Screening & Prevention of CardiovascularDisease

Lynne PowellAdvanced Nurse Practitioner & Clinical Practice Educator

Aim

To give you an understanding of the principles of screening and identify

risk factors for cardiovascular disease

Objectives

• Discuss and explore the criteria for screening• Have an understanding of cardiovascular disease

• Look at the policies in Wales that drive screening for cardiovascular disease

• Discuss cardiovascular disease prevention, risk assessment and the tools used.

• Identify the risk factors for cardiovascular disease

• How to use a risk assessment tool

What is Screening?

‘Screening is a public health service in which members of a defined population, who do not already perceive

themselves to be at risk of, or are already affected by a disease or its complications, are asked a question or

offered a test, to identify those individuals who are more likely to be helped than harmed by further tests or

treatment to reduce the risk of a disease or its complications’

(UK National Screening Committee 2000)

What is Screening?

Screening is a process of identifying apparently healthy people who may be at increased risk of a disease or condition.

They can then be offered information, further tests and appropriate treatment to reduce their risk and/or any complications arising

from the disease or condition.

The NSC Criteria for Screening• The condition should pose an important health

problem• The natural history of the condition should be

understood• There must be a safe and validated test or examination• Treatment of the disease at an early stage should be

beneficial• The screening programme must reduce mortality and

morbidity• The test must be acceptable to the population• The programme must provide value for money

Extended Screening

Since original criteria were developed the breadth of screening has extended to

include risk factors (eg. blood pressure or cholesterol) or susceptibility for disease (eg. genetic markers for cancer or HIV status).

Limitations of Screening

• Can reduce the risk of developing a condition but cannot offer a guarantee of protection.

• Screening is therefore increasingly presented as RISK REDUCTION

• Although may benefit populations, not all participants will benefit and some may even be harmed.

Intention of screening

To identify disease in a community who do not have symptoms, early in the disease process so that intervention

and management can hopefully reduce mortality and suffering from the

disease.

Remember

• Screening has the potential to cause harm• Benefits must outweigh the harm• Informed consent is very important• Inclusion should be voluntary• People do not have symptoms• Quality assurance

What is Cardiovascular Disease?

‘Disease of the heart and blood vessels’

Also known as Coronary Heart Disease (CHD) and Ischaemic Disease.

(Cardiac Disease NSF for Wales, 2009)

CVD cont.• Narrowing of the arteries that supply the heart and is due to a gradual build up of fatty material called atheroma.

• The narrowing can cause myocardial infarction, angina and other forms of chronic heart disease.

• Other forms of CVD include stroke, transient ischaemic attack and peripheral vascular disease.

Cardiovascular Disease (CVD)• CVD is the main cause of death in the UK accounting for

over 216,000 deaths in 2004: around 4 out of every 10 deaths. The main forms of CVD are coronary heart disease (CHD) and stroke

• CHD accounts for approx 50% of CVD deaths • Stroke accounts for approx 25% of CVD deaths

• CVD is one of the main causes of premature death: 32% in men and 24% in women

(BHF, 2006)

Cardiovascular Disease (CVD)• CHD causes over 105,000 deaths a year in the UK:

• approx 21% deaths in men • approx15% deaths in women

• This compares to around 33,000 deaths a year from lung cancer, 16,000 deaths from colorectal cancer and 12,000 deaths from breast cancer.

(BHF, 2006)

Cardiovascular Disease

• Around 230,000 people in the UK suffer a heart attack each year

• In around 30% of heart attacks the patient dies

• Death rates from CHD have been falling in the UK since the late 1970’s; for adults under 65yrs they have fallen by over 44% in the last 10 years

• Whereas mortality from CHD is falling rapidly, morbidity from CHD and other circulatory disease appears to be rising, especially in older age groups.

(BHF, 2006)

Economic CostsCHD causes health care system in UK around £3.5 million a year

• Hospital care for CHD patients accounts for 79% of these costs

• buying and dispensing drugs accounts for a further 16%.

