Cardiology

• Atherosclerosis


  Combination of atheromas (fatty deposits in the artery walls) and sclerosis (hardening or stiffening of the blood vessel walls)
• Atherosclerosis


  • Affects the medium and large arteries
  • Caused by chronic inflammation and activation of the immune system in the artery wall
  • Causes deposition of lipids in the artery wall, followed by development of fibrous atheromatous plaques
• Atheromatous plaques


  Result in stiffening, stenosis, and plaque rupture
• Stiffening of artery walls

  Leads to hypertension (raised blood pressure) and strain on the heart as it tries to pump blood against extra resistance
• Stenosis


  Leads to reduced blood flow (e.g. in angina)
• Plaque rupture


  Creates a thrombus that can block a distal vessel and cause ischaemia
• Non-modifiable risk factors for cardiovascular disease

  • Older age
  • Family history
  • Male
• Modifiable risk factors for cardiovascular disease

  • Raised cholesterol
  • Smoking
  • Alcohol consumption
  • Poor diet
  • Lack of exercise
  • Obesity
  • Poor sleep
  • Stress
• Medical co-morbidities that increase risk of atherosclerosis

  • Diabetes
  • Hypertension
  • Chronic kidney disease (CKD)
  • Inflammatory conditions, such as rheumatoid arthritis
  • Atypical antipsychotic medications
• End results of atherosclerosis

  • Angina
  • Myocardial infarction
  • Transient ischaemic attacks
  • Strokes
  • Peripheral arterial disease
  • Chronic mesenteric ischaemia
• Primary prevention


  For patients that have never had a diagnosis of cardiovascular disease
• Secondary prevention


  After a diagnosis of angina, myocardial infarction, TIA, stroke or peripheral arterial disease
• Optimising modifiable risk factors

  • Address diet, exercise and obesity
  • Stop smoking
  • Reducing alcohol consumption
  • Optimise treatment of co-morbidities (such as diabetes)
• NICE dietary recommendations for cardiovascular disease prevention

  • Total fat less than 30% of total calories (primarily monounsaturated and polyunsaturated fats)
  • Saturated fat less than 7% of total calories
  • Reduced sugar intake
  • Wholegrain options
  • At least 5 a day of fruit and vegetables
  • At least 2 a week of fish (one being oily)
  • At least 4 a week of legumes, seeds and nuts
• NICE exercise recommendations for cardiovascular disease prevention

  • Aerobic activity for a total of at least 150 minutes at moderate intensity or 75 minutes at vigorous intensity per week
  • Strength training activities at least 2 days a week
• QRISK3 score


  Estimates the percentage risk that a patient will have a stroke or myocardial infarction in the next 10 years
• NICE guidelines recommend offering a statin (atorvastatin 20mg at night) for primary prevention when QRISK3 score is above 10%
• NICE guidelines recommend offering atorvastatin 20mg for primary prevention in patients with chronic kidney disease (eGFR less than 60 ml/min/1.73 m2) or type 1 diabetes for more than 10 years or over 40 years
• Draft NICE guidelines advise atorvastatin 20mg can be considered for primary prevention in patients with a QRISK3 score below 10%
• Statins


  Reduce cholesterol production in the liver by inhibiting HMG CoA reductase
• NICE recommend checking lipids 3 months after starting statins and increasing the dose to aim for a greater than 40% reduction in non-HDL cholesterol, checking adherence before increasing the dose
• NICE recommend checking LFTs within 3 months of starting a statin and again at 12 months, statins can cause a transient and mild rise in ALT and AST in the first few weeks of use
• Rare and significant side effects of statins

  • Myopathy (causing muscle weakness and pain)
  • Rhabdomyolysis (muscle damage)
  • Type 2 diabetes
  • Haemorrhagic strokes (very rarely)
• Ezetimibe


  Works by inhibiting the absorption of cholesterol in the intestine, can be used as an alternative when statins are not tolerated or in combination with a statin when statins alone are inadequate
• PCSK9 inhibitors


  Monoclonal antibodies that lower cholesterol, highly specialist treatments given as a subcutaneous injection every 2-4 weeks
• 4 As for secondary prevention of cardiovascular disease

  • Antiplatelet medications (e.g., aspirin, clopidogrel and ticagrelor)
  • Atorvastatin 80mg
  • Atenolol (or an alternative beta blocker – commonly bisoprolol) titrated to the maximum tolerated dose
  • ACE inhibitor (commonly ramipril) titrated to the maximum tolerated dose
• After a myocardial infarction, patients are offered dual antiplatelet treatment initially, with aspirin 75mg daily (continued indefinitely) and clopidogrel or ticagrelor (generally for 12 months before stopping)
• Clopidogrel is the antiplatelet of choice in peripheral arterial disease and following an ischaemic stroke
• Familial hypercholesterolaemia


  Autosomal dominant genetic condition causing very high cholesterol levels, heterozygous means only one copy of the gene is abnormal (occurs in about 1 in 250 people), homozygous means both copies of the gene are abnormal (very rare condition causing extremely high cholesterol)
• Key features for clinical diagnosis of familial hypercholesterolaemia

  • Family history of premature cardiovascular disease
  • Very high cholesterol (e.g., above 7.5 mmol/L in an adult)
  • Tendon xanthomata
• Management of familial hypercholesterolaemia involves specialist referral for genetic testing and testing of family members, and treatment with statins