NICE guidelines for the management of patients with acute chest pain

# Overview
In the 2016 update of the stable chest pain guideline, National Institute for Health and Clinical Excellence (NICE) has dramatically changed its approach to new-onset stable chest pain aiming to find a more cost-effective strategy including NO use of pretest probability risk scores or NO use of functional tests, such as stress echocardiography, as a first-line investigation. The suggestion is to use CT coronary angiography in  with typical or atypical chest pain. In addition, there is no recommendation for any diagnostic testing if chest pain is non-anginal. Also, perfusion imaging is offered in the setting of uncertainty about the functional significance of coronary lesions. However, the recommendation of the European Society of Cardiology (ESC2013) is functional tests as the initial investigation.

# NICE Guidelines for the Management of Patients with Acute Chest Pain 
- Symptoms suggestive od acute coronary syndromes:
- Pain in the chest and/or other areas (for example, the arms, back or jaw) lasting longer than 15 minutes 
- Chest pain associated with nausea and vomiting, marked sweating, breathlessness, or particularly a combination of these 
- Chest pain associated with hemodynamic instability 
- New onset chest pain, or abrupt deterioration in previously stable angina, with recurrent chest pain occurring frequently and with little or no exertion, and with episodes often lasting longer than 15 minutes
- If the patient is currently pain-free, but had chest pain in the last 12 hours, and resting 12-lead ECG is abnormal or not available or develops further chest pain after recent (confirmed or suspected) ACS, evaluation about ACS is warranted.
- Management of ACS:
- Transferring the patient to hospital immediately
- Taking a resting 12-lead ECG 
- Managing pain with TNG and/or an opioid
- Giving a single dose of 300 mg aspirin unless the person is allergic, and other neccessary therapeutic interventions
- Checking  oxygen saturation and administer oxygen if appropriate
- Monitoring the patient
- Assessment of patients with suspected ACS in the hospital:
- Physical examination to determine:
- Hemodynamic status
- Signs of complications, including pulmonary oedema, cardiogenic shock
- Signs of non-coronary causes of acute chest pain, such as aortic dissection
- Taking a detailed clinical history unless a STEMI is confirmed from the resting 12-lead ECG (regional ST-segment elevation or presumed new LBBB)
- The characteristics of the pain
- Other associated symptoms
- Any history of cardiovascular disease
- Routinely administration of oxygen is not recommended, but monitoring  oxygen saturation and pulse oximetry as soon as possible, ideally, before hospital admission is recommended.
- Indications for supplemental oxygen:
- Oxygen saturation (SpO2) of less than 94% who are not at risk of hypercapnic respiratory failure, aiming for SpO2 of 9498%
- Chronic obstructive pulmonary disease who are at risk of hypercapnic respiratory failure, to achieve a target SpO2 of 8892% until blood gas analysis is available.
- Patients with acute chest pain should be monitored for:
- Exacerbations of pain and/or other symptoms
- Pulse and blood pressure
- Heart rhythm
- Oxygen saturation by pulse oximetry
 Repeated resting 12-lead ECGs
 Checking pain relief
- Use of biochemical markers for diagnosis of an acute coronary syndrome:
- Use of high-sensitivity troponin tests is not recommended, if ACS is not suspected
- For patients at high or moderate risk of MI (as indicated by a validated tool), performing high sensitivity troponin tests is reasonable.
- For patients at low risk of MI :
- Performing a second high-sensitivity troponin test
- Considering a single high-sensitivity troponin test only at presentation to rule out NSTEMI , if the first troponin test is below the lower limit of detection (negative).
- A detectable troponin on the first high-sensitivity test does not necessary for patients with confirmed MI.
- For diagnose of ACS use of biochemical markers such as natriuretic peptides and high-sensitivity C-reactive protein  are not recommended.
- Checking biochemical markers of myocardial ischemia (such as ischemia-modified albumin) as opposed to markers of necrosis is not recommended  in patients with acute chest pain.
- Factors should be considered for interpreting high-sensitivity troponin:
- the clinical presentation
- The time from onset of symptoms
- The resting 12-lead ECG findings
- The pre-test probability of NSTEMI
- The length of time since the suspected ACS
- The probability of chronically elevated troponin levels in some patients
- That 99th percentile threshold for troponin I and T may differ between sexes.
- Universal definition of myocardial infarction:
- Detection of rising and/or falling of cardiac biomarkers values (preferably cardiac troponin (cTn) with at least one value above the 99th percentile of the upper reference limit and at least one of the following:
- Symptoms of ischaemia
- New or presumed new significant ST-segment-T wave(ST-T) changes or new left bundle branch block (LBBB)
- Development of pathological Q waves in the ECG
- Imaging evidence of new loss of viable myocardium  or new regional wall motion abnormality
- Identification of an intracoronary thrombus by angiography
- When a raised troponin level is detected in patients suspected ACS, other causes for raised troponin should be excluded (for example, myocarditis,aortic dissection or pulmonary embolism)
- In patients with chest pain without raised troponin levels and no resting 12-lead ECG changes, determine whether their chest pain  is likely to be cardiac.
- Ifmyocardial ischemia is suspected, follow the recommendations on stable chest pain.
- Clinical judgment is important to decide on the timing of any further diagnostic investigations.
- Routinely use of non-invasive imaging or exercise ECG in the initial assessment of acute cardiac chest pain is not recommended.
- Chest computed tomography (CT) is recommended to rule out other diagnoses such as pulmonary embolism or aortic dissection, not to diagnose ACS.
- Chest X-ray is helpful to exclude complications of ACS such as pulmonary oedema, or other diagnoses such as pneumothorax or pneumonia.
- If an ACS has been excluded but patients have risk factors for cardiovascular disease, following appropriate guidance is recommended, for example, the NICE guidelines on cardiovascular disease and hypertension.