Unstable Angina And NSTEMI

Question 0

Define unstable angina/angina pectoris

Answer 0

Chronic discomfort with at least one:
1) occurs at rest or with minimal exertion lasting >10mins
2) severe and of new onset within the last 4-6 weeks
And/or
3) occurs with crescendo pattern (more severe, prolonged, frequent)

Question 1

Define stable angina

Answer 1

Chest or arm discomfort, reproducibly associated with physical exertion or stress, relieved in 5-10 mins by rest or sublinguala

Question 2

Define NSTEMI

Answer 2

UA + evidence of myocardial necrosis plus elevated biomarkers

Question 3

4 pathologic processes in ua/nstemi

Answer 3

• plaque rupture or erosion with a superimposed thrombus
• dynamic obstruction like in Prinzmetal’s angina
• progressive mechanical obstruction
• unstable angina secondary to myocardial oxygen demand and/or decreased supply, eg tachycardia or anemia

Question 4

How many ua/nstemi pts present with LMCA stenosis? With 1 vessel dse? With 2 vessel dse?

Answer 4

5%
40%
30%
While 15 percent have three vessel dse

Question 5

Compare thrombi of stemi vs nstemi

Answer 5

Stemi - red, fibrin and cell rich

Nstemi, ua - white/platelet rich

Question 6

PE of ua/nstemi

Answer 6

Can be u/r
If large area of ischemia: 
Diaphoresis
Pale, cool skin
Sinus tachy
3rd/4th heart sound
Hypotension

Question 7

ECG findings of ua/nstemi

Answer 7

St segment depression
Transient st elevation
T-wave inversion
T wave changes are sensitive for ischemia but less specific unless >=0.3mV

Question 8

Risk of death in 1 mo. In ua/nstemi

Risk of recurrent infarction

Risk of recurrent ACS

Answer 8

1-10%
3-5%
5-15%

Question 9

Broadly speaking; anti-ischemic treatment of ua/nstemi

Answer 9

Bed rest, nitrates, beta blockers (use with caution in acute HF[risk of shock] an you can consider CCBs diltiazem or verapamil if contraindicated)
But also start ACEIs and statins eg atorvastatin 80mg

Question 10

How you give nitrates in ua/nstemi

Answer 10

SL or buccal spray if in pain
Switch tO IV if still in pain after 3doses 5 mins apart:
Nitroglycerin 5-10ug/min in nonabsorbable tubing, titrate in increments of 10ug/min every 3-5 mins until relieved or sbp<100

Can shift to oral nitrates if pain free for past 12-24h

Question 11

Only absolute contraindications to nitrates

Answer 11

Hypotension

Use of suldenafil or similar in 24-48h

Question 12

Indication of morphine sulfate in ua/nstemi

Dosing and administration

Answer 12

Pts with ssx not relieved after 3 serial NGL tablets or whose ssx recur with adequate anti-ischemc therapy
Give 2-5mg IV, repeated evey 5-30mins as needed

Question 13

Dose of aspirin recommended in ua/nstemi

Answer 13

325mg/d as initial dose

75-162 for long term

Question 14

Clopidogrel: class and MOA

Answer 14

Thienopyridine

Inactive prodrug whose active metabolite blocks the platelet P2Y12 component of ADP receptor

Question 15

Findings of the CURE Trial re: clopidogrel: ups and downs

Answer 15

In combination with aspirin: 20% less risk of death, MI, stroke
But inc risk of major bleed by 1%

Question 16

Why do some (up to 1/3) of patients have a low response to clopidogrel?

What do you do about it?

Answer 16

Genetic variant of the cytochrome p450 system: variant of 2C19 gene –> reduced conversion of clopidogrel to active metabolite

Consider prasugrel

Question 17

When do you avoid beta blockers in ua/nstemi?

Answer 17

PR interval>0.24s
Second or third degree heart block
Heart rate <90
Shock
LV failure
Severe reactive airways disease

Question 18

When to avoid morphine in ua/nstemi

Answer 18

Hypotenstion, resp depression, confusion, obtundation

Question 19

When not to give CCBs in ua/nstemi

Answer 19

Evidence of LV dysfunction (for diltiazem or verapamil)

Pulmonary edema

Question 20

Discuss positive and negative aspects of prasugrel vs clopidogrel

Answer 20

Advantage: dec CV death, MI, stroke
Decreased risk of stent thrombosis

Disadvantage: inc risk major bleeding

Question 21

Contraindications to prasugrel use

Answer 21

Prior stroke

TIA

Question 22

Reversible ADP inhibitor

Answer 22

Ticagrelor

Dec mortality and cv death without known inc in major bleed

Question 23

Mainstay of anticoagulant tx

Dosing and administration

Answer 23

Unfractionated hep

Bolus 60-70 u/kg, mac 500 u, IV
Infusion 12-15 U/kg/hr
Titrate to ptt 50-70s

Question 24

Advantage of LMWH/enoxaparin vs ufh

Administration

Answer 24

Reduced cardiac events

1mg/kg SC q12, can have 30mg IV loading dose

Question 25

Renal adjustment of lmwh

Answer 25

If crea clearance is less than 30cc/min adjust to half or 1mg/kg OD

Question 26

Mechanism of action of fondaparinux

Answer 26

Indirect factor Xa inhibitor

Equivalent early efficacy with enox but lower bleeding

Question 27

Fondaparinux administratiob

Answer 27

2.5mg SC OD

Question 28

What is early invasive management in ua/nstemi

Answer 28

Coroangio in 48 hours

Then PCI or CABG

Question 29

When do you give early invasive management? (Class I recommendations) (9)

Answer 29

Recurrent angina at rest or low level activity despite tx
Elevated TnT or TnI
New ST depression
Recurrent angina or ischemia with chf sx, rales, MR
Positive stress test
Ef less than 40%
Decreased BP, sustained VT, PCI less than 6mos/prior CABG