Definizione e RidefinizioneDefinizione e Ridefinizione

dell’Infarto Miocardico Acutodell’Infarto Miocardico Acuto

U.O. Cardiologia – Azienda Ospedaliera S.M. Misericordia - Udine

Antonio Di ChiaraAntonio Di Chiara

CORSI LEARNING CENTER ANMCO – Firenze, 1 ottobre 2001CORSI LEARNING CENTER ANMCO – Firenze, 1 ottobre 2001

INFARTO MIOCARDICO RIDEFINITOINFARTO MIOCARDICO RIDEFINITO

DEFINIRE UNA MALATTIADEFINIRE UNA MALATTIA

• Una definizione clinica poggia su 2 parametri– diagnosi reale gold standard anatomo-patologico

– metodo clinico pratico diagnostico, sensibile e specifico

• Cura dei pazienti– Diagnosi

– Terapia

– Prognosi

• Classificare le malattie– Studio/ricerca

– Epidemiologia

Definizione Anatomo PatologicaDefinizione Anatomo Patologica

• L’infarto miocardico è

caratterizzato da

morte cellulare dovuta

a ischemia prolungata,

che si manifesta con

necrosi coagulativa o a

bande di contrazione

DEFINIZIONE “CLASSICA” di INFARTO MIOCARDICODEFINIZIONE “CLASSICA” di INFARTO MIOCARDICOWorld Health Organization. Nomenclature and criteria for diagnosis of World Health Organization. Nomenclature and criteria for diagnosis of

ischemich heart disease. Circulation 1979:59:607ischemich heart disease. Circulation 1979:59:607

Criteri per definire un Infarto Miocardico Acuto(almeno due dei seguenti)

1. Storia di dolore toracico tipico per ischemia miocardica

2. Modificazioni evolutive tipiche all’ECG3. Aumento e discesa dei marcatori biochimici di

danno miocardico

a. Le alterazioni ECG tipiche (ST e onde Q) compaiono in metà dei casi

b. Un terzo dei pazienti ha sintomi atipicic. I marcatori di danno miocardico non erano specifici

CRITERI CLINICI DI DEFINIZIONECRITERI CLINICI DI DEFINIZIONEDI INFARTO MIOCARDICODI INFARTO MIOCARDICO

ECG

Clinica

Biochimici

Imaging– eco2D– scintigrafia

E’ SUFFICIENTE UNA SOLA DEFINIZIONE ?E’ SUFFICIENTE UNA SOLA DEFINIZIONE ?

Definizione di Infarto & Trial Clinici-EpidemiologiciDefinizione di Infarto & Trial Clinici-Epidemiologici

0 1 2 3 4 5 6Time (months)

0

4

8

12

16

20

% P

atie

nts

CONS

INV

19.4%

15.9%

Primary EndpointPrimary Endpoint

Death, MI,Death, MI, RehospRehosp for ACS at 6 Monthsfor ACS at 6 Months

0 1 2 3 4 5 6Time (months)

0

4

8

12

16

20

% P

atie

nts

CONS

INV

19.4%

15.9%

Primary EndpointPrimary Endpoint

Death, MI,Death, MI, RehospRehosp for ACS at 6 Monthsfor ACS at 6 Months

Definizioni & Evidence Based MedicineDefinizioni & Evidence Based Medicine

1° Endpoint• Death

• Re-hosp for ACS

• MI

“natural”

CK-mb>3% CK

CK>2 X u.n.l.

“PCI”

CK/CKmb> X 3 u.n.l.

new Qwave (>30 ms)

“CABG”

CK/CKmb> 5 X u.n.l.

new Qwave (>30 ms)Cannon CP et al. Am J Cardiol 1998; 82:731-6Cannon CP et al. Am J Cardiol 1998; 82:731-6

Troponina ITroponina ITroponina TTroponina T

““This consensus conference proposed the This consensus conference proposed the

concept that any amount of myocardial concept that any amount of myocardial

necrosis caused by ischemia should be necrosis caused by ischemia should be

labeled as an infarct”labeled as an infarct”

Le troponine sono marcatori di danno Le troponine sono marcatori di danno

(necrosi) miocardico dotati della più alta (necrosi) miocardico dotati della più alta

sensibilità e specificità. Forniscono quindi sensibilità e specificità. Forniscono quindi

un test diagnostico ideale.un test diagnostico ideale.

INFARTO MIOCARDICO RIDEFINITOINFARTO MIOCARDICO RIDEFINITOA Consensus Document of The Joint European Society of A Consensus Document of The Joint European Society of

Cardiology/American College of Cardiology. Cardiology/American College of Cardiology. ((Eur Heart J 2000; 21: 1502 - Eur Heart J 2000; 21: 1502 - JACC JACC Vol. 36, No. 3, 2000:959)Vol. 36, No. 3, 2000:959)

Criteria for acute, evolving or recent MI1. Typical rise and gradual fall (troponin) or more rapid rise and fall

(CK-MB) of biochemical markers of myocardial necrosis with at least one of the following:

1. ischemic symptoms;2. development of pathologic Q waves on the ECG; 3. ECG changes indicative of ischemia (ST segment elevation or

depression); 4. coronary artery intervention (e.g., coronary angioplasty).

