What Coronary Artery Disease Is — The Road That Feeds the Heart, Narrowed and Blocked

Even the Heart Needs Blood to Beat

The heart pumps blood through the entire body without ever resting. That blood carries oxygen to the leg muscles and the brain as well. But because the heart is also a muscle that squeezes blood out, that muscle itself must also receive blood carrying oxygen to move. The heart is a unique organ that sends blood to feed its own muscle (PMID 28333376).

The path that supplies blood to the heart muscle is separate, and this article is about how that path gets diseased. It is a common disease. Every year, 7.4 million people worldwide die from this disease, making it the leading cause of death at 13.2% of all deaths. This is according to a tally from a review paper published in 2017 (PMID 27993119).

Meanwhile, in wealthy countries, the number of new patients has steadily decreased over the past few decades. Experts think this may be thanks to improvements in treatment when things suddenly block up, and in prevention that stops the disease beforehand (PMID 33605111). This means it is a disease where treatment and prevention both have room to step in.

This article follows in order how that path narrows, when a narrowed path falls short, what happens when it suddenly blocks and why every single minute is precious, and what is done to open it back up and keep it from blocking again. Unfamiliar terms are explained right where they appear.

The Path Into the Heart Muscle

The vessels that carry blood leaving the heart are called arteries. The coronary arteries are the arteries that supply the blood pumped out by the heart to the heart muscle itself. Thick branches stretch along the surface of the heart, and thinner branches splitting off from them enter the muscle.

How much blood flows through this path is determined together by several factors. The force of the muscle squeezing and pressing on the vessel, the pressure pushing blood into the vessel, substances released by the working muscle, the inner wall of the vessel, nerves, and hormones are all involved. Coming together, they adjust the flow so that oxygen enters as much as the heart muscle needs (PMID 28333376). When the path is fine, it means that the necessary amount enters under normal conditions.

What makes this path diseased is a lump growing within the artery wall. Atherosclerosis is a disease where fat and cells accumulate inside the wall of an artery, forming a lump and narrowing that spot. Plaque is the lump formed inside the artery wall in that way. What the lump is made of and how it grows is covered separately in "What Cholesterol Is and Why We Measure It".

Coronary artery disease is a disease where atherosclerosis develops in the coronary arteries, narrowing or blocking the path to the heart muscle. The cause of this disease is atherosclerosis, and all the stories in this article also start from here (PMID 40179933).

This disease grows quietly for a long time. At first, there are no symptoms at all. Afterwards, it reveals itself in various forms. Sometimes the chest hurts when exerting effort, sometimes the path suddenly blocks, sometimes the heart fails to send its share of blood, and sometimes it comes as sudden cardiac death (PMID 27091673).

The risk builds up over a lifetime. In a 2025 report, an expert committee organized by the medical journal The Lancet traces the time when that risk starts building all the way back to inside the mother's womb (PMID 40179933).

The coronary arteries are the path the heart supplies to its own muscle, and this disease is one where a lump grows within the wall of that path.

When a Narrowed Path Struggles Under Effort

Walking on flat ground is fine, but climbing stairs makes the chest tighten. Standing still and resting for a few minutes makes it subside. This pain arrives after physical exertion or emotional tension puts stress on the heart. It lasts for 3 to 5 minutes and usually arrives in a fixed spot (PMID 3051692).

Ischemia is a state where the blood coming in falls short compared to the oxygen the tissue uses. Even when the path narrows, when resting, enough blood usually gets in to meet the need. When climbing stairs, because the heart beats harder and faster to use more oxygen, the narrowed path cannot let in that much. The idea that ischemia occurs in the heart muscle because the coronary arteries have narrowed is the long-standing framework for understanding this disease (PMID 40179933).

Angina is the pain or tightening feeling that comes to the chest when the heart muscle falls into ischemia. It occurs when the incoming oxygen fails to meet the demands of the heart muscle (PMID 33944871), and it is the representative appearance in which coronary artery disease reveals itself (PMID 40086653). That pain tightening on the stairs is angina. However, there are also cases where ischemia is present but there is no pain at all (PMID 3051692).

Angina can stay the same for months or years. It comes when exerting a similar degree of effort, and the pattern where it subsides upon resting does not change. Angina with a pattern stabilized like this is experienced by nearly 10 million adults in the United States alone (PMID 33944871).

