Exam 1: Acute Coronary Syndromes Flashcards
What is Acute Coronary Syndrome (ACS)?
Heart Attack
(an imbalance in demand of oxygen by heart tissue and the supply of oxygen the heart is getting)
(AKA: not enough oxygen for heart)
What are the worst arteries for ischemia to happen in and why?
-Right Coronary artery
Left main coronary artery
-These coronary arteries are high up in the heart and have other coronary arteries feeding off of them
-Therefore, if ischemia happens here, the heart attack will be larger because oxygen will also be cut off to the vessels downstream from it
What is the most severe acute coronary syndrome?
STEMI
What causes ischemia?
-An atherosclerotic plaque forms
-The plaque ruptures
-Platelets adherence is activated, they aggregate and activate the clotting cascade at the area
-Fibrin and platelets form a clot that blocks blood/oxygen flow
What is a Type 1 ACS?
Spontaneous MI
(from atherosclerotic plaque rupture)
*what we mainly talk about
What is a Type 2 ACS?
MI Secondary to Ischemic Imbalance
(oxygen supply/demand mismatches to the heart, not getting enough blood flow)
-Ex: vasospasm, anemia, hypotension
*Not necessarily due to plaque
What is the median age of ACS presentation?
68 years old
What gender is more likely to have ACS?
Males
(3 Males : 2 Females)
What are the risk factors for ACS?
-Older age
-Male
-Family history of CAD
-Peripheral artery disease
-Diabetes
-Renal insufficiency
-Prior MI
-Smoking
What are some precipitating factors for ACS?
-Exercise
-Weather (cold or warm)
-Diet (large meal)
-Emotions (fright, anger, stress)
-Coitus (sexual activity)
-Walking against wind
-Smoking
(these increase oxygen demand)
What are the signs of Acute Coronary Syndrome?
-Retrosternal chest pain
(can radiate to shoulder, down left arm, to back, or to jaw)
**Mostly occurs at rest
*Crushing, radiating pain
What are the symptoms of Acute Coronary Syndrome?
-Nausea
-Vomiting
-Diaphoresis (cold sweat)
-SOB
-Anxiety
*Chest pain
What are the atypical symptoms of ACS?
-Epigastric pain
*Indigestion
-Stabbing or pleuritic pain
-Dyspnea (SOB) without chest pain
Who is more likely to experience atypical ACS symptoms?
-Elderly
-Females
-Diabetics
-Impaired renal function
-Dementia
When should a patient call 911?
If they are experiencing chest pain and high risk features like:
-Continuing chest pain
-Severe dyspnea
-Syncope/presyncope (fainting)
-Palpitations
Why should patients experiencing ACS be transported to the hospital by ambulance instead of driving themself?
-Treatment/testing can be initiated on the way to the hospital
Upon arriving at the hospital for a suspected ACS, how soon should a patient have an ECG?
Within 10 minutes!
Note: all patients with acute chest pain should receive this
What does the P wave on an ECG show?
Atria contracting
What does the QRS wave on an ECG show?
Ventricle contracting
What does the T wave on an ECG show?
Ventricle relaxing
Note*
See lecture 1 slide 24 for ECG waves, know which is which
What is the order of the waves on an ECG?
P-Q-R-S-T
What changes can be seen on an ECG when a patient experiences a STEMI?
ST elevation
Q wave changes
(not present on initial ECG, develops over hours to days)
Why is the Q wave often not present initially on an ECG with a STEMI?
An ‘electrical hole” is there
(scar tissue cannot conduct electricity)
-Not acute damage, it is from old damage that accumulates over time from scar tissue
What may be seen on an ECG for NSTEMI or Unstable Angina?
-May be normal
-May have:
-ST depression
-ST elevation
-T wave inversion (upside down)
*Unlikely to have Q wave change
*No ST segment elevation
Note:
See lecture 2 slide28 for NSTEMI and UA ECG picture
What patients should have their troponin levels measured?
