Chronic stable angina - Cardiology Flashcards
Definition of Chronic stable angina
Angina means cardiac pain that result from mismatch between myocardial O2 demand and myocardial O2 supply.
Etiology of Chronic stable angina
- Decrease oxygen supply:
1 Obstructive coronary artery disease (CAD)
▪ Atherosclerosis the most common
▪ Vasospasm: variant angina
▪ Vasculitis
▪ Coronary embolism
▪ Coronary dissection.
2 Functional causes
▪ Severe anaemia
▪ Hypoxia - Increase myocardial oxygen demand (act as precipitating factor):
o Left ventricular hypertrophy
o Tachy-arrhythmias
Risk factors of chronic stable angina (A+++++++++)
- Old age
- Male gender
- Sedentary life
- Diabetes mellitus
- Hypertension
- Dyslipidemia
- Smoking
- Central obesity
Clinical presentation of Chronic stable angina (A++)
A Anginal chest pain
1- Constricting/heavy discomfort to the chest, jaw, neck, shoulders, or arms.
2- Symptoms brought on by exertion, emotion, cold weather and heavy meals.
3- Symptoms relieved within 5min by rest or nitro-glycerine (GTN).
▪ All the 3 features = typical angina.
▪ Only 2 features = atypical angina.
▪ 0–1 feature = non-anginal chest pain.
4- Anginal pain usually lasts for less than 15 minutes.
5- Anginal pain could be only in the chest, in the chest and referring, or only in the referred areas
B- Angina equivalents; dyspnea, fatigue, nausea, sweatiness, and faintness.
C- Features that make angina less likely:
1- Pain that is continuous or lasting for seconds is less likely relates to ischemic origin
2- Pleuritic localized chest pain or that worse with swallowing is mostly nonischemic pain.
Examination of Chronic stable angina (A++++)
o General examination: could pick up risk factors / complications of ischemic heart disease
▪ Hypertension
▪ Peripheral artery disease (week peripheral pulsations / abnormal ankle brachial index)
▪ Arrhythmia: premature ventricular extrasystoles / atrial fibrillation
o Local examination: is usually normal in CCS. However, it important to rule out other causes of chest pain:
▪ Herpes zoster
▪ Aortic stenosis
Investigations used in Chronic coronary syndrome (stable angina) (A+++++)
o To check for ethology / risk factors
▪ Fasting blood sugar / 2 hours post prandial / HBA1C
▪ Lipid profile
▪ Kidney function tests
▪ CBC
▪ Chest X ray could pick up rib fracture or dilated aortic root
o To confirm the diagnosis of chronic coronary syndrome
▪ ECG: usually is normal in between attacks
- If performed during the attack: you could pick up ischemic ECG changes
▪ Echocardiography: usually normal in between attacks
- If performed during the attack: you could pick up ischemic wall motion abnormality with or without diastolic dysfunction or systolic dysfunction
- Could pick up other potential causes of chest pain
o Pericardial effusion could refer to pericarditis
o Aortic stenosis
o Aortic aneurysm
▪ Stress test to unmask exercise induced ischemic heart disease (stress could be exercise or pharmacological stress using dobutamine or adenosine)
* Stress ECG
* Stress echocardiography
* Stress myocardial perfusion imaging
* Stress cardiac MRI
▪ Non-invasive coronary imaging: CT coronary angiography is recommended as a good negative test in patients less likely to have coronary artery disease
▪ Invasive coronary angiography is recommended in patients with positive stress test
Treatment of Chronic stable angina (A++++++)
1- Life-style modification to prevent risk factors, incidence, prevalence or complications
and disability:
▪ Smoking cessation.
▪ Weight reduction.
▪ Physical exercise.
▪ Healthy diet.
▪ Reduce stress.
2- Medical therapy:
A. Anti-anginal drugs for symptom relief
▪ 1st line therapy:
1- Short acting nitrates
▪ Sublingual nitroglycerine or nitroglycerine spray
▪ Used during the attack of angina or shortly before exertion
▪ It is not recommended to give nitrates to patient on sildenafil to avoid profound hypotension and shock
▪ Nitrates work by
* Coronary vasodilation and increasing coronary blood supply
* Decreasing the O2 demand by decreasing preload (venodilatation) and afterload (vasodilatation)
2- Beta blockers or Calcium channel blockers (non-dihydropyridines)
▪ Both groups decrease contractility and heart rate with subsequent reduction in myocardial oxygen demand
▪ Target heart rate: 50-60 beat / min
▪ Selective B1 blockers are useful: carvedilol, bisoprolol, metoprolol
▪ Non DHP CCBs: verapamil and diltiazem
▪ Avoid betablocker in variant angina as it produces coronary spasm
▪ Avoid Non DHP CCBs in heart failure with reduced systolic function as they worsen heart failure
▪ 2nd line therapy: Long-acting nitrates
o Oral and transdermal patches are available
o It is important to leave 8 hours nitrates free period to avoid nitrates tolerance
o Headache is a common side effect that could be managed with paracetamol
▪ 3rd line therapy:
1- Nicorandil
▪ It relaxes coronary vascular smooth muscle by stimulating guanylyl cyclase and increasing cyclic GMP (cGMP) levels
▪ Also, it results in activation of K+ channels and hyperpolarization
▪ Avoid combining nicorandil with nitrates
2- Trimetazidine
▪ It is a cytoprotective drug that inhibits β-oxidation of free fatty acid and increases the metabolic rate of glucose.
▪ Therefore, it changes the heart fuel from fatty acids to glucose with subsequent reduction in lactic acid production and angina
3- Ranolazine
▪ It blocks IKr, the rapid portion of the delayed rectifier potassium current, and prolongs the QTc interval in a dose-dependent fashion
▪ Ranolazine exerts its therapeutic effects without negative chronotropic, dromotropic, or inotropic actions neither at rest, nor during exercise
4- Ivabradine
▪ Funny Na channel blocker
▪ Possible alternative to beta-blockers (or rate-limiting calcium antagonists) for rate control if contra-indicated or not tolerated.
▪ May cause visual disturbance (phosphenes) due to retinal sideeffects
▪ It has cytochrome P450 3A4 drug interactions
B. Drugs that prevent the progression of disease and prevent development of acute coronary syndrome (details in drug appendix)
* Lipid lowering drugs (for life) (patients who has chronic stable angina are considered at very high risk of developing acute myocardial infarction. Therefore, they must undergo LDL reduction to very low levels using one ormore of the following
o Statins: atorvastatin or rosuvastatin that inhibit cholesterol synthesis
o Ezetimibe that inhibits GIT absorption
o PCSK9 inhibitors (inhibit bad PCSK9 (PCSK9 degrades LDL receptors at liver and prevent LDL uptake into liver with subsequent increase in LDL levels in blood)
o Inclisiran is RNA interfering therapy prevent synthesis of bad PCSK9
* Antiplatelets (for life)
o Low dose aspirin (75-100 mg once daily)
o Clopidogrel is used in chronic stable angina only if aspirin is contraindicated (aspirin allergy)
* ACEI (for life): only in chronic angina patient who has history of DM, hypertension, systolic dysfunction, CKD, or prior myocardial infarction
3- Revascularization.
- Revascularization with PCI (percutaneous coronary intervention) or CABG (coronary artery bypass graft) in the following indications
o Coronary stenosis > 90 % in one or more coronary arteries
o Coronary stenosis (50-90%) with one of the following
▪ Refractory angina
▪ Systolic dysfunction
▪ Positive noninvasive stress test
▪ Significant ischemia with invasive hemodynamic assessment
