3. Hospitalizations in the U.S. Due to Acute
Coronary Syndromes (ACS)
Acute Coronary
Syndromes*
1.57 Million Hospital Admissions - ACS
UA/NSTEMIā STEMI
1.24 million
Admissions per year
.33 million
Admissions per year
Heart Disease and Stroke Statistics ā 2007 Update. Circulation 2007; 115:69-171.
*Primary and secondary diagnoses. ā About 0.57 million NSTEMI and 0.67 million UA.
4. Acute Coronary Syndrome
Definition:
The spectrum of acute ischemia related syndromes ranging from UA to MI
with or without ST elevation that are secondary to acute plaque rupture or plaque
erosion.
[----UA---------NSTEMI----------STEMI----]
A constellation of symptoms related to obstruction of coronary arteries with
chest pain being the most common symptom in addition to nausea, vomiting,
diaphoresis etc.
5. Signs and symptoms of
ACS presentation
ļ± Symptoms may include:
ā¢ chest discomfort (tightness, pressure, heaviness) at rest or for a prolonged period
(> 10 minutes, not relieved by sublingual nitrates)
ā¢ recurrent chest discomfort
ā¢ discomfort associated with syncope/acute heart failure.
ļ± The pain may spread to other parts of the upper body, including:
ā¢ Back, neck, jaw, arm(s), shoulder(s) or epigastric pain.
ļ± The person may also experience:
ā¢ Dyspnoea (shortness of breath), diaphoresis (profuse perspiration), dizziness,
nausea or vomiting
ā¢ Recent research shows that women, the elderly and people with diabetes are
less likely to experience chest pain as a symptom.
6.
7. Anginal equivalent syndrome
ā¢ Patients who are experiencing ACS, yet do not complain of typical chest
pain; rather, these patients note atypical pain, dyspnea, weakness,
diaphoresis, or emesisāthese complaints, in fact, are the manifestation of
the ACS event.
ā¢ Patients with altered cardiac pain perception e.g., the elderly or patients
with longstanding diabetes mellitus, are potentially at risk to present with
anginal equivalent syndromes.
ā¢ The most frequently encountered anginal equivalent chief complaint is
dyspnea, which is found in 10% to 30% of patients with AMI, often due to
pulmonary edema.
8. CHARACTERISTICS OF
TYPICAL ANGINAL CHEST PAIN
CHARACTERISTIC SUGGESTIVE OF ANGINA LESS SUGGESTIVE OF
ANGINA
TYPE OF PAIN DULL PRESSURE/CRUSHING
PAIN
SHARP/STABBING
DURATION 2-5 MIN, <20 MIN SECONDSTO
HOURS/CONTINUOUS
ONSET GRADUAL RAPID
LOCATION/CHEST WALL
TENDERNESS
SUBSTERNAL, NOT TENDER
TO PALP.
LATERAL CHEST
WALL/TENDER TO PALP.
REPRODUCIBALITY WITH EXERTION/ACTIVITY WITH BREATHING/MOVING
AUTONOMIC SYMPTOMS PRESENT USUALLY ABSENT
9. ā¢ STEMI: ST elevation, elevated cardiac enzymes
ā¢ NSTEMI: ST depression, T-wave inversion, elevated cardiac enzymes
ā¢ Unstable Angina: Non specific EKG changes, normal cardiac enzymes
Based on ECG and cardiac enzymes, ACS is classified into:
14. Unstable
Angina STEMINSTEMI
Non occlusive thrombus
Non specific ECG
Normal cardiac
enzymes
Non-occlusive thrombus
sufficient to cause
tissue damage & mild
myocardial necrosis
ST depression +/-
T wave inversion on
ECG
Elevated cardiac
enzymes
Complete thrombus
occlusion
ST elevations on ECG
or new LBBB
Elevated cardiac
enzymes
More severe symptoms
16. Gender Differences in MI
Females, when compared to males:
-present with MI later in life
-have poorer prognosis and high morbidity
-are 2x as likely to die in the first weeks
-are more likely to die from the first MI
-have higher rates of unrecognized MI
17. At least 2 of the following
ā¢ History ( angina or angina equivalent)
ā¢ Acute ischemic ECG changes
ā¢ Typical rise and fall of cardiac markers
ā¢ Absence of another identifiable etiology
Diagnosis of ACS
18. Diagnosis
Diagnosis requires a rise and/or fall in serum levels of cardiac markers
(preferably troponin) together with:
ļ¼ Defined clinically by patient history
ļ¼ ECG (new ST-T wave changes, new left bundle branch block or evolving
pathological Q waves)
ļ¼ Imaging evidence of new regional wall motion abnormality.
