- 1. The search for the verylow risk chest pain patient who goes home/who stays in?
2. Chest Pain No one factor can allow safe discharge
- Past Hx: CAD, risk factors
- Initial Biomarkers (troponin)
3. Endpoints for diagnosing ACS
- Done for significant stenosis
- Stenosis can be present without ACS
- Injury biomarkers (e.g., Troponin) cannot detect stenosis
- 40 yo with substernal chest pressure for 3 hours
- No radiation or associated symptoms
- Ongoing, not intermittent
- Cigarette smoker, no other risks
5. Lee Goldman Ann Int Med 2003; 139:987
- The sobering bottom line is that 2 decades of research has taught us that without compelling evidence for a noncardiac cause, there is no absolutely fail-safe way to exclude myocardial ischemia or infarction at the time of a patient's initial presentation. A short period of monitoring and measuring serial biomarker levels in a chest pain evaluation unit is an attractive approach for patients with an uncertain diagnosis.
6. Life threatening causes of Chest Pain
7. Missed MI Pope JH et al.NEJM 2000; 342:1163-1170
- Prospective multicenter studyMay 1993-December 1993
- 8% were proven to have AMI, 7% unstable angina.
- 21% other cardiac etiologies, 55% noncardiac
- 19 (2.1%) of 889 patients with AMI were discharged home ;
- 17 of 19 ECGs no evidence of ischemia, and 2 normal.
- 22 of 966 (2.3%) with unstable angina were mistakenly discharged.In retrospect, none of the 22 patients ECGs showed evidence of ischemia and 2 were normal.
- Non-whites, women, chief complaint of dyspnea, and a normal ECGall correlated with mistaken discharge.
8. Most recent data, with troponin Is the initial diagnostic impression of noncardiac chest pain adequate to exclude cardiac disease? MillerCD, Ann EM December 2004; 44(6):565-574
- 1992 thought to be noncardiac (75% d/ced to home)
- Physicians blinded to trop results, did not use them
- Of 1992, 71 (2.4%) had first trop > 0.6 - 1.0
- Troponin assay is critical.
- Our trop today is a new generation high sensitivity troponin
- Very sensitive, but how much more?
9. Inverse relation between % with a "rule out MI evaluation" and the miss MI rate.Graff: Am J Cardiol, Volume 80(5):563-568, 9/1/1997 10. Use of chest pain centers vs. admission 4.5% MI miss rate 0.4% MI miss rate Graff: Am J Cardiol, Volume 80(5):563-568, 9/1/1997 $124 per patient cost savings 11. Risk factors for complications death, MI, CHF, shock, v fib, v tach
- ST elevation > ST depression > T wave inversion
- Normal has lower risk of complications, even if MI present
- worse than previous angina
Brush JE et al.NEJM 312:1137-1141, 1985.Karlson BW et al.Eur Heart J 15:1558-65, 1994.Yusuf S et al.Eur heart J 5:690-96, 1984. 12. Patients with Acute MI sent home from the ED Multicenter Chest Pain Study Lee TH., et al.Clinical characteristics and natural history of patients with acute myocardial infarction sent home from the emergency room.Am J Cardiol 1987; 60:219-24.
- 2.5% of all patients sent home had MI's-- 26%of these died
- 0.7% (n=9) of chest pain patients who were sent home died
- Avg. EP 65 CP patients home per year
- 6 of 9 deaths were misread ECG's
- 13 of 35 MI's sent home had evidence of acute ischemia
- 5 of 35 were less than 42 years old
13. 39 yo with atypical CP 14. Diagnostic ECG
- ST-T abnormalitiesnot secondary to abnormal depolarization(i.e., abnormal QRS, e.g., LVH)
- ST depression>/= 1 mm in2 consecutive leads(corresponds to a coronary distribution)
- Changed from previous ECG
- T-wave inversion>/= 1 mm in2 consecutive leads
- Changed from previous ECG
15. Normal ECG
- Sinus rhythm with normal p-waves
- ST elevation/depression < 0.5 mm relative to corresponding PR segments.
- No LVH, abnormal Q-waves, or conduction abnormalities(QRS must be < 100 ms)
- Size of T-waves is proportional to R-waves and T-wave axis is close to QRS axis
- Normal R-wave progression
16. Nondiagnostic ECG
- ST-T abnormalities secondary to abnormal depolarization (i.e., abnormal QRS, e.g., LVH)
- Minor, non-dynamic ST or T-wave abnormalities, such as ST depression < 1 mm and T-wave flattening or inversion < 1 mm
- May be changed from previous ECG, but is not specific for ischemia or infarction
17. Sensitivity and specificity of ECG for MI as diagnosed by CK-MB Goldman L; Ann Int Med 2003; 139:987 18. Normal or Nondiagnostic ECG Karlson and Rouan combined data AMI as defined by CK-MB, MI rate will be higher in this age of troponin definition of MI
- Diagnostic ECG 2979 (STEMI or UA/NSTEMI)
- nl ECG & AMI 125 ( 6.4% of AMI , 3.4% of nl ECG, 1.1% of all pts with CP)
- NS ECG & AMI 442 ( 23% of AMI , 9% of NS ECG,3.7% of all pts. with CP )
- NlorNS ECG & AMI 567 ( 29% of all AMI , 6.4% of all nl or NSECG,4.8% of all pts with CP)
19. Diagnostic vs. nondiagnostic (nonspecific) ECG MI Diagnosis by CK-MB (Trop)
- Approx 45% (25%) of AMI has diagnostic STE
- Approx 26% (15%) of AMI has diagnostic ST depression or T-wave inversion
- Approx 23% (50%) of AMI is abnormal but nondiagnostic
- 8-15% some evidence of ischemia or infarction not known to be old
- Approx 6% (10%) of AMI has normal ECG
- Normal with pain vs. without pain
- Chase et al. Acad EM 13:1034, Oct 2006
Welch RD et al.JAMA Oct. 2001;286(16):1977-1984 20. Continuous 12-lead or ST segment monitoring
- Non-diagnostic ECG may turn diagnostic
- Labor and equipment intensive
- Routine use is for high risk patients
- In high risk patients with ongoing symptoms
- Increases sensitivity for STEMI from 46% to 62% (33%) of all MI as measured by CK-MB
- Use serial EKGs every 15 minutes
Fesmire et al. Ann Emerg Med 1998; 31:3-11 21. Atypical Symptoms of MI Canto JG, Shlipak MG, Roger WJ, et al.Prevalence, clinical characteristics, and mortality among patients with myocardial infarction presenting without chest pain.JAMA 2000;283:3223-3229. NRMI data .
- 33% of patients with MI (by CK-MB) present without chest pain
- Other studies confirm this:
- Of MI patients, 42% of those age > 75 years and63%-75% of those age > 85 years donotcomplain of chest pain (CP)
- Up to 30% of MI is silent
22. Characteristic No Chest Pain (33%) Chest Pain (67%) Mean age 74 years 67 years Received reperfusion 25% 74% Adjusted in-hospital mortality 23.3% 9.3% (OR: 2.17-2.26) Women 49% 38% Prior Heart Failure 26% 12% ST elevation on initial ECG 23% 47% LBBB on initial ECG 10% 5.4% Atypical Symptoms(continued--Canto et al.) 23. History Alternans
- Kappa values for historical and physical exa