underwent PCI with stent implantation. Drug eluting stents were used less frequently in France(22%) than Spain (54%) or the UK (42%). In France, antiplatelets were more frequently received in the ambulance (21%); a 200-299mg aspirin-loading dose was most frequently received (50%) and more than a third of patients received a clopidogrel-loading dose of over 300mg (34%). At 12 months in France, 86% were still receiving aspirin, 75% clopidogrel, and 73% combination treatment. There was considerable country-variation in ACS management. These results provide a benchmark of physician practice to compare with guidelines.

Strategies and Therapies for Reducing Ischemic and Vascular Events (STRIVE®)

The Strategies and Therapies for Reducing Ischemic and Vascular Events (STRIVE) acute coronary syndromes critical pathway toolkit has been updated based on the 2009 focused updates of the American College of Cardiology/American Heart Association guidelines for the management of patients with ST-segment elevation myocardial infarction (STEMI) and American College of Cardiology/American Heart Association/Society for Cardiovascular Angiography and Interventions guidelines on percutaneous coronary intervention (PCI). This review highlights the major changes cited in the focused updates, which have been incorporated into the STRIVE standing orders for STEMI and unstable angina/non-ST-segment elevation myocardial infarction (UA/NSTEMI). The updated STEMI and UA/NSTEMI standing orders and other tools are available to clinicians online on the STRIVE Web site.

Clinical Risk Stratification in the Emergency Department Predicts Long-Term Cardiovascular Outcomes in a Population-Based Cohort Presenting With Acute Chest Pain

The long-term cardiovascular outcomes of a population-based cohort presenting to the emergency department (ED) with chest pain and classified with a clinical risk stratification algorithm are not well documented. The Olmsted County Chest Pain Study is a community-based study that included all consecutive patients presenting with chest pain consistent with unstable angina presenting to all EDs in Olmsted County, Minnesota. Patients were classified according to the Agency for Health Care Policy and Research (AHCPR) criteria. Patients with ST elevation myocardial infarction and chest pain of noncardiac origin were excluded. Main outcome measures were major adverse cardiovascular and cerebrovascular events (MACCE) at 30 days and at a median follow-up of 7.3 years, and mortality through a median of 16.6 years.The 2271 patients were classified as follows: 436 (19.2%) as high risk, 1557 (68.6%) as intermediate risk, and 278 (12.2%) as low risk. Thirty-day MACCE occurred in 11.5% in the high-risk group, 6.2% in the intermediate-risk group, and 2.5% in the low-risk group (p < 0.001). At 7.3 years, significantly more MACCE were recorded in the intermediate-risk (hazard ratio [HR], 1.91; 95% confidence intervals [CI], 1.33-2.75) and high-risk groups (HR, 2.45; 95% CI, 1.67-3.58). Intermediate- and high-risk patients demonstrated a 1.38-fold (95% CI, 0.95-2.01; p = 0.09) and a 1.68-fold (95% CI, 1.13-2.50; p = 0.011) higher mortality, respectively, compared to low-risk patients at 16.6 years. At 7.3 and at 16.6 years of follow-up, biomarkers were not incrementally predictive of cardiovascular risk.In conclusion, a widely applicable rapid clinical algorithm using AHCPR criteria can reliably predict long-term mortality and cardiovascular outcomes. This algorithm, when applied in the ED, affords an excellent opportunity to identify patients who might benefit from a more aggressive cardiovascular risk factor management strategy.

