From the Guidelines
A microinfarction is a very small area of tissue death (necrosis) resulting from inadequate blood supply, typically affecting an area less than 1 cm in diameter, and can be identified through sensitive biomarkers such as troponin or specialized imaging techniques 1. The concept of microinfarction is closely related to the universal definition of myocardial infarction, which has been refined over the years to include various types of myocardial infarctions, such as spontaneous, procedure-related, and those occurring in the setting of critically ill patients 1. Some key points about microinfarctions include:
- They can occur in various organs, including the heart, brain, kidneys, and other tissues
- They represent minor tissue damage that may not be detected by traditional diagnostic methods
- Their cumulative effect over time can lead to organ dysfunction
- The pathophysiology involves microvascular obstruction, which can result from microemboli, platelet aggregation, inflammation, or small vessel disease
- These events are particularly common in patients with risk factors such as diabetes, hypertension, and hyperlipidemia, which contribute to microvascular damage and dysfunction It is essential to note that the definition and classification of myocardial infarction, including microinfarctions, have evolved over time, and the current understanding is based on the third universal definition of myocardial infarction, which emphasizes the importance of biomarkers, imaging, and clinical presentation in diagnosing and managing myocardial infarctions 1. In clinical practice, the identification and management of microinfarctions are crucial to prevent long-term organ damage and improve patient outcomes. The use of sensitive biomarkers and imaging techniques can help detect microinfarctions early, allowing for prompt intervention and treatment. Overall, microinfarctions are an important aspect of cardiovascular disease, and their understanding and management are critical to improving patient care and outcomes.
From the Research
Definition of Microinfarction
There is no direct evidence of a universal definition of microinfarction in the provided studies. However, the studies discuss the universal definition of myocardial infarction (MI), which may be related to microinfarction.
Myocardial Infarction Definition
- The universal definition of myocardial infarction (MI) is based on troponin elevation together with ischemic symptoms, ischemic ECG changes, and imaging evidence 2.
- An acute myocardial infarction (AMI) is characterized by evidence of myocardial necrosis in a clinical setting of acute myocardial ischemia 3.
- Diagnostic criteria include a rise and/or fall of serially tested cardiac biomarkers (preferentially cardiac troponins) with at least one value above the 99th percentile of the upper reference limit combined with symptoms of ischemia, new changes on electrocardiogram (ECG), imaging evidence of a new loss of viable myocardium or new regional wall motion abnormalities or the identification of an intracoronary thrombus by angiography or autopsy 3.
Classification of Myocardial Infarction
- MIs are classified into five types as to whether they are spontaneous, secondary to imbalance between coronary artery blood supply and demand, related to sudden death, or related to revascularization procedures 2.
- The classification system includes type 4a (peri-percutaneous coronary intervention) and type 4b (stent thrombosis) 4.
Clinical Relevance
- MI is associated with a significantly increased risk of cardiovascular death, with a consistent relationship across all types as defined by the universal classification system 4.
- The occurrence of any MI is associated with a 5-fold higher risk of death at 6 months 4.
Note: There are no research papers to assist in answering the question about the universal definition of microinfarction. The provided studies discuss the universal definition of myocardial infarction (MI), which may be related to microinfarction.