19 - NSTEMI Flashcards
(35 cards)
1
Q
Risk factors for ACS
A
- Atherosclerosis
- Same risk factors as in other manifestations of ASCVD
2
Q
Acute coronary syndrome (ACS)
A
- Spectrum of conditions involving abrupt reduction in coronary perfusion, usually due to thrombus formation secondary to unstable atherosclerotic plaque
- Divided into non-ST elevation acute coronary syndrome (NSTE ACS) & ST-elevation MI (STEMI)
- NSTE ACS further divided into unstable angina & non-ST elevation MI (NSTEMI)
3
Q
Difference in ECG between NSTE ACS and STEMI
A
- NSTE ACE = lack of ST-segment elevation (may have ST depression and/or T-wave inversion)
- STEMI = ST-segment elevation in 2 or more contiguous ECG leads or new left bundle branch block (LBBB)
4
Q
Difference in biomarkers between NSTE ACS and STEMI
A
- NSTE ACS = troponin elevated in NSTEMI, no in unstable angina
- STEMI = troponin elevated
5
Q
Difference in physiology between NSTE ACS and STEMI
A
- NSTE ACS = partial occlusion of larger artery or total occlusion of small artery
- STEMI = total or near-total occlusion of larger artery
6
Q
Difference in ischemia between NSTE ACS and STEMI
A
- NSTE ACS = partial-thickness myocardial ischemia w/ (NSTEMI) or w/o (UA) infarction
- STEMI = full-thickness MI
7
Q
Difference in incidence between NSTE ACS and STEMI
A
- NSTE ACS = approx. 2/3 of ACS
- STEMI = approx. 1/3 ACS
8
Q
Difference in ECG between unstable angina and NSTEMI
A
Both have presence or absence of markers of ischemia (ST depression or T-wave inversion)
9
Q
Difference in biomarkers between unstable angina and NSTEMI
A
- Unstable angina = no significant troponin increase
- NSTEMI = troponin increased
10
Q
Difference in physiology between unstable angina and NSTEMI
A
Both have partial occlusion of larger artery or total occlusion of small artery
11
Q
Difference in ischemia between unstable angina and NSTEMI
A
- Unstable angina = ischemia but not infarction (yet)
- NSTEMI = ischemia w/ infarction
12
Q
Difference in incidence between unstable angina and NSTEMI
A
- Unstable angina = minority
- NSTEMI = majority
13
Q
ECG features of NSTE ACS
A
- ST-segment depression
- T-wave inversion
- Non-specific changes may be present; may be normal
14
Q
How is NSTE ACS diagnosed?
A
- Symptomatic presentation similar to angina sx, although pain/discomfort unremitting (> 20 min) & may be more severe
- Px more likely to lack classic sx = elderly, diabetics, female, renal failure, & dementia
- 12-lead ECG (completed & read w/in 10 min); ST-depression and/or inverted T-waves
- Troponin measured 2x (perhaps more)
15
Q
Goals of therapy for NSTE ACS
A
- Increase myocardial O2 supply (prevent thrombus progression)
- Decrease myocardial O2 demand
- Overall goal = minimize myocardial necrosis
16
Q
Initial tx for acute management of NSTE ACS
A
- ASA + P2Y12 inhibitor (clopidogrel, ticagrelor)
- Anticoagulant (fondaparinux subcut, enoxaparin subcut, UFH infusion)
- Nitroglycerin subling prn
- O2 if O2 sat < 90%
- Morphine or fentanyl prn for severe pain
17
Q
Antiplatelet therapy for initial tx of NSTE ACS
A
- ASA 160-325 mg once (chew & swallow, non-EC) then 81 mg daily
- P2Y12 inhibitor
- Clopidogrel 300-600 mg once (give 600 mg if urgent angiogram required), then 75 mg daily
- Ticagrelor 180 mg once, then 90 mg BID
- Prasugrel rarely used b/c dramatically increases surgical bleeding risk for 7 days after giving it
18
Q
Anticoagulant therapy for initial tx of NSTE ACS
A
- Fondaparinux 2.5 mg subcut q24h if CrCl > 30 mL/min; avoid if weight > 120 kg
- Enoxaparin 1 mg/kg subcut q12h if CrCl > 30 mL/min; avoid if weight > 150-160 kg
- Unfractionated heparin (UFH) IV; preferred if CrCl < 30 mL/min or weight > 150-160 kg
19
Q
Other agents for initial tx of NSTE ACS
A
- Nitroglycerin (0.4 mg spray or 0.3 mg tab subling q5min prn chest pain/discomfort) if SBP > 90 mmHg
- Morphine or fentanyl IV prn (only if needed; never use NSAIDs or COX-2 inhibitors)
- BZDs may be given to mitigate anxiety
20
Q
Describe PCI for acute management of NSTE ACS
A
- Percutaneous coronary intervention (PCI)
- Allows for:
- Confirmation of diagnosis or to rule out a coronary origin
- Identification of culprit lesion(s)
- Assessment for PCI or CABG
- Stratify px short- & long-term risk
- If angiography identifies a culprit lesion & anatomy is amenable to PCI, one or more intracoronary stent(s) are placed
- 2 types of stents:
- Bare metal (more likely to have restenosis; require shorter minimum duration DAPT)
- Drug-eluting (DES) *most common (impregnated w/ antiproliferative drug to minimize restenosis; require longer minimum duration DAPT)
21
Q
Describe CABG for acute management of NSTE ACS
A
- If anatomy is not amenable to PCI, coronary artery bypass grafting may be considered (approx. 10% of NSTE ACS may require urgent CABG)
- 3 types of grafts:
