Acute Coronary Syndrome

David Aymond, MD

ACS

• Definition: Myocardial ischemia typically due to atherosclerotic plaque rupture Coronary thrombosis

• ACS is a spectrum: UA vs NSTEMI vs STEMI-Unstable angina/NSTEMI: angina that is new onset,

crescendo, or at rest; typically <30mns + TWI or ST-depression

*NSTEMI is term used with this history/EKG with slightly elevated Troponin/CK-MB

-STEMI: Angina at rest >30mns with ST elevations and markedly elevated enzymes (2x upper limit of NL)

How to Triage (ACC/AHA 2007 Guidelines update for UA/NSTEMI)

- This is based solely on Pre-test Probability, these the risk of short term death or non fatal MI

Feature High (any) Intermediate (no high features)

Low (no high/inter. Features)

History Chest/arm pain like prior angina; h/o CAD (inc MI); TRS > 3; Age > 75

Chest or L arm painAge>70Male, DM

Atypical Sx

Exam HoTN, diapho, CHF, MR PAD or CVD Pain rep. on palpation

ECG New STD (>1mm), TWI in mult. Leads

Old Qw, STD (.5-.9mm), TWI TWF/TWI (<1m) in dominant leads

Biomarkers + Tn or CK-MB Normal Normal

Triage

• If hx and initial EKG and biomarkers non-dx, repeat ECG and biomarkers 12 h later

• If low likelihood, CE remain NL and remain pain free, have r/o MI; but if clinical suspicion high based on Hx still need to evaluate for UA/inducible ischemia: if pt has no historical/exam that’s IM/High, can do ETT as outPt w/in 72

hrs (0% mortality, .5% MI) (Ann Emerg Med 2006; 47-427)

• If has IM RF’s for ACS based on hx, admit and evaluate • If ECG or biomarker abnl or high likelihood ACS, then admit

and evaluate

Conservative vs Early Invasive Approach

Conservative approach taken if low risk (- Tn, no ST dep, TRS 0-2, and NO CHF); conservative approach means medical Rx with Pre-d/c stress test; angio only if strongly + ETT; this is SOC in Unstable Angina

Early Invasive approach taken if high risk (+TN, ST dep, TRS> 3, s/s CHF); early invasive approach means Med Rx + angiography w/in 24-48 hrs; this is SOC for NSTEMI

Med Rx=EMONACAGB

Medical ManagementEnoxaparin: 1mg/kg BID; 10% dec death/MI (JAMA 2004;292:89); greatest benefit in CONS

strategyMorphine: consider if pulmonary edema or persistent SxOxygen: keep SaO2 >90%Nitrates: dec anginal sx, no dec in mortalityASA: 162-325mg x 1 crushed/chewed; then 75-325/day; 50-70% dec in D/MI (NEJM

1988;319:1105); if ASA allergy, use ClopidogrelCoronary angiography: only if high risk/NSTEMI within 24-48 hrsClopidogrel: give w/ ASA 20% dec. CVD/MI/stroke, inc. benefit if given upstream prior to

PCI, but need to D/C 5 days prior to CABG (NEJM 2001; 345:494; Lancet 2001; 358:257)ACE-I/ARB: esp if CHF and SBP>100Glycoprotein IIb-IIIa inhibitors: only if TRS>3 will benefit be increased (JACC 2003; 41:895)Beta-Blockers: PO, titrate to keep HR 50-60; IV if ongoing pain=13% dec in progression to

MI (JAMA 1988; 260:2259); contraindicated in hypotension, bradycardia and ADHF

TIMI Risk ScoreRISK FACTOR Score Score Total D/MI/UR

Age > 65 1 0-1 5%

> 3 RF for CAD 1 2 8%

Known CAD 1 3 13%

ASA use in past 7 d 1 4 20%

Severe Angina (>2 episodes in 24 hrs)

1 5 26%

ST deviation > 0.5 mm

1 6-7 41%

+ Tn/CK-MB 1

GRACE Risk Score

• GRACE= Global Registry for Acute Coronary Events

• Very large, multi-national randomized trial• When you compare the TIMI, PURSUIT and

GRACE risk score for validation of end points, the GRACE is “more advantageous and easier to use; it can categorize a patients risk of death/MI and can help tailor therapy to match the intensity of the patients ACS”

Algorithm for the evaluation and management of patients suspected of having an ACS.

Braunwald E et al. Circulation 2000;102:1193-1209

Copyright © American Heart Association