-All patients presenting to the ED with acute chest pain and suspected ACS
*measure ASAP
What is troponin?
A myocardial injury biomarker
(released from injured heart cells into blood stream)
What is the gold standard for ACS detection?
Troponin
What are the two troponin tests and which one is preferred?
High sensitivity troponin (*preferred)
Conventional troponin
Why is high sensitivity troponin preferred?
-Greater sensitivity and negative predictive values
-Shorter time from onset of chest pain to a detectable concentration
What units are high sensitivity and conventional troponin measured in?
High sensitivity: ng/L
Conventional: ng/mL
What is sensitivity vs specificity?
Sensitivity: Likelihood of detecting a disease when it exists (true positive rate)
Specificity: Likelihood of not detecting a disease when it does not exist (true negative rate)
What does troponin detect?
Myocardial injury
What value for HIGH SENSITIVITY TROPONIN indicates damage to the heart?
> 14 ng/L
What value for CONVENTIONAL TROPONIN indicates damage to the heart?
> 0.05 ng/mL
When we check troponin, how many times do we check it?
Check 3 levels over 12 hours
*because damage is currently happening and there may not be much at the first level but it will trend upwards
Does elevated troponin levels immediately mean a patient is having an MI?
NO
-could also be a pulmonary embolism
-have to use multiple factors to diagnose
What are the differences between Stable Angina and Unstable Angina?
Stable Angina
-Chest pain occurs during physical exertion
-Predictable
-Relieved by rest
-< 5 minutes
Unstable Angina
-Chest pain occurs at rest, while sleeping, or with little exertion
-Surprise
-More severe, longer (can be >30mins)
-Does not go away with rest
What are the differences between unstable angina and NSTEMI?
UA:
Less ischemia
Does not elevate troponin
NSTEMI
-Elevated troponin
What are the differences between NSTEMI and STEMI?
Both:
-Chest pain
-Elevated troponin
NSTEMI:
-No ST segment elevation
(may have ST depression or T wave inversion)
STEMI:
-ST elevation!!!
What does a thrombolysis in myocardial infarction (TIMI) risk score tell us?
Risk of experiencing either death, MI, or urgent need for revascularization within 14 days
What range of points indicates “low risk” on the TIMI risk score?
0-2
What range of points indicates “medium risk” on the TIMI risk score?
3-4
What range of points indicates “high risk” on the TIMI risk score?
5-7
What are the complications of ACS?
-Heart failure
-Valvular dysfunction
-Arrhythmias
-Bradycardia/heart block
-Pericarditis (swelling of sack around heart)
-Stroke secondary to LV thrombus
-Cardiogenic shock (BP cannot keep up to profuse organs)
-Death
What is ventricular remodeling?
Changes in shape, size, and function of left ventricle after ACS
**leads to heart failure
What 3 things are usually included in MACE?
-Stroke
-MI
-Cardiovascular death
What are the two initial recommendations for patients presenting to the ED with symptoms of ACS?
ECG within 10 minutes
Serial troponin levels
If the initial ECG a patient receives is not diagnostic but they are still experiencing symptoms of ACS what should be done?
Perform serial ECGs
*Every 15-30 minutes for the first hour
Who should receive MONA?
UA, NSTEMI, and STEMI patients
*immediately upon arrival!
What are the 4 components to MONA?
Morphine
Oxygen
Nitroglycerin
Aspirin
What is the initial dose of morphine given to patients?
4-8 mg IV, followed by 2-8mg IV every 5-15 mins
What are the side effects of morphine?
-Sedation
-Respiratory depression
-Nausea/vomiting
Why should NSAIDs be discontinued and avoided during hospitalization for ACS patients?
They lead to sodium and water retention
*This increases risk of MACE
When is oxygen initiated and what is its saturation goal?
