Cardiovascular Epidemiology Flashcards
what are the 2 types of risk factors for cardiovascular epidemiology?
- reversible
- irreversible
what are irreversible risk factors of cardiovascular epidemiology?
- age
- sex
- family history
what are reversible risk factors of cardiovascular epidemiology?
- smoking
- obesity
- diet
- exercise
- hypertension
- diabetes
- stress
what is a key factor to someone getting cardiovascular disease?
largely a genetic problem
but can do actions that will make someone more likely to contract
what technique is used to lower a patients risk of cardiovascular disease?
patient centred and controlled risk modification
what 4 factors must the patient have for effective risk modification?
- information
- belief
- motivation
- behavioural change
what is healthcare professional in risk modification?
assess where patient is in risk modification route and give them appropriate advice and assistance to help them along
what are the 2 classes of prevention for cardiovascular disease?
primary
secondary
what is primary prevention?
Stop the risk which is going to give you the disease
why is primary prevention hard?
- Hard as people don’t believe they are going to get the disease
- Not real to them yet - ignorant
- Motivation to make a change can be difficult if don’t have the awareness
methods of primary prevention?
- Exercise, diet & not smoking
- Assess total risk
Medical treatment if high risk
what is secondary prevention?
Once contracted how to stop it getting worst
- Motivation to fix the risk factors will be higher
why is secondary prevention easier?
Motivation to fix the risk factors will be higher as already contracted the disease
methods of secondary prevention?
- Exercise, diet & not smoking
- medical treatment to reduce risk
how can methods of primary prevention be assessed?
- Family history
- Diet
- Smoking
- Test cholesterol
- Test blood pressure
- Test for diabetes (Type 2)
what will the dentist role is primary prevetion?
See the dentist as a preventative measure - check up
- Primary prevention for oral disease is common practice small add on for wider diseases (tend to not see doctor till sick)
- dentist sees when well and encourage practices to keep them well
Assess areas of risk
- And direct them to appropriate healthcare professional or give advice on diet, cancer screening programmes, BP check
how can someone present with CV disease?
- angine
- heart attack (myocardial infarction)
- stroke
- claudication
what are 4 approaches to prevention of CV disease?
- lifestyle changes
- control total cholesterol
- control hypertension
- anti-platelet drugs (aspirin)
how can total cholesterol be controlled?
- statin treatment
- reduce cholesterol <5.0mmol/L or 25%
when is hypertension controlled in CV prevention?
- moderate hypertension with evidence of CV disease
- reduce blood pressure to tager of <140/85
when is anti-platelet drugs used in CV disease prevention?
- identified cardiovascular disease
- when high risk with no identified disease
what are the 2 categories of drugs used in CV disease prevention/
- prevent further disease e.g. lower BP
- reduce symptoms of current disease e.g. improve chest pains
what types of drug are used in CV disease to prevent further disease?
- anti platelet drugs
- lipid lowering drugs
- anti-arrhythmics
- anticoagulants
what types of drug are used in CV disease to reduce symptoms of current disease?
- anti platelet drugs
- lipid lowering drugs
- anti-arrhythmics
- anticoagulants
3 anti-platelet drugs
- aspirin
- clopidrogel
- dipyridamole
how does aspirin work?
Inhibits platelet aggregation
- Alter the balance between Throboxane A2 and Prostacycli
Irreversible for the life of the platelet.
(All platelets in blood at that time will not work; Platelet life is 7-10days; aspirin every day stops new ones being made)
75mg to prevent platelet function (lower than painkiller/analgesia dose)
how does clopidogrel work?
inhibits ADP induced platelet aggregation
how does dipyridamole work?
inhibits platelet phophodiesterase
what does using drugs in combination cause?
increased effect
what does anti-platelet drugs (used alone or in combination do)
significantly reduce the chance of a heart attack or stroke
- Only in an ‘at risk’ population
(the 2 main diseases of platelets sticking onto to BV walls)
what is a negative of anti-platelet drugs?