19. STEMI
ā¢ Compromised left ventricular (LV) function may result in pulmonary
edema with development of pulmonary bibasilar crackles and jugular
venous distention; a fourth heart sound can be present with small
infarcts or even mild ischemia, but a third heart sound is usually
indicative of more extensive damage. Pericardial rub may be heard.
20. ā¢ An ST-segment elevation myocardial infarction (STEMI) can be confirmed by an
ECG.
ā¢ A 12-lead ECG should be performed and interpreted expeditiously.
ā¢ STEMI is defined as presentation with clinical symptoms consistent with an ACS
with ECG features including any of:
ļ¼ Persistent ST-segment elevation ā„ 1 mm in two contiguous limb leads
ļ¼ ST-segment elevation ā„ 2 mm in two contiguous chest leads
ļ¼ New left bundle branch block (LBBB) pattern.
STEMI ā what is it?
23. Serum cardiac markers
IDEAL MARKER:
ā¢ High concentration in
myocardium
ā¢ Myocardium specific
ā¢ Released early in injury
ā¢ Proportionate to injury
ā¢ Non expensive testing
24. Advantages
Myoglobin
1. High sensitivity
2. Useful in early detection of MI
3. Detection of reperfusion
4. Most useful in ruling out MI
CK-MB
1. Rapid, cost-efficient, accurate
assays
2. Ability to detect early
reinfarction
Troponins
1. Powerful for stratification
2. Greater sensitivity and specificity
than CK-MB
3. Detection of recent MI up to 2
weeks after onset
4. Useful for selection of therapy
5. Detection of reperfusion
25. Diadvantages
CK-MB
1. Lack of specificity with skeletal
muscle disease/injury
2. Low sensitivity during early MI
(<6 h) or late (>36 h) after
symptom onset and for minor
myocardial damage
Myoglobin
1. Very low specificity with
skeletal muscle injury or disease
2. Rapid return to normal
Troponins
1. Low sensitivity in early phase of
MI (<6 h after symptom onset)
2. Limited ability to detect late minor
re-infarction
26.
27. ā¢ Cardiac Imaging
ļ¼ 2D ECHO may reveal wall motion abnormality and LV dysfunction. It may
also detect RV infarction, Ventricular aneurysms, pericardial effusion
and LV Thrombus.
ļ¼ Myocardial perfusion imaging with TI201 and Tc99m - sestamibi reveals
defect in most patient.
28. Time from symptom onset and likely outcome
< 1 hour
Aborted heart attack or only little heart muscle damage
1ā2 hours
Minor heart muscle damage only
2ā4 hours
Some heart muscle damage with moderate heart muscle salvage
4ā6 hours
Significant heart muscle damage with only minor heart muscle salvage
6ā12 hours
No heart muscle salvage (permanent loss) with potential infarct
healing benefit
> 12 hours
Reperfusion is not routinely recommended if the patient is
asymptomatic and haemodynamically stable
29. Therapy STEMI
ā¢ Once STEMI is suspected or diagnosed, the immediate concerns are to
ensure the patients stability and to intervene to limit infarct size by
restoring the blood flow to the infarct artery as soon as possible.
ā¢ Abolute and relative contraindication to therapies must be considered and
relative risk assessed. Choices may be limited for the availability of
specialized procedures, need to transport to another facility, significant co-
morbidities, bleeding risk,etc.
30. Early Therapy
ā¢ Patients presenting with suspected myocardial ischemia should undergo a rapid
evaluation, that is a 12 lead ECG, cardiac markers and related laboratory tests.
ā¢ Should be treated with oxygen
ā¢ Sublingual Nitroglycerin (unless systolic pressure is <90 mm Hg), and Aspirin, 160
to 325 mg orally.
