ISCHAEMIC HEART DISEASE Acute Coronary Syndromes

JD MarxDepartment of Cardiology

University of the Free State

Acute Coronary SyndromesPATHOPHYSIOLOGY

Intermittent, partial or total occlusion of coronary artery responsible for acute myocardial ischaemia

Several factors play a role

Acute Coronary SyndromesPATHOPHYSIOLOGY

Unstable angina MI Ischemic stroke/TIACritical leg ischemiaIntermittentclaudicationCV death

Atherosclerosis

Stable angina intermittent claudication

Thrombosis

MI=myocardial infarction ACS=acute coronary syndromes TIA=transient ischemic attack CV=cardiovascular

ACS

Acute Coronary Syndromes

Vulnerable plaque present in most patients Culprit lesions most often a low grade lesion

1. Atherosclerotic Lesions in ACS

Acute Coronary SyndromesMultiple Unstable Lesions

Acute Coronary Syndromes

0%5%

10%15%20%25%30%35%40%45%

MACROPHAGES T LYMPHOCYTES

7%

25%29%

6%

29%

43%

RECU

RREN

T UA

P

2. Inflammation in ACS

Acute Coronary Syndromes

Thrombosis on ulcerated or ruptured plaque plays pivotal role

› Platelet Thrombus

› Fibrin Thrombus

3. Thrombus in ACS

Platelet Adhesion

Tissue factor, vWF

COLLAGEN I

GP lb- IX

GP IIb - IIIa

GP Ia - IIa

Plaque rupture, endothelial damage, fibrous cap erosion

Platelet Activation and Aggregation

PlateletThrombin

ADP

Thromboxane A2

Epinephrine

Serotonin

Collagen

PAR-1

PAR-4P2Y1

P2Y12

TXA2-R

5HT2AAnionicphospholipidsurfaces

GP IIbGP IIIa

GP VI

Platelet

GP IIIaGP IIb

Fibrinogen

GP Ia

Platelet Aggregation

Flowingdisc-

shapedplatelet

Rollingball-shaped

platelet

Hemisphere-shapedplatelet

Spreadingplatelet

FIRM, BUT REVERSIBLEADHESION

IRREVERSIBLEADHESION

Scanning electron micrograph of discoid, dormant platelets

Activated, aggregating platelets illustrating fibrin

strands

Platelet Thrombus

Thrombus on Plaque Rupture

Microembolization in Unstable Angina

Courtesy of C. Michael Gibson, MS, MD, Director TIMI Data Coordinating Center, Brigham & Women’s Hospital, Associate Chief of Cardiology, Interventional Cardiologist, Beth Israel Deaconess Medical Center, Harvard Medical School.

Acute Coronary Syndromes

Thrombosis on ulcerated or ruptured plaque plays pivotal role

› Platelet Thrombus

› Fibrin Thrombus

3. Thrombus in ACS

Fibrin Thrombus

Can play an important etiological role

Acute Coronary Syndromes4. Coronary Artery Spasm in ACS

Acute Coronary SyndromesPATIENT WITH MYOCARDIUM AT RISK

CLINICAL PRESENTATION

Unstable Angina Pectoris› Angina of recent onset ( 1 month )› Angina at rest› Worsening angina› Early post infarction angina

Non ST-segment elevation myocardial infarction› Cardiac enzymes elevated e.g. troponins,CK, MB-CK

ST-segment elevation myocardial infarction› Normal progression to Q-wave infarction

Acute Coronary SyndromesUnstable Angina Pectoris &

Non ST-segment elevation infarctionTREATMENT

1. Medical Stabilizationa) General

i. Hospitalizationii. Monitor as appropriateiii. Pain reliefiv. Sedation as necessary Identify and treat

precipitating factors e.g. anaemia, tachiarrhythmias

Acute Coronary SyndromesTREATMENT

b) Drugsi. Antithrombotic • Antiplatelet e.g.. Aspirin• Anticoagulant e.g.. Heparin

ii. Antianginal• Nitrates• β-Blockers• Calcium Antagonists

iii. Disease Modifying Drug• Statins• ACE Inhibitors

Acute Coronary SyndromesTREATMENT

2. Coronary AngiographyEvaluate coronary anatomy

Depending on clinical and anatomic findings an appropriate

long term treatment is determined.

Acute Coronary SyndromesLONG TERM TREATMENT

Medical therapy

Coronary angioplasty

Coronary artery Bypass Graft surgery

Diffuse Disease

MAHOMED

Right Coronary Artery

Before PTCA After PTCA

Stenting

LAD BEFORE STENT LAD AFTER STENT

Multi vessel disease: Surgery

Patent LIMA

Patent SVG

Thank you