Nursing Practice Keywords: Acute coronary syndrome/ Myocardial infarction/Unstable angina Review This article has been Cardiology double-blind peer reviewed In this article... l Pathophysiology and risk factors for acute coronary syndrome l Signs, symptoms, diagnosis and treatment of ACS l Priorities in nursing care for patients with ACS Diagnosis, management and nursing care in acute coronary syndrome Key points Authors Selina Jarvis is research nurse and former Mary Seacole development scholar, Acute coronary King’s College Hospital Foundation Trust; Selva Saman is consultant, Port Shepstone 1syndrome is Regional Hospital, Port Shepstone, South Africa. a common and potentially Abstract Acute coronary syndrome refers to a range of potentially life-threatening life-threatening conditions that affect the coronary artery blood supply to the heart, and is a common condition associated presentation in patients with coronary heart disease. Understanding the diagnostic with coronary approaches, as well as pharmacological and coronary interventions is crucial, given heart disease the prevalence of ACS. This article discusses current evidence-based guidance in the Primary management of ACS and the critical role of nurses. 2 percutaneous coronary intervention Citation Jarvis S, Saman S (2017) Diagnosis, management and nursing care in acute within 12 hours of coronary syndrome. Nursing Times; 113: 3, 31-35. symptom onset is the first-line treatment Pharmacological very three minutes one person is Treatment aims to ease symptoms, 3 management in admitted to a UK hospital with improve coronary artery blood flow and the acute phase acute coronary syndrome (British prevent complications. Immediate man- focuses on pain EHeart Foundation, 2017), a agement, combined with cardiac rehabili- relief and prevention common and life-threatening condition tation and secondary prevention, can of further clot associated with coronary heart disease. ACS improve patients’ outcomes and quality of formation while (Box 1) refers to a range of conditions life. Nurses have a key role in: minimising the risk affecting the blood supply to the heart mus- l Facilitating and administering prompt of bleeding cles (myocardium); these include unstable treatment to patients; After discharge angina, non-ST segment elevation myocar- l Promoting the swift recognition of 4 from hospital, dial infarction (NSTEMI) and ST segment deterioration; patients need elevation myocardial infarction (STEMI). l Providing holistic care and secondary ACS can result from a sudden drop in psychosocial support; prevention involving blood flow through the coronary arteries l Encouraging patients to engage in medications, cardiac supplying the different regions of the myo- healthy secondary-prevention rehabilitation and cardium. This can compromise the myo- behaviours. lifestyle changes cardium, leading to reversible ischaemia or Nurses play a a complete loss of blood supply, which in Pathophysiology 5 crucial role in turn leads to myocardial infarction and Most ACS cases are caused by atheroscle- delivering care and ultimately myocardial cell death (necrosis). rosis, which takes place in the coronary psychological In-hospital mortality from ACS has arteries, often decades before a cardiac support at all fallen from 20% to around 5% over the past event. The formation of an atherosclerotic stages of the 30 years, which may be due to better drug plaque begins with low-grade inflamma- patient journey therapies, prompt recognition and treat- tion in the inner layer of blood vessels. The ment protocols (National Institute for endothelial cells lining blood vessels sus- Health and Care Excellence, 2013a). Timely tain injury, change shape and become management is crucial to reduce the risk increasingly permeable to fluid, lipids and of mortality and further cardiac events. white blood cells. Circulating cholesterol Nursing Times March 2017 / Vol 113 Issue 3 31 www.nursingtimes.net Nursing Practice Review carriers, especially low-density lipopro- Box 1. Universal definition of ACS tein (LDL), can enter the arterial wall and undergo oxidation. White blood cells are A rise in blood troponin level above the 99th percentile of the normal range and/or a involved and transform into macrophages, fall in troponin alongside one or more of the following criteria: which engulf LDL; when they become lipid l Symptoms suggestive of cardiac ischaemia laden they are referred to as foam cells. l New electrocardiogram changes indicating new ischaemia (change to the ST These lipid-rich plaques contain inflam- segment or T wave or new left bundle branch block) matory cells, cellular debris, smooth l Development of a pathological Q wave in the ECG muscle cells with cholesterol, and a fibrous l Imaging evidence of new loss of viable myocardium or new regional wall motion capsule. Over time they can progress and abnormality (abnormal movement of heart muscle) cause luminal narrowing of the blood Sources: Adapted from NICE (2014) and Thygesen et al (2012) vessel, thereby limiting blood flow. ACS is usually triggered by the rupture of