Coronary Artery Disease: Diagnosis and Management Dr. Christopher Flood

Objectives… • To understand the diagnosis and management of acute coronary syndromes. • To understand the ways that major cardiac events are treated in a hospital setting, and the impact of this on future management in the general practice setting • To understand the guidelines that apply to appropriate referral to Cardiac Rehabilitation.

Topics to follow... 1. Initial assessment of cardiac chest pain 2. Diagnosis and treatment of Acute Coronary Syndromes, including pathophysiology 3. Assessment of chest pain occurring after revascularisation (PCI or surgery) • either persistent or recurrent

1. Initial assessment of cardiac chest pain

Angina Pectoris • Angina is a symptom • Literally a ‘strangling in the chest’ • Typical (“textbook”) Angina is easy to diagnose: – Chest heaviness on exertion – Relieved by rest – Radiation to the arm – +/- sweating, dyspnea

Angina Pectoris • ATYPICAL Angina is much harder: – Symptoms at rest – Sharp chest pain – Arm pain only • ‘Angina equivalents’ – episodes of dyspnea without pain – perspiration/ clammy without pain

Angina Pectoris • Unstable angina denotes – Pain at rest – Increasing frequency (crescendo) and/or – New onset. • Critical coronary stenoses may sometimes produce an atypical pattern of pain

Angina Pectoris • Jaw pain (or neck or teeth) is a common trap! • Pre-test probability is not always useful in an individual. • Not uncommonly, we see patients whose presenting symptoms are not angina, but who are incidentally found to have IHD. This does not necessarily confirm that an atypical symptom is due to IHD. • Diabetics are a special risk group.

Prinzmetal Angina • A syndrome of Angina due to coronary artery spasm: – Often occurs at rest, circadian variation – May be superimposed on a fixed stenosis. – Aetiology related to endothelial dysfunction, parasympathetic activation – can be provoked during angiography for diagnostic reasons.

Assessment of symptoms • May be quite difficult, especially in an outpatient setting. • Intermittent symptoms can usually be assessed as an outpatient. • Ongoing symptoms, without another definite explanation, are ideally treated in hospital. • Common differential diagnoses are gastrointestinal and musculoskeletal syndromes.

Outpatient Assessment • Outpatient assessment of past or intermittent symptoms may include: – Stress testing – Stress echocardiogram – Nuclear perfusion studies (Sestamibi) – CT coronary angiography – Referral for Formal Coronary Angiography, depending on symptoms, comorbidities, objective evidence of ischaemia

Assessment • With non- or less-invasive cardiac investigations, the pre-test probability should always be taken into account • A normal result should not deter further treatment or investigation if symptoms are suspicious and ongoing

Acute Assessment • The initial aim of assessing possible cardiac symptoms is to diagnose or rule out an ACUTE CORONARY SYNDROME.

1. Initial assessment of cardiac chest pain 2. Diagnosis and treatment of Acute Coronary Syndromes, including pathophysiology

The Enemy… Atherosclerosis Endothelial cell injury leads to plaque formation, which reduces lumen size and limits blood flow Plaque rupture leads to thrombosis…

Human coronary artery in which there is large, lipid-rich plaque

Platelet Adhesion and Activation Normal platelets in flowing blood

Platelets adhering to damaged endothelium and undergoing activation

Aggregation of platelets into a thrombus

Platelet thrombus Platelets

Platelets adhering to subendothelial space

Endothelial cells Subendothelial space

Adapted from: Ferguson JJ. The Physiology of Normal Platelet Function. In: Ferguson JJ,Chronos N, Harrington RA (Eds). Antiplatelet Therapy in Clinical Practice. London: MartinDunitz; 2000: pp.15–35.

Acute Coronary Syndromes • The term (ACS) includes – Myocardial infarction with ST elevation – Non-ST elevation infarcts – Unstable angina pectoris • The definition depends on ECG and Troponin results.

Acute Coronary Syndromes Pathophysiology: • Infarcts involve plaque rupture • STEMI are due to plaque rupture leading to complete occlusion of a vessel • NSTEMI are also due to plaque rupture, with distal embolisation of thrombus or plaque. The ECG changes present will depend on what degree of occlusion occurs to the artery • Unstable angina does not involve any myocardial damage, and usually does not involve plaque rupture

Acute Coronary Syndromes • ECG shows ST segment elevation: – STEMI - Myocardial infarction with ST elevation – Troponin will be elevated • ECG shows no ST elevation (may be “normal”) – NSTEMI- Non-ST elevation infarct – Troponin will be elevated • Troponin level does NOT rise: – Unstable angina pectoris

Acute Coronary Syndromes • • • •

• •

Symptoms may be typical or atypical >90% have so-called “typical” symptoms STEMI -easiest to diagnose on ECG NSTEMI- much harder to diagnose – the initial ECG may be near normal (it is rarely completely normal) Remember that a Troponin level may not show elevation for several hours, so may not be useful initially. The recognition of the special case of NSTEMI and Troponin limitation lies behind the recommendation to send the patient to hospital if suspicious symptoms, even if the initial ECG is normal.

