JH IM Board Review - Coronary Artery Disease II Flashcards
ACS includes (3):
- UA.
- NSTEMI.
- STEMI.
All 3 syndromes occur when …
A VULNERABLE PLAQUE RUPTURES.
==> PLT activation and aggregation ==> Intracoronary thrombus.
Definition of UA:
- Angina at rest (>20min).
- New-onset exertional angina of at least class III in severity (ie w/ mild exertion).
- Preexisting angina that has increased in frequency or duration or that is now brought on w/ less exertion than before.
Definition of NSTEMI:
Clinically similar to UA, but distinguished by evidence of myocardial necrosis (ie elevation in serum cardiac enzymes).
ECG does not show ST elevation.
Definition of STEMI:
Elevated cardiac enzymes and ECG criteria that include >1mm ST segment elevation in two or more contiguous limb leads.
Or >2mm ST segment elevation in 2 or more contiguous PRECORDIAL leads.
Of note, a new or presumed new LBBB is …
NO LONGER considered a STEMI equivalent. (2013 ACC/AHA)
==> Must employ other ECG criteria to diagnose MI in these cases.
NSTEMI vs STEMI - ECG:
NSTEMI ==> ST depressions, T inversions, nonspecific ST-T changes.
STEMI ==> ST elevation.
NSTEMI vs STEMI - Vessel at time of catheterization:
NSTEMI ==> 30-40% occluded.
STEMI ==> >80%.
NSTEMI vs STEMI - Type of clot?
NSTEMI ==> Rich in PLTs (white).
STEMI ==> Rich in fibrin (red).
NSTEMI vs STEMI - Extent of disease?
NSTEMI ==> More likely collateral formation and multivessel disease.
STEMI ==> More commonly single vessel.
NSTEMI vs STEMI - Tx:
NSTEMI ==> Thrombolysis NOT recommended — GP IIb/IIIa inhibitors can be useful.
STEMI ==> Thrombolysis beneficial — GP IIb/IIIa inhibitors usually not indicated (unless PCI performed).
NSTEMI vs STEMI - Hospital mortality?
NSTEMI ==> Lower.
STEMI ==> Higher.
NSTEMI vs STEMI - Reinfarction rate?
NSTEMI ==> Higher after d/c.
STEMI ==> Lower after d/c.
NSTEMI vs STEMI - Long-term prognosis?
NSTEMI ==> Higher 1y mortality rate after d/c.
STEMI ==> Lower 1y mortality rate after d/c.
Of note, …-…% of ACSs are clinically silent.
20-30%.
TIMI (thrombolysis in MI) risk score for UA/NSTEMI - RFs:
7
- > 65y.
- 3 or more coronary artery RFs.
- Prior coronary stenosis >50%.
- > 2 anginal events in past 24h.
- Aspirin use in past 7 days.
- ST-segment changes.
- Positive cardiac markers.
Risk of adverse cardiac event by TIMI score:
0-1 ==> 4.7% (Low risk).
2 ==> 8.3% (Low risk).
3 ==> 13.2% (Intermediate risk).
4 ==> 19.9% (Intermediate risk).
5 ==> 26.2% (High risk).
6-7 ==> 41% (High risk).
Calculate GRACE (Global Registry of Acute Coronary Events) 2.0 risk score.
Incorporates (7):
- Age.
- HR.
- SBP.
- Killip class.
- Presence of cardiac arrest.
- ST-segment change.
- Troponins.
The GRACE 2.0 score estimates …
6mo mortality.
Always consider other diagnoses that can mimic ACS (3):
- AD.
- Acute pericarditis.
- PE.
AD - ECG can reveal ST elevations if the …
Dissection involves one or more of the coronary arteries.
typically affect the RCA first
Management of UA/NSTEMI - Medical therapy consists of (6):
- Antiplatelet therapy.
- Antithrombotic therapy.
- Beta blockers.
- Nitrates.
- CCBs.
- Statins.
UA/NSTEMI - Antiplatelet therapy consists of …
- Aspirin.
- Thienopyridines.
- GpIIb/IIIa inhibitors.
UA/NSTEMI - Aspirin leads to more than …% relative reduction in risk of MI and death.
50%.
Should be continued INDEFINITELY.
UA/NSTEMI - Thienopyridines - Clopidogrel:
Reduces adverse cardiac events in pts with UA/NSTEMI when given in addition to aspirin.
==> Continue for at least 12mo if PCI with DES.
==> 1 month if PCI with BMS.
==> 9 mo if NO PCI.
UA/NSTEMI - Prasugrel should be avoided in pts who may be potential candidates for …
CABG.
UA/NSTEMI - Role of GpIIb/IIIa:
Clear benefit demonstrated in both UA and NSTEMI.
==> The greatest benefit is seen in pts who have positive troponins and are treated with PCI.
Abciximab has clear benefit in …
UA/NSTEMI undergoing PCI.
NO BENEFIT in pts with UA/NSTEMI who do NOT require PCI.
Antithrombotic therapy is a/w …
Lower rates of MI and death in pts with ACS.
Enoxaparin compared to UFH in UA/NSTEMI?
Superior to UFH in reducing death, MI, and recurrent ischemic events in pts who are treated CONSERVATIVELY.
==> No difference in pts treated invasively, and also a/w higher rate of bleeding.
Fondaparinux can be used …
Both with conservative strategy and as an invasive strategy in pts with UA/NSTEMI.
==> Preferable to UFH or enoxaparin in pts with increased risk of bleeding.
Direct thrombin inhibitor - Bivalirudin is an option only in pts in whom …
An early invasive approach is planned.
==> If high risk of bleeding exists, then bivalirudin monotherapy can be considered instead of heparin/GpIIb/IIIa inhibition combination.