Acute Coronary Syndrome Main Page
ST Elevation Myocardial Infarction Microchapters
Home
Patient Information
Overview
Pathophysiology
Pathophysiology of Vessel Occlusion
Pathophysiology of Reperfusion
Gross Pathology
Histopathology
Causes
Differentiating ST elevation myocardial infarction from other Diseases
Epidemiology and Demographics
Risk Factors
Triggers
Natural History and Complications
Risk Stratification and Prognosis
Pregnancy
Diagnosis
Diagnostic Criteria
History and Symptoms
Physical Examination
Laboratory Findings
Electrocardiogram
EKG Examples
Chest X Ray
Cardiac MRI
Echocardiography
Coronary Angiography
Treatment
Pre-Hospital Care
Initial Care Oxygen Nitrates Analgesics Aspirin Beta Blockers Antithrombins The coronary care unit The step down unit STEMI and Out-of-Hospital Cardiac Arrest Pharmacologic Reperfusion Reperfusion Therapy (Overview of Fibrinolysis and Primary PCI) Fibrinolysis Reperfusion at a Non–PCI-Capable Hospital:Recommendations Mechanical Reperfusion The importance of reducing Door-to-Balloon times Primary PCI Adjunctive and Rescue PCI Rescue PCI Facilitated PCI Adjunctive PCI CABG Management of Patients Who Were Not Reperfused Assessing Success of Reperfusion Antithrombin Therapy Antithrombin therapy Unfractionated heparin Low Molecular Weight Heparinoid Therapy Direct Thrombin Inhibitor Therapy Factor Xa Inhibition DVT prophylaxis Long term anticoagulation Antiplatelet Agents Aspirin Thienopyridine Therapy Glycoprotein IIbIIIa Inhibition Other Initial Therapy Inhibition of the Renin-Angiotensin-Aldosterone System Magnesium Therapy Glucose Control Calcium Channel Blocker Therapy Lipid Management
Pre-Discharge Care
Recommendations for Perioperative Management–Timing of Elective Noncardiac Surgery in Patients Treated With PCI and DAPT
Post Hospitalization Plan of Care
Long-Term Medical Therapy and Secondary Prevention Overview Inhibition of the Renin-Angiotensin-Aldosterone System Cardiac Rehabilitation Pacemaker Implantation Long Term Anticoagulation Implantable Cardioverter Defibrillator ICD implantation within 40 days of myocardial infarction ICD within 90 days of revascularization
Case Studies
Case #1
Case #2
Case #3
Case #4
Case #5
ST elevation myocardial infarction risk stratification and prognosis On the Web
Most recent articles
Most cited articles
Review articles
CME Programs
Powerpoint slides
Images
Ongoing Trials at Clinical Trials.gov
US National Guidelines Clearinghouse
NICE Guidance
FDA on ST elevation myocardial infarction risk stratification and prognosis
CDC on ST elevation myocardial infarction risk stratification and prognosis
ST elevation myocardial infarction risk stratification and prognosis in the news
Blogs on ST elevation myocardial infarction risk stratification and prognosis
Directions to Hospitals Treating ST elevation myocardial infarction
Risk calculators and risk factors for ST elevation myocardial infarction risk stratification and prognosis

Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]

Overview[edit | edit source]

Five variables explain 90% of the prognosis in STEMI: Advanced age,sinus tachycardia, reduced systolic blood pressure, heart failure or Killip class of two or greater, and anterior myocardial infarction location. Two main risk-stratification scores are used when assessing a patient with ST elevation MI and acute coronary syndromes; the TIMI Risk Score (for STEMI), and the GRACE risk score (for acute coronary syndrome.