Then there are times when angina suddenly becomes stronger and lasts longer. This change must be investigated as soon as possible. This is because the death of heart muscle quite frequently follows behind such a change (PMID 3051692).

Angina occurs even if the thick path has not narrowed. There is a test that puts a drug visible on X-rays (a contrast agent) inside the coronary arteries to take a picture of the shape of the path. According to a European expert consensus document, up to 70% of people who received this test did not have a place narrowed enough to block the path, and such cases are more common in women (PMID 32624456).

A considerable number of these people experience ischemia for other reasons. It is due to abnormalities such as spasms where the vessel suddenly clamps down, or tiny blood vessels too small to catch on the test images failing to work properly. Compared to people without symptoms, these individuals experience more frequent heart and blood vessel trouble and repeated hospitalizations (PMID 32624456). This means that even if no narrowed spot is seen in the pictures, the ischemia is real.

A narrowed path holds up under normal conditions, but falls short when the heart uses more oxygen, and that shortage reveals itself as angina.

When a Road Suddenly Blocks

Roads suddenly blocking usually start with a plaque tearing open. Because blood has the property of clotting at a damaged vessel site to seal the wound, a blood clot forms on top of the torn plaque as well. That this is the main mechanism of sudden cardiac events has been known for 30 years (PMID 40019413, PMID 25544119).

There is also a typical plaque shape that has been cited as prone to rupturing. It is a plaque with a lot of fat inside, covered by a thin cap made of tough fibrous tissue. The blood can also clot when the surface erodes without the cap tearing. In studies directly looking inside the vessel, this mechanism accounted for up to 40% of acute events (PMID 40019413).

Acute coronary syndrome is a bundled name for diseases caused by a sudden decrease in blood flow to the heart. More than 7 million people worldwide receive this diagnosis each year (PMID 35166796). Angina that becomes sudden, severe, and prolonged, as we saw earlier, also falls into this bundle (PMID 35166796).

At the center of this bundle is myocardial infarction. Myocardial infarction is a disease where a coronary artery is blocked, and the heart muscle behind it dies because it fails to receive oxygen. Dead muscle cannot be reversed. However, before the muscle dies, there are many ways to protect the vulnerable muscle (PMID 3051692). Treatments to quickly open the blocked path all hinge on this difference.

Acute coronary syndrome is first divided by the shape of the electrocardiogram. An electrocardiogram is a graph that records the flow of electricity generated when the heart beats, using electrodes attached to the body. Every time the heart beats, a few waves pass across the graph, and one section between them is called the ST segment. It is divided into two depending on whether this section is elevated or not (PMID 41358986).

ST-segment elevation myocardial infarction is a myocardial infarction where a section called the ST segment rises on the electrocardiogram, meaning the coronary artery is completely blocked. It accounts for about 30% of acute coronary syndrome. The remaining roughly 70% are cases where this section does not rise, meaning the vessel is partially blocked or repeatedly blocked and opened (PMID 35166796). This distinction is used again in the treatment timetable later.

In women, the presentation looks a bit different. Experiencing acute coronary syndrome even without a narrowing large enough to block the vessel is more common in women, and mostly in younger women. In a registry dataset of 10,019 acute coronary syndrome patients, such cases were 20.9% of female patients and 6.6% of male patients (PMID 35760149). When comparing only patients with a narrowing large enough to block the vessel, there was no sex difference in the proportions of the two forms divided by the electrocardiogram (PMID 35760149).

When a plaque ruptures or erodes and blood clots on top of it, the road suddenly blocks, and the side where the ST segment rises on the electrocardiogram is the case where the vessel is completely blocked.

Signals Inside the Chest, Signals Outside the Chest

For a person who arrives at the hospital with acute coronary syndrome, the most common symptom is a chest discomfort that occurs at rest. Roughly 79% of men and roughly 74% of women experience this. Symptoms that do not explicitly point to the heart, such as shortness of breath, also appear in roughly 40% of men and roughly 48% of women. Such symptoms sometimes occur alone, but they happen more often alongside chest pain (PMID 35166796).

Women more often than men complained of pain between the shoulder blades, nausea or vomiting, and shortness of breath, and less often of chest pain and cold sweats. Even so, the most common symptom for both sexes was chest pain, and the other symptoms also overlapped substantially. The authors of a meta-analysis pooling 27 studies comparing men and women concluded that since these differences have been recognized for many years, we should stop slapping the labels "typical" and "atypical" onto symptoms (PMID 32363989).