Initiate when saturation < 90%
Goal: Maintain saturation >90%
What dose should sublingual NGT be initiated at?
0.3-0.4 mg every 5 minutes x 3
(for ischemic pain)
*NOTE: Give this first, then start IV dosing if needed
What dose should IV nitroglycerin be given at?
Start: 10 mcg/min
Titrate: By 5 mcg/min every 5 mins
Max: 200mcg/min
**NOTE: give this after the SL dose if needed
Can we use transdermal NTG for ACS?
NO
-onset of action is not rapid enough
-takes a longer time to absorb in skin
What is tachyphylaxis?
When a drug loses part of or its entire efficacy over time as the body develops tolerance to it
(seen in nitrates)
Why are nitrates contraindicated with phosphodiesterase inhibitors?
Both medications cause vasodilation
-this leads to severe hypotension
What dose of aspirin should be given to all ACS patients presenting to the hospital?
162-325mg chewable aspirin x 1 dose immediately
Can enteric coated aspirin be given to patients presenting to the ED?
YES
*it has to be chewed so it will absorb quickly
If the patient already takes a baby aspirin and took their dose that morning, do you still give them a loading dose of aspirin (325mg)?
YES
-If they just took their dose, you can give an additional 81mg tablets x 3
(makes a total dose of 324mg with the baby aspirin)
What are the 3 reperfusion strategies?
Percutaneous Coronary Intervention (PCI)
Coronary Artery Bypass Graft (CABG)
Fibrinolytic therapy
What is a coronary angiography and what does it show?
A catheter inserted into the radial + femoral artery and fed up to the heart
Dye gets injected into the coronary arteries
X-ray is taken and shows the blocked arteries (areas where dye does not reach)
Stent is placed in blocked arteries
OVERALL: shows which arteries in the heart have blockages
What is a PCI?
Procedure where a small balloon is used to reopen a blocked artery to increase blood flow
*A stent is placed if needed to keep artery open
ASSOCIATE PCI WITH A STENT
What is a CABG?
Open-heart surgery
-a vein or artery from another part of the body is removed and attached to the heart to “bypass” the blocked artery/arteries
How does a fibrinolytic work?
Changes plasminogen to plasmin
Plasmin breaks down fibrin into fibrin degraded products
What are the 3 fibrinolytics?
Tenecteplase (TNK-tPA)
Reteplase (rPA)
Alteplase (tPA)
What fibrinolytic is preferred?
No preference for one over the other
Who should receive reperfusion therapy?
All eligible STEMI patients whose symptoms began in the last 12 hours
What is preferred: a PCI or a Fibrinolytic?
PCI (STENT or CABG)
*if hospital is able to perform these procedures, they should do it
Upon arriving at the hospital, how quickly should a patient receive a fibrinolytic?
within 30 minutes
Upon arriving at the hospital, how quickly should a patient receive a STENT?
within 90 minutes
When is fibrinolytic therapy recommended?
For STEMI patients at non-PCI-capable hospitals that are at least 120 mins away from a PCI-capable hospital
Are fibrinolytics used for NSTEMI or UA?
NO
What reperfusion strategies are used for NSTEMI/UA?
Early Invasive: (Coronary Angiography +/- Revascularization)
Ischemia Guided: (Medical Management)
When is early invasive reperfusion therapy (Coronary Angiography +/- Revascularization) used in NSTEMI/US patients?
Preferred for patients with high risk features:
-Refractory angina
-New-onset Heart Failure
-Rising troponin
-New ST-segment depression
What is ischemia-guided reperfusion therapy (Medical Management)?
Treatment with evidence-based medications
*No heart catheterization unless the patient becomes high risk
What are the 3 options you may find when performing a heart cath?
- It wasn’t a blockage, misdiagnosed
- You see a blockage and put a STENT in
- You find profuse disease with lots of blockages, pull the cath out, and schedule a CABG
What is the standard dose of aspirin to give a patient immediately upon presentation to the hospital?