ā¢ Opiates relieve pain and also reduce anxiety, the salutary effects of which have
been known for decades and should not be underestimated.
31. Fibrinolytic therapy
ā¢ Early reperfusion of an occluded coronary artery is indicated for all
eligible candidates.
ā¢ Fibrinolytic agents administered early in the course of an acute MI
reduce infarct size, preserve LV function, and reduce short-term and
long-term mortality.
ā¢ Multiple studies conclude that greatest mortality benefit is seen if
fibrinolytics are administered within the first 12 hours of symptom
onset, but it is reasonable to administer fibrinolytics to patients
whose onset of symptoms exceeds 12 hours but who have continued
clinical or ECG evidence of ischemia.
33. ā¢ After administration of fibrinolytics for
STEMI, the patient should be monitored
for signs and symptoms of adequate
reperfusion within 90 minutes, as
indicated by relief of symptoms and/or
hemodynamic/ electrical instability
coupled with at least a 50% resolution of
the highest initial ST elevation.
ā¢ Patients who receive fibrinolytics for
STEMI and have at least one high-risk
feature should have cardiac
catheterization for risk stratification and
potential percutaneous revascularization,
even if this involves immediate transfer
from the presenting hospital to a PCI-
capable facility.
High-risk features include
ā¢ Extensive ST-segment elevation (>2 mm
ST elevation in two anterior leads),
ā¢ New-onset LBBB,
ā¢ Previous MI,
ā¢ Killip class 2 or 3 or Left ventricular
ejection fraction (LVEF) ā¤ 35%,
ā¢ Systolic blood pressure ā¤ 100 mm Hg,
ā¢ Heart rate ā„ 100 bpm, or
ā¢ Right ventricular involvement.
34. Fibrinolytic agents Used in ST elevation MI
Streptokinase 1.5 million intravenous over 30-60 mins
Alteplase (tPA) a 15-mg bolus, then 0.75 mg/kg (up to 50 mg) IV over the initial 30
minutes, and 0.5 mg/kg (up to 35 mg) over the next 60 minutes
Reteplase (rPA) two 10-U boluses 30 minutes apart
Tenecteplase (TNK-tPA) IV Bolus adjusted for weight
(30mg if < 60 kg; 35mg if 60-70 kg; 40 mg if 70-80 kg, 45mg if 80-90
kg; 50mg if > 90 kg)
35. Reperfusion Therapy
ā¢ It includes angioplasty, with or without deployment of an intracoronary Bare-
metal or Drug-eluting stent, with support of pharmacological measures to
prevent thrombosis.
i. Percutaneous coronary intervention
ā¢ Recent meta-analyses comparing direct PTCA with fibrinolytic therapy have
suggested lower rates of mortality and re-infarction among those receiving
direct PTCA. Thus direct angioplasty, if performed in a timely manner (ideally
within 60 minutes) by highly experienced personnel, may be the preferred
method of revascularization, since it offers more complete revascularization with
improved restoration of normal coronary blood flow and detailed information
about coronary anatomy.
36. There are certain subpopulations in which primary PCI is clearly preferred, and other
populations in which the data are suggestive of benefit.
37. Coronary Stents
ā¢ The use of coronary stents has been shown to reduce restenosis and adverse cardiac
outcomes in both routine and high-risk PCI.
ā¢ A large, randomized, multicenter trial involving 900 patients did not show a difference
in mortality at 6 months but did show improvement in ischemia driven target vessel
revascularization and less angina in the stented patients compared to balloon
angioplasty alone.
ā¢ Whether to use a bare metal stent or a drug-eluting stent in acute MI is a question that
has not yet been addressed definitively by clinical trials; selection is currently based on
both patient and angiographic characteristics.
38. ā¢ Early recognition and diagnosis of STEMI are key to achieving the
desired door-to-needle (or medical contactāto-needle) time for
initiation of fibrinolytic therapy of 30 minutes or door-to-balloon (or
medical contactāto balloon) time for PCI under 90 minutes.
ā¢ Achieving reperfusion in timely matter correlates with improvement
in ultimate infarct size, LV function, and survival.
ā¢ The ultimate goal is to restore adequate blood flow through the
infarct-related artery to the infarct zone, as well as to limit
microvascular damage and reperfusion injury.
