Cardiovascular diseases (CVDs)
- CVDs are the number one cause of death globally: more people die annually from CVDs than from any other cause (1).
- An estimated 17.3 million people died from CVDs in 2008, representing 30% of all global deaths(1). Of these deaths, an estimated 7.3 million were due to coronary heart disease and 6.2 million were due to stroke (2).
- Low- and middle-income countries are disproportionally affected: over 80% of CVD deaths take place in low- and middle-income countries and occur almost equally in men and women (1).
- The number of people who die from CVDs, mainly from heart disease and stroke, will increase to reach 23.3. million by 2030 (1,3). CVDs are projected to remain the single leading cause of death (3).
- Most cardiovascular diseases can be prevented by addressing risk factors such as tobacco use, unhealthy diet and obesity, physical inactivity, high blood pressure, diabetes and raised lipids.
- 9.4 million deaths each year, or 16.5% of all deaths can be attributed to high blood pressure (4). This includes 51% of deaths due to strokes and 45% of deaths due to coronary heart disease (5).
What are cardiovascular diseases?
Cardiovascular diseases (CVDs) are a group of disorders of the heart and blood vessels and they include:
- coronary heart disease – disease of the blood vessels supplying the heart muscle;
- cerebrovascular disease - disease of the blood vessels supplying the brain;
- peripheral arterial disease – disease of blood vessels supplying the arms and legs;
- rheumatic heart disease – damage to the heart muscle and heart valves from rheumatic fever, caused by streptococcal bacteria;
- congenital heart disease - malformations of heart structure existing at birth;
- deep vein thrombosis and pulmonary embolism – blood clots in the leg veins, which can dislodge and move to the heart and lungs.
Heart attacks and strokes are usually acute events and are mainly caused by a blockage that prevents blood from flowing to the heart or brain. The most common reason for this is a build-up of fatty deposits on the inner walls of the blood vessels that supply the heart or brain. Strokes can also be caused by bleeding from a blood vessel in the brain or from blood clots.
What are the risk factors for cardiovascular disease?
The most important behavioural risk factors of heart disease and stroke are unhealthy diet, physical inactivity, tobacco use and harmful use of alcohol. Behavioural risk factors are responsible for about 80% of coronary heart disease and cerebrovascular disease (1).
The effects of unhealthy diet and physical inactivity may show up in individuals as raised blood pressure, raised blood glucose, raised blood lipids, and overweight and obesity. These “intermediate risks factors” can be measured in primary care facilities and indicate an increased risk of developing a heart attack, stroke, heart failure and other complications.
Cessation of tobacco use, reduction of salt in the diet, consuming fruits and vegetables, regular physical activity and avoiding harmful use of alcohol have been shown to reduce the risk of cardiovascular disease. The cardiovascular risk can also be reduced by preventing or treating hypertension, diabetes and raised blood lipids.
Policies that create conducive environments for making healthy choices affordable and available are essential for motivating people to adopt and sustain healthy behavior.
There are also a number of underlying determinants of CVDs, or "the causes of the causes". These are a reflection of the major forces driving social, economic and cultural change – globalization, urbanization, and population ageing. Other determinants of CVDs include poverty, stress and hereditary factors.
What are common symptoms of cardiovascular diseases?
Symptoms of heart attacks and strokes
Often, there are no symptoms of the underlying disease of the blood vessels. A heart attack or stroke may be the first warning of underlying disease. Symptoms of a heart attack include:
- pain or discomfort in the centre of the chest;
- pain or discomfort in the arms, the left shoulder, elbows, jaw, or back.
In addition the person may experience difficulty in breathing or shortness of breath; feeling sick or vomiting; feeling light-headed or faint; breaking into a cold sweat; and becoming pale. Women are more likely to have shortness of breath, nausea, vomiting, and back or jaw pain.
The most common symptom of a stroke is sudden weakness of the face, arm, or leg, most often on one side of the body. Other symptoms include sudden onset of:
- numbness of the face, arm, or leg, especially on one side of the body;
- confusion, difficulty speaking or understanding speech;
- difficulty seeing with one or both eyes;
- difficulty walking, dizziness, loss of balance or coordination;
- severe headache with no known cause; and
- fainting or unconsciousness.
People experiencing these symptoms should seek medical care immediately.
What is rheumatic heart disease?
Rheumatic heart disease is caused by damage to the heart valves and heart muscle from the inflammation and scarring caused by rheumatic fever. Rheumatic fever is caused by streptococcal bacteria, which usually begins as a sore throat or tonsillitis in children.
Rheumatic fever mostly affects children in developing countries, especially where poverty is widespread. Globally, almost 2% of deaths from cardiovascular diseases is related to rheumatic heart disease, while 42% of deaths from cardiovascular diseases is related to ischaemic heart disease, and 34% to cerebrovascular disease (2).