Prolong the bleeding time following dental extraction
- Not a significant problem individually
- Drug combinations increase the risk
what are new anti-platelet drugs?
- Prasugrel
- Ticagrelor
Only prescribed in conjunction with aspirin
Only licenced for Acute Coronary Syndromes
- Small use in population currently
Poor evidence of bleeding risk in dentistry
what can happen if atherosclerosis occurs?
Plug platelets will narrow and block artery
- Can suddenly get with split ruptures platelet adhere quickly big blockage in artery
anti-platelet drug can help this
what is the prevalence of atherosclerosis?
Everyone has but can limit how bad it comes:
- By takin aspirin
- Having a good diet and exercise regime
Present in healthy and young increases with age
- Genetic related problem depends upon your genes and Chemical factors in body
what are 4 oral anticoagulants?
- warfarin
- rivaroxiban
- apixaban
- dabigatran
what are the benefits and negatives of warfarin?
- Cheapest and most common
- Need to monitor how effective - too much poison too little ineffective
- Individual tailored dose - blood tests regularly
how does warfarin work?
Coumarin based anitcoagulant
Inhibits synthesis of Vitamin K dependent clotting factors
- 2, 7, 9,10 (slow – 2 days)
- Protein C, Protein S (quick)
Some already in blood so once used already in blood then clotting factors levels will drop
If you want them to not clot now not very good drug
- Initial Hypercoagulation
Anticoagulation takes 2-3 days
- Often HEPARIN used concurrently initially
how long does it take for warfarin to cause an effect?
2-3 days
how long does it take for warfain’s effect to be lost?
2-3 days
why must warfarin’s effect be monitored?
very easily upset and displaced
- drug and food interactions
- plasma protein binding
- liver metabolism
can change warfarin’s metabolism and effectiveness
how to monitor warfain?
INR test (internationalised normalised ratio) - standardised prothrombin time (PT)
what is INR test
internationalised normalised ratio
- Compare results from one lab to another lab
- Whether patient is adequately anti coagulated or not
- Ratio compared to control sample
what is the therapeutic INR range?
2-4
what happens if warfarin INR is less than 2?
risk of clot
what happens if warfarin INR is more than 4?
risk of bleed
what should you assume when prescribing a drug to a patient on warfarin?
all drugs will interact with warfarin
- Get INR tested day after prescribing – can effect protein binding and metabolism
what are new oral anticoagulants? (NOACs)
- Rivaroxaban x1 daily – (aXi)
- Apixaban x2 daily – (aXi)
- Dabigatran x2 daily – (dTi)
(aXi) activated factor X
(dTi) direct thrombin inhibitors
what are properties of new oral anticoagulants? (4)
Short half life
No ‘anticoagulant test’ used
- Bioavailability predictable
May only be a short course – DVT
- Postpone extraction until stopped
Rapidly lost
- Unlike warfarin 2 days to start 2 days to lost
Effect more predictable and controllable
New oral anticoagulant dental drug interactions
mainly safe so able to treat patients safely with less worry of interactions
Safe with ‘Dental’ Antibiotics (except Macrolides- Erythromycin and Clarithromycin)
Safe with Antifungals – topical and fluconazole
Safe with Local Anaesthetics
Safe with Antivirals
NSAID will prolong action and inhibit platelets – avoid
what others drugs are used in combination to prevent CV disease (target most problems?
- statins
- beta-adrenergic blockers
- diuretics
- calcium channel blockers
- ACE inhibitos
what do lipid lowering drugs do?
inhibit cholesterol synthesis in liver
- reduce total cholesterol and LDL
what are lipid lowering drugs?