2. Pathologic findings of an acute MI.

Criteria for established MI1. Development of new pathologic Q waves on serial ECGs. The

patient may or may not remember previous symptoms. Biochemical markers of myocardial necrosis may have normalized, depending on the length of time that has passed since the infarct developed.

2. Pathologic findings of a healed or healing MI.

Biochemical indicators for detecting myocardial necrosis

• Maximal concentration of troponin T or I exceeding the decision limit (99th percentile of the values for a reference control group) on at least one occasion during the first 24 h after the index clinical event

• Maximal value of CK-MB (preferably CK-MB mass) exceeding the 99th percentile of the values for a reference control group on two successive samples, or maximal value exceeding twice the upper limit of normal for the specific institution on one occasion during the first hours after the index clinical event. Values for CK-MB should rise and fall; values that remain elevated without change are almost never due to MI.

• In the absence of availability of a troponin or CK-MB assay, total CK (greater than two times the upper reference limit) or the B fraction of CK may be employed, but these last two biomarkers are considerably less satisfactory than CK-MB.

INFARTO MIOCARDICO RIDEFINITOINFARTO MIOCARDICO RIDEFINITOA Consensus Document of The Joint European Society of A Consensus Document of The Joint European Society of

Cardiology/American College of Cardiology. Cardiology/American College of Cardiology. ((Eur Heart J 2000; 21: 1502 - Eur Heart J 2000; 21: 1502 - JACC JACC Vol. 36, No. 3, 2000:959)Vol. 36, No. 3, 2000:959)

ECG Changes Indicative of Myocardial Ischemia That May Progress to MI

1. Patients with ST segment elevation:New or presumed new ST segment elevation at the J point in two or more contiguous leads with the cut-off points >0.2 mV in leads V1, V2 or V3 and > 0.1mV in other leads (contiguity in the frontal plane is defined by the lead sequence aVl, I, inverted aVr, II, aVf, III).

2. Patients without ST segment elevation:ST segment depression (in two cont. leads)T wave abnormalities only (>1mm, in two cont. leads)

ECG Changes in Established MIAny Q wave in leads V1 through V3, Q wave > 30 ms in

leads I, II, aVl, Avf, V4, V5 or V6. The Q wave changes must be present in any two contiguous leads, and be > to 1 mm depth.

INFARTO MIOCARDICO RIDEFINITOINFARTO MIOCARDICO RIDEFINITOA Consensus Document of The Joint European Society of A Consensus Document of The Joint European Society of

Cardiology/American College of Cardiology. Cardiology/American College of Cardiology. ((Eur Heart J 2000; 21: 1502 - Eur Heart J 2000; 21: 1502 - JACC JACC Vol. 36, No. 3, 2000:959)Vol. 36, No. 3, 2000:959)

• Various assays for these marker proteins are available, and the diversity of such assays has led to substantial confusion, much of which should be solved by standardization.

• The term myocardial infarction should be used when there is evidence of cardiac damage, as detected by marker proteins in a clinical setting consistent with myocardial ischemia.

• Patients who undergo interventional procedures and cardiac surgery have large numbers of elevations because of the procedures themselves. Classification of elevations, their significance, and the care of patients that results should be individualized to these groups.

Circulation. 2000;102:1216-1220

• …measurable blood troponin ‘blip’ should automatically attract the label of ‘myocardial infarction’. A vociferous minority…. argued against the proposal. It has immense consequences for potential public misunderstanding…...

• Interventional cardiologists and cardiac surgeons will not be pleased to have to tell postoperative patients with a trivial rise in troponins that they had a myocardial infarction. Epidemiologist preferred the term ‘myocardial injury’ for events involving only minor damage.

• …it is not comprehensive for living cases and it virtually ignores fatal ones

• …suitable for recruiting survivors for clinical trials, unusable for general use

• Patients who arrive in hospital 24 or 48 h after the onset of their infarct will still have an elevated troponin level that remains abnormal for 3–14 days

• Patients with infarction who are first seen many days, weeks, or months after their infarction can still meet the diagnosis for ‘established infarction’.

• The patient who dies shortly after arriving in CCU represents a problem,…this is true today and will remain true in the future.

• .. the ‘new’ definition of myocardial infarction was already being widely used before our meeting in Nice took place.

• … further work in this area that will undoubtedly result in revisions to the currently recommended definition.

Eur Heart J, Vol. 22, issue 7, April 2001Eur Heart J, Vol. 22, issue 7, April 2001