Prognosis[edit | edit source]

Factors Associated with a Poor Prognosis in STEMI[edit | edit source]

While we as physicians often labor under the impression that we can dramatically change a patient's prognosis, it is noteworthy that 90% of the predictive information regarding 30 day mortality is contained in the following 5 baseline variables that can be modified to only a limited degree: ^[1]

1. Advanced age
2. Sinus tachycardia
3. Reduced systolic blood pressure
4. Heart failure or Killip class of two or greater
5. Anterior myocardial infarction location

Sinus tachycardia, hypotension, Killip class, and anterior MI are all essentially markers of poor pump function on admission. These risk factors for 30 day mortality have been well validated in a multivariate analysis of 41,020 patients in the GUSTO-I trial. Advanced age was the most significant factor associated with higher 30-day mortality. The rate was only 1.1% in the youngest decile (< 45 years) and climbed to 20.5% in patients > 75 (adjusted chi 2 = 717, P < .0001). Other variables most closely associated with an increased risk of mortality were lower systolic blood pressure at randomization (chi 2 = 550, P < .0001), higher Killip class (chi 2 = 350, P < .0001), elevated heart rate (chi 2 = 275, P < .0001), and the presence of an anterior infarction (chi 2 = 143, P < .0001). When taken together, these five baseline characteristics contained 90% of the prognostic information. Other significant though less important factors included previous myocardial infarction, height, time to treatment, diabetes, weight, smoking status, type of thrombolytic, previous bypass surgery, hypertension, and prior cerebrovascular disease. When these variables were combined, a validated model was created which stratified patients according to their mortality risk and accurately estimated the likelihood of death.

Other Prognostic Variables not Identified in GUSTO I[edit | edit source]

Other risk factors include, serum creatinine concentration ^[2], and peripheral vascular disease.^[3][4]

Left Ventricular Function as a Risk Stratifier[edit | edit source]

Assessment of left ventricular ejection fraction may increase the predictive power of some risk stratification models.^[5] The prognostic importance of Q-waves is debated.^[6] Prognosis is significantly worsened if a mechanical complication (papillary muscle rupture, myocardial free wall rupture, and so on) were to occur.

There is evidence that case fatality of myocardial infarction has been improving over the years in all ethnicities.^[7]

The Smokers Paradox[edit | edit source]

Interestingly, although tobacco abuse is a risk factor for CAD and STEMI, smoking is associated with a lower risk of mortality among patients who present with STEMI ^[8][9] This is due, at least in part, to the finding that smokers who present with STEMI are, on average, at least a decade younger than non-smokers. Smokers more often have involvement of the right coronary artery rather than the left anterior descending artery as well. Smokers paradoxically have better myocardial perfusion following reperfusion therapy than non smokers ^[10].

The TIMI Risk Score[edit | edit source]

The Thrombolysis in Myocardial Infarction TIMI Risk Score ^[11] and TIMI Risk Index ^[12] are two prognostic indices that have been validated in clinical trials and epidemiologic studies to predict 30-day mortality among patients with STEMI.

The TIMI risk score for STEMI was created from simple arithmetic sum of independent predictors of mortality weighted according to the adjusted odds ratios from logistic regression analysis. The risk score was derived from 14,114 patients enrolled in the Intravenous nPA for Treatment of Infarcting Myocardium Early II trial (TIME II). The TIMI risk score was subsequently validated in an unselected heterogeneous community population through the National Registry of Myocardial Infarction (NRMI) 3 & 4. The TIMI Risk Score incorporates eight clinical variables (age, systolic blood pressure [SBP], heart rate [HR], Killip class, anterior ST elevation or left bundle branch block on electrocardiogram, diabetes mellitus, history of hypertension or angina, low weight and time to treatment >4 hours) and assigns them a point value based on their odds ratio for mortality.

