Acute Coronary Syndrome: Sensitivity and Specificity

Introduction: ACS is distinguished from stable angina by:

* Rest angina, which is usually more than 20 minutes in duration

* New onset angina that markedly limits physical activity

* Increasing angina that is more frequent, longer in duration, or occurs with less exertion than previous angina

ACS is divided into 3 major categories, namely unstable angina (defined by no serum marker elevation), NSTEMI (serum markers but no ST elevations), and STEMI.

STEMI (ST-segment Elevation Myocardial Infarction, aka ST-elevation MI) - Strict ECG definition: New ST elevation at the J-point in two contiguous leads with the cut-off points: >=0.2 mV in men or >=0.15 mV in women in leads V2-V3 and/or >=0.1 mV in other leads, in the absence of LVH and RBBB.

Cardiac Enzymes timecourse (sens/spec data) from Circulation PMID 10190875:

http://circ.ahajournals.org/cgi/content/full/99/13/1671/T2

Cardiac Enzymes timecourse, from UpToDate:

http://www.uptodate.com/online/content/image.do?imageKey=CARD%2F3187

Other clinical findings: JAMA. 2015 Nov 10;314(18):1955-65 PMID: 26547467 (old) JAMA. 1998 Oct 14;280(14):1256-63. PMID: 9786377

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Prevalence

Population / Calculator	Prevalence	Comments / Study / Link
TIMI risk score	12%	http://www.mdcalc.com/uanstemitimiscore http://jama.ama-assn.org/cgi/content/abstract/284/7/835
500	10%
	0%
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The sensitivity and specificity of findings for Acute Coronary Syndrome are listed below. See the left navigation bar to change the display.

Pre-Test Probability (Prevalence): %.	Post-Test Probability (Predictive Value): %.	Switch to display mode.
Note that calculating probabilities from more than one** finding is inherently inaccurate because findings are not independent. (For example, using two positive findings that share a common pathogenesis is likely to overestimate the true probability.)

Sensitive Findings
Finding	Result	Sensitivity	Specificity
[ + ] Trans-Thoracic Echocardiography	+ 0 -	93%	60%
by wall motion abnormalities in this study PPV of WMA was 31% - specificity is low because of old WMAs Study: Circulation. 1991 Sep;84(3 Suppl):I85-92. PMID: 1884510
[ + ] No Chest Wall Tenderness	+ 0 -	91.7%	27.8%
patients presenting to the ED with chest pain, initially normal EKG and no history of unstable angina. Study: Acad Emerg Med. 2002 Mar;9(3):203-8. PMID: 11874776

Negative Findings
Finding	Result	Sensitivity	Specificity
[ + ] Tenderness to Palpation	+ 0 -	5.5%	80%
pain reproduced on palpation Study: JAMA. 2015 Nov 10;314(18):1955-65 PMID: 26547467

Poorly Diagnostic Findings
Finding	Result	Sensitivity	Specificity
[ + ] History of Coronary Artery Disease	+ 0 -	41%	79%
Study: JAMA. 2015 Nov 10;314(18):1955-65 PMID: 26547467

Findings With Unspecified Accuracy
Finding	Result	Sensitivity	Specificity
[ + ] HEART Score		No accuracy specified.
PLR = 13. threshold 7-10 Study: JAMA. 2015 Nov 10;314(18):1955-65 PMID: 26547467

Sensitive and Specific Findings
Finding	Result	Sensitivity	Specificity
[ + ] CK-MB Subforms	+ 0 -	96%	98%
at 10 hours Study: Circulation 1999 Apr 6;99(13):1671-7. PMID 10190875
[ + ] Troponin I	+ 0 -	92.3%	94.6%
at 10 hours Study: Circulation 1999 Apr 6;99(13):1671-7. PMID 10190875
[ + ] Troponin T	+ 0 -	87%	93%
at 10 hours Study: Circulation 1999 Apr 6;99(13):1671-7. PMID 10190875
[ + ] CK-MB Subforms	+ 0 -	91%	89%
within first 6 hours Study: Circulation 1999 Apr 6;99(13):1671-7. PMID 10190875

