ACUTE CORONARY SYNDORME EARLY RISK STRATIFICATION Sarah Jamison March 2003.
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Transcript of ACUTE CORONARY SYNDORME EARLY RISK STRATIFICATION Sarah Jamison March 2003.
ACUTE CORONARY ACUTE CORONARY SYNDORME SYNDORME
EARLYEARLYRISK STRATIFICATIONRISK STRATIFICATION
Sarah JamisonMarch 2003
OverviewOverview
Definition of Acute coronary syndrome (ACS)
Factors used to determine risk stratification– History– Examination– ECG changes– Biochemical cardiac markers
– Initial management
Definitions – Definitions – Acute coronary Acute coronary syndromesyndrome
Any constellation of clinical symptoms that are compatible with acute myocardial ischemia.
It encompasses a spectrum fromAMI NSTEMI UA
NSTEMI – acute process of myocardial ischemia resulting in myocardial necrosis.The initial ECG does not show ST elevation
Definitions – Definitions – Acute coronary Acute coronary syndromesyndrome
UA – an acute process of myocardial ischemia that does not result in myocardial necrosis
Why be concerned re risk Why be concerned re risk stratification………stratification………
1) Are the symptoms a manifestation of ACS
2) Therapy/ site of care will vary dependent on diagnosis
3) To determine prognosis/short term survival
HISTORYHISTORY
History – diagnosing ACSHistory – diagnosing ACS
5 most important factors that relate to the likelihood of ischemia due to CAD…
– 1) Nature of the anginal symptoms– 2)Prior Hx of CAD– 3)Sex– 4)Age– 5)Number of traditional risk factors present
– Beware – women and elderly
History – diagnosing ACSHistory – diagnosing ACS
High – Chest/L) arm pain as chief symptom,similar to previous anginaKnown Hx of CAD (including MI)
Intermediate – Chest/L) arm pain as chief symptomAge>70yrs/Male/Diabetes
Low – Probable ischemic symptoms in absence of any of the intermediate likelihood characteristicsRecent cocaine use
History – short term risk of History – short term risk of death or nonfatal MI in unstable death or nonfatal MI in unstable anginaangina High – Accelerating tempo of ischemic
symptoms in preceding 48hrsPain – Prolonged ongoing (>20min) rest pain
Intermediate – Prior MI, peripheral or CVS/CABG/Aspirin usePain – Prolonged (>20min) rest angina, now resolved, with moderate or high likelihood of CAD.Rest angina (<20min) or relieved with rest or SL NTG
History – short term risk of History – short term risk of death or nonfatal MI in unstable death or nonfatal MI in unstable
anginaangina Low – New onset or progessive angina
(Marked limitiation/or inability to carry out any physical activity) over the past 2/52. Without prolonged (>20min) rest pain but with moderate or high likelihood of CAD
In patients that meet diagnostic criteria for UA/NSTEMI, the recent tempo of ischemic symptoms is the strongest predictor of risk of death
PHYSICAL EXAMINATIONPHYSICAL EXAMINATION
Examination - diagnosing ACSExamination - diagnosing ACS
High – Transient MR, hypotension,diaphoresis, pulmonary oedema
Intermediate – Extracardiac vascular disease
Low – Chest discomfort reproduced by palpation
Examination - short term risk of Examination - short term risk of death or nonfatal MI in UAdeath or nonfatal MI in UA
High – Pulmonary odema, most likely secondary to ischemiaNew or worsening MR murmurS3 or new/worsening creps
Hypotension / Bradycardia / TachycardiaAge > 75yrs
Intermediate – Age >70yrs
Examination - short term risk of Examination - short term risk of death or nonfatal MI in UAdeath or nonfatal MI in UA
Cardiogenic shock occurs in up to 5% of patients with NSTEMI and mortality rates are greater than 60%
THE ECGTHE ECG
ECG - diagnosing ACS ECG - diagnosing ACS
High – New, or presumably new, transient ST- segment deviation ( 0.05 mV) or T-wave inversion ( 0.2mV) with symptoms
Intermediate – Fixed Q waves / Abnormal ST segments or T waves not documented to be new
Low – T wave flattening or inversion in leads with dominant R waves / Normal ECG
ECG - diagnosing ACSECG - diagnosing ACS
A completely normal ECG in a patient with chest pain DOES NOT exclude the possibility of ACS.