ā¢ The latter is accomplished with adjunctive and ancillary treatments.
39.
40. Adjunctive therapy
1. Aspirin:
ā¢ Reduce mortality in acute infarction to the same degree as fibrinolytic
therapy, and its effects are additive to fibrinolytics. In addition, aspirin
reduces the risk of reinfarction.
ā¢ Unless contraindicated, all patients with a suspected ACS (STEMI,
NSTEMI, UA) should be given aspirin as soon as possible.
2. Thienopyridines:
ā¢ Clopidagrel
ā¢ Prasugrel
Patients presenting with MI should be considered
for a thienopyridine regardless of whether or not
they underwent reperfusion therapy. The duration
of thienopyridine use in this population has yet to
be defined.
41. 3. Anticoagulants:
Administration of full-dose heparin
after fibrinolytic therapy with tPA is
essential to diminish re-occlusion
after successful reperfusion.
4. Glycoprotein llb/IIIa Receptor
antagonist:
Role in STEMI uncertain. Not
routinely recommended.
42.
43. 5. Nitrates:
ā¢ They reduce myocardial oxygen demand by decreasing preload and
afterload, and they may also improve myocardial oxygen supply by
increasing sub-endocardial perfusion and collateral blood flow to the
ischemic region.
ā¢ Also reduce platelet aggregation.
ā¢ Nitrates are first-line agents for the symptomatic relief of angina
pectoris and when MI is complicated by congestive heart failure.
44. 6. Ī² Blockers:
ā¢ Routine use of intravenous beta-blockers in the absence of systemic
hypertension is no longer recommended.
ā¢ Relative contraindications to oral beta-blockers include,
ļ¼ heart rate less than 60 bpm,
ļ¼ systolic arterial pressure less than 100 mm Hg,
ļ¼ moderate or severe LV failure,
ļ¼ signs of peripheral hypoperfusion,
ļ¼ shock,
ļ¼ PR interval greater than 0.24 second, second- or third-degree AV
block,
ļ¼ active asthma, or
ļ¼ reactive airway disease.
45. 7. ACE inhibitors
ā¢ Improve hemodynamic, functional capacity and symptoms, and
survival in patients with chronic congestive heart failure. Moreover,
ACE inhibitors prevent the development of congestive heart failure in
patients with asymptomatic LV dysfunction
8. Lipid Lowering agents
ā¢ All patients with ACS should be started on a statin prior to discharge
unless there is a contraindication
9. Calcium channel blockers
ā¢ May be useful for patients whose postinfarction course is
complicated by recurrent angina, because these agents not only
reduce myocardial oxygen demand but also inhibit coronary
vasoconstriction.
47. NTSEMI and Unstable angina
ā¢ Non-ST-elevation MI (NSTEMI) applies to patients with suspected MI in the
absence of other plausible causes of troponin elevation (e.g. sepsis,
pulmonary embolus).
ā¢ On physical examination, patients with NSTEMI may have a ānormalā ECG
reading, or show minor changes (occurs in up to 50% of patients).
ā¢ All patients with NSTEMI should have their risk stratified to direct
management decisions.
ā¢ The management of patients with NSTEACS requires evolving risk
stratification:
Clinical assessment, assessment of Cardiac biomarkers and Time.
48. ECG Changes
NSTEMI:
ā¢ ST depressions (0.5 mm at least) or T wave inversions ( 1.0 mm at
least) without Q waves in 2 contiguous leads with prominent R
wave or R/S ratio >1.
ā¢ Isolated T wave inversions:
ā¢ can correlate with increased risk for MI
ā¢ may represent Wellenās syndrome:
ā¢ critical LAD stenosis
ā¢ >2mm inversions in anterior precordial leads
Unstable Angina:
ā¢ May present with nonspecific or transient ST segment depressions
or elevations
50. Evolving Risk Stratification
ā¢ Provides prognostic information
ā¢ Determines treatment and level of
intervention
Low risk patients ---> early discharge,
High risk ---> admission to high care
ā¢ Helps decongest the casualty and make
available medical resources to more
needy patients.
