Acute Coronary Syndromes 1 Flashcards
Define ACS, STEMI, NSTEMI & unstable angina. Initial mangement & management of STEMI
What is ACS?
Spectrum of conditions which includes STEMI, NSTEMI and unstable angina
What does ACS result from?
ACS (e.g. STEMI, NSTEMI, unstable angina) result from formation of a thrombus on atheromatous plaque in a coronary artery
Definitive diagnosis of ACS is based on the following 3 things
ECG changes
Clinical presentation
Measurement of biochemical cardiac markers
What is a STEMI usually caused by
Complete and persistent blockage of coronary artery resulting in myocardial necrosis with ST-segment elevation seen on ECG
What is NSTEMI caused by
Partial or intermittent blockage of artery, which usually results in myocardial necrosis
ECG may show ST-segment depression, T-wave inversion, or may be normal
What is unstable angina caused by
Partial or intermittent blockage of artery which does not result in myocardial necrosis
ECG may show ST-segment depression, T-wave inversion, or may be normal
How would you differentiate between NSTEMI and unstable angina?
The partial or intermittent blockage of the coronary artery usually results in myocardial necrosis in NSTEMI, not in unstable angina
A high-sensitivity blood test for serum troponin
Troponin as a differentiation test for NSTEMI and unstable angina
- High sensitivity blood test for serum troponin are used to differentiate these
- Troponin elevated in NSTEMI due to the myocardial necrosis, but is normal in unstable angina
What are the non drug treatment options available following an ACS
- Revascularisation procedures e.g. percutaneous coronary intervention (PCI) or coronary arrest bypass graft (CABG)
- These help restore blood flow when it is limited or blocked
- These are often appropriate alongside drug treatment for pt with ACS
Initial management - pain relief in ACS
ASAP: GTN (sublingual or buccal)
IV opioids e.g. morphine may be administered, esp if acute MI is suspected
Aims of initial management of ACS
- Provide supportive care & pain relief & prevent progression of cardiac injury
- Start as soon as ACS suspected, but treatment should not delay transfer to hospital
- Pain relief: GTN (sl or buccal), IV opioids esp if acute MI
- Loading dose of aspirin ASAP (if given before arrival at hospital, a note saying it has been given should be sent with pt)
- Only offer other anti platelets once in hospital according to their diagnosis and RF
- Do not routinely administer oxygen but monitor pt oxygen saturation (ideally before admission) and offer supplemental oxygen is indicated
- Monitor all pt admitted in hospital for hyperglycaemia (if BG>11mol/L, give insulin)
Aims of management of STEMI
Restore adequate coronary blood flow ASAP and reduce mortality
Management of STEMI - reperfusion therapy
- Immediately assess eligibility (irrespective of age, ethnicity or sex) for coronary reperfusion therapy
- Deliver coronary reperfusion therapy (primary PCI or fibrinolysis) ASAP in eligible patients
- Do not use level of consciousness after cardiac arrest caused by suspected acute STEMi to determine whether pt is eligible for coronary angiography (with follow on PCI if indicated)
What is coronary angiography
- Performed to detect obstruction in coronary arteries
- Uses a special dye (contrast material) and x-rays to see how blood flows through the arteries in your heart
- If blocked, follow up PCI may be indicated to help restore blood flow
Initial drug therapy in acute STEMI
- Single loading dose of 300mg aspirin ASAP unless evidence of allergy
- Do NOT offer routine glycoprotein IIb/IIIa inhibitors or fibrinolytic drugs before arrival at catheter lab to pt with acute STEMI who have primary PCI planned
What is the preferred coronary reperfusion strategy for people with acute STEMI and when should it be performed
- Coronary angiography with follow on primary PCI
- Preferred strategy for people with acute STEMI if:
- presentation within 12 hours of symptom onset
- primary PCI can be delivered within 120 mins of the time when fibrinolysis could have been given
When would you offer coronary angiography with follow on PCI
- Acute STEMI & cardiogenic shock who present within 12 hours of onset of symptoms of STEMI
- Acute STEMI presenting more than 12 hours after onset of symptoms if there is evidence of continuing MI
Site of arterial access for people undergoing coronary angiography
Consider radial in preference to femoral artery
Dual anti platelet therapy for people with acute STEMI having primary PCI
Aspirin + prasugrel/ticagrelor/clopidogrel
- Choice of second anti platelet depends on planned intervention (primary PCI, fibrinolysis, conservative management) and pt bleeding risk
- Prasugrel is preferred for most pt undergoing primary PCI unless bleeding risk outweighs effectiveness
- If pt already taking oral AC, give aspirin + clopidogthrl
- Aspirin alone may be appropriate for some pt with high bleeding risk not undergoing PCI
Prasugrel dose and considerations
- Initially 60mg for one dose, then maintenance is either 5mg or 10mg daily for usually up to 12 months depending on weight and age
- 75 and over or body weight under 60kg: 5mg daily
- Body weight over 60kg: 10mg daily
- In 75 and over, think about whether the bleeding risk outweighs its effectiveness
Antithrombin therapy during primary PCI for STEMI
For pt undergoing primary PCI with radial access: unfractionated heparin + bailout glycoprotein IIb/IIIa inhibitor in combination with dual anti platelet therapy
Femoral access: bivalirudin (unlicensed) + bailout glycoprotein IIb/IIIa inhibitor in combination with dual anti platelet therapy
Thrombus extraction during primary PCI
Consider thrombus aspiration during primary PCI for people with acute STEMI
Do not routinely use mechanic thumbs extraction during primary PCI for people with acute STEMI
When to offer complete or culprit vessel only revascularisation with PCI in people with acute STEMI treated by primary PCI
- Offer complete revascularisation with PCI for pt with acute STEMI & multi -vessel coronary artery disease w/o cariogenic shock
- Consider culprit vessel only revascularisation with PCI during index procedure for people with acute STEMI and multi vessel coronary artery disease WITH cardiogenic shock
- Consider doing these during index hospital admission
Drug eluding stents in primary PCI
If stunting is indicated, offer a drug-eluding one to people with acute STEMI undergoing revascularisation by primary PCI
