ACS- Calibrating your Dispo-Meter

ACS- CALIBRATING YOUR DISPO-METER

1) What is the risk of ACS in young patients presenting to the ED with Chest Pain?

Marsan R et al. “Evaluation of a clinical decision rule for young adults pts w/CP” Acad Emerg Med. Jan 2005.
Prospective, observational study of 1023 pts age 24-39 with CP (Excl cocaine CP)

Outcome – ACS (AMI/Unstable angina) at 30d

- Overall risk = 5.4%
- No cardiac Hx + No RFs (HTN, hyperchol, Tobacco, FHx) = 1.8%
- No cardiac Hx + No RFs + nl ECG = 1.0%
- No cardiac Hx + No RFs + nl ECG + 1 set normal enzymes = 0.14%
- No cardiac Hx + nl ECG + pos Rfs (ie smoker) = 1.3%
- (note = “normal EKG” is true normal; ie, no t-wave inversions etc. )




2) What % of pts with negative inpt evaluation for CP have ACS w/in 1 year?


Prina L et al. “Outcome of pts with a final dx of CP of undetermined origin admitted under the suspicion of ACS” Annals of EM. Jan 2004.


Retrospective chart review of 230 pts with DC dx of CP unknown origin
- 79% had ETT, Stress ECHO, MIBI or cath
- Overall 1 year rate of ACS = 4.4% (10 pts)
o Those with testing = 3.3%
o Those without testing = 8.2%
- Risk greatest in those with pre-existing CAD

- CONCLUSION - Pts with preexisting CAD/RFs should be considered at risk for adverse coronary events, even after a recently negative study


3) Do conventional cardiac RFs (DM, HTN, smoking, hypercholesterolemia, family hx of CAD) help identify those pts with ACS who present to the ED?


Han J et al. “The Role of Cardiac RF Burden in diagnosing ACS in the Emergency Department Setting” Annals of EM. Feb 2007.
Post-hoc analysis of itrACS registry (10,806 ED visits for suspected ACS)
Excludes + cocaine/amphetamine, left AMA, incomplete records.

- LIKELIHOOD RATIOS (by age group):


- CONCLUSIONS: Cardiac RFs have little role in diagnosing ACS in ED setting, especially in older patients (may have some limited utility in patients < 40)





4) How much does a clearcut alternative non-cardiac cause of chest pain lessen the probability of ACS?


Hollander J, Chase M et al. “Relaionship between a clear-cut alternative noncardiac diagnosis and 30-day outcome in ED pts with chest pain” Acad Emerg Med. March 2007.


Prospective cohort study of 1995 pts >30 with CP in urban, tertiary ED
Collected demographic/clinical data and whether MD (residents) thought clear cut alternative Dx after ED evaluation
Outcomes: Death, MI, revascularization within 30days
- Those with clear-cut alternative still had 4% event rate at 30d (LR(-) 0.45)


- CONCLUSIONS – Clear-cut alternative Dx reduces likelihood of ACS, but not to level safe enough to allow discharge from ED.




5) What are the presenting symptoms of pts diagnose with ACS who didn’t complain of chest pain?


Breiger D L et al. “ACS without chest pain, an underdiagnoses and undertreated high-risk group; insights from the global registry of acute coronary events. Chest. Aug 2004.


Multinational prospective observational study of 1763 pts w/o ACS, >18, admitted for ACS
- Most common presentations w/o chest pain:
o Dyspnea = 49.3%
o Diaphoresis = 25.2%
o Nausea/vomitting = 24.3%
o Syncope = 19.1%
- These pts generally older, women, or had hx HTN, DM or heart failure.



6) Which pts with new onset Afib should have further evaluation for ACS?


Zimetbaum P et al. “Incidence and predictors of MI among pts w/Afib” JACC. Oct 2000..

Prospective cohort study of 255 pts presenting to ED w/ primary Dx of AF
- 190 admitted, 109 (57%) had a standard r/o MI protocol
- Incidence of MI = 5.5% (6 pts)
- Predictors of MI




(Major ST segement change = >2mm depression or any ST elevation
- Note – small #MIs lead to large confidence intervals