an atherosclerotic plaque in the wall of a cor- Fig 1. STEMI changes in ACS coronary intervention (PCI). Often they will onary artery; this causes activation, adhe- communicate with the cardiology team sion and aggregation of platelets and the Blocked before arrival, which will facilitate urgent clotting systems, leading to the formation blood flow coronary reperfusion strategies (coronary of a thrombus. If the thrombus completely angioplasty with/without stents placed in occludes the coronary artery, the section of the affected coronary artery) once the the myocardium supplied by that artery is patient has arrived in hospital. starved of oxygen, leading to myocardial cell Primary PCI has become the first-line necrosis, and typical ST elevation changes treatment in patients with STEMI pre- are seen on an electrocardiogram (Fig 1). In senting within 12 hours of onset of symp- addition, cardiac enzymes are released from toms, provided it can be given within damaged myocardial cells (troponin I and T, 120 minutes of the time in which throm- Atheroma creatinine kinase MB isoenzyme), which can bolysis could be given (NICE, 2013a). If pri- be measured in the blood. mary PCI is not available or there is a delay, thrombolysis may be performed (using Atheroma lining Risk factors for ACS coronary artery drugs such as alteplase and reteplase) after ACS is more common in men, older people discussion with the on-call cardiologist – and those with a family history of if there are no major contraindications. Ischaemia Infarction ischaemic heart disease. Modifiable risk If the ECG does not reveal an MI but car- factors include smoking, obesity, hyper- ACS = acute coronary syndrome. STEMI = ST diac ischaemia is suspected, patients tension, dyslipidaemia and poor diet. Life- segment elevation myocardial infarction should be admitted and have serial 12-lead style changes such as smoking cessation, ECGs to assess any dynamic changes. If weight loss, exercise, adherence to blood- there is myocardial damage, cardiac pressure drugs, tight glucose control in syncope or autonomic symptoms such as enzymes (typically troponins T and I) are patients with diabetes, and management of sweating, nausea, tachycardia or vomiting raised, which can help confirm the diag- dyslipidaemias can be useful in both pri- may also occur (with or without chest nosis. NICE (2013b) advises that troponin mary and secondary prevention. pain). Close attention to vital signs is crit- be included in the initial assessment on ical as patients can deteriorate and become admission and a second sample be taken Signs and symptoms haemodynamically unstable or develop 10-12 hours after symptoms began. Patients typically present with central heart failure and arrhythmias. Increases or decreases of troponin above chest pain or tightness described as dull or or below the normal limit on the repeat test crushing; it can radiate to the jaw or down Diagnosis and first investigations can confirm NSTEMI. A negative troponin the left arm and normally lasts for >15 min- A thorough clinical history and physical and no ECG changes can support a decision utes. Some patients, however, such as examination should be undertaken and to discharge patients who may have those with diabetes, older people or supported by an ECG. This helps delineate unstable angina. These patients should women, may not have chest pain. the treatment pathway and, in cases of receive follow-up in a rapid chest pain clinic Mnemonics, such as SOCRATES, can be STEMI, decide whether the patient needs or in cardiology; their risk of adverse cardiac used to assess patients’ chest pain: urgent reperfusion. If ACS is suspected, events is 0.2% (Weinstock et al, 2015). l S – site of pain; the emergency services should be called Fig 2 outlines the principles of ACS diag- l O – onset of pain; and, on arrival, paramedics should per- nosis and management. l C – character of the pain; form an immediate ECG. Many paramedics l R – any radiation; are trained to recognise ECG changes seen Risk prediction l A – associated factors; in STEMI, which include ST elevation of Adults with NSTEMI or unstable angina l T – timing of the pain; ≥1mm height in two adjacent chest leads, should be assessed for their risk of future l E – exacerbating/alleviating factors; for ST elevation of ≥2mm in two adjacent limb adverse cardiovascular events using an example, position or inspiration; leads, and new left bundle branch block. established risk scoring system that predicts l S – severity of the pain using a rating If STEMI is suspected, paramedics will six-month mortality (NICE, 2013b). This scale of 1-10 (10 being the worst pain). aim to take patients directly to a ‘heart attack helps to plan clinical management and PETER LAMB Shortness of breath, palpitations, centre’ that offers primary percutaneous decide on the best place of care (for example, Nursing Times March 2017 / Vol 113 Issue 3 32 www.nursingtimes.net Fig 2. Overview of ACS diagnosis and management antiplatelet drugs is used. This drug class includes clopidogrel and the faster-acting prasugrel and ticagrelor.