Every 40 seconds someone in the United States has a heart attack, that is 790,000 Americans having a heart attack every year. When dealing with heart attacks time is of the essence, fast diagnosis and treatment is essential to limiting damage to the heart. A study published in the Canadian Medical Association Journal (CMAJ), describes a simple laboratory score that is safer and faster at diagnosing patients who visit the emergency room with heart attack symptoms.
Heart attacks, also called myocardial infractions, occur when the flow of blood to the heart is blocked, most often due to the formation of plaques. Plaques consist of cholesterol, fat and other substances that attach to the artery wall; when the plaque dislodges blood cells will form a clot in its place leading to restricted or blocked blood flow. When blood flow is interrupted the heart muscle can be damaged or destroyed. Symptoms may include nausea, shortness of breath, pressure or aching in the chest or arms, fatigue, and cold sweats among other things. Risk factors for heart attack include age, high blood pressure, weight, cholesterol levels, family history, stress, physical activity, and many other factors such as drug use.
When an individual arrives at a hospital suffering from a heart attack, doctors will diagnosis and determine if the individual has a complete blockage of an artery, known as a ST-elevation myocardial infarction (STEMI) or partial blockage, known as a non-ST-elevation myocardial infarction (NSTEMI). When tested doctors will analyze levels of a protein found in the heart muscles known as cardiac-specific troponoin, levels of cardiac-specific troponin in the blood help determine if heart injury has occurred. However, these tests can take time and involve numerous blood tests. The study published by an international team of researchers sought to create a better diagnosis method that was faster and safe compared to cardiac troponin measurements.
Researchers from Canada, Australia, New Zealand, and Germany combined blood tests available at hospitals around the world to create a single score known as a laboratory score or clinical chemistry score to diagnosis heart attack. The clinical chemistry score was validated as a predictor of a heart attack on 4245 patients from emergency department studies in four countries. When using a high-sensitivity chorionic troponin test up to 25 heart attacks/deaths were missed, compared to only one with a low risk clinical chemistry score. A high-risk clinical chemistry score identified about 75% of patients at high risk for heart attack, compared to 40% with the high-sensitivity cardiac troponoin test. The clinical chemistry score also showed no gender differences. The scores could be useful in standardizing diagnosis and improving safety when it comes to heart attack diagnosis.
"Adoption of the clinical chemistry score algorithm would standardize reporting of high-sensitivity cardiac troponin test results, how the tests are interpreted in the normal range, and represent an option less susceptible to both analytical and preanalytical errors. This could result in the safest laboratory approach for physicians to use at presentation in the emergency department," says first author Dr. Peter Kavsak of McMaster University in Hamilton, Ontario.
To learn more about current heart attack diagnosis methods watch the video below!
Sources: CMAJ, Center for Disease Control, American Heart Association, Mayo Clinic