Key facts
- A heart attack, or acute myocardial infarction, happens when blood flow to part of the heart muscle is suddenly cut off, most often by a clot forming on a ruptured fatty deposit inside a coronary artery.
- Ischaemic heart disease (IHD), also known as coronary heart disease (CHD), is the underlying condition behind most heart attacks. Acute coronary syndrome (ACS) refers to a spectrum of acute presentations caused by reduced blood flow to the heart that require urgent medical care. A heart attack is one of the most serious forms of ACS. IHD is the leading cause of death worldwide. It was responsible for 9 million deaths in 2021, around 13% of all deaths globally.
- Deaths from ischaemic heart disease have risen by 2.7 million since 2000, even as age-standardized death rates fell by roughly 15% over the same period. Population growth and ageing are driving the absolute rise; better prevention and treatment are behind the underlying rate decline.
- Heart attack and stroke together account for 85% of all deaths from cardiovascular disease (CVD), and more than three quarters of CVD deaths occur in low- and middle-income countries.
- Most heart attacks can be prevented by controlling a small number of behavioural and metabolic risk factors: tobacco use, an unhealthy diet, physical inactivity, harmful use of alcohol, overweight and obesity, raised blood pressure, raised blood glucose and raised blood lipids.
- Time lost is heart muscle lost. Recognizing symptoms early and reaching emergency care within the first hours substantially improves the chance of survival and recovery.
Overview
A heart attack occurs when one of the coronary arteries that supply blood to the heart muscle becomes blocked, usually by a blood clot that forms where a fatty deposit (atherosclerotic plaque) has ruptured. Starved of oxygen, the affected section of heart muscle begins to die within minutes, which is why a heart attack is a medical emergency rather than something that can wait until morning.
Clinicians describe heart attack as part of an acute coronary syndrome (ACS), which also includes angina, a milder and usually temporary form of chest pain caused by reduced rather than blocked blood flow. Heart attack itself is sometimes divided into two main types depending on the electrocardiogram pattern and extent of damage: ST-elevation myocardial infarction (STEMI), usually involving complete blockage of an artery, and non-ST-elevation myocardial infarction (NSTEMI), usually involving partial blockage. Both require urgent treatment, though the specific approach differs.
A heart attack is not the same thing as a cardiac arrest, even though the two are frequently confused and can occur together. A heart attack is a circulation problem in one part of the heart; a cardiac arrest is an electrical malfunction that causes the heart to stop beating altogether. A heart attack can trigger a cardiac arrest, but many heart attacks do not.
Symptoms
The classic warning sign is pain or discomfort in the centre of the chest, often described as pressure, tightness or squeezing rather than a sharp pain. This may spread to one or both arms, the shoulders, jaw, neck or back. Other common symptoms include shortness of breath, nausea or vomiting, light-headedness, a cold sweat and pale skin.
Symptoms can vary considerably between individuals. Women, older people and people with diabetes are more likely to experience atypical presentations, including breathlessness, fatigue, indigestion-like discomfort or back and jaw pain without prominent chest pain. In some cases, particularly in people with diabetes-related nerve damage, a heart attack causes little or no pain at all, a pattern known as a silent heart attack that is often only discovered later through routine testing.
Anyone experiencing these symptoms should seek emergency medical care immediately rather than waiting to see if they pass.
Causes and risk factors
The underlying cause of nearly all heart attacks is atherosclerosis, a gradual build-up of fatty deposits along the inner walls of the arteries that can develop silently over decades before a plaque ruptures and triggers a clot.
A relatively small set of risk factors accounts for most of this process. Behavioural risk factors include tobacco use, a diet high in salt, sugar and unhealthy fats, physical inactivity, and harmful use of alcohol. Air pollution is an important environmental contributor. Over time, these behaviours tend to produce a set of measurable intermediate risk factors, principally raised blood pressure, raised blood glucose, raised blood lipids, and overweight or obesity, each of which independently raises the risk of a heart attack and can be identified and managed in primary care long before an event occurs.