325mg
What is the maintenance dose of aspiring that patients should be on the rest of their lives?
81 mg
(preferred dose but could be up to 325mg)
What is one counseling point for aspirin?
Take with food
How long is DAPT recommended for STEMI, NSTEMI, and UA?
12 months
When would we use Cangrelor for antiplatelet therapy (IV only)?
*Option for LOADING DOSE ONLY
-Use during PCI if patient did not already receive loading dose because it works really fast
What is the preferred loading dose of clopidogrel (Plavix)?
600 mg
(over 300mg)
*Unless you used a fibrinolytic, then use 300mg due to bleeding risk
What is the loading dose of Cangrelor?
30mcg/kg, followed by 4mcg/kg/min for 2 hours
When would we not use a loading dose of a P2Y12 inhibitor?
Already took a fibrinolytic + > 75 years old
When would we use a 300mg loading dose of Clopidogrel instead of 600mg?
Already took a fibrinolytic + 75 years old or YOUNGER
What is the most commonly used P2Y12 inhibitor?
Clopidogrel
*Prodrug
-Common due to insurance coverage
True or False: Clopidogrel is a prodrug
True
True or False: Ticagrelor is more effective than Clopidogrel
True
-greater inhibition of platelet aggregation
What trial showed the effectiveness of Ticagrelor vs Clopidogrel?
PLATO trial
(showed ticagrelor decreased the endpoint slightly more)
How does ticagrelor affect aspirin dosing?
Max dose of Aspirin should be 81 mg when used in combination with ticagrelor
What are the side effects of ticagrelor?
Dyspnea (SOB)
Ventricular pauses
Why is prasugrel not commonly used?
It inhibits platelet aggregation more than clopidogrel
**This gives it a high bleeding risk
**Highest bleeding risk of all
When is Prasugrel contraindicated?
Patients with history of TIA/stroke
What patients is prasugrel not recommended in?
75 years old or older
<60kg
High bleeding risk
What PSY12 inhibitors are prodrugs/ not prodrugs?
Clopidogrel: Prodrug
Prasugrel: Prodrug
Ticagrelor: Not a prodrug
Why would we switch from Clopidogrel to Ticagrelor/Prasugrel?
Inadequate response
Why would we switch from Ticagrelor to Clopidogrel?
Bleeding
Cost
Dyspnea*
Adherence*
Why would we switch from Prasugrel to Clopidogrel?
Bleeding
Cost
Stroke/TIA***
For an STEMI or NSTEMI/ UA with PCI (early invasive strategy) what P2Y12 is preferred?
Any could be used
*Ticagrelor or Prasugrel preferred
For an NSTEMI/UA with Ischemia Guided Therapy, what P2Y12 is preferred?
Clopidogrel or Ticagrelor
For a STEMI with a fibrinolytic used, what P2Y12 inhibitor is preferred?
Clopidogrel
Which type of stent is associated with a higher rate of late STENT thrombosis?
(bare metal or DES)?
Drug eluting stent (DES)
*may not be preferred if patient cannot comply with prolonged DAPT
What drug is released from a Drug Eluting Stent (DES)?
Anti-rejection drug
-Everolimus, Zotarolimus, Ridaforolimus
*prevents body from rejecting the stent
What are 2 counseling points for Ticagrelor?
Take BID dosing 12 hours apart (morning and night)
Tell doctor if you experience shortness of breath
When should aspirin be held before underrgoing a CABG?
DOES NOT NEED TO BE HELD
When do the P2Y12 inhibitors need to be held before a CABG?
Ticagrelor- 3 days
Clopidogrel- 5 days
Prasugrel- 7 days
**If emergency CABG, try to hold for 24 hours
What are the 3 GP IIb/IIIa inhibitors?
Abciximab
Eptifibatide
Tirofiban
*potent IV antiplatelets
When are GP IIb/IIIa inhibitors given?