Specific Findings
Finding	Result	Sensitivity	Specificity
[ + ] Continuous Electrocardiogram	+ 0 -	68%	99%
continuous monitoring of ST segments Study: Ann Emerg Med 1998 Jan;31(1):3-11. PMID 9437335
[ + ] Hypotension	+ 0 -	3.1%	99%
Systolic < 100 mmHg Study: JAMA. 2015 Nov 10;314(18):1955-65 PMID: 26547467
[ + ] Troponin T	+ 0 -	10.5%	98.4%
at 2 hours Study: Circulation 1999 Apr 6;99(13):1671-7. PMID 10190875
[ + ] Tachycardia	+ 0 -	3.2%	98%
heart rate > 120 Study: JAMA. 2015 Nov 10;314(18):1955-65 PMID: 26547467
[ + ] Peripheral Artery Disease	+ 0 -	7.5%	97%
Study: JAMA. 2015 Nov 10;314(18):1955-65 PMID: 26547467
[ + ] Troponin I	+ 0 -	15.8%	96.8%
at 2 hours Study: Circulation 1999 Apr 6;99(13):1671-7. PMID 10190875
[ + ] Sgarbossa Criteria	+ 0 -	37.2%	96.6%
in patients with LBBB, Sgarbossa et al proposed the following ECG criteria for acute MI: ST elevation >= 1mm concordant with QRS ST depression >= 1mm in V1, V2, or V3 ST elevation >= 5mm discordant with QRS In the HERO-2 trial, a positive ECG represented either of the first two criteria, with the last one dropped (previously they had used a scoring system). The numbers above are from HERO-2; note that replication in a community setting gave a sensitivity of only 10% with a specificity of 100%. Study: N Engl J Med. 1996 Feb 22;334(8):481-7. PMID: 8559200 J Am Coll Cardiol. 2005 Jul 5;46(1):29-38. PMID: 15992631 JAMA. 1999 Feb 24;281(8):714-9. PMID: 10052441
[ + ] Troponin T	+ 0 -	61.7%	96.1%
at 6 hours Study: Circulation. 1999 Apr 6;99(13):1671-7. PMID: 10190875
[ + ] Abnormal Prior Stress Test	+ 0 -	12%	96%
Study: JAMA. 2015 Nov 10;314(18):1955-65 PMID: 26547467
[ + ] Pain Radiating to Shoulders or Arms	+ 0 -	11%	96%
radiating to both arms Study: JAMA. 2015 Nov 10;314(18):1955-65 PMID: 26547467 Acad Emerg Med. 2002 Mar;9(3):203-8. PMID: 11874776
[ + ] ST Depression	+ 0 -	25%	95%
Study: JAMA. 2015 Nov 10;314(18):1955-65 PMID: 26547467
[ + ] Tachypnea	+ 0 -	10%	95%
Study: JAMA. 2015 Nov 10;314(18):1955-65 PMID: 26547467
[ + ] Crackles	+ 0 -	9.2%	95%
or rales Study: JAMA. 2015 Nov 10;314(18):1955-65 PMID: 26547467
[ + ] Troponin I	+ 0 -	57.5%	94.3%
at 6 hours Study: Circulation. 1999 Apr 6;99(13):1671-7. PMID: 10190875
[ + ] ECG	+ 0 -	32%	91%
ischemic changes Study: JAMA. 2015 Nov 10;314(18):1955-65 PMID: 26547467 Ann Emerg Med 1998 Jan;31(1):3-11. PMID 9437335
[ + ] CK-MB Subforms	+ 0 -	21.1%	90.5%
at 2 hours Study: Circulation 1999 Apr 6;99(13):1671-7. PMID 10190875
[ + ] Myoglobin	+ 0 -	78%	89%
within first 6 hours Study: Circulation 1999 Apr 6;99(13):1671-7. PMID 10190875
[ + ] Myoglobin	+ 0 -	26.3%	87.3%
at 2 hours Study: Circulation 1999 Apr 6;99(13):1671-7. PMID 10190875
[ + ] T-Wave Inversion	+ 0 -	24%	87%
Study: JAMA. 2015 Nov 10;314(18):1955-65 PMID: 26547467
[ + ] Exertional Chest Pain	+ 0 -	35.3%	85%
patients presenting to the ED with chest pain, initially normal EKG and no history of unstable angina. Study: Acad Emerg Med. 2002 Mar;9(3):203-8. PMID: 11874776