Management of patients with unstable angina / non-ST-elevation myocardial infarction: a critical review of the 2007 ACC /AHA guidelines

Background:In 2007, the American College of Cardiology/American Heart Association (ACC/AHA) published new guidelines for the diagnosis and management of patients with unstable angina/non-ST segment elevation myocardial infarction (UA/NSTEMI). These guidelines include some important updates on the use of clopidogrel, fondaparinux, bivalirudin and low-molecular-weight heparins (LMWHs) all of which have published landmark clinical trials in patients with acute coronary syndromes (ACS) since the publication of the 2002 guidelines. While these 2007 guidelines are more comprehensive and up-to-date compared with the recommendations published in 2002, they also raise many questions for practising emergency physicians and cardiologists.Methods:This article presents a critical review of the 2007 ACC/AHA UA/NSTEMI guidelines, highlighting some of the areas of controversy, with the aim of providing some further guidance to practising physicians.Conclusions:Despite recent updates to the ACC/AHA UA/NSTEMI guidelines, additional factors need to be taken into consideration in the management of UA/NSTEMI patients. Integrating initial responses with early or selectively invasive strategies and the risks of complications in subsequent procedures require careful consideration. Protocol development within an institution is required to risk-stratify patients rapidly, provide optimum precatheterisation medical management and allow seamless and rapid transitions to the catheterisation laboratory in patients at risk for adverse events.

Updated Strategies and Therapies for Reducing Ischemic and Vascular Events (STRIVE) Unstable Angina/Non-ST Elevation Myocardial Infarction Critical Pathway Toolkit

The Strategies and Therapies for Reducing Ischemic and Vascular Events (STRIVE) acute coronary syndromes (ACS) critical pathway toolkit, developed in 2002, has been revised and updated. The updated toolkit is based on the American College of Cardiology/American Heart Association 2007 guidelines for the management of patients with unstable angina/non-ST-segment elevation myocardial infarction (UA/NSTEMI). This review highlights the major revisions to the UA/NSTEMI guidelines and illustrates and describes the revised STRIVE critical pathway tools, which include pathway flowcharts, standing orders, pocket cards, posters, and form letters. These materials are being made available online to help physicians, nurses, and hospitals implement the new guidelines and thus improve the quality of care and outcomes for patients with ACS.

TIMI risk score underestimates prognosis in unstable angina/non‐ST segment elevation myocardial infarction

To determine the value of the TIMI risk score in the individual risk stratification of patients with unstable angina/non-ST segment elevation myocardial infarction (UA/NSTEMI). TIMI risk score is a validated tool to identify groups of patients at high risk for major cardiac events. Its prognostic value in individual patients with current diagnostic tools and therapy is unknown. TIMI risk score was assessed in patients with UA/NSTEMI admitted to six Belgian hospitals and related to clinical outcome at 30 days. Of the 500 patients enrolled, 49.4% were placed in the low TIMI risk group (score = 0-3) and 50.6% in the high-risk group (score = 4-7). Multivariate analysis identified raised cardiac markers and invasive strategy, but not high TIMI risk score as independent predictors of death and new myocardial infarction (MI). Moreover, the incidence of death and MI in the low TIMI risk group with positive cardiac markers was not lower than in the high TIMI risk group with positive markers: 15.1% versus 17.8% (P = 0.7). TIMI risk score is of limited value for individual risk stratification. The presence of positive cardiac markers (troponin) appears to be a more powerful prognostic marker.

The impact of obesity on mortality in UA/non-ST-segment elevation myocardial infarction

Obesity is associated with diabetes mellitus and advanced coronary artery disease (CAD). Once a non-ST-elevation acute coronary syndrome has occurred, the association between obesity and prognosis is poorly defined. This study was designed to assess the impact of obesity on outcome after unstable angina/non-ST-segment elevation myocardial infarction (UA/NSTEMI) treated with early revascularization. In a prospective cohort study in 1676 consecutive patients with UA/NSTEMI we examined the association between presence of obesity and all-cause mortality. All patients underwent coronary angiography and, if appropriate, early catheter-based revascularization. Patients were divided into four groups according to body mass index (BMI): normal, 18.5-24.9 (n = 551); overweight, 25-29.9 (n = 824); obese, 30-34.9 (n = 244); and very obese, above 35 (n = 48). Obese and very obese patients were younger and had a higher incidence of hypertension, diabetes mellitus, elevated cardiac troponin T, and C-reactive protein levels. The angiographic extent of CAD was similar among the BMI groups. Median follow-up was 17 (interquartile range 6-31) months. Cumulative 3-year mortality rates were 9.9% for normal BMI, 7.7% for overweight, 3.6% for obese, and 0 (no death) for very obese (log-rank P = 0.043). Obese and very obese patients had less than half the long-term mortality when compared with normal BMI patients [hazard ratio (HR) 0.38, 95% confidence interval (CI) 0.18-0.81, P = 0.012]. This result remained significant after adjustment for confounding prognostic factors including coronary status and left ventricular function (adjusted HR 0.27, 95% CI 0.08-0.92, P = 0.036). Obesity is associated with improved outcome after UA/NSTEMI treated with early revascularization.