Older people are different again. In those 65 and older, acute coronary syndrome is the leading cause of death, and it can present without chest pain. Upon arrival at the emergency room, the most common complaint in this age group is still chest pain. However, older adults who arrived without chest pain were twice as likely to die as those who arrived with chest pain (PMID 23647882).

The causes of chest pain are broad. They range from life-threatening conditions like a heart attack or a blocked blood vessel in the lungs, to much more common and harmless conditions like tension in the chest muscles and a disease where stomach acid flows backward (PMID 33331950). This means that symptoms alone cannot tell you which of these it is. Therefore, evaluation is done at a hospital equipped to perform electrocardiograms and blood tests.

The hospital takes an electrocardiogram and draws blood to measure a single protein. Troponin is a protein that leaks into the blood when heart muscle cells are injured. A review synthesizing multiple studies notes that if acute coronary syndrome is suspected, an electrocardiogram should be taken within 10 minutes of arrival (PMID 35166796). The 2021 chest pain guidelines jointly issued by American societies designate the high-sensitivity troponin test, which detects even very small amounts, as the primary blood test to look at (PMID 35775423).

There is a reason why both tests are necessary. Among people experiencing acute chest pain, roughly 10% are ultimately diagnosed with acute coronary syndrome. That is about one in ten, but symptoms alone cannot single out who that one person is. Furthermore, even in the emergency room, the initial interview, physical examination, and electrocardiogram alone could neither confirm nor rule out this disease. A risk score calculated by factoring in even the first troponin value provided more information (PMID 26547467).

Chest pain is the most common, but signals outside the chest are also numerous, and what they are is sorted out at the hospital using an electrocardiogram and troponin.

Time Is Muscle

There is a saying in this field: "Time is muscle" (PMID 32861583). The length of time a vessel was blocked directly relates to permanent muscle damage and death (PMID 26385072). It means that time flowing while the vessel remains blocked is muscle lost.

Reperfusion is a treatment that reopens a blocked coronary artery to get blood flowing to the heart muscle again. Opening it in time reduces muscle damage, shrinks the area that dies, and lowers complications and death (PMID 24902975).

There are two ways to open it. One is melting the blood clot with medication, and the other is a procedure. Coronary intervention is a procedure where a thin tube is pushed into an artery to widen a narrowed or blocked coronary artery from the inside using a balloon. The widened site is usually left with a small, mesh-like tube called a stent. Stents greatly reduced the rate of the site narrowing again compared to using just a balloon (PMID 18313480).

A study that splits patients into two treatments by a random draw to compare the results is called a randomized trial. Because the two groups are similar from the start, it is easy to attribute differences in results to the treatment. In multiple randomized trials, this procedure resulted in fewer deaths, recurrent myocardial infarctions, and strokes than the side that melted blood clots with medication (PMID 18313480). That is why it is the preferred choice if it can be done in time (PMID 24902975).

The time measured by hospitals starts at the hospital door. Door-to-balloon time is the time from when a patient walks through the hospital door to when the blocked coronary artery is opened with a balloon. A door-to-balloon time of 90 minutes or less has become the benchmark for how well a hospital treats ST-segment elevation myocardial infarction (PMID 32021496).

An observational study does not assign treatments, but observes things as they actually happen. When 32 prospective observational studies following patients forward, totaling 299,320 people, were pooled and re-analyzed, ST-segment elevation myocardial infarction patients with a door-to-balloon time exceeding 90 minutes had a higher short-term death risk (PMID 29437704).

There are also analyses that set different reference times. When symptom-to-balloon time and door-to-balloon time were each divided at 120 minutes, the group within 120 minutes had fewer deaths than the group that exceeded it. This analysis pooled 10 studies, mostly observational, covering 71,099 people. The two groups were separated not by individual patients, but by the average or median time of each study (PMID 32842962).

One review summarizes this timetable in terms of treatment outcomes like this: in ST-segment elevation myocardial infarction, reopening the artery with coronary intervention within 120 minutes of arrival reduces death from 9% to 7%. Places where the procedure cannot be performed within 120 minutes use clot-dissolving medication first. They then transfer the patient to a capable hospital with the goal of performing the procedure within 24 hours (PMID 35166796).