Symptoms of rheumatic heart disease
- Symptoms of rheumatic heart disease include: shortness of breath, fatigue, irregular heart beats, chest pain and fainting.
- Symptoms of rheumatic fever include: fever, pain and swelling of the joints, nausea, stomach cramps and vomiting.
- Early treatment of streptococcal sore throat can stop the development of rheumatic fever. Regular long-term penicillin treatment can prevent repeat attacks of rheumatic fever which give rise to rheumatic heart disease and can stop disease progression in people whose heart valves are already damaged by the disease.
Why are cardiovascular diseases a development issue in low- and middle-income countries?
- Over 80% of the world's deaths from CVDs occur in low- and middle-income countries.
- People in low- and middle-income countries are more exposed to risk factors such as tobacco, leading to CVDs and other noncommunicable diseases. At the same time they often do not have the benefit of prevention programmes compared to people in high-income countries.
- People in low- and middle-income countries who suffer from CVDs and other noncommunicable diseases have less access to effective and equitable health care services which respond to their needs (including early detection services).
- As a result, many people in low- and middle-income countries die younger from CVDs and other noncommunicable diseases, often in their most productive years.
- The poorest people in low- and middle-income countries are affected most. At the household level, sufficient evidence is emerging to prove that CVDs and other noncommunicable diseases contribute to poverty due to catastrophic health spending and high out of pocket expenditure.
- At macro-economic level, CVDs place a heavy burden on the economies of low- and middle-income countries. Noncommunicable disease including cardiovascular disease and diabetes are estimated to reduce GDP by up to 6.77% in low- and middle-income countries experiencing rapid economic growth, as many people die prematurely (1).
How can the burden of cardiovascular diseases be reduced?
Very cost effective interventions that are feasible to be implemented even in low resource settings have been identified by WHO for prevention and control of cardiovascular diseases.
Heart disease and stroke can be prevented through healthy diet, regular physical activity and avoiding tobacco smoke. Individuals can reduce their risk of CVDs by engaging in regular physical activity, avoiding tobacco use and second-hand tobacco smoke, choosing a diet rich in fruit and vegetables and avoiding foods that are high in fat, sugar and salt, and maintaining a healthy body weight and avoiding the harmful use of alcohol.
Comprehensive and integrated action is the means to prevent and control CVDs.
- Comprehensive action requires combining approaches that seek to reduce the risks throughout the entire population with strategies that target individuals at high risk or with established disease.
- Examples of population-wide interventions that can be implemented to reduce CVDs include: comprehensive tobacco control policies, taxation to reduce the intake of foods that are high in fat, sugar and salt, building walking and cycle paths to increase physical activity, providing healthy school meals to children.
- Integrated approaches focus on the main common risk factors for a range of chronic diseases such as CVD, diabetes and cancer: unhealthy diet, physically inactivity and tobacco use.
There are several intervention options available. Some of these interventions can be implemented even by non-physician health workers in close- to- client facilities. They are very cost effective and high impact interventions and have been prioritized by WHO. For example:
- People at high risk can be identified early in primary care, using simple tools such as specific risk prediction charts. If people are identified early, inexpensive treatment is available to prevent many heart attacks and strokes.
- Survivors of a heart attack or stroke are at high risk of recurrences and at high risk of dying from them. The risk of a recurrence or death can be substantially lowered with a combination of drugs – statins to lower cholesterol, drugs to lower blood pressure, and aspirin.
- In addition surgical operations are sometimes required to treat CVDs. They include coronary artery bypass, balloon angioplasty (where a small balloon-like device is threaded through an artery to open the blockage), valve repair and replacement, heart transplantation, and artificial heart operations.
- Medical devices are required to treat some CVDs. Such devices include pacemakers, prosthetic valves, and patches for closing holes in the heart.
There is a need for increased government investment in prevention and early detection through national programmes aimed at prevention and control of noncommunicable diseases including CVDs.
(1) Global status report on noncommunicable disaeses 2010. Geneva, World Health Organization, 2011.
(2) Global atlas on cardiovascular disease prevention and control. Geneva, World Health Organization, 2011.
(3) Mathers CD, Loncar D. Projections of global mortality and burden of disease from 2002 to 2030. PLoS Med, 2006, 3(11):e442.
(4) Lim SS, Vos T, Flaxman AD, Danaei G, Shibuya K, Adair-Rohani H et al. A comparative risk assessment of burden of disease and injury attributable to 67 risk factors and risk factor clusters in 21 regions, 1990-2010: a systematic analysis for the Global Burden of Disease Study 2010. Lancet, 2012, 380(9859):2224–2260.
(5) The global burden of disease: 2004 update. Geneva, World Health Organization, 2008.