Therapy for acute coronary syndromes and myocardial infarctions Flashcards
What are the two main goals of ACS therapy?
Increase myocardial oxygen supply
Decrease myocardial oxygen demand
What arteries are used for access to carry out PCI?
Femoral or radial
Describe the mechanism of action of thrombolytic agents
Are all serine proteases which act by converting plasminogen to plasmin, a natural fibrinolytic agent. Plasmin lyses clots by breaking down the fibrinogen and fibrin contained in the clot
Name some fibrin specific thrombolytic agents
Alteplase
Reteplase
Tenecteplase
Alteplase
Name a non-fibrin specific thrombolytic agent
Streptokinase
Name some contraindications when using thrombolytic agents
Prior intracranial haemorrhage Known structural cerebral lesion Known malignant intracranial neoplasm Ischaemic stroke within 3 months Suspected aortic dissection Active bleeding or bleeding diathesis Significant closed head trauma or facial trauma in last 3 months
Describe the mechanism of action of aspirin
Inhibits thromboxane A2 production, which normally stimulates platelet aggregation and vasoconstriction
What enzyme is responsible for clopidogrel metabolism into its active form?
CYP2C19
Describe the binding of clopidogrel to its target and its action
Irreversibly inhibits P2Y12 SDP receptor
Blocks activation of GP IIb/IIIa pathway in platelet aggregation
Name a DDI possibly associated with clopidogrel
PPIs - reduce effects of the drug, though evidence for this is poor
Describe the mechanism of resistance to clopidogrel
14% of population have low CYP2C19 levels and show resistance
Lead to development of ticagrelor
Describe the mechanism of action of fondaparinux
selective inhibitor of clotting factor Xa
What is glycoprotein IIb/IIIa?
Integrin complex found on platelets which acts as a receptor for fibrinogen, aiding in platelet activation and clot formation
What contraindications are associated with GP IIa/IIIa receptor inhibitors?
Bleeding
Thrombocytopenia (decreased platelets in blood)
Describe some patients at risk of cariogenic shock
Age > 70 yo
HR > 110bpm
BP < 120mmHg
Why are beta blockers being decreasingly used?
Thought to increase likelihood of cardiogenic shock
When should beta blockers not be used?
At risk of cariogenic shock
Symptoms of coronary vasospasm
Cocaine use
According to treatment SIGN 148, what should ACS be treated with immediately?
Aspirin and ticagrelor, followed by long term aspirin
How long should patients with ACS undergo anti-platelet therapy following diagnosis?
at least 6 months
What drugs are those with ACS put on for the long term?
Aspirin
Statins
ACEIs if they have unstable angina/ had an MI
Who are put on ACEIs?
Those who have unstable angina
Have had an MI
Have signs of LV dynsfunction/HF
What do those who have suffered an MI and have signs of left ventricular hypertrophy specifically get put on?
Eplerenone, K+ sparing diuretic