ā¢ Risk stratification should be ongoing ā at
admission, 6-8 hrs, 24hrs, discharge
51. Evolving risk stratificationā¦
Admit to coronary care unit or high
dependency unit:
ā¢ Estimate ischemic risk,
estimate bleeding risk, choose
augmented antithrombotic
therapy
ā refer for angiography to
determine surgery/PCI, or
medical therapy.
53. Evolving risk stratificationā¦
Intermediate-risk NSTEACS
Recurrent ischemia or elevated troponin?
YES
ā¢ admit to CCU or high dependency unit:
ļ§ estimate ischemic risk, estimate
bleeding risk, choose augmented
antithrombotic therapy
ārefer for angiography to determine
surgery/PCI, or medical therapy.
NO
ā¢ undertake stress test (e.g. exercise ECG):
āpositive ā refer for angiography to determine
surgery/PCI, or medical therapy
ānegative ā proceed to discharge patient with
urgent cardiac follow-up (on upgraded medical
therapy) according to long-term management
after control of myocardial ischemia.
54. Evolving risk stratificationā¦
Appropriate period of
observation. Consider if
stress test (e.g. exercise
ECG) needed?
Stress test (e.g. exercise ECG)
using treadmill.
YES
Proceed to discharge patient with urgent
cardiac follow-up (on upgraded medical
therapy) according to long-term
management after control of myocardial
ischemia.
NO
55. ā¢ Age ā„ 65 years =1 point
ā¢ At least 3 risk factors for CAD =1 point
ā¢ Prior coronary stenosis of ā„ 50% =1 point
ā¢ ST-segment deviation on ECG presentation =1 point
ā¢ At least 2 anginal events in prior 24 hours =1 point
ā¢ Use of aspirin in prior 7 days =1 point
ā¢ Elevated serum cardiac biomarkers =1 point
Variables Used in the TIMI Risk Score
57. GRACE Risk Score
Variable Odds ratio
Older age 1.7 per 10 y
Killip class 2.0 per class
Systolic BP 1.4 per 20 mm Hg ā
ST-segment deviation 2.4
Cardiac arrest during presentation 4.3
Serum creatinine level 1.2 per 1-mg/dL ā
Positive initial cardiac biomarkers 1.6
Heart rate 1.3 per 30-beat/min
ā
58. Management
ā¢ It Includes increasing myocardial oxygen demand delivery by improving
perfusion and decreasing myocardial oxygen demand.
ā¢ Reversing myocardial ischemia and confirming the diagnosis of ACS is
essential priority.
ā¢ Oxygen should be administered to patients with dyspnea, hypoxemia or
evidence of heart failure or shock.
ā¢ If precipitating reversible causes such as fever, anemia, hypoxemia,
infection, hypertension, anxiety, hyperthyroidism, arrhythmias or any drug
ingestion (eg cocaine, ephedrine) can be identified, they should be treated
aggressively.
ā¢ Further management includes relief of pain and anti- ischemic therepy,
therepy for platelet aggregation/thrombosis, ongoing risk stratification
and consideration of invasive reperfusion procedures.
60. 2. Antiplatelet therapy
ā¢ The current guidelines recommend a loading dose of 300 to 600mg
of clopidogrel in patients of UA/NSTEMI, followed by 75 mg daily.
The duration of clopidogrel may depend upon whether or not the
patient has received stent.
3. Anti thrombin therapy
Recommendation
Low risk : Aspirin + Anticoagulant + either a glycoprotein IIb/IIIa inhibitor or a
thienopyridine
High Risk: Aspirin + Anticoagulant + a glycoprotein IIb/IIIa inhibitor + a
thienopyridine
61. Interventional Management
In patients with High Risk, following treatment with anti-ischemic and
antithrombotic agents, coronary arteriography is carried out within ~ 48 h of
admission, followed by coronary revascularization (PCI or coronary artery
bypass grafting), depending on the coronary anatomy.
In low-risk patients, the outcomes from an
invasive strategy are similar to those
obtained from a conservative strategy,
which consists of anti-ischemic and
antithrombotic therapy followed by
āwatchful waiting,ā and in which coronary
arteriography is carried out only if rest pain
or ST-segment changes recur or there is
evidence of ischemia on a stress test.