Atherosclerosis
Athero – soft or porridge-like. Sclerosis – hardening. Atherosclerosis is a combination of atheromas (fatty deposits in the artery walls) and sclerosis (the process of hardening or stiffening of the blood vessel walls). Atherosclerosis affects the medium and large arteries. It is caused by chronic inflammation and activation of the immune system in the artery wall. This causes deposition of lipids in the artery wall, followed by the development of fibrous atheromatous plaques.
These plaques cause:
- Stiffening of the artery walls leading to hypertension (raised blood pressure) and strain on the heart trying to pump blood against resistance
- Stenosis leading to reduced blood flow (e.g. in angina)
- Plaque rupture giving off a thrombus that blocks a distal vessel leading to ischaemia, for example in acute coronary syndrome)
Atherosclerosis Risk Factors
It is important to break these down into modifiable and non-modifiable risk factors. There is nothing we can do about non-modifiable risk factors, but we can do something about the modifiable ones.
Non-Modifiable Risk Factors
- Older age
- Family history
- Male
Modifiable Risk Factors
- Smoking
- Alcohol consumption
- Poor diet (high sugar and trans-fat and reduced fruit and vegetables and omega 3 consumption)
- Low exercise
- Obesity
- Poor sleep
- Stress
Medical co-morbidities increase the risk of atherosclerosis and should be carefully managed to minimise the risk:
- Diabetes
- Hypertension
- Chronic kidney disease
- Inflammatory conditions, such as rheumatoid arthritis
- Atypical antipsychotic medications
TOM TIP: Think about risk factors when taking a history from someone with suspected atherosclerotic disease (such as someone presenting with chest pain) and ask about their exercise, diet, past medical history, family history, occupation, smoking, alcohol intake and medications. This will help you score highly in exams and when presenting to seniors.
End Results of Atherosclerosis
- Angina
- Myocardial Infarction
- Transient Ischaemic Attacks
- Stroke
- Peripheral Vascular Disease
- Mesenteric Ischaemia
Prevention of Cardiovascular Disease
You can consider the prevention of cardiovascular disease to fall into two main categories:
Primary Prevention – for patients that have never had cardiovascular disease in the past.
Secondary Prevention – for patients that have had angina, myocardial infarction, TIA, stroke or peripheral vascular disease.
Optimise modifiable risk factors
For primary and secondary prevention of cardiovascular disease it is essential to optimise the modifiable risk factors:
- Advice on diet, exercise and weight loss
- Stop smoking
- Stop drinking alcohol
- Tightly treat co-morbidities (such as diabetes)
Primary Prevention of Cardiovascular Disease
Perform a QRISK 3 score. This will calculate the percentage risk that a patient will have a stroke or myocardial infarction in the next 10 years. If they have more than a 10% risk of having a stroke or heart attack over the next 10 years (i.e. their QRISK 3 score is above 10%) then you should offer a statin (current NICE guidelines are for atorvastatin 20mg at night).
All patients with chronic kidney disease (CKD) or type 1 diabetes for more than 10 years should be offered atorvastatin 20mg.
NICE recommend checking lipids at 3 months and increasing the dose to aim for a greater than 40% reduction in non-HDL cholesterol. Always check adherence before increasing the dose.
NICE also recommend checking LFTs within 3 months of starting a statin and again at 12 months. They don’t need to be checked after that if they are normal. Statins can cause a transient and mild rise in ALT and AST in the first few weeks of use and they often don’t need stopping if the rise is less than 3 times the upper limit of normal.
Secondary Prevention of Cardiovascular Disease
Secondary prevention after developing cardiovascular disease can be remembered as the 4 As:
- A – Aspirin (plus a second antiplatelet such as clopidogrel for 12 months)
- A – Atorvastatin 80mg
- A – Atenolol (or other beta-blocker – commonly bisoprolol) titrated to maximum tolerated dose
- A – ACE inhibitor (commonly ramipril) titrated to maximum tolerated dose
Notable Side Effects of Statins
- Myopathy (check creatine kinase in patients with muscle pain or weakness)
- Type 2 diabetes
- Haemorrhagic strokes (very rarely)
Usually, the benefits of statins far outweigh the risks and newer statins (such as atorvastatin) are mostly very well tolerated.
Last updated October 2018