- 1-6% of these patients it will be proven that they have had a NSTEMI
- 4% will be diagnosed with unstable angina
ECG - short term risk of death or ECG - short term risk of death or nonfatal MI in unstable anginanonfatal MI in unstable angina
High – Angina at rest with transient ST-segment changes > 0.05mVBundle – branch block, new or presumed newSustained ventricular tachycardia
Intermediate – T wave inversion >0.2mVPathological Q waves
Low – Normal/unchanged ECG during an episode of chest pain
ECG - short term risk of death or ECG - short term risk of death or nonfatal MI in unstable anginanonfatal MI in unstable angina
Risk factors ranked in order for risk of death in patients with ACS– 1) Confounding ECG patterns – bundle branch
pattern,paced rhythm, LV hypertrophy
– 2) ST segment deviation
– 3) Isolated T wave inversion or normal ECG
ECG pattern remains an independent predictor of death, after adjusting for clinical findings and biochemical cardiac markers
Biochemical cardiac Biochemical cardiac markersmarkers
Biochemical cardiac markersBiochemical cardiac markers
Useful in both the diagnosis of myocardial necrosis and estimation of prognosis
Prognosticaly there is a quantitative relationship between the magnitude of elevation of marker levels and the risk of an adverse event
BCM - diagnosing ACSBCM - diagnosing ACS
High – Elevated troponins or CK-MB
Intermediate – Normal
Low - Normal
A- myoglobin/CK-MB isoforms after AMIB – Cardiac Troponin after AMIC - CK-MB after AMID – Cardiac Troponin after UA
BCM - short term risk of death BCM - short term risk of death or nonfatal MI in unstable or nonfatal MI in unstable anginaangina
High – Elevated TnT > 0.1 ng/ml
Intermediate – Slightly elevated TnT (> 0.01 but <0.1 ng/ml)
Low - Normal
BCM – Creatine Kinase (CK-MB)BCM – Creatine Kinase (CK-MB)
Advantages - Rapid, cost- efficient accurate assays. Able to detect early reinfarction
Disadvantages – Loss of specificityLow sensitivity during very early MI (6hr after sxs onset) or later after sxs onset (>36hr) and for minor myocardial damage
BCM – CK-MB isoformsBCM – CK-MB isoforms
Advantages – Early detection of early MI (3-6hrs after onset of sxs)
Disadvantages – Specificity profile similar to that of CK-MBCurrent assays require special expertise (used predominately in research centers)
BCM - MyoglobinBCM - Myoglobin
Advantages – High sensitivityUseful in early detection of MI (2hrs after onset of sxs)Most useful in ruling OUT a MI
Disadvantages - Very low specificity in setting of skeletal muscle injury or diseaseRapid return to normal
Should not be used in isolation
BCM – Cardiac TroponinsBCM – Cardiac Troponins
Advantages - Powerful tool for risk stratification
Greater sensitivity and specificity than CK-MB
Detection of recent onset of MI up to 2 wks after onset
Useful for selection of therapy
BCM – Cardiac TroponinsBCM – Cardiac Troponins
Disadvantages - Low sensitivity in very early phase of MI (< 6hrs after onset of sxs) and requires repeat levels
Limited ability to detect late minor reinfarction
BCM – Other markersBCM – Other markers
CRP – Patients without biochemical evidence of myocardial necrosis but who have an elevated CRP are at an increased risk of an adverse outcome
Other – Elevated levels of interleukin-6, serum amyloid A, have similar predictive value as CRP
Putting it together - Putting it together - managementmanagement
Assign patients with chest pain to 1 of 4 groups– 1) Noncardiac
– 2) Chronic stable angina
– 3) Possible ACS
– 4) Definite ACS
Putting it togetherPutting it together
Most important baseline features assoc with death (Boersma et al)
AgeHeart rateSystolic BPST- segment depressionSigns of heart failureElevation of cardiac markers
Putting it togetherPutting it together
7 point risk score (Antman et al)
Age (>65yrs)More than 3 coronary risk factorsPrior angiographic coronary obstructionST – segment deviationMore than 2 angina events within 24hrsUse of aspirin within 7 daysElevated cardiac markers
ANY QUESTIONSANY QUESTIONS??????????????
SummarySummary
Risk stratification in ACS involves assessment of
HistoryExamination ECGBiochemical cardiac markers
Risk stratification is used in determining management and assessing prognosis
SummarySummary
High risk patients – 1.7% risk of death after 30 days
Intermediate patients – 1.2% risk of death after 30 days
Low risk patients – no death after 30 days