Demand, Non-ST-Elevation Myocardial Infarction (NSTEMI) Guidelines

Pathophysiology

A demand, non-ST-elevation myocardial infarction (NSTEMI) is a type 2 myocardial infarction caused by an imbalance between myocardial oxygen supply and demand, rather than by atherosclerotic plaque rupture with thrombosis, as stated by the American Heart Association 1, 2
Type 2 MI occurs when conditions other than primary coronary artery plaque rupture contribute to an imbalance between myocardial oxygen supply and demand, resulting in myocardial injury and necrosis, according to the American College of Cardiology 2
The myocardial injury in Type 2 MI is detected by elevated cardiac troponin levels with at least one value above the 99th percentile upper reference limit, as reported in Cardiovascular Research 4

Patients may present with typical chest pain or with atypical symptoms, especially in women, elderly, diabetics, and critically ill patients, as noted by the American College of Cardiology 3
Laboratory findings include elevated cardiac troponin levels with a characteristic rise and/or fall pattern, as stated by the American Heart Association 2, 4

The American College of Cardiology/American Heart Association guidelines emphasize that management strategies for Type 2 MI differ from those for Type 1 MI, and treatment should focus on both the underlying cause of the supply-demand mismatch and the myocardial injury 6
Addressing the precipitating factor (e.g., correcting anemia, controlling arrhythmias, optimizing blood pressure) is essential, as recommended by the American Heart Association 2
Antiplatelet therapy may be appropriate depending on the clinical context, but is not universally indicated as it would be in Type 1 MI, according to the American College of Cardiology 7

The prognosis of Type 2 MI depends largely on the severity of the underlying condition causing the supply-demand imbalance, as stated by the American Heart Association 1
Patients with Type 2 MI often have multiple comorbidities that contribute to worse outcomes, as reported by the American College of Cardiology 6