• Primary Prevention and Primary Care 4%

(BHF, 2006)

Policies in Wales that drive screening for cardiovascular

disease

Review of Health and Social Care in Wales (2003)

Builds on the Wanless Report and Identifies that services need to be realigned to focus on prevention and early intervention

Designed for Life (2003) • Sets the direction and requirements for the NHS

describes the kind of health and social care services the people of Wales can expect by 2015

• Improve health and reduce ill health and where possible eliminate inequalities in health

• Support the role of people in promoting their health individually and collectively

• Provide quality assured clinical treatment and care appropriate to need and based on evidence

The Cardiac Disease National Service Framework (NSF) for Wales (WAG 2009)

Everyone at high risk of developing coronary heart disease and all those who have been diagnosed as having the disease should have access to a multi factorial risk assessment and be offered an appropriate treatment plan.

Health Evidence Bulletin: CHD • Summarizes the best current evidence to support the development of guidelines and care pathways at national and local levels

• Develop, implement and monitor evidence based programmes to address tobacco use, diet and physical activity, targeted at the most disadvantaged communities in Wales.

The NSF for CHD

• Everyone who may be at risk of developing CVD is to be offered a risk assessment.

• All those found to be at high risk together with those who have established CHD, occlusive arterial disease, diabetes or familial hypercholesterolaemia, are offered lifestyle advice and appropriate treatment.

Cardiovascular disease prevention, risk assessment

and the tools used.

Prevention of CVD

Primary prevention aims to prevent the development of CVD in high risk individuals

Secondary prevention aims to prevent further events in those patients with established CVD

How do we assess risks?• CVD Risk Assessment Tools• Based on research• They identify high-risk people for primary prevention

• They are an aid to making a clinical decision• Usually based on groups of people with untreated levels of blood pressure and cholesterol levels.

• There are limitations to all the risk tools• They can under estimate risk in people with a family history of CVD and certain high risk ethnic groups

Cardiovascular Risk Prediction Charts

• ASSIGN – Scotland includes deprivation & family history

• QRISK13 – GP population, computer based• Reynold’s Risk Score – risk in females• ETHRISK – UK ethnic groups• UKPDS – diabetes• INDANA – focuses on patients with hypertension• Joint British Societies Coronary Risk Prediction Chart (JBS2)

Joint British Societies Coronary Risk Prediction Chart (JBS2)

• Was considered the most accurate and preferred method for estimating CVD risk for different societies.

• Not appropriate for people with established CVD, familial high cholesterol, chronic renal dysfunction or diabetes.

• Estimates the absolute 10 year risk of developing CVD

• Based on the Framingham Heart Study.

Framingham Heart Study• Began in 1948.• More than 10.000 residents of Framingham, Massachusetts, USA.

• Collected data on blood pressure, diabetic status, smoking and causes of death.

• People with pre-existing disease were excluded• This data was used to define the risk factors for CVD.

• This study is ongoing

QRISK2-2013

• Framingham score under estimated the risk in certain ethnicities.

• QRISK is a computer generated risk assessment tool.• Developed from QRISK1 and the Framingham score.• Includes BMI; family history; age, ethnicity; areas of

deprivation, personal clinical information including previous heart attack (myocardial infarction)

• Still estimates the 10 year risk

What are the Risk Factors for CVD?

Modifiable

Non-modifiable

Modifiable Risk Factors

• Smoking • Poor diet• Lack of physical exercise• Regular excessive alcohol consumption• Abdominal obesity• Hypertension• Diabetes• Dyslipidaemia

Non-modifiable Risk Factors

• Gender• Age• Ethnic origin• Family history• Genetic

Who should have a CVD risk assessment?

•All adults aged over 40 years or more•Adults of any age who have;

• A strong family history of early CVD• A 1st degree relative with a hereditary cholesterol

disorder

People with existing cardiovascular disease and/or diabetes do not need to be assessed as

they are already known to be high risk

What does screening involve?Assessing lifestyle factors;• Smoking• Diet• Physical activity• Alcohol consumption• Blood pressure• Weight & Height (BMI); waist

circumferenceBlood tests for glucose and cholesterol levelsAgeGenderFamily history

Measurement of Obesity• There are various ways in which to measure different aspects of

obesity. They include Body Mass Index (BMI), skin fold thickness, waist circumference, waist to hip ratio and bio-impedance.