STATINS - HMG coA Reductase inhibitors
- Simvastatin – (a ‘prodrug’ – metabolised in liver to give an active drug)
- Atorvastatin
what are possible side effects of statins (lipid lowering drugs)
possible myositis with some drug interactions (muscle inflammation – some don’t tolerate well)
- includes antifungals (FLUCONAZOLE interaction)
Omit statin during antifungal treatment. – then restart – Ok as long term acting drug
what are beta-adrenergic blockers?
atenolol (selective; beta 1 only)
propranolol (non- selective; beta 1 and 2)
many others; all end in -olol
where is beta 2?
present in lungs and brain
(involved in anxiety)
- if block reduce anxiety but more likely to get asthma
what are beta-adrenergic blockers role in CV prevention?
Stop arrhythmias leading to cardiac arrest (Ventricular fibrillation – VF)
- Blocks effects of adrenaline on heart
- Slow it down, less excitability and function less well
Reduces heart muscle excitability
- Don’t want heart to be over stressed
- Want electrical excitability to be less
Prevent increase in heart rate
- Cause postural hypotension (slower when sitting up)
- Prevent unusual heart rhythms which can lead to heart attacks
Reduce heart efficiency
- Make heart failure worse
what are diuretics role in CV prevention?
Antihypertensive and for Heart Failure
- Thiazide diuretics (bendroflumethiazide)
- Loop diuretics (frusemide)
what do diuretics work?
Increase salt and water LOSS
o Reduce plasma volume
o Reduce cardiac workload
side effects of taking diuretics
- can lead to Na+/K+ imbalance if not monitored carefully (electrolyte imbalance)
- Can lead to dry mouth in the elderly
what age group are diuretics more effective on?
elderly than young
how can diuretic action be increased?
use a combination of diuretics that act on different areas of the renal structure to increase fluid lost
what do nitrates do?
Dilate VEINS
- Reduce preload to the heart
Dilate resistance arteries
- Reduce cardiac workload (afterload)
- Reduce cardiac oxygen consumption
Dilate collateral coronary artery supply
- Reduce anginal pain
how does nitrates dilating veins do to prevent CV?
reduces preload to the heart
how does nitrates dilating resistance arteries prevent CV?
reduces cardiac workload (afterload)
reduces cardiac oxygen consumption
how does nitrates dilating collateral coronary artery supply prevent CV?
reduces anginal pain
what is a short acting nitrate?
Glyceryl Trinitrate (GTN) - Emergency management of angina pectoris
Pain will go away when spray under tongue if angina but if cardiac arrest will not go away
what is a long acting nitrate?
Isosorbide Mononitrate
- Prevention of angina pectoris
methods of administration for nitrates?
- Sublingual - short acting
- Transdermal - long acting
- Intravenous
inactivated by first-pass metabolism
side effect of nitrates?
headache
how do calcium channel blockers help prevent CV?
hypertension - reduce
how do calcium channel blockers act on smooth muscle in peripheral blood vessels?
- Relaxation and vasodilation
Nifedipine, amlodipine (-pine)
how do calcium channel blockers act on smooth muscle in heart?
- Slow conduction of pacing impulses
Verapamil
what is a risk of taking calcium channel blockers?
make gums bigger
- gingival hyperplasia (lumpy fibrous gums)
what do angiotensin converting enzyme (ACE) inhibitors do?
Inhibit conversion of angiotensin I to angiotensin II (Change angiotensin II production)
- Angiotensin II is a Vasoconstrictor (Make BP higher)
- Body compensates as perceived drop in BP by making angiotensin II (as less angiotensin II present)
prevents aldosterone dependent reabsorption of salt and water
2 main actions of ACE inhibitors
- reduce blood pressure
- reduce excess salt and water retention
side effects of ACE inhibitors
- cough
- hypertension
- angio oedema
- lichenoid reaction
ACE inhibitors examples
- Enalapril
- Ramapril
- Lisinopril
end in -pril
what are angiotensin II blockers?
don’t stop production just prevent effect (same effect as ACE inhibitors, different mechanism)
- losartan
end in -artan