Time is tied to outcomes on the non-ST-elevation side as well. In the same review, for high-risk patients, a treatment involving looking inside the vessel with a tube and reopening it within 24 to 48 hours was associated with reduced death. Death dropped from 6.5% to 4.9% (PMID 35166796).

Looking at it in terms of muscle: for every hour of delay from the start of symptoms to reperfusion, there was a relationship where the share of muscle at risk that survived was lower by an absolute value of 13.1%. "By an absolute value" means that whatever percentage survived, that exact magnitude is subtracted directly from it. This is an analysis pooling 38 studies that imaged heart muscle using magnetic resonance imaging (MRI), covering 5,106 people (PMID 32988935).

The authors interpret that the protection gained by reducing the time to reperfusion leaves behind more muscle. They also note that there was high variability between studies (PMID 32988935).

Yet the clock is already running before the hospital door. The total time the muscle goes without blood is counted from the moment chest pain begins. This is the sum of the time from symptoms to the hospital door, plus the time from the door to the balloon. While in-hospital time has decreased over the years, cutting pre-hospital time remains a task ahead (PMID 32021496).

Let us follow a single person. Sitting on the couch in the evening, they feel a crushing sensation in the center of their chest and shortness of breath. Chest discomfort at rest is the most common symptom in acute coronary syndrome, and shortness of breath usually accompanies chest pain (PMID 35166796). At first, they wait, thinking it feels like indigestion.

Attributing symptoms to something other than the heart has been cited as a factor delaying hospital arrival. This is the result of a review summarizing 28 studies from China (PMID 20938251). This waiting also counts toward the time the muscle goes without blood (PMID 32021496).

Coming by ambulance can set things in motion before reaching the hospital. Taking an electrocardiogram in the ambulance, pre-activating the catheterization laboratory—the room where blocked vessels are opened—before the patient arrives, and letting patients with clear diagnoses and stable conditions bypass the emergency room. These are strategies medical systems use to reduce this delay (PMID 24902975, PMID 34053616).

Among these, the strategy of pre-activating the catheterization laboratory has been compared separately. In an analysis gathering observational studies of patients suspected of having an ST-segment elevation myocardial infarction, the group with pre-hospital catheterization laboratory activation had a door-to-balloon time 33.1 minutes shorter than the group activated from the emergency room. Short-term death was lower by 26 per 1,000 people, and long-term death by 54 per 1,000 people (PMID 36120483). The two compared groups were those whose catheterization laboratory was awakened pre-hospital versus in the emergency room, and it is not a comparison between calling an ambulance and not calling one.

When the blocked vessel opens in the catheterization laboratory, blood enters the muscle again. The 13.1% per-hour relationship seen earlier was obtained using time measured from the start of symptoms. Therefore, the wait on the couch is included in that time (PMID 32988935). Among these, the time patients and families can reduce is the waiting at the very beginning. A 2000 review placed public education to reduce the delay in calling for help at the very top of four strategies to reduce the time until clot-dissolving medication is given (PMID 11142275).

Women experience delays at multiple stages of this timeline. Among patients undergoing coronary intervention for ST-segment elevation myocardial infarction, both the door-to-balloon time and the symptom-to-balloon time were longer for women (PMID 34334335). A 2021 review suggests that the common belief that women have a lower risk of myocardial infarction can lead to delays by both patients and medical staff (PMID 32861583). Meanwhile, in acute coronary syndromes caused by atherosclerosis, treatments known to be effective in men are also effective in women (PMID 38466532).

It has also become apparent that there are limits to reducing in-hospital time alone. A 2014 review notes that even though door-to-balloon times decreased, in-hospital mortality remained virtually unchanged over the preceding several years. It argues that other factors, such as patient-side delays, must be addressed together (PMID 24902975). The conclusion that efforts to lower door-to-balloon times did not translate into reduced deaths points in the same direction (PMID 26385072).

One interpretation for why this happens is that the relationship between time and risk is a curved line (PMID 29437704). This means that even if time increases by the same amount, the magnitude by which risk increases differs depending on which interval the increase occurred in.

The sooner a blocked vessel is opened, the more muscle is saved, and that time runs from the exact moment symptoms begin.