Which patient is having an infarct ?

Which patient is having an infarct ? • BOTH of them !!!

Urgent Coronary Angiography • Angiography with a view to coronary intervention (stenting or surgery) is mandatory for Acute Coronary Syndromes • This is proven, evidence-based medicine. • Shown to improve outcomes significantly with an ‘early invasive strategy’. • Acute infarcts are taken to directly to the Cath Lab for investigation and treatment.

Coronary artery stenting • May occur as part of a presentation for an acute coronary syndrome, either as an emergency treatment for an infarct, or during the hospital stay. • May also occur semi-electively, after the event, such as when ischaemia is detected on follow-up testing. • PCI= percutaneous coronary intervention

Coronary artery stenting • Remains the Gold standard treatment for urgent hospital treatment of infarcts • Thrombolysis is not commonly used now except in facilities without the availability of urgent angiography.

Case Study: 63 yo male • • • • • •

Recent onset of exertional angina Hypertension, hypercholesterolemia, obese Presents with a prolonged episode of pain Troponin elevated with minor ECG changes. Diagnosis is NSTEMI Echo normal right and left ventricular size and systolic function. Valves normal.

• Medications commenced: Metoprolol, Atorvastatin, Aspirin.

Case Study: 63 yo male • Diagnosis is NSTEMI

Treatment • Angiography shows severe LAD disease and occluded RCA. • Options include medical therapy, stenting, surgery

Case Study • Soon after underwent PCI with drug-eluting stents. • Pre PCI commenced on clopidogrel

Mechanisms of Angioplasty • Disruption of the plaque and the arterial wall. • Loss of elastic recoil. • Redistribution and compression of plaque components. • Inhibit platelet activation and thrombus formation. • The advent of stenting markedly increased success of the procedure.

What is a stent ? • Stainless steel cylindrical matrix, collapsed onto a balloon. • When the balloon is inflated, the stent struts lock into place.

Stents are often classified as: –Bare-metal Stents (BMS) or –Drug-eluting stents

Medical therapy • The standard and evidence-based medical therapy after acute cardiac syndromes are: – Statin – Aspirin – Ace inhibitor/AT2 – Betablocker – Clopidogrel • SAAB-C

1. Initial assessment of cardiac chest pain 2. Diagnosis and treatment of Acute Coronary Syndromes, including pathophysiology 3. Assessment of chest pain occurring after revascularisation (PCI or surgery) • either persistent or recurrent

Restenosis and Acute thrombosis The two complications of PCI you need to know • Restenosis generally occurs within 3 – 12 months of PCI • Can occur in up to 30% of patients with bare metal stents, 1% of patients with DES • Most patients with restenosis have a recurrence of their symptoms • Acute thrombosis is a sudden onset of Acute Coronary Syndrome, frequently due to cessation of Anti-Platelet agents. Moliterno, D. J. & Topol, E. J.

RE-STENOSIS

ACUTE THROMBOSIS: INTRODUCING THE ENEMY

Back to the case study…

Six months later… • Patient presents complaining of skin bruising, and a probable skin cancer (BCC) is noted. • He is told to cease clopidogrel and aspirin for 5 days then to recommence every second day. • 3 days later, he has chest pain and comes back for review. • An ECG is done.

ECG

ECG

ST elevation, inferior leads

Lead one is missing!!!

What to do ? • Patient is taken to the catheter lab for coronary angiography. • Acute stent thrombosis found, repeat stenting • Anti-platelet agents must be given.

Acute Stent Thrombosis Cessation of anti-platelet therapy results in a very high risk of acute thrombus formation within the stent, resulting in an acute infarct.

Post-procedure Recurrent Pain after PCI may be due to an issue with the procedure: – side branch occlusion – dissection or haematoma – distal embolisation – These will be obvious to the proceduralist at the time and should be conveyed on discharge from hospital

Post-PCI Otherwise, an Atypical chest pain (‘an awareness’) is common in the first couple of weeks after PCI – focal wall stretching with stimulation of vessel adventitial nerves – probable psychological factors (“I can feel the stent when I bend forward”) These patients can be managed conservatively.

Complications After CAGs • Graft occlusion or inadequate revascularisation • Often difficult due to overlay of musculoskeletal, sensory nerve and wound pain. • Further angiography may be required • Patients with diffuse disease are less likely to be pain free after CAGs.