*In addition to aspirin and P2Y12i
At time of PCI
*no benefit to giving it before hand
*NOTE: not routinely used
What cases would warrant use of a GP IIb/IIIa inhibitor?
NSTEMI: high risk features (such as positive troponin)
STEMI: large thrombus burden
*inadequate P2Y12i loading
**As “bail out”: if thrombus develops during procedure or low blood after stenting
What is the bolus dose of Abciximab?
0.25 (mg/kg IV)
What is the bolus dose of Eptifibatide?
180 x2 (mcg/kg IV)
What is the bolus dose of Tirofiban?
25 (mcg/kg IV)
What is the brand name of Abciximab?
ReoPro
What is the brand name of Eptifibatide?
Integrilin
What is the brand name of Tirofiban?
Aggrastat
When is anticoagulation therapy recommended?
In addition to antiplatelet therapy
-Improve vessel patency
-Prevent re-occlusion
What factors does unfractionated heparin (UFH) affect?
Anti-Xa
Anti-IIa
*note: enoxaparin also affects these two factors
What is heparin induced thrombocytopenia (HIT)?
-Drop in platelet count
-Increased thrombosis
*Caused by the formation of antibodies that activate platelets
What are the 2 screening tests used if HIT is suspected?
Enzyme-linked immunosorbent assay (ELISA)
*quick, high false positive, re-
check if positive
Serotonin release assay (SRA)
*gold standard
Should a patient with a history of HIT be re-challenged with unfractionated Heparin or LMWH?
NO
-if a patient experiences HIT, never give heparin again
What are 2 benefits of using Unfractionated Heparin (UFH?)
Quick onset
Short half life
How is unfractionated heparin (UFH) dosed?
Given as a continuous infusion (IV drip)
*Dosed based on the:
-Activated partial thromboplastin time (aPTT)
-Activated clotting time (ACT)
How is Enoxaparin (Lovenox) eliminated?
By the kidneys
accumulates in renal impairment
*CALCULATE CrCl FOR THIS DRUG
Which factor is affected most by Enoxaparin?
Factor Xa
(also has anti-IIa properties but higher ratio of Xa)
What type of drug is Bivalirudin?
Direct thrombin inhibitor
What drug class should we not use Bivalirudin with?
GPIIa/IIb inhibitors
except for “bail out”!
How does Bivalirudin compare to UFH?
-Conflicting results
-May not be as effective for MACE and stent thrombosis
-May have lower bleeding risk
What type of drug is Fondaparinux?
Factor Xa inhibitor
When do we use Fondaparinux?
**Not commonly used
*Use in patients with history of HIT
DO NOT USE ALONE FOR PCI
Why do we not use Fondaparinux alone for PCI?
High rates of thrombosis
*if patient is already receiving fondaparinux and needs a PCI, give UFH or bivalirudin as well
When is Fondaparinux contraindicated?
CrCl < 30ml/min
What is a benefit of UFH for renal dosing?
UFH can be used in all degrees of renal function!
-dose not adjusted
What anticoagulants are used with PCI?
UFH and Bivalirudin
ONLY THESE 2
-no enoxaparin or fondaparinux
When is Bivalirudin preferred leading up to a PCI?
When there is a high bleeding risk
What 4 long-term medications (maintenance) should a patient with ACS be started on?
-Beta blockers
-Statins
-ACEi/ARB
-Nitroglycerin prn
How soon after an ACS should a patient be started on a beta blocker?
Within the first 24 hours
What are some reasons not to start a beta blocker?
-Bradycardia
-Heart failure or other low-output state
(beta blockers will make it worse)
-Risk for cardiogenic shock
-PR interval > 0.24s
-Second or third degree heart block
-Active asthma or reactive airway disease
What are the 4 commonly used beta blockers post-MI?
Metoprolol
Carvedilol
Propranolol
Atenolol
If a patient has HFrEF, what beta blockers can be used?
