ISCHAEMIC HEART DISEASE Acute Coronary Syndromes JD Marx Department of Cardiology University of the Free State

Acute Coronary Syndromes PATHOPHYSIOLOGY  Intermittent, partial or total occlusion of coronary artery responsible for acute myocardial ischaemia  Several factors play a role

Acute Coronary Syndromes PATHOPHYSIOLOGY Unstable angina MI Ischemic stroke/TIA Critical leg ischemia Intermittent claudication CV 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 Syndromes Multiple Unstable Lesions

Acute Coronary Syndromes T LYMPHOCYTES 7% 25% 29% 6% 29% 43% RECURRENT UAP 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 Platelet Thrombin ADP Thromboxane A 2 Epinephrine Serotonin Collagen PAR-1 PAR-4 P2Y 1 P2Y 12 TXA2-R 5HT 2 A Anionic phospholipid surfaces GP IIb GP IIIa GP VI Platelet GP IIIa GP IIb Fibrinogen GP Ia

Platelet Aggregation Flowing disc- shaped platelet Rolling ball-shaped platelet Hemisphere- shaped platelet Spreading platelet FIRM, BUT REVERSIBLE ADHESION IRREVERSIBLE ADHESION 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 Syndromes 4. Coronary Artery Spasm in ACS

Acute Coronary Syndromes PATIENT 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 Syndromes Unstable Angina Pectoris & Non ST-segment elevation infarction TREATMENT 1.Medical Stabilization a)General i.Hospitalization ii.Monitor as appropriate iii.Pain relief iv.Sedation as necessary Identify and treat precipitating factors e.g. anaemia, tachiarrhythmias

Acute Coronary Syndromes TREATMENT b)Drugs i.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 Syndromes TREATMENT 2.Coronary Angiography Evaluate coronary anatomy Depending on clinical and anatomic findings an appropriate long term treatment is determined.

Acute Coronary Syndromes LONG 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

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