The TIMI Risk Score was developed and validated in clinical trials of fibrinolytic therapy, but it has also been reported to be prognostic in community-based real-world registries ^[13] as well as elderly patients ^[14]. The TIMI risk score for TIMI is calculated by adding the numbers assigned to the different criteria shown below. The total possible score is 14.^[11]

Risk Factor	Points
Demographic data and medical history
Age ≥75 years	3
Age 65–74 years	2
History of diabetes mellitus or hypertension or angina	1
Physical examination
Systolic blood pressure <100	3
Heart rate >100	2
Killip class II–IV	2
Weight <67 kg	1
Evaluation at presentation
Anterior ST elevation or left bundle branch block	1
Time to therapy >4 hours	1

Interpretation of TIMI Risk Score for STEMI[edit | edit source]

Score	30 Day Mortality (%)[11]
0	0.8%
1	1.6%
2	2.2%
3	4.4%
4	7.3%
5	12.4%
6	16.1%
7	23.4%
8	26.8%
>8	35.9%

The TIMI Risk Index incorporates age, HR and SBP (HR x [age/10] x 2/SBP), and has been validated in unselected patients ^[15], registries ^[16] and population-based cohorts ^[17]

GRACE Risk Score[edit | edit source]

• The Global Registry of Acute Coronary Events (GRACE) risk score for ACS:
  • The GRACE risk score was created from a multivariable logistic regression model using ACS patients enrolled in the GRACE registry (N=11389).
  • The GRACE risk score was validated using subsequent cohort of patients enrolled in GRACE (n=3972) and the Global Use of Strategies to Open Occluded Coronary Arteries IIb (GUSTO-IIb) trial (n=12142).

Calculation of Grace Risk Score for In-Hospital Mortality[edit | edit source]

The total GRACE risk score is calculated by adding the points assigned to the different variable shown below. The highest total possible score 363.^[18]

Variable	Points
Age (years)
<30	0
30–39	8
40–49	25
50–59	41
60–69	58
70–79	75
80–89	91
≥90	100
Heart rate (beats/minute)
<50	0
50–69	3
70–89	9
90–109	15
110–149	24
150–199	38
≥200	46
Systolic blood pressure (mmHg)
<80	58
80–99	53
100–119	43
120–139	34
140–159	24
160–199	10
≥200	0
Initial serum creatinine (mg/dL)
0.0–0.39	1
0.4–0.79	4
0.8–1.19	7
1.2–1.59	10
1.6–1.99	13
0.2–3.99	21
≥4	28
Killip class
I	0
II	20
III	39
IV	59
Cardiac arrest at admission	39
Elevated cardiac markers	14
ST segment deviation	28

Interpretation of Grace Risk Score for In-Hospital Mortality[edit | edit source]

A nomogram for the probability in-hospital mortality has been developed based on the GRACE score. Shown below is the probability of in-hospital mortality by the corresponding GRACE score value.^[18]

Score	Probability of in-hospital mortality (%)
≤60	≤0.2%
70	0.3%
80	0.4%
90	0.6%
100	0.8%
110	1.1%
120	1.6%
130	2.1%
140	2.9%
150	3.9%
160	5.4%
170	7.3%
180	9.8%
190	13%
200	18%
210	23%
220	29%
230	36%
240	44%
≥250	≥52%

Grace Risk Score for All-Cause Mortality From Discharge to 6 Months[edit | edit source]

Calculation of the GRACE Score for All-Cause Mortality From Discharge to 6 Months[edit | edit source]

The total GRACE risk score is calculated by adding the points assigned to the different variable shown below.^[19] The highest total possible score 263.

Variable	Points
Age (years)
<40	0
40–49	18
50–59	36
60–69	55
70–79	73
80–89	91
≥90	100
Heart rate (beats/minute)
≤49.9	0
50–69.9	3
70–89.9	9
90–109.9	14
110–149.9	23
150–199.9	35
≥200	43
Systolic blood pressure (mmHg)
<80	24
80–99.9	22
100–119.9	18
120–139.9	14
140–159.9	10
160–199.9	4
≥200	0
Initial serum creatinine (mg/dL)
0.0–0.39	1
0.4–0.79	3
0.8–1.19	5
1.2–1.59	7
1.6–1.99	9
0.2–3.99	15
≥4	20
History of congestive heart failure	24
History of myocardial infarction	12
Elevated cardiac markers	15
ST segment depression	11
No in-hospital PCI	14

References[edit | edit source]

Template:WikiDoc Sources