Opening Again, and Keeping Them Open

In people with stable angina who experience chest pain only upon exertion, myocardial infarction or death occurs on average at a rate of 3 to 4% per year (PMID 33944871). For these individuals, the treatment that reopens narrowed pathways is mostly percutaneous coronary intervention. Compared with medical therapy alone, this treatment did not reduce death or myocardial infarction, and that remained true even when ischemia was moderate to severe. Instead, there were clear benefits for angina and quality of life (PMID 33944871).

The same review notes that lifestyle habits and preventive medications should be refined first, and when angina impairs quality of life, drugs are generally tried first before choosing a procedure (PMID 33944871).

Instead of widening the path, doctors sometimes build a detour around it. Coronary artery bypass graft surgery connects blood vessels harvested from other parts of the body to create a new path bypassing the blocked or narrowed site.

There is an analysis combining 11 randomized trials and 11,518 people that compared the two methods. The subjects were patients without acute myocardial infarction who had multiple narrowed coronary arteries or a narrowing in the main stem before it branches on the left side of the heart. All patients were selected by a heart team. Over 5 years, death was 11.2% in the percutaneous coronary intervention group and 9.2% in the bypass surgery group (PMID 29478841).

The difference was clear in patients with multi-vessel disease, and particularly among those with diabetes (15.5% versus 10.0%). It was similar in patients without diabetes (8.7% versus 8.0%) and in patients with main stem narrowing (10.7% versus 10.5%). The authors add that longer follow-up is needed (PMID 29478841). This means that which approach is right depends on the shape of the narrowing and the individual.

Work remains even after opening the pathway. Cardiac rehabilitation is a program centered on exercise training, supplemented with psychological support and education when needed (PMID 34741536). A 2021 Cochrane review that pooled randomized trials included 85 randomized trials and 23,430 people. Compared with a control group that did not exercise, the risk of myocardial infarction between 6 and 12 months was 0.72 times, and all-cause hospitalization was 0.58 times. Both mean these outcomes were lower in the group that underwent rehabilitation (PMID 34741536).

All-cause death may have decreased slightly to 0.87 times. However, the 95% confidence interval—the range likely to contain the true value—was 0.73 to 1.04, which stretched to include no reduction (PMID 34741536).

The authors concluded that rehabilitation provides important benefits by reducing the risk of myocardial infarction, substantially cutting hospitalizations, and improving quality of life up to 12 months, and they consider that it may also reduce cardiac death over a longer horizon. The magnitude of improvement in quality of life was small. However, fewer than 15% of the participants were women (PMID 34741536).

Despite these benefits, it is underused. The rates of referral and participation in cardiac rehabilitation remain low (PMID 28318815), and women are referred less often than men (PMID 27807732). Although various measures to reduce recurrence and improve the distant future for those who have experienced an event have proven effective, the rates of actually starting and continuing them are low (PMID 28618916). One review lists smoking cessation, weight management, a Mediterranean diet, and exercise therapy as the core components of treatment (PMID 40086653).

Some voices call for looking further ahead. The 2025 Lancet Commission considers the current framework centered on ischemia and acute events—that is, the way of treating the disease after blood is deficient or a pathway is blocked—to be too late. It therefore argues for shifting toward finding and halting plaque itself early across the lifespan (PMID 40179933).

The Commission also estimated that eliminating risk factors such as smoking, high blood pressure, high cholesterol, and poor diet by 2050 could lower the mortality rate of this disease by 82.1% (PMID 40179933). This is a proposal by the Commission, and 82.1% is an estimate under the assumption that all risk factors are completely eliminated.

Blocked pathways are opened with procedures or bridged with detours, and the work of keeping them from blocking again falls to rehabilitation and recurrence prevention.

Where to Look Next

This is where the primer ends. There are a few topics we only mentioned in passing.

The pathways the blood pumped by the heart takes are covered in How the Heart Moves Blood — Four Chambers, Four Doors, Two Loops, and blood pressure, a major risk factor for this disease, in What Blood Pressure Measures — Two Numbers, and an Answer That Changes With Where You Measure. How the lumps inside the walls grow leads to What Cholesterol Is and Why We Measure It — Four Lines on a Blood Test, and the Packages They Name.

What happens when the same thing occurs on the way to the brain, and why time determines the outcome there as well, is explored in What a Stroke Actually Is — Blocked, Burst, and the Clock.

