Lecture 3 - Acute Coronary Symptoms Flashcards
cause of ACS?
rupture of atherosclerotic plaque with subsequent platelet adherence, activation, and aggregation, and the activation of the clotting cascade.
Ultimately, clot forms composed of fibrin and platelets
Unstable Angina vs NSTEMI
UA = not positive for cardiac enzymes, no cell death, ischemia (not infarction)
NSTEMI = positive for cardiac enzymes, death of myocardium (infarction), no ST elevation
STEMI will be…
occlusive thrombus
Fibrin rich
want drugs to dissolve fibrin
UA/NSTEMI
Mural Thrombus
mostly platelets, use anti-platelet drugs
TIMI Risk score NSTEMI
Low = 0-2 Medium = 3-4 High = 5-7
ACS Non-pharmacologic therapy
EKG
Oxygen (O2 < 90%)
Cardiac Enzymes
Bed Rest
ACS Pharmacologic Therapy
Aspirin 325mg non-ec Nitrates Morphine?? Anti-coagulant Anti-platelet Statin
Class I recommendation: Nitroglycerin
SL = 0.4mg q5min for 3 doses
IV = 5-10mcg/min, titrate up to 75-100 mcg/min
Avoid in pt with hypotension ( SBP < 90) or right ventricular infarcts
Class I recommendation: Morphine
2-4mg IV q5-15min until pain relief or ADR
may worsen outcomes in NSTEMI
Monitor BP,HR, RR, naloxone present
Class I recommendation: Beta-Blockers
All pts w/o CI in 1st 24hrs
Oral > IV preferred
CI: Signs of HF, low output state (HR <60, SBP <90)
CCBs
generally 2nd line
wary of SL short acting nifedipine = reflex tachycardia leading to MI
Plavix is…
clopidogrel
Effient is…
Prasugrel
Brilinta is…
ticagrelor
Aspirin info
Decreases morbidity/mortality,
DOESNT IMPACT CHEST PAIN
Dosing: 325 mg qd
MOA: irreversibly inhibit COX, inhibiting platelet aggregation
don’t use EC, 81 mg dose preferred for maintenance
Clopidogrel Dosing
Dosing: 300-600 mg loading, higher = faster inhibition
Maintenance: 75mg qd
Clopidogrel interactions
Pro drug, CYP450 metabolism
PPIs inhibit CYP450, so co-admin appress to increase risk of reinfarction
Prasugrel info
more potent irreversible platelet inhib compared to clopidogrel
approved for pt managed with PCI
Prasugrel Dosing
60mg loading dose, continue 10 mg once daily w or w/o food
consider 5mg once daily for pt <60kg
Prasugrel considerations
don’t start in….
> 75 yr old
previous history of TIA or stroke
likely to undergo CABG, start after
BW < 60kg
Ticagrelor MOA
reversibly binds to ADP receptor P2Y12
Ticagrelor Dosing
Loading: 180 mg once w/ Aspirin 325
Maintenance dose: 90 mg bid w/ 81mg aspirin
if on for longer than 12 months, can possibly reduce to 60mg BID
Ticagrelor Drug Interactions
Carbamazepine,Phenytoin
Ticagrelor Adverse effects
Dyspnea, dissipates in 2-4 weeks
bleeding
Cangrelor (Kengreal) MOA
reversibly binds to ADP
Cangrelor Dosing
Loading: 30mcg/kg IV bolus
Maintenance Dose: 4mcg/kg/min IV for duration of PCI or 2hrs
Doesn’t interact with Ticagrelor, but does with Prasugrel or clopidogrel (load after stoping infusion not during)***
GP IIB and IIIA inhibitors are used….
adjunctive anti platelet in some cases usually
Integrilin (Eptifibatide)
Dose has to be loaded, and given by infusion. Has renal dosing
Discontinue infusion with OD
Aggrastat (Tirofiban)
Dose has to be loaded, and given by infusion. Has renal dosing
Discontinue infusion with OD
Xa inhibitor
Fondaparinux (Arixtra)
Direct thrombin inhibitor
Bivalirudin (angiomax)
Dabigatran (Pradaxa)
Low molecular weight heparin
Enoxaparin (Lovenox)
Dalteparin (Fragmin)
Enoxaparin (Lovenox) Dosing
1mg/kg q12h (CrCl > 30/min)
1mg/kg q24h (CrCl <30/min)
Usually round to next syringe or next 10mg
what to monitor Enoxaparin
Scr
Platelets
Anti-factor Xa lvls
Fondaparinux (arixtra) info
Class 3 rec
Avoid using as solo in PCI, used w/ Heparin
Fondaparinux (arixtra) Dosing
STEMI: 2.5mg IV Day 1, then 2.5mg subcut q24h
NSTEMI: 2.5mg SQ once daily
caution CrCl 30-50ml/min
**Don’t use if CrCl < 30ml/min
Monitor: Scr, Anti-factor Xa lvls
Bivalirudin (Angiomax) info
Dosing: IV bolus + IV infusion
Monitor: Scr, can monitor aPTT
Dose adjustment for severe Renal failure
NSAID use in ACS?
Black box warning
increased risk of mortality, reinfarction, HTN, etc
Unstable Angina Clinical Presentation
- Typical rise and gradual fall (troponin) or more rapid rise/fall (CK-MB) with at least one of the following….
- Ischemic Symptoms
- Development of Q waves on ECG
- ECG changes indicative of ischemia
- Imaging of myocardium abnormality
CK-creatinine phosphokinase info
peak at 24 hrs, normalizes in 2 days
Troponins info
Elevations may persist up to 2 weeks
Treating pt presenting with ACS
- Triage
- Asses risk of CV death/ recurrent ischemia
- General care (ASA, NTG, Statin…consider O2/BB/Morphine)
- Choose invasive or non-invasive initial strategy
- select second antiplatelet to add to ASA
- choose an anticoagulant agent
Statins use
High-intensity statin during hospital care
Atorva 40-80* or Rosa 20*-40
consider moderate intensity if >75yr old or not candidate for high intensity
Irreversible, nonselective COX-1 Inhib
Aspirin
Irreversible P2Y12 antagonist
Clopidogrel
Prasugrel
Reversible P2Y12 antagonist
Ticagrelor
Cangrelor
GPIIb/IIIa inhibitors
Abciximab
Eptifibatide
Tirofiban
PAR-1 Antagonist
Vorapaxar
Enoxaparin Advantage and Disadvantage
Advantage:
Lower incidence of HIT
Less monitoring
Twice Daily dosing instead of continuous infusion
Disadvantage: unsure dosing in obese/renal impairment longer duration not always wanted harder to reverse only in certain syringe sizes
Fondaparinux Advantage and Disadvantage
Advantage:
once daily dose
No incidence of HIT
Disadvantage: Lack of reversibility Catheter thrombosis Longer duration of action unsure of universal dosing for all pt renal dosing CrCL < 30 ml/min
Bivalirudin Advantage and Disadvantage
Advantages:
no incidence of HIT
may req less use of GPIIb/IIIa inhib
Disadvantages:
lack of reversibility
continuous infusion
not studied in ACS pts w/ conservative management strategy