- Internal mammary (usually left internal mammary); most reliable, usually grafted to LAD
- Saphenous vein
- Radial artery
- P2Y12 inhibitor should be held prior to CABG if possible (clopidogrel x 5 days; ticagrelor x 5 days; prasugrel x 7 days)
- Anticoagulants should be managed as follows pre-CABG if possible
- UFH – continue uninterrupted
- Enoxaparin or fondaparinux – last dose 24 h pre-op
- CABG should be performed w/o delay in px w/ hemodynamic instability, ongoing MI, or very high-risk coronary anatomy, regardless of antiplatelet or anticoagulant tx
22
Q
In-hospital goals of therapy for NSTE ACS
A
- Prevent recurrent ischemia
- Prevent cardiac arrhythmias, heart failure/cardiogenic shock, & other complications
- Initiate therapies for secondary prevention
23
Q
In-hospital strategies for management of NSTE ACS
A
- Antithrombotics (antiplatelets & anticoagulants) part of initial tx
- Beta-blocker & statin (may be part of initial tx)
- ACE inhibitor or ARB
- Rapid acting nitroglycerin (part of initial tx)
- Maybe MRA
24
Q
Antiplatelet therapy for in-hospital tx of NSTE ACS
A
- DAPT regardless of tx approach (PCI, CABG, or medical management)
- ASA 81 mg for maintenance dose & ticagrelor may be preferred P2Y12 inhibitor
- ASA + (clopidogrel or ticagrelor) are acceptable choices for medical management
- PPI indicated in combination w/ DAPT in px at risk of GI bleeds (history of GI ulcer/hemorrhage, anticoagulant therapy, chronic NSAID/corticosteroid use)
25
Anticoagulant therapy for in-hospital tx of NSTE ACS
- Anticoagulants d/c after revascularization
- For medical management:
- - UFH continued for 48 h to 7 days
- - Enoxaparin & fondaparinux continued for up to 8 days or hospital discharge
- Following d/c of full anticoagulation, initiate VTE prophylaxis & continue until discharge
26
Beta-blocker therapy for in-hospital tx of NSTE ACS
- Reduce early post-ACS mortality (reduce risk of ventricular arrhythmias)
- Recommended w/in 24 h of hospital admission for NSTE ACS in the absence of CIs or risk factors for cardiogenic shock (age > 70, HR > 110 beats/min, SBP < 120 mmHg)
- - Avoid early beta-blockers in above px if LV function poor or unknown
- Preference for beta 1-selective agents (bisoprolol, metoprolol); carvedilol may also be used if LVEF = 40% or less
27
Statin therapy for in-hospital tx of NSTE ACS
- Indicated in all px w/ CAD
- Should be initiated early in hospital course (may be part of initial therapy)
- High-potency preferred, regardless of LDL-C
- Weeks to months to achieve significant benefit
28
ACE inhibitor/ ARB therapy for in-hospital tx of NSTE ACS
- ACE inhibitors strongly recommended in px w/
- - LV systolic dysfunction (LVEF = 40% or less, hypertension, diabetes mellitus, chronic kidney disease)
- ARB recommend in px intolerant of ACE inhibitors (ex: cough)
- RAAS inhibition also used in absence of indications listed above for secondary prevention
- Caution for acute kidney injury, hyperkalemia, hypotension
29
Nitroglycerin therapy for in-hospital tx of NSTE ACS
- Rapid acting sublingual nitroglycerin may be used to treat intermittent ischemic pain in hospitalized NSTE ACS px
- - *Doesn’t change outcomes
- - Px w/ unresolving or recurrent ischemic pain require urgent revascularization
- IV infusion may allow for some delay until a pt is able to undergo revascularization if needed – still doesn’t change outcomes
30
Mineralocorticoid receptor antagonist (MRA) therapy for in-hospital tx of NSTE ACS
- Recommended in px w/ LV dysfunction (LVEF = 40% or less) & symptomatic heart failure or diabetes
- - Eplerenone was agent studied for this indication; spironolactone likely has similar benefit
- Benefit long-term
31
Which medications should be given at discharge from hospital after an NSTE ACS?
All px should receive (unless CI) (Mnemonic AABCC – ASA, ACE/ARB, beta-blocker, cholesterol, clopidogrel or alternative)
- Antiplatelets (DAPT)
- Beta-blocker
- Statin
- ACE inhibitor/ARB
- Rapid-acting nitroglycerin
32
Goals of long-term therapy for secondary prevention of NSTE ACS
- Prevent harmful myocardial remodeling
- Stabilize existing atherosclerotic plaque & impair growth of new plaque
- Decrease risk of recurrent ASCVD events including ACS
- Decrease long-term morbidity & mortality
33
Which medications are used for secondary prevention of NSTE ACS?
Same medications as given as discharge
- DAPT continued preferably for 1 year regardless of tx approach; life-long ASA 81 mg daily continued following DAPT
- Ezetimibe = optional add-on in high-risk px willing/able to take
34
Non-pharms for long-term therapy after NSTE ACS
- Cardiac rehab
- Smoking cessation
- Diet, exercise
35
Post-discharge LVEF assessment
Px w/ pre-discharge LVEF = 40% or less should have repeat ECG 6-12 weeks after MI, & after complete revascularization & optimal medical therapy