The story of how improved numbers and improved people can diverge—such as when a narrowed pathway is reopened but deaths do not decrease—is covered in Better Numbers, Better Patients? — An Introduction to Surrogate Endpoints. How to read numbers like "from 9% to 7% mortality" or "26 people per 1,000" is answered in What Does "50% Lower Risk" Mean in People? — Reading Relative Risk, Absolute Risk, and NNT.

Arrhythmias, where the heart's electrical signals are disrupted, and atrial fibrillation, the most common among them, continue in What Atrial Fibrillation Is — The Upper Chambers That Lost the Beat, and the Blood That Pools There.

Source Papers

• "Regulation of Coronary Blood Flow." (2017) — PMID 28333376 — The heart is the only organ that supplies its own blood via the coronary circulation, and tissue pressure, perfusion pressure, myogenic, metabolic, endothelial, neural, and hormone mechanisms work together to regulate coronary resistance and meet the oxygen demands of the myocardium.
• "Pathophysiology of Myocardial Infarction and Acute Management Strategies." (2017) — PMID 27993119 — Coronary artery disease accounts for 13.2% of all deaths annually (7.4 million people) and is the leading cause of death worldwide.
• "Epidemiology and the Magnitude of Coronary Artery Disease and Acute Coronary Syndrome: A Narrative Review." (2021) — PMID 33605111 — Incidence has been declining for decades in developed countries, which may be thanks to improvements in acute care and primary and secondary prevention.
• "The Lancet Commission on rethinking coronary artery disease: moving from ischaemia to atheroma." (2025) — PMID 40179933 — Coronary artery disease is caused by atherosclerosis. Risk accumulates from inside the womb throughout life. The commission considers the ischemia-centric framework flawed and argues for redefining it around the atheroma, estimating that eliminating risk factors by 2050 could reduce mortality by 82.1%.
• "Coronary Atherosclerosis: Pathophysiologic Basis for Diagnosis and Management." (2016) — PMID 27091673 — Coronary atherosclerosis progresses over a long time and manifests as asymptomaticity, stable angina, acute coronary syndrome, heart failure, and sudden death.
• "[Angina pectoris]." (1988) — PMID 3051692 — Angina pain occurs in typical locations 3 to 5 minutes after physical or mental stress "when demand arises." Asymptomatic ischemia also exists. Unstable angina, where angina pain suddenly becomes more severe and prolonged, not infrequently progresses to acute myocardial infarction and must be recognized quickly. Infarction cannot be reversed, but before that happens there are many means to protect the vulnerable myocardium.
• "Diagnosis and Management of Stable Angina: A Review." (2021) — PMID 33944871 — About 10 million US adults suffer from stable angina, which occurs when myocardial oxygen supply fails to keep up with demand. The average annual risk of myocardial infarction and death is 3 to 4%. Revascularization (mainly intervention) did not reduce death or myocardial infarction compared with optimal medical therapy (even in moderate-to-severe ischemia), but it did benefit angina and quality of life. The authors emphasize lifestyle and preventive medications and recommend procedures usually after trying medications.
• "Management of angina pectoris." (2025) — PMID 40086653 — Angina is the main manifestation of ischemic heart disease. Smoking cessation, weight management, a Mediterranean diet, and exercise therapy are essential components of treatment.
• "An EAPCI Expert Consensus Document on Ischaemia with Non-Obstructive Coronary Arteries…" (2020) — PMID 32624456 — Expert consensus statement. Up to 70% of patients undergoing invasive angiography have no obstructive lesions, and it is more common in women. INOCA is caused by spasm or microvascular dysfunction, and it is not benign, as it is associated with more frequent cardiovascular events and repeat hospitalizations compared with people without symptoms.
• "Vulnerable or High-Risk Plaque: A JACC: Cardiovascular Imaging Position Statement." (2025) — PMID 40019413 — Plaque rupture with thrombus has been known for 30 years as the main mechanism of acute coronary syndrome and sudden death, and the prototypical form is a thin fibrous cap covering a large lipid core. In intravascular imaging studies, surface erosion causes up to 40% of acute coronary syndromes.
• "Pathophysiology of Atherosclerotic Plaque Development." (2015) — PMID 25544119 — Plaque rupture and resulting intracoronary thrombosis are considered to cause the majority of acute coronary syndromes.
