Coronary Artery Disease and Stable Angina Flashcards
How does myocardial ischaemia occur?
When there is an imbalance between supply of oxygen, and demand of oxygen by the heart.
Broad categories of causes of myocardial ischaemia.
Mechanical obstruction
Decrease in the flow of oxygenated blood
Increased demand.
Examples of myocardial ischaemia due to mechanical obstruction.
Atheroma
Thrombosis
Spasm
Embolus
Coronary ostial stenosis
Coronary arteritis
Give exampes of myocardial ischaemia due to decrease in the flow of oxygenated blood to myocardium.
Anaemia
Carboxyhaemoglobulinaemia
Hypotension
Examples of myocardial ischaemia due to higher demand of oxygen.
Thyrotoxicosis
Myocardial hypertrophy
Aortic stenosis
Hypertension
Most common cause of myocardial ischaemia.
Obstructive coronary artery disease (CAD) in the form of coronary atherosclerosis.
Risk factors of CAD.
Age
Gender
Race
FH
Hyperlipidaemia
Diabetes
Smoking
Hypertension
Investigations of CAD.
Full lipid profile
QRISK assessment
CT Coronary Angiography is the Gold Standard diagnostic investigation. This involves injecting contrast and taking CT images timed with the heart beat to give a detailed view of the coronary arteries, highlighting any narrowing.
Lifestyle modifications in CAD.
Reduced fat intake
More fruits
Less sugars
More fish and unsalted nuts, seeds and legumes.
BMI below 25 kg/m2
No more than 14 units per week.
Statin therapy in CAD.
20 mg atorvastatin as primary prevention if QRISK > 10%.
Atorvastatin 80 mg if there is already established cardiovascular disease.
Different types of angina.
Classical angina or typical angina
Atypical angina
Non-angina chest pain
Stable angina
Unstable angina
Refractory angina
Vasospastic or variant (Prinzmetal’s) angina
Microvascular angina
Characteristic of classical angina or typical angina.
Heavy, tight, or grippin central or retrosternal pain that may radiate to the jaw and/or arms (usually only throat tightness or arm heaviness).
Pain occurs with exercise or emotional stress
Pain eases rapidly upon rest or with GTN.
Diabetics and/or hypertensives might also be dyspnoeic.
If it is very severe autonomic features such as fear, sweating and nausea might also be present.
Characteristic of atypical angina.
Chest pain with 2 out of 3 of the following…
Heavy, tight, or grippin central or retrosternal pain that may radiate to the jaw and/or arms.
Pain occurs with exercise or emotional stress
Pain eases rapidly upon rest or with GTN.
Characteristics of non-angina chest pain.
Chest pain with 1 out of 3 of the following…
Heavy, tight, or grippin central or retrosternal pain that may radiate to the jaw and/or arms.
Pain occurs with exercise or emotional stress
Pain eases rapidly upon rest or with GTN.
Characteristics of unstable angina.
Angina of recent onset (< 24 h) or deterioration in previous stable angina with symptoms occuring at rest.
Characteristics of refractory angina.
Patients with severe coronary disease in whom revascularisation is not possible and angina is not controlled by medical therapy.
What is vasospastic or variant (Prinzmetal’s) angina?
Angina that occurs without provocation usually at rest, as a result of coronary artery spasm.
It occurs more frequently in women.
Usually ST segment elevation on the ECG during the pain.
What is microvascular angina?
Exercise induced angina but normal or unobstructed coronary arteries.
Intracoronary acetylcholine may cause coronary spasm.
They are often highly symptomatic and difficult to treat however the prognosis is good.
Canadian Cardiovascular Society functional classification of angina.
I - No angina with ordinary activity, only with strenous.
II - Angina during ordinary activity, e.g. walking up hills, walking rapidly upstairs, mild limitation of activities.
III - Angina with low levels of activity, 50-100 m walk on the flat, walking up one flight of stairs.
IV - Angina at rest
Which differentials can mimic stable angina closely?
GORD
MSK discomfort
Pulmonary disease
Angina usually reflects coronary artery disease (CAD).
What other disease may cause typical symptoms in absence of CAD?
Aortic stenosis
Hypertensive heart disease
Hypertrophic cardiomyopathy
A good taken history of stable angina.
Precipitants to anginal attacks
Relieving factors
Stability of symptoms
Risk factors
Occupation
Assessment of intensity, length and regularity of exercise
Basic dietary assessment
Alcohol intake
Drug history
Family history
When is stable angina unlikely?
If the pain is continuous, very prolonged, unrelated to activity, brought on by breathing or associated with other symptoms such as dizziness and dysphagia.
Examination for stable angina.
Usually no abnormal findings.