Sustained release:
-Metoprolol succinate
-Carvedilol
-Bisoprolol
When would we consider IV beta blockers?
Only with hypertension or ongoing ischemia
*use Metoprolol tartrate 5mg IV q5min
(up to 3 doses)
What are the 4 selective beta blockers?
Atenolol
Metoprolol
Bisoprolol
Nebivolol
Why is there controversy over using a beta blocker in patients who abuse cocaine?
-Cocaine stimulates both alpha and beta receptors
-Giving a beta blocker allows all of the cocaine to stimulate alpha receptors
(causes unopposed alpha effects)
-can cause hypertensive complications or increased troponin
In patients who abuse cocaine, what type of beta blocker is best to use?
Non-selective BB
*such as carvedilol that blocks some alpha receptors too
NOTE: do not use BB if cocaine is in their system, only after
When should we avoid starting or increasing a beta blocker?
During an acute heart failure exacerbation
(fluid overload, SOB)
Why do we avoid beta blockers during acute heart failure exacerbations?
-Slow down the heart rate and decrease cardiac output
-Can cause pulmonary edema
If a patient with an acute heart failure exacerbation is already taking a beta blocker, can they continue their maintenance dose?
YES
-better outcomes observed
Why are beta blockers used for ACS?
To prevent future heart attacks and help the patient live longer
(typically used for BP, important to make distinction)
What are the “hold parameters” for beta blockers?
HR < 60 consider, definitely if < 50
BP <90/60
What ejection fraction is considered HFrEF?
39% or less
When are calcium channel blockers used in ACS patients?
Non-DHP given to patients with recurrent ischemia and CONTRAINDICATIONS TO BB
(diltiazem or verapamil)
What patients should Non-DHP CCBs not be used in?
LV dysfunction (HFrEF)**
Increased risk for cardiogenic shock
PR interval >0.24s
2nd or 3rd degree AV block without a cardiac pacemaker
What statins should ACS patients receive?
High intensity
Atorvastatin 40-80mg
Rosuvastatin 20-40mg
True or False: Statins help lower cholesterol but should be taken with ACS even if your cholesterol is normal
True
*lifelong treatment
Which high intensity statin tends to have less problems with muscle pain?
Rosuvastatin
What patients should receive ACE inhibitors?
All ACS patients
*Especially with:
-HFrEF
-DM
-CKD
When should ACEi be started after an ACS?
Use cautiously within first 24 hours
-may cause hypotension or renal dysfunction
*Best to add them after 24 hours due to the large amount of other drugs added during this period
What 4 ACEi and 1 ARB are used in ACS?
Captopril
Lisinopril
Ramipril
Trandolapril
Valsartan (ARB)
When do we not want to use an ACEi?
-Hypotension/shock
-Bilateral renal artery stenosis or history of worsening renal function with ACEi/ARB use
-Acute renal failure
-Drug allergy/angioedema
What needs to be monitored with ACEi?
Serum creatinine
(will increase a bit, >30% is a problem)
Potassium (increases)
BP (decreases)
Angioedema (rare)
If a patient experiences angioedema while on an ACEi, what should be done with their dosing?
STOP the drug, seek medical attention
What medications are included in triple antithrombotic therapy?
Oral anticoagulant
Aspirin
P2Y12 inhibitor
For patients with Afib, how long should they receive triple antithrombotic therapy after ACS?
Discontinue aspirin after 1-4 weeks after PCI
Continue P2Y12i and anticoag (warfarin) for 1 year
After year, restart aspirin
Who should receive nitroglycerin?
All ACS patients
(0.3-0.4 mg SL)
How often do nitroglycerin tablets need to be replaced once opened?
Every 3-6 months
What is an important counseling point for sublingual NTG spray?
It needs to be PRIMED
Nitrolingual: spray first 5 sprays into air
Nitromist: Spray first 10 sprays into air