• "Diagnosis and Treatment of Acute Coronary Syndromes: A Review." (2022) — PMID 35166796 — Acute coronary syndrome is a sudden decrease in cardiac blood flow, including ST-elevation myocardial infarction, non-ST-elevation myocardial infarction, and unstable angina, and is diagnosed in over 7 million people worldwide each year. Chest discomfort at rest occurs in 79% of men and 74% of women, and nonspecific symptoms occur in 40% of men and 48% of women. An electrocardiogram is performed within 10 minutes of arrival. ST elevation represents complete occlusion in about 30%, and the remaining roughly 70% involve partial or intermittent occlusion. Primary intervention within 120 minutes reduces mortality from 9% to 7%, and if not feasible, transfer after thrombolysis with a goal of intervention within 24 hours. High-risk non-ST elevation is associated with angiography and revascularization within 24 to 48 hours reducing mortality from 6.5% to 4.9%. High-sensitivity troponin is used to evaluate non-ST-elevation myocardial infarction.
• "Non-ST-segment elevation acute coronary syndrome: understanding the full spectrum to guide management." (2026) — PMID 41358986 — Acute coronary syndromes are dichotomized by electrocardiogram into ST-elevation myocardial infarction and non-ST-elevation acute coronary syndrome.
• "Sex Differences in the Clinical Presentation of Acute Coronary Syndromes." (2022) — PMID 35760149 — Among 10,019 registered patients, non-obstructive coronary acute coronary syndrome accounted for 20.9% of women and 6.6% of men, predominantly younger women. There were no sex differences in presentation among patients with obstructive lesions.
• "Sex Differences in Symptom Presentation in Acute Coronary Syndromes: A Systematic Review and Meta-analysis." (2020) — PMID 32363989 — 27 papers. Women had higher odds of pain between the scapulae, nausea/vomiting, and dyspnea, and lower odds of chest pain and sweating. The most common symptom for both sexes was chest pain, with substantial overlap. The authors conclude that we should no longer attach "atypical/typical" labels to symptoms.
• "Acute coronary syndromes in older adults: a review of literature." (2014) — PMID 23647882 — In people aged 65 and older, acute coronary syndrome is the leading cause of death and may present without chest pain. Chest pain is still common upon arrival, but older adults who arrive without chest pain are twice as likely to die as older adults with chest pain.
• "Does This Patient With Chest Pain Have Acute Coronary Syndrome?…" (2015) — PMID 26547467 — About 10% of acute chest pain patients are diagnosed with acute coronary syndrome. Initial history, physical examination, and electrocardiogram alone could neither confirm nor rule it out, and HEART and TIMI scores incorporating the first troponin provided more information.
• "High-Sensitivity Cardiac Troponin and the 2021 AHA/ACC/ASE/CHEST/SAEM/SCCT/SCMR Guidelines…" (2022) — PMID 35775423 — The 2021 US chest pain guidelines recognize high-sensitivity cardiac troponin as the preferred marker.
• "[Chest pain]." (2021) — PMID 33331950 — Causes of acute chest pain range from acute myocardial infarction and pulmonary embolism to much more common and harmless chest wall muscle strain and gastroesophageal reflux.
• "Sex Disparities in Myocardial Infarction: Biology or Bias?" (2021) — PMID 32861583 — The notion that women have a lower risk of myocardial infarction leads to delays by both patients and medical staff. This is especially concerning in ST-elevation myocardial infarction, where "time is muscle."
• "Door to Balloon Time: Is There a Point That Is Too Short?" (2015) — PMID 26385072 — Ischemia time is directly related to permanent myocardial damage and death. Efforts to lower door-to-balloon time have not led to reduced mortality.
• "Reperfusion strategies in acute coronary syndromes." (2014) — PMID 24902975 — Timely reperfusion reduces myocardial damage, infarct size, morbidity, and mortality, and primary intervention is the preferred method when feasible in a timely manner. Prehospital electrocardiograms, pre-activating the cath lab, and bypassing the emergency department have reduced door-to-balloon times, but in-hospital mortality has barely changed, and patient-side delays must be addressed.
• "Reperfusion strategies in acute ST-elevation myocardial infarction: an overview of current status." (2008) — PMID 18313480 — Primary angioplasty was superior to thrombolysis in mortality, reinfarction, and stroke (across multiple randomized trials and meta-analyses). Stents significantly reduced restenosis compared with balloon angioplasty.