Case Study Mr. V.G. (The sky is falling! The sky is falling!) • 63yo male • Severe 3 vessel coronary disease • Waited 4 months for CAGs (anxiety ++) • Post-CAGs, ongoing disabling chest pain • Appeared musculoskeletal & sensory nerve stimulation • Reviewed by surgeon, analgesia, REHAB

Case Study Mr V.G. • In the setting of chronic ongoing chest pain and reassurance, suddenly develops an exertional component with some dyspnea • Sestamibi scan performed – significant inferior ischaemia noted • Repeat angiography showed occluded RCA vein graft

Case study- Mr. V.G. • Repeat angiography showed occluded vein graft to RCA and circumflex • Fortunately able to be treated with stenting to the native RCA, with some supply to the Cx via the ‘skip’ part of the vein graft. • Exacerbation of anxiety with ongoing chronic pain, but relief of exertional component.

Cardiac Rehab Programs • The National Heart Foundation and the World Health Association recommend that all patients with cardiovascular disease are routinely referred to a cardiac rehabilitation program. • There is firm evidence that three-phase rehab programs (inpatient, outpatient and maintenance) provide a range of short and long-term benefits. • Only 10-15% of patients discharged after a cardiac event will attend cardiac rehab.

Conclusions • Infarcts are notoriously difficult to diagnose in an outpatient setting, especially NSTEMI. • Angiography with PCI is the gold-standard hospital treatment for STEMI and continues to rapidly evolve. • After the initial assesment, medical therapy and consideration of further intervention (Bypass surgery or stenting) is undertaken. • A decision regarding medical therapy, stenting or bypass is based on the specific patient- coronary anatomy, LV function, surgical risk, long-term prognosis.

Conclusions • After stenting, ‘DUAL ANTIPLATELET THERAPY’ is indicated, the length of time depending on the procedure and the type of stent implanted. • Aspirin and Clopidogrel (or Prasugrel) • Stopping these prematurely increases the risk of an acute infarct by SEVENTY TIMES. • Always speak to the cardiologist if it is thought these could be stopped or withheld

Conclusions REINFORCE TO EACH PATIENT THE IMPORTANCE OF STRICTLY CONTINUING THEIR ASPIRIN AND CLOPIDOGREL THERAPY

PCI • Percutaneous coronary intervention (PCI) has PROVEN survival and MI-prevention benefits in patients with acute coronary syndromes (ACS), and it reduces angina frequency and improves exercise tolerance in patients with stable coronary artery disease (CAD).

Conclusions… • Urgent angiography +/- PCI remains the treatment of choice for acute coronary syndromes, especially ST elevation infarcts.

Your Role in the After Care of Patients following Major Cardiac Events • • • • • •

Look for and manage complications Titrate or continue medications Counselling Risk factor modification Ensure enrolment in rehabilitation Ensure cardiac follow-up has been arranged

UNDERSTAND DIAGNOSIS AND MANAGEMENT OF ACS •

Chest pain assessment is difficult; send to hospital if could be ACS.

•

ECG and troponin will classify the patient (STEMI,NSTEMI and UAP) and determine treatment

•

ACS patients managed by angiography and intervention as needed

•

Anticoagulants and anti-platelet agents always given.

UNDERSTAND IMPLICATIONS OF HOSPITAL TREATMENT OF

ACS

•

STEMI and NSTEMI patients managed by angiography and intervention as needed

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UAP or possible cardiac pain may be sent home for outpatient testing, to return if ongoing or recurrent symptoms

•

Medical therapy essential (SAAB-C)

•

Adherence to Antiplatelet regime essential especially after stenting,

•

For drug-eluting stents usually >12 months therapy.

UNDERSTAND GUIDELINES FOR REFERRAL TO CARDIAC REHAB AFTER ACS

•

This one is easy...

•ALL

OF THEM

www.christopherflood.com.au

D r. C hristopher Floo d MB,BS (Hons), B.Med.Sc, FRACP Interventional and General Cardiologist Wahroonga Westmead Castle Hill Blacktown Sydney Adventist Hospital, Wahroonga

www.christopherflood.com.au

Persistent vs recurrent pain • Persistent pain after revascularisation may be: – Non-cardiac, musculoskeletal – Small vessel disease – Incomplete revascularisation • Recurrent angina after revascularisation is far more ominous: – With stenting, denotes restenosis or acute thrombosis – With CAGs, denotes graft failure

Acute phase chest pain

Chronic phase chest pain Stable angina

Atypical / noncardiac

Typical, troponin, compromised

Clinical monitoring

Angiogram

Major procedural complication

PCI/CABG

Nil obvious

Medical treatment ? spasm

Unstable angina

Assess ischaemia & viability

-ve

+ve

No lesions or progression

Rule out noncardiac cause

Angiogram

Obstructive lesions

PCI/CABG

• Proceeded to coronary angiography

Long stay, disabled, prognosis poor

Discharge home, back at work soon, normal life