Check weight and height to establish BMI
BP
Presence of murmurs, especially to rule out aortic stenosis
Evidence of hyperlipidaemia (lipid arcus, xanthelasma, tendon xanthoma)
Check for anaemia
Check for thyrotoxicosis
Check for peripheral vascular dsiease and carotid bruits.
Investigations in stable angina.
FBC and biochemical screen with glucose and HbA1c
Full lipid profile
Resting 12-lead ECG
Thyroid function test
GFR
Echocardiography (regional wall motion abnormalities, LVEF, diastolic function)
Ambulatory ECG to check for paroxysmal arrhythmias and vasospastic angina.
CXR
Cardiac catherisation (CTCA) or functional imaging such as SPECT, stress echocardiography or stress MRI.
How to test for angina likelihood and concurrent CAD.
Divided into non-anginal chest pain, atypical angina or typical angina (in terms of symptoms)
Further divided into high risk (diabetes, smoking and hyperlipidaemia) and low risk (none of the high risks)
Further divided into age.
If the estimated likelihood of CAD is 61-90% what should be done?
Offer invasive coronary angiography.
If the estimated likelihood of CAD is 30-60% what should be done?
Offer functional imaging as the first line diagnostic investigation such as stress MRI, echo or myoview.
If the estimated likelihood of CAD is 10-29% what should be done?
Offer CT calcium scoring as the first-line diagnostic investigation.
If score is 0 there is very minimal likelihood there is significant CAD.
If score is 1-400 CTCA or stress perfusion imaging should be considered.
If above 400 coronary angiography should be considered.
Can ECG be used to diagnose or exclude stable angina for people without known CAD?
NO
For men older than 70 with atypical or typical symptoms, what percentage estimate should be assumed?
> 90%
For women older than 70 what percentage estimate should be used?
61-90% unless high risk with typical symptoms then >90%
Treatment algorithm of stable angina.
Information, lifestyle modification, short-acting nitrates and secondary prevention (all patients should be given aspirin 75 mg OD or clopidogrel if not tolerated.) Statin, ACEi considered.
Short-acting nitrate is symptom relief (short term)
Give beta-blocker (bisoprolol or atenolol) or CCB (amlodipine or diltiazem) for symptoms control.
(Long term relief)
(If these are not tolerated try long-acting nitrate or ivabradine 5 - 7.5 mg BD (not if < 70 bpm), nicorandil or ranolazine (375 mg BD up to 750 mg, to be used in chronic and by consultant)) Isosorbide mononitrate (long-acting nitrate) can be used as second line.
If they are still symptomatic…
If still symptomatic…
Consider revascularisation such as PCI or CABG.
Non-cardiac chest pain.
Costochondritis
GORD
PE
Pneumonia
Pneumothorax
Psychogenic/psychosomatic
Explain PCI.
Process of dilating a coronary artery steonis by introduction of an inflatable balloon and metallic stent via radial artery.
What can be used to assess the severity of a stenosis prior to PCI?
Fractional flow reserve.
What does an FFR of more than 0.8 suggest?
That no stent should be introduced and treatment should be medical.
Complications of PCI.
Bleeding
Haematoma
Dissection
Pseudoaneurysm from arterial puncture site.
MI
Stroke
Death
What stents are available?
Bare metal stents (20-30% risk of restenosis iwthin 6-9 months)
1st generation drug-eluting stents (reduces restenosis but late and very late stent thrombosis)
2nd generation DES (better safety, efficacy and recommended for most patients).
Treatment after PCI.
Dual antiplatelet therapy of aspirin and clopidogrel for 6-12 months.
Explain CABG.
Autologous veins or arteries are anastomosed to the ascending aorta and to the native coronary arteries distal to the area of stenosis.
Involves opening the chest along the sternum (causing a midline sternotomy scar).
When is PCI preferred?
Patients with single or double-vessel disease not involving proximal LAD or left main stem vessel.
CABG and PCI are both appropriate with proximal LAD stenosis, LMS or three-vessel disease without diabetes mellitus and a low SYNTAX score of 0-22.
When is CABG preferred to PCI?
Three-vessel disease and diabetes or elevated SYNTAX score 22 and in patients with LMS and SYNTAX > 22.
What are the four principles to stable angina management?
RAMP
R – Refer to cardiology (urgently if unstable)
A – Advise them about the diagnosis, management and when to call an ambulance
M – Medical treatment
P – Procedural or surgical interventions
When is PCI indicated?
Their symptoms are not satisfactorily controlled with optimal medical treatment and
revascularisation is considered appropriate and
CABG is not appropriate.
When is CABG indicated?
Coronary angiography indicates left main stem disease or proximal three-vessel disease.