• "The AngelMed Guardian® System in the Detection of Coronary Artery Occlusion: Current Perspectives." (2020) — PMID 32021496 — Total ischemia time is from the start of chest pain to reperfusion, being the sum of symptom-to-door time and door-to-balloon time. A door-to-balloon time of 90 minutes or less became a quality indicator, and while in-hospital time has decreased, shortening prehospital time remains a challenge.
• "Coronary intervention door-to-balloon time and outcomes in ST-elevation myocardial infarction: a meta-analysis." (2018) — PMID 29437704 — 32 papers, 299,320 people. A door-to-balloon time exceeding 90 minutes was associated with an increased risk of short- and medium-to-long-term mortality. The time-risk relationship is non-linear, which may explain why population effects have been lacking despite improvements in door-to-balloon times in the US.
• "Time-to-reperfusion in patients with acute myocardial infarction and mortality in prehospital emergency care: meta-analysis." (2020) — PMID 32842962 — 10 observational studies and randomized trials, 71,099 people. Symptom-to-balloon or door-to-balloon times under 120 minutes had fewer deaths than those exceeding it.
• "MRI for measuring therapy efficiency after revascularisation in ST-segment elevation myocardial infarction…" (2020) — PMID 32988935 — 38 papers, 5,106 people. For every hour that reperfusion was delayed, the myocardial salvage index decreased by an absolute value of 13.1%. The authors interpret minimizing reperfusion time as leading to greater salvage, while heterogeneity between studies was large.
• "Prehospital delay for acute coronary syndrome in China." (2010) — PMID 20938251 — 28 papers. Older age, attributing symptoms to non-cardiac causes, lack of insurance, transportation accessibility, and being female were factors in prehospital delay.
• "Prehospital Evaluation, ED Management, Transfers, and Management of Inpatient STEMI." (2021) — PMID 34053616 — Patients with clear and stable diagnoses are suggested to bypass the emergency department.
• "Prehospital Activation of the Catheterization Laboratory Among Patients With Suspected ST-Elevation Myocardial Infarction Outside of a Hospital…" (2022) — PMID 36120483 — Systematic review of observational studies. The prehospital cath lab activation group had 26 fewer short-term deaths per 1,000 people, 54 fewer long-term deaths per 1,000 people, and a door-to-balloon time that was 33.1 minutes shorter.
• "Reducing time to treatment in acute myocardial infarction." (2000) — PMID 11142275 — The first of four strategies to shorten treatment time is public education to reduce delays in seeking help.
• "The Effect of Sex on Door-to-Balloon Time in Patients Presenting With ST-Elevation Myocardial Infarction…" (2022) — PMID 34334335 — Door-to-balloon and symptom-to-balloon times were longer in women.
• "Acute Coronary Syndrome in Women: An Update." (2024) — PMID 38466532 — Treatments known to be effective in men with atherosclerotic acute coronary syndrome are also effective in women. Closing the diagnosis and treatment gap remains to be done.
• "Mortality after coronary artery bypass grafting versus percutaneous coronary intervention with stenting for coronary artery disease: a pooled analysis of individual patient data." (2018) — PMID 29478841 — 11,518 patients with multivessel or left main disease not having an acute myocardial infarction (11 trials). 5-year mortality: intervention 11.2% vs bypass 9.2%. Multivessel + diabetes 15.5% vs 10.0%, left main 10.7% vs 10.5%. Longer follow-up needed.
• "Exercise-based cardiac rehabilitation for coronary heart disease." (2021) — PMID 34741536 — Cochrane review of 85 trials, 23,430 people. At 6 to 12 months, myocardial infarction RR 0.72, total hospitalizations RR 0.58, total mortality RR 0.87 (95% CI 0.73 to 1.04). Long-term reduction in cardiovascular mortality is possible. Women accounted for less than 15% of participants. The authors conclude that rehabilitation provides important benefits.
• "The role of cardiac rehabilitation in patients with heart disease." (2017) — PMID 28318815 — Guidelines support rehabilitation after acute coronary syndrome, bypass, or stents, but referral and participation remain low.
• "Acute Coronary Syndromes: Differences in Men and Women." (2016) — PMID 27807732 — Women receive guideline-based care less often and are referred for cardiac rehabilitation less often.
• "Who needs secondary prevention?" (2017) — PMID 28618916 — Secondary prevention comprises comprehensive measures to reduce recurrence and improve long-term prognosis, and while proven effective, initiation and persistence rates are low.