Mauritius Medical Association

Percutaneous Coronary Interventions (PCI) In Acute Coronary Thrombosis

June 2008 Dr U.S RAMJUTUN, Consultant Cardiologist, Victoria Hospital

Anterior heart showing coronary vessels

Right Coronary Artery Posterior Interventricular Aorta Left Main Coronary Artery Left Circumflex Branch Left Anterior Descending Marginal Branch

Inferior AMI II, III, AVF

Location of infarctions

Septal AMI V1, V2 Anterior AMI V3, V4 Lateral AMI V5, V6 - ( I, AVL )

Acute Myocardial Infarction

(Wavefront phenomenon) Occlusive thrombus on a plaque of atheroma 15 minutes 2 hours 6 hours % necrosis 0% 50% 90%

Wavefront phenomenon of ischaemic cell death

15 Minutes 40 Minutes 3 Hours Nonischaemic Ischaemic (viable) Necrotic >6 Hours

Acute Coronary Syndrome Initiating Events

1 Plaque rupture 2 Thrombus formation 3 Vasoconstriction

Lipid pool

Plaque Rupture

Lipid-rich plaque Fissure Plaque disruption Occlusive thrombus Acute MI, Q-wave Subocclusive thrombus Unstable angina/ Non-Q-wave MI

Thrombus Formation

Platelet Adhesion

Thrombus Formation

Platelet Aggregation

Thrombus Formation

Fibrin Threads

Acute Coronary Syndrome

SUDDEN DEATH Unstable Angina Coronary Arterial Thrombosis Non-Q-Wave Myocardial Infarction SUDDEN DEATH Q-Wave Myocardial Infarction SUDDEN DEATH

Acute Coronary Syndrome ( ACS )

History

NSTE ACS STE ACS

ECG Unstable angina Non Q wave MI Q wave MI Outcome

ECG changes indicative of an AMI.

Evolving

myocardial infarction has been established as: Patients with ST segment elevation, i.e. new ST segment elevation at the J point with the cut off points  0.2mV in V1 through V3 and  0.1mV in other leads or New LBBB

Established

myocardial infarction may be defined by: • Q wave in leads V1 through V3, OR • Q wave  0.03s in leads I, II , aVL, aVF, V4, V5, or V6.

Evolution of an acute

myocardial

infarction

A.

Onset B.

15 Minutes C.

> 1 Hour D.

> 24 Hours E.

Days Later F.

Months later

Elevation of cardiac markers

7x upper limit of normal Total CK 6x 5x 4x 3x 2x 1x 0 20 Troponin I CK-MB 40 60 80 100 120 140 Hours from onset of infarction 160

Management of Patients with ST Elevation

Eligible for thrombolysis Thrombolyse ST elevation



12 h Aspirin+Clopidogrel Beta-blocker etc.

> 12 h Thrombolysis contraindicated Not a candidate for reperfusion therapy Persistent symptoms ?

Primary PTCA or CABG Other medical therapy: ACE inhibitors ? Nitrates Anticoagulants No Yes Consider Reperfusion Therapy

Thrombolysis

• Perhaps the most significant advances in the early treatment of acute myocardial infarction (AMI) in the last decade are reperfusion therapy (thrombolysis) and angioplasty.

• Many clinical trials have established early thrombolytic therapy as a recommended treatment for patients with ST-segment elevation or new Left Bundle Branch Block. • Although thrombolysis is not without risk, the benefits, in terms of lives saved, far outweigh these risks.

80

Benefits for Early Diagnosis and Thrombolytic Treatment

40 20 0-1 hrs 1-2 hrs 37/1000 Absolute 35-day Mortality Reduction Versus Treatment Delay Per 1000 Patients Treated 2-3 hrs 29/1000 3-6 hrs 26/1000 6-12 hrs 18/1000 12-24 hrs 9/1000 0 0 3 6 9 12 15 18 21 24 Treatment delay (h)

Contraindications and Cautions for Fibrinolysis in STEMI

Absolute Contraindications • Any prior intracranial hemorrhage • Known structural cerebral vascular lesion (e.g., arteriovenous malformation) • Known malignant intracranial neoplasm (primary or metastatic) • Ischemic stroke within 3 months EXCEPT acute ischemic stroke within 3 hours NOTE: Age restriction for fibrinolysis has been removed compared with prior guidelines.

Contraindications and Cautions for Fibrinolysis in STEMI

Absolute Contraindications • Suspected aortic dissection • Active bleeding or bleeding diathesis (excluding menses) • Significant closed-head or facial trauma within 3 months

Contraindications and Cautions for Fibrinolysis in STEMI

Relative Contraindications • History of chronic, severe, poorly controlled hypertension • Severe uncontrolled hypertension on presentation (SBP > 180 mm Hg or DBP > 110 mm Hg) • History of prior ischemic stroke greater than 3 months, dementia, or known intracranial pathology not covered in contraindications • Traumatic or prolonged (> 10 minutes) CPR or major surgery (< 3 weeks)

Contraindications and Cautions for Fibrinolysis in STEMI

Relative Contraindications • Recent (< 2 to 4 weeks) internal bleeding • Noncompressible vascular punctures • For streptokinase: prior exposure (> 5 days ago) or prior allergic reaction to these agents • Pregnancy • Active peptic ulcer • Current use of anticoagulants: the higher the INR, the higher the risk of bleeding

Reperfusion Options for STEMI Patients

Step 1: Select Reperfusion Treatment.

If presentation is < 3 hours and there is no delay to an invasive strategy, there is no preference for either strategy.

Fibrinolysis generally preferred



Early presentation ( ≤ 3 hours from symptom onset and delay to invasive strategy)



Invasive strategy not an option

   Cath lab occupied or not available Vascular access difficulties No access to skilled PCI lab 

Delay to invasive strategy

 Prolonged transport  Door-to-balloon more than 90 minutes  > 1 hour vs fibrinolysis (fibrin-specific agent) now

Reperfusion Options for STEMI Patients

Step 2: Select Reperfusion Treatment.

If presentation is < 3 hours and there is no delay to an invasive strategy, there is no preference for either strategy.

Invasive strategy generally preferred



Skilled PCI lab available

 Door-to-balloon < 90 minutes •

High Risk from STEMI

 Cardiogenic shock, Killip class ≥ 3 

Contraindications to fibrinolysis,

including increased risk of bleeding and ICH 

Late presentation

 > 3 hours from symptom onset 

Diagnosis of STEMI is in doubt

Percutaneous coronary interventions PCI (balloon angioplasty, stenting, debulking, brachytherapy etc) • Primary PCI • Rescue PCI • Facilitated PCI • Ischaemia driven PCI • Late PCI • Etc.

Primary PCI for AMI

• 1977- first PCI (Gruntzig) • 1979- first primary PCI (Rentrop P et al.) • 2003-metaanalysis of 23 randomized trials: superiority of primacy PCI compared to thrombolysis • Pivotal studies: PAMI (1993), GUSTO IIb(1997), DANAMI 2 (1997) PRAGUE 1&2(2000,2003) etc.