The impact of platelet count on mortality in unstable angina/non–ST-segment elevation myocardial infarction

Expanding the knowledge of pathogenesis of arteriosclerosis points at a central role of platelets in the development of acute coronary syndromes. Therefore, we sought to determine the impact of platelet count on long-term outcome in unstable angina/non-ST-segment elevation myocardial infarction (UA/NSTEMI) receiving contemporary treatment. This prospective cohort study included 1616 consecutive patients with UA/NSTEMI. All patients underwent coronary angiography and, if appropriate, subsequent catheter-based revascularization within 24 hours of admission. Patients were divided in quintiles according to platelet count. The primary end point was all-cause mortality during long-term follow-up of up to 60 months. During follow-up (median 17 months, interquartile range 6-31 months), 89 deaths and 74 nonfatal myocardial infarctions occurred. Patients with higher platelet counts were younger, more often female, and had lower height and weight as compared with patients with lower platelet counts. Mortality was significantly lower among patients in the second quintile of platelet count (181-210 x 10(9)/L) as compared with the other quintiles (hazard ratio 0.39, 95% CI 0.19 to 0.81, P = .011). Kaplan-Meier survival analysis showed cumulative 4-year mortality rates of 12.5%, 3.8%, 10.4%, 9.8%, and 11.4% for patients in the first, second, third, fourth, and fifth quintiles. This association persisted after multivariate adjustment. No association of platelet count and nonfatal myocardial infarctions was observed. We found a nonlinear association between platelet count and long-term mortality. The lowest mortality was observed in patients with a platelet count between 181 and 210 x 10(9)/L.

Invasive therapy along with glycoprotein IIb/IIIa inhibitors and intracoronary stents improves survival in non–ST-segment elevation acute coronary syndromes: a meta-analysis and review of the literature

Current evidence suggests that routine invasive therapy in the setting of unstable angina/non–ST-segment elevation myocardial infarction (UA/NSTEMI) reduces the incidence of composite end points (i.e., death, myocardial infarction, or angina.). The 2002 American College of Cardiology/American Heart Association guidelines recommend invasive therapy in high-risk patients, although it is unknown if such an approach improves survival. We conducted a meta-analysis on 5 studies in 6,766 UA/NSTEMI patients who were randomized to either routine invasive versus conservative therapy in the era of glycoprotein IIb/IIIa inhibitors and intracoronary stents. Compared with conservative therapy, an invasive approach suggested a reduction in mortality at 6 to 12 months (risk ratio [RR] 0.80, 95% confidence interval [CI] 0.63 to 1.03) and at 24 months (RR 0.77, 95% CI 0.60 to 0.99). The composite end point of death or myocardial infarction was reduced throughout all periods of follow-up: at 30 days (RR 0.61, 95% CI 0.45 to 0.84), at 6 months (RR 0.75, 95% CI 0.63 to 0.89), and at 12 months (RR 0.78, 95% CI 0.65 to 0.92). For the same composite end point at 6 to 12 months, men benefited from invasive therapy (RR 0.68, 95% CI 0.57 to 0.81), as did troponin-positive patients (RR 0.74, 95% CI 0.59 to 0.94). The results for women (RR 1.07, 95% CI 0.82 to 1.41) and troponin-negative patients (RR 0.82, 95% CI 0.59 to 1.14) were equivocal. Routine invasive therapy in UA/NSTEMI patients along with adjunctive use of glycoprotein IIb/IIIa inhibitors and intracoronary stents improves survival. Enhanced risk stratification is needed in women and troponin-negative patients so that invasive therapy may be more effectively recommended in these groups.

