ORIGINAL ARTICLE Critical Pathways in Cardiology •  Volume 11, Number 3, September 2012 www.critpathcardio.com | 139 Abstract: Although current practice guidelines provide an evidence-based approach to the management of acute coronary syndromes, application of the evidence by individual physicians has been suboptimal. This gap between comprehensive guidelines and actual practice stimulated Oman Heart Association to issue a simplified series for the management of the common cardiac abnormalities to be applied by the entire cardiac caregivers all over the country. This simplified approach for the management of non–ST- elevation acute coronary syndrome provides a practical and systematic means to implement evidence-based medicine into clinical practice. Key Words: acute coronary syndrome, ischemic risk, bleeding risk, anti- ischemic therapy, antiplatelet therapy, anticoagulant agents, anti-remodeling therapy, antilipid agents, coronary revascularization (Crit Pathways in Cardiol 2012;11: 139–146) “A cute coronary syndromes” represent the spectrum of myo- cardial ischemia, including ST-elevation myocardial infarc- tion (STEMI), non-ST-elevation myocardial infarction (NSTEMI), and unstable angina pectoris (UA) (Fig. 1). The most common cause of UA/NSTEMI is reduced myocardial perfusion that results from coronary artery narrowing caused by a thrombus that developed on a disrupted atherosclerotic plaque and is usually nonocclusive. Microembolization of platelet aggregates and components of the dis- rupted plaque are believed to be responsible for the release of myo- cardial markers in many of these patients. An occlusive thrombus/ plaque can also cause this syndrome in the presence of an extensive collateral blood supply. RISK STRATIFICATION Ischemic Risk The early mortality risk in UA/NSTEMI relates to the extent of myocardial damage and resulting hemodynamic compromise From the *Ministry of Health, Sultanate of Oman; †Sultan Qaboos University Hospital, Muscat, Sultanate of Oman; ‡Diwan Medical Services, Sultanate of Oman; §Armed Forces Hospital, Muscat, Sultanate of Oman; and ¶Royal Oman Police Hospital, Muscat, Sultanate of Oman. Reprints: Mohammed H. El-Deeb, Department of Cardiology, Royal Hospital, Muscat, Sultanate of Oman. E-mail:deebcardio@hotmail.com Copyright © 2012 by Lippincott Williams & Wilkins ISSN: 1535–282X/12/1103–0139 DOI: 10.1097/HPC.0b013e31825ac653 2012 Oman Heart Association Simplified Guidelines for the Management of Patients With Unstable Angina/Non–ST-Elevation Myocardial Infarction Mohammed H. El-Deeb, MB Bch, MSc, MD,* Abdullah M. Al Riyami, MD, MRCP,* Abdullah A. Al Riyami, MB Bch, FRCP, PhD,* Kadhim J. Sulaiman, MD, FRCPI, FRCP(Glasgow), FECS* Rashid Shahrabani, MD, FRCP,* Mohamed Al Mukhaini, MD, FRCPC, FACC,* Najib Al Rawahi, MD, FRCPC, ABIM,* Mohamed B. Al Riyami, MD, MRCP,* Adil B. Al Riyami, MD, MRCP, ABIM, FRCPC,† Mansour Sallam, MB Bch, MSc, MD,† Said Al Hinai, MB CHB, MRCP, ABIM, FRCPC,‡ Yahia Al Wahshi, MD, FRCP,§ Prashanth Panduranga, MBBS, MD, MRCP (UK), MRCPE,* and Abdul Malik Al Kharusi, MB Bch, MRCPI,¶; on behalf of the OHA ACS Task Force and is less than in patients with STEMI. In contrast, long-term out- come—for both mortality and nonfatal events—is actually worse for patients with UA/NSTEMI compared with STEMI. This finding probably results from the greater likelihood of recurrence of ACS in patients with UA/NSTEMI, as well as their older age, greater extent of coronary disease, prior MI, and comorbidities such as diabetes mellitus and impaired renal function. Early risk stratification is important to identify patients at high immediate and long-term risk of death and cardiovascular events, and in whom intensive medical therapy and an early invasive strategy may reduce that risk. It is equally important to identify patients at low risk in whom potentially hazardous and costly invasive and medical treatments provide little benefit or in fact may cause harm. In patients with a suspected NSTE ACS, diagnosis and short-term ischemic risk stratification should be based on a combination of clinical history, physical findings, electrocardiogram (ECG), and biomarkers. Although several risk stratification tools are available, one that is frequently used is the Thrombolysis in Myocardial Infarction (TIMI) risk score. This tool combines 7 simple variables in an evenly weighted scale. A more comprehensive approach based on a combi- nation of clinical history, physical findings, ECG, troponin (Tn), and laboratory findings is shown in Table 1, which should be used as a general guidance rather than a rigid rule. Electrocardiogram A 12-lead ECG should be obtained within 10 minutes after first medical contact and immediately read by an experienced physician. If the initial ECG is not diagnostic but the patient remains symptomatic and there is high clinical suspicion for ACS, serial ECGs, initially at 15- to 30-minute intervals, should be performed to detect the poten- tial for development of ST-segment elevation or depression. After admission, ECG should be repeated after 6 and 24 hours in the case of recurrence of symptoms and before hospital discharge. Troponin Blood has to be drawn promptly for Tn (cardiac Tn T or I) measurement. The result should be available within 60 minutes. Where available, high-sensitivity Tn assays should be used in prefer- ence to conventional assays. When using high-sensitivity Tn assay, a test should be inter- preted as positive if the level is ≥99th centile for the reference pop- ulation or if there is a change of ≥50% above the initial baseline level. Although Tn accurately identifies myocardial necrosis, it does not inform as to the cause or causes of necrosis; these can be mul- tiple and include noncoronary causes. A positive result should be