Body Mass Index (BMI)• The most common method of measuring obesity is the Body

Mass Index (BMI). BMI is calculated by dividing body weight (kilograms) by height (metres) squared.

• BMI is the most widely used approach in the UK, but it is important to note that it is not a direct measure of body fat mass or distribution, and BMI measures may be skewed by very high muscle mass. The relationship between BMI and health also varies with ethnicity.

• In children and adolescents BMI varies with age and sex, for this reason a growth reference must be used.

Skin fold thickness• Skin fold thickness refers to the measurement of subcutaneous fat located directly

beneath the skin by grasping a fold of skin and subcutaneous fat and measuring it using calipers. It is used mainly to determine relative fatness and the percentage of body fat. Measurement requires callipers and some basic training.

Waist circumference and waist to hip ratio• The circumference of the waist is sometimes used as a simple measure of body

fatness, though it can be subject to measurement error. Adult waist circumference cut points are:

• Increased risk of health problems: Men≥ 94cm Women ≥ 80cm• Greatly increased risk of health problems: Men ≥ 102cm Women ≥ 88cm• Waist to hip ratio examines fat distribution and in practice is used less frequently,

given the established links between waist circumference alone and health risk.

Bio-impedance• This measures the impedance or opposition to the flow of a very small electric

current as it passes through the body. As lean mass is made up of 73% water and fat has no water content, this method estimates lean tissue mass (which acts as a conductor) and fat mass (which acts as an insulator), through changes in voltage. Home machines are available for bio-impedance measurement though these can be inaccurate as they often estimate from the legs only.

Joint British Societies’ cardiovascular disease (CVD) risk prediction chart

Assessment score• High Risk = 20% or more (2 in 10 chance or more of

developing CVD within the next 10 years• Moderate Risk = 10% - 20% (between 1in 10 and 2 in 10

chance)• Low Risk = less than 10% chance (less than 1 in 10

chance)

• HIGH RISK = medication to lower cholesterol and/or blood pressure and lifestyle advice including healthy eating, smoking cessation, physical activity & safe alcohol limits.

Case Studies for week 3

QRisk calculator online

Case Study 1

Mrs Lewis is a 42 year old lady, non – smoker , with a blood pressure of 120/70 and a cholesterol of 3.9 mmol/l.

• What is this lady’s current risk ?

Case Study 2

A 52 year old male who is currently smoking 20 cigarettes a day, has a systolic blood pressure of 158mmHg and a non fasting cholesterol of 7.0mmol/l.

1. What is his 10 year risk of a CVD event?

2. 3 months later, he has stopped smoking his systolic blood pressure is 140 and his cholesterol remains 7.0mmol/l.

Has his risk changed ?

Case study 3

A 50 year old woman who is a non-smoker, does not have diabetes, and has a blood pressure of 120/80 and a total cholesterol of 8.2mmol/l.

1. What is this woman’s current level of risk?

2. How would that risk change if she then told you that her father died aged 45 years of an MI?

reference• BNF 62 (Sept 2011) bnf.org. • British Heart Foundation (2006) Coronary Heart Disease Statistics. London;

British Heart Foundation• http://www.eguidelines.co.uk/eguidelinesmain/gip/vol_2/may_99/wood_chd_m

ay99.htm#.UsGeLhZCgfE (accessed 13/12/13).

• JBS2 (2005) Joint British Societies’ guidelines on prevention of cardiovascular disease in clinical practice. BMJ Journals volume 91 supplement v

• Health in Wales NHS Wales www.wales.nhs.uk/healthtopics/conditions/coronaryheartdisease (accessed 13/12/13).

• QRISK Predicting cardiovascular risk in England and Wales: prospective derivation and validation of QRISK2, BMJ 2008;336:1475-82. (accessed 13/12/13).

• NSC (National Screening Committee) www.screening.nhs.uk