Age, sex and family history also influence risk and cannot be modified, but they rarely act alone. Social and economic conditions matter too: poverty, chronic stress, rapid urbanization and limited access to healthy food and health services all shape how often the modifiable risk factors above go undetected and untreated.
Diagnosis
A suspected heart attack is diagnosed using a combination of the person's symptoms, an electrocardiogram (ECG) to detect characteristic changes in the heart's electrical activity, and a blood test for cardiac troponin, a protein released into the bloodstream when heart muscle is damaged. Coronary angiography, in which a thin catheter is used to image the coronary arteries directly, confirms the location and severity of the blockage and often allows treatment to proceed in the same procedure.
Treatment
The priority in a heart attack is restoring blood flow to the affected part of the heart as quickly as possible. Where available, this is usually done through primary percutaneous coronary intervention, commonly called angioplasty, in which a catheter is used to open the blocked artery and typically insert a stent to keep it open. Where rapid access to angioplasty is not possible, clot-dissolving medicines known as thrombolytics can be given instead.
Alongside emergency reperfusion, a small group of medicines forms the backbone of both immediate and long-term treatment: aspirin and other antiplatelet drugs to prevent further clotting, beta-blockers to reduce the heart's workload, angiotensin-converting enzyme inhibitors to protect heart function, and statins to lower cholesterol and stabilize remaining plaques. Some people go on to need coronary artery bypass surgery, in which a healthy blood vessel is used to reroute blood around a severely blocked artery. Structured cardiac rehabilitation, combining supervised exercise, risk factor management and psychological support, improves long-term outcomes after a heart attack but remains underused, particularly in low-resource settings.
Prevention
Because atherosclerosis develops over many years, prevention works best when it starts early and continues throughout life. At the individual level, this means not using tobacco, eating a diet rich in fruit, vegetables and whole grains and low in salt and saturated fat, staying physically active, limiting alcohol, and treating raised blood pressure, diabetes and raised blood lipids where they are present.
At the population level, governments can shift these odds substantially through tobacco control measures, policies that reduce salt and industrially produced trans-fat in the food supply, urban planning that supports physical activity, and action on air quality. Evidence from many countries shows that well-implemented hypertension and cholesterol management programmes in primary care are both effective and inexpensive relative to the cost of treating a heart attack once it occurs.
WHO response
The World Health Organization considers prevention, early detection, and management as public health priority and a central component of its work on cardiovascular disease and noncommunicable diseases more broadly.
In 2016, WHO launched the Global HEARTS Initiative to support countries in strengthening cardiovascular disease prevention and management through primary health care. The WHO HEARTS, and HEARTS-D technical packages for cardiovascular disease and diabetes management at primary health care, are built around six modules: healthy-lifestyle counselling, evidence-based treatment protocols, access to essential medicines and technology, risk-based cardiovascular disease management, team-based care, and systems for monitoring.
To reduce the overall 10-year risk of cardiovascular disease, WHO promotes implementation of its Best Buys and other recommended interventions for NCD prevention and control. These include drug therapy, such as antihypertensive medicines and statins, combined with counselling for individuals who have experienced a heart attack or stroke, and for people at high risk (≥20%) of a fatal or non-fatal cardiovascular event within the next 10 years, based on the WHO cardiovascular risk prediction charts.
To strengthen the organization and delivery of acute cardiovascular care, WHO has developed the Framework for the care of acute coronary syndrome and stroke, which provides guidance for countries on improving access to timely, equitable, and quality care across the continuum of services, from emergency recognition and referral to definitive treatment and rehabilitation.
Core medicines used in the prevention and treatment of heart attack, including aspirin, beta-blockers, angiotensin-converting enzyme inhibitors and statins, are included on the WHO Model List of Essential Medicines.
Under the Global action plan for the prevention and control of noncommunicable diseases 2013–2020, WHO Member States agreed to reduce the global prevalence of raised blood pressure by 25% between 2010 and 2025, and to ensure that at least 50% of eligible people receive drug therapy and counselling to prevent heart attack and stroke by 2025. WHO also monitors global and country-level trends in ischaemic heart disease mortality through its Global Health Estimates programme, which underpins the figures reported here.