Acute Coronary Syndrome: Likelihood Ratios

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

[Edit Diagnosis] [Merge dx] [Add prevalence]

Tags: Cardiac Problem Tag this Diagnosis.

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%
More, Edit...

The likelihood ratios of findings for Acute Coronary Syndrome are listed below. See the left navigation bar to change the display.

Good Positive and Negative Likelihood Ratios

Finding	+LR	-LR	Comments, Study
CK-MB Subforms Duplicate	48	0	at 10 hours Study: Circulation 1999 Apr 6;99(13):1671-7. PMID 10190875
Troponin I Duplicate	17.1	0.1	at 10 hours Study: Circulation 1999 Apr 6;99(13):1671-7. PMID 10190875
Troponin T Duplicate	12.4	0.1	at 10 hours Study: Circulation 1999 Apr 6;99(13):1671-7. PMID 10190875
CK-MB Subforms Duplicate	8.3	0.1	within first 6 hours Study: Circulation 1999 Apr 6;99(13):1671-7. PMID 10190875
Trans-Thoracic Echocardiography	2.3	0.1	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
Myoglobin Duplicate	7.1	0.2	within first 6 hours Study: Circulation 1999 Apr 6;99(13):1671-7. PMID 10190875
Continuous Electrocardiogram	68	0.3	continuous monitoring of ST segments Study: Ann Emerg Med 1998 Jan;31(1):3-11. PMID 9437335
Troponin T Duplicate	15.8	0.4	at 6 hours Study: Circulation. 1999 Apr 6;99(13):1671-7. PMID: 10190875
Troponin I Duplicate	10.1	0.5	at 6 hours Study: Circulation. 1999 Apr 6;99(13):1671-7. PMID: 10190875

Good Negative Likelihood Ratio

No Chest Wall Tenderness

1.3

0.3

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

Good Positive Likelihood Ratio

Finding	+LR	-LR	Comments, Study
Sgarbossa Criteria	10.9	0.7	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 Duplicate	6.6	0.9	at 2 hours Study: Circulation 1999 Apr 6;99(13):1671-7. PMID 10190875
ST Depression	5	0.8	Study: JAMA. 2015 Nov 10;314(18):1955-65 PMID: 26547467
Troponin I Duplicate	4.9	0.9	at 2 hours Study: Circulation 1999 Apr 6;99(13):1671-7. PMID 10190875
ECG	3.6	0.7	ischemic changes Study: JAMA. 2015 Nov 10;314(18):1955-65 PMID: 26547467 Ann Emerg Med 1998 Jan;31(1):3-11. PMID 9437335
Hypotension	3.1	1	Systolic < 100 mmHg Study: JAMA. 2015 Nov 10;314(18):1955-65 PMID: 26547467
Abnormal Prior Stress Test	3	0.9	Study: JAMA. 2015 Nov 10;314(18):1955-65 PMID: 26547467
Pain Radiating to Shoulders or Arms	2.8	0.9	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
Peripheral Artery Disease	2.5	1	Study: JAMA. 2015 Nov 10;314(18):1955-65 PMID: 26547467
Exertional Chest Pain	2.4	0.8	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
CK-MB Subforms Duplicate	2.2	0.9	at 2 hours Study: Circulation 1999 Apr 6;99(13):1671-7. PMID 10190875
Myoglobin Duplicate	2.1	0.8	at 2 hours Study: Circulation 1999 Apr 6;99(13):1671-7. PMID 10190875
History of Coronary Artery Disease	2	0.7	Study: JAMA. 2015 Nov 10;314(18):1955-65 PMID: 26547467
Tachypnea	2	0.9	Study: JAMA. 2015 Nov 10;314(18):1955-65 PMID: 26547467

Negative Findings

Tenderness to Palpation

0.3

1.2

pain reproduced on palpation

Study: JAMA. 2015 Nov 10;314(18):1955-65 PMID: 26547467

Poorly Diagnostic Findings

Finding	+LR	-LR	Comments, Study
Tachycardia	1.6	1	heart rate > 120 Study: JAMA. 2015 Nov 10;314(18):1955-65 PMID: 26547467
Crackles	1.8	1	or rales Study: JAMA. 2015 Nov 10;314(18):1955-65 PMID: 26547467
T-Wave Inversion	1.8	0.9	Study: JAMA. 2015 Nov 10;314(18):1955-65 PMID: 26547467

Findings With Unspecified Accuracy

HEART Score

No accuracy specified.

PLR = 13. threshold 7-10

Study: JAMA. 2015 Nov 10;314(18):1955-65 PMID: 26547467