Use of fractional flow reserve versus stress perfusion scintigraphy after unstable angina: Effect on duration of hospitalization, cost, procedural characteristics, and clinical outcome

ObjectivesThe present study sought to determine the value of fractional flow reserve (FFR) compared with stress perfusion scintigraphy (SPS) in patients with recent unstable angina/non–ST-segment elevation myocardial infarction (UA/NSTEMI). BackgroundFractional flow reserve, an invasive index of stenosis severity, is a reliable surrogate for SPS in patients with normal left ventricular function. An FFR ≥0.75 can distinguish patients after myocardial infarction (MI) with a positive SPS from those with a negative SPS. However, the use of FFR has not been investigated after UA/NSTEMI. MethodsSeventy patients who had recent UA/NSTEMI and an intermediate single-vessel stenosis were randomized to either SPS (n = 35) or FFR (n = 35). Patients in the SPS group were discharged if the SPS revealed no ischemia, whereas those in the FFR group were discharged if the FFR was ≥0.75. Patients with a positive SPS and those with an FFR <0.75 underwent percutaneous transluminal coronary angioplasty. ResultsThe use of FFR markedly reduced the duration and cost of hospitalization compared with SPS (11 ± 2 h vs. 49 ± 5 h [−77%], p < 0.001; and $1,329 ± $44 vs. $2,113 ± $120, respectively, p < 0.05). There were no significant differences in procedure time, radiation exposure time, or event rates during follow-up, including death, MI, or revascularization. ConclusionsThese data indicate that: 1) the use of FFR in patients with recent UA/NSTEMI markedly reduces the duration and cost of hospitalization compared with SPS; and 2) these benefits are not associated with an increase in procedure time, radiation exposure time, or clinical event rates.

Acute Coronary Syndrome

Acute coronary syndrome consists of acute myocardial infarction associated with electrocardiographic ST segment elevation (STEMI) and unstable angina/non-ST segment elevation myocardial infarction (UA/NSTEMI). Theses three conditions are differentiated primarily by clinical, electrocardiographic, and laboratory presentations correlating with the duration and extent of thrombotic occlusion as a consequence of plaque rupture. Acute coronary syndrome is now the most prevalent presentation of ischemic heart disease in Korea as well as developed countries. Q-wave acute myocardial infarction is the most easily identified syndrome ; persistent angina and ST-segment elevation are characteristic of sudden total or near-total thrombotic arterial occlusion. Urgent reperfusion is the mainstay of therapy, whereas UA/NSTEMI is usually associated with severe coronary obstruction but not total occlusion of the culprit coronary artery. The distinction between unstable angina and non-Q wave, non-ST segment elevation myocardial infarction is often not clear at the initial presentation of patients. Unstable angina is defined as angina pectoris with at least one of the following three features : ① It occurs at rest usually lasting more than 20 minutes. ② It is severe and described as frank pain and of new onset within 1 month. ③ It occurs with a crescendo pattern (more severe, prolonged, or frequent than previously). Some patients with this pattern of ischemic discomfort, especially those with prolonged rest pain, develop evidence of myocardial necrosis on the basis of the release of cardiac markers and thus have a diagnosis of NSTEMI. This diagnosis has been based on the elevation of serum creatine kinase (CK)-MB, level but recently troponin T and I assays are used to define ischemic myocardial damage based on their higher sensitivity for myocardial necrosis and prognostic implication. Troponin has become the standard myocardial marker. A certain number of patients have elevated levels of troponins in the absence of significant CK elevation. Several studies have shown that despite nondiagnostic CK levels, an elevated troponin level often indicates a poor prognosis.Successful treatment strategies for acute coronary syndrome that improve survival include anticoagulant, antiplatelet, thrombolytic, and interventional approaches.