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Glossary of Scientific Terms

Abstract: a summary of research that includes the study’s objectives, methods, results and conclusions. Abstracts are presented at scientific meetings and are presented as oral or poster presentations, or they may be published only in the meeting supplement that includes all accepted abstracts.

Please note: Abstracts presented at American Heart Association’s scientific meetings are not peer-reviewed, rather, they are curated by independent review panels and are considered based on the potential to add to the diversity of scientific issues and views discussed at the meeting. The findings are considered preliminary until published as a full manuscript in a peer-reviewed scientific journal.

Cardiac arrest: An electrical malfunction that occurs when the heart stops beating unexpectedly. Immediate CPR can triple a person’s chances of survival.

Please note: Cardiac arrest is not the same thing as a heart attack, therefore, the terms are not interchangeable. Please review these resources: Heart Attack and Sudden Cardiac Arrest Differences | American Heart Association

Clinical trial: A research study in which one or more human subjects are assigned to one or more interventions, such as a new medicine, therapy, or surgery, and may include a placebo (a sham treatment or harmless pill) or other group that received no treatment, to evaluate the effects of those interventions on health-related biomedical or behavioral outcomes.

Control: Any factor of a research study that remains unchanged or unaffected by other variables to serve as a benchmark or point of comparison.

CPR (cardiopulmonary resuscitation): a lifesaving action used when someone isn’t breathing or their heart isn’t beating that combines chest compressions and rescue breathing to help get oxygen-rich blood to the brain.

Cross-sectional study: Observational research study of people based on specified criteria or a study analyzing different groups based on specific criteria at a single point in time.

Double-blind controlled trial: Research study in which scientists and subjects are unaware of who received which treatment, or treatment vs. a placebo (sham treatment or harmless pill)

Guideline: An American Heart Association Guideline is published in one of the Association’s peer-reviewed scientific journals and provides the official, evidence-based clinical practice recommendations for the diagnosis and treatment of a particular condition. Guidelines may be produced collaboratively with other medical societies such as the American College of Cardiology or the Heart Failure Society of America.

Heart attack: A circulation problem that occurs when a blocked artery prevents oxygen-rich blood from reaching a section of the heart. If the blocked artery is not reopened quickly, the part of the heart normally nourished by that artery begins to die.

Note: A heart attack is not the same as cardiac arrest, therefore, these terms are not interchangeable. Please review these resources: Heart Attack and Sudden Cardiac Arrest Differences | American Heart Association

Incidence: The number or rate of persons (usually a percentage) in a specific population who develop a condition during a particular time period.

Late-Breaking clinical trials: Usually large-scale research clinical trials involving participants that compare treatments or interventions. The results of late-breaking clinical trials may potentially change treatment standards or guideline recommendations.

Longitudinal study: Study of individuals over a period of time set by the researchers.

Observational study: Study in which researchers recruit participants without assigning participants to a specific intervention or treatment. An observational study may also be an analysis of previously collected health data or information, not a new study for which people are recruited to participate in.

Please note: Observational studies cannot prove a direct cause-and-effect relationship of any associations found in the data analysis.

Peer Review – The detailed evaluation process by which scientific experts and scholars critically review and assess the quality and scientific merit of the research in a study. Articles that pass this process are published in peer-reviewed scientific journals. Peer-reviewed scientific journals may include the research of scholars who have collected their own data using an experimental study design, survey or various other study methodologies.

Phase I Trial: First step in testing a new treatment in humans evaluates the safety, side effects, dosage range, and method of delivery of the medication or therapy. The main goal in a phase I trial is to ensure the treatment is safe enough to move on to the next phase of testing.

Phase II Trial: Next level of early testing treats people using the dose and method that the phase 1 trial found was safest and focuses on the effectiveness of a treatment and continues to monitor for safety including possible adverse events or side effects. Many phase II trials use a method called randomization to assign people to different treatments, doses or applications to help researchers learn which treatment works best.

Phase III Trial: Large-scale study to confirm the treatment’s effectiveness, monitor for side effects and compare it to standard treatments. These trials are crucial in helping to provide a thorough understanding of how the treatment works in diverse populations and different medical settings. This stage of testing is to prove that the treatment is equally effective – works as well or better than existing treatments.

Phase IV Trial: Post FDA-approval safety evaluation. After a treatment is approved and available to the public, Phase IV trials are conducted to observe the long-term effects of the treatment. These trials involve thousands of participants and can help identify any rare or long-term side effects, and ensure the treatment’s safety over time. Phase IV trials can also explore other potential uses for the treatment beyond the original FDA-approval.

Placebo: An element of a research study that resembles the treatment but has no therapeutic properties, such as a sugar pill or saltwater injection. The placebo effect is a psychological phenomenon that may cause the study’s subject/s to experience a perceived benefit even when the treatment was not the medication or therapy being tested.

Prevalence: The proportion of persons in a specific population who have a condition or health factor at or during a particular time period.

Prospective study: An observational research study where individuals are followed over time and data about them is collected as their characteristics or circumstances change. It is a study to test and gauge the study’s hypothesis – a possible outcome. .

Randomized, placebo-controlled study: A research study with participants chosen at random to receive treatment and then compared to a group who received no treatment or a sham treatment (placebo group).

Relative risk: A method that compares how much more or less likely a specific event or occurrence, such as developing a health condition, is for two distinct groups. It quantifies the probability of those exposed to a certain risk factor versus those who were not exposed.

Retrospective study: An observational research study into previous data, analysis or review of past research or data; this type of study looks backward in time, usually examines previous medical records, or other health data or information, and/or results of interviews with participants.

Science Advisory: An American Heart Association Science Advisory is usually published in one of the Association’s 14 peer-reviewed scientific journals and clarifies the Association’s position on specific scientific issues. They are peer reviewed and are focused on a particular scientific area or topic.

Scientific Statement: An American Heart Association Scientific Statement promotes greater awareness about cardiovascular diseases and stroke issues and helps facilitate informed health care decisions. A Scientific Statement outlines what is currently known about a topic and what areas need additional research and is published in one of the Association’s 14 scientific journals. While a Scientific Statement informs the development of guidelines, it does not make treatment recommendations. It represents the consensus of leading experts, undergoes blinded peer-review and is designed to increase health care professionals’ knowledge and awareness of effective state-of-the-art science related to causes, prevention, detection or management of heart diseases and stroke.