Acute Coronary Syndromes¶

Anna Berry

Background¶

Completely or partially occluding thrombus on a disrupted atherothrombotic coronary plaque leading to myocardial ischemia/infarction
STEMI: Elevated troponin & elevation in ST segment or new LBBB with symptoms
- > 0.1 mV in at least 2 contiguous leads
- Exception, in V2-V3:
- > 0.2 mV in men older than 40 y/o
- > 0.25 in men younger than 40 y/o
- > 0.15 mV in women
NSTEMI: Evidence of myocardial necrosis (elevated troponin) w/o ST segment elevation
Unstable Angina: Angina without evidence of myocardial necrosis (normal troponin)
Other causes of myocardial injury: coronary spasm, embolism, imbalance of oxygen demand and supply 2/2 fever, tachycardia, hypo-/hypertension

Classic Angina: dyspnea on exertion, substernal, pressure or vice-like quality, improved with rest. Note that response nitroglycerin is no longer in the guidelines.
Anginal Equivalents: nausea, weakness, epigastric pain (esp. in age > 65 y/o, women, diabetics)
Change in patient’s baseline angina, especially onset at rest
Physical Exam: sinus tachycardia, diaphoresis
If large infarct, can present with symptoms of acute heart failure

EKG: Compare to prior EKG and assess for
- New ST elevations or ST depressions
- T wave inversions: not specific but more concerning if deep (> 0.3mV)
- Biphasic T waves and deep T wave inversions in leads V2 & V3 (Wellens' sign [LAD])
Cardiac biomarkers: troponin I is most sensitive for myocardial injury
ACC/AHA guidelines recommend both EKG and trop q2-6 hours
- Consider this if high suspicion for ACS despite normal initial markers
- If negative x2, OK to stop trending
Other labs: lipid panel, TSH, A1C

Medical management followed by left-heart catheterization within 48 hours
General: bedrest, telemetry, repeat EKG with recurrent chest pain, NPO at midnight
Place cath case request (see “pre-catheterization” management below)

Antiplatelet agents

ASA 325 mg loading dose then 81 mg daily after
Do not give P2Y12 receptor blocker until discussed with cardiology fellow
Clopidogrel: prodrug that is metabolized to active form (can have undermetabolizers), irreversible inhibition
Ticagrelor: reversible inhibitor
Prasugrel: prodrug but more rapidly metabolized than clopidogrel with less variation, irreversible inhibition, do not use w/ age > 75 or weight \< 60 kg
Prasugrel and ticagrelor are superior to clopidogrel but have higher bleeding risk
Cangrelor: IV, rarely used

Anti-coagulants

Unfractionated heparin drip
Type this in Epic and select “nursing managed” protocol for “ACS”
VA: it can be found under the “Orders” tab along the left-hand column.
Enoxaparin (LMWH) can be used but requires preserved renal function (CrCl > 30) and most interventionalists prefer heparin prior to LHC

Ensure pt. is NPO at MN for planned cath
Continue anticoagulation with heparin gtt
Place cardiac catheterization request (must be in cardiology context). Can also call cath lab to ensure pt. is scheduled appropriately

The most appropriate guidance for post-cath care is in the cardiac catheterization report
VUMC: Epic Cardiac tab Cardiac Catheterization/Intervention Report
VA: Note tab Post-Procedure note and Cardiac Catheterization note
If there is a delay in filing the final report at VUMC: Review the Cardiac Catheterization Nursing Documentation which shows if stents were deployed

Medical management w/o intervention: stop heparin unless directed in report
If indication for CABG (ex: Left main, proximal LAD), continue heparin gtt until surgery
PCI placed: stop heparin and continue/start DAPT as directed by cardiology
Other medical indication for anticoagulation (DVT/PE, atrial fibrillation): restart ~ six hours after catheterization

6 - 8 hours post catheterization (typically can be signed out as 0000 cath check), only needed for femoral arterial access
Look, listen, feel: evaluate for hematoma & pseudoaneurysm; call fellow if concerned
Small amount of bruising and mild tenderness at the site is normal
Listen above and below the site for a bruit; the area should be soft
Hypotension after femoral access is concerning for RP bleed
- STAT CBC, CT A/P & call the cardiology fellow
Femoral oozing: Cardiology fellow, will need to hold pressure
Radial oozing: instruct nurse to re-inflate the TR band and restart the clock on deflation

Echo prior to discharge
DAPT: Aspirin 81 mg daily and P2Y12 agent
Beta blocker in all patients within 24 hours
Metoprolol, carvedilol & bisoprolol have proven mortality benefit with reduced EF
High intensity statin (ex: rosuvastatin 40 or atorvastatin 80). See outpatient lipids section
ACEi/ARB if anterior STEMI
Lifestyle Modification: weight loss, smoking cessation, diabetes control
See heart failure section for management of HFrEF

VT/VF, sinus bradycardia, third-degree heart block, new VSD, LV perforation, acute mitral regurgitation, pericarditis and cardiogenic shock; More common with STEMI CCU post-cath

Initiate treatment if there is true concern for ACS and bleeding risk acceptable, medications can always be discontinued
TIMI score: >2 correlates with ↑ mortality, indicating a need for aggressive treatment
ACC Guideline Clinical App is a useful resource with summaries of guideline-based recs

Last update: 2022-05-29 04:25:01