Beyond Blocked Arteries: New MI Definition

A significant update to the classification of myocardial infarctions (MIs), commonly known as heart attacks, has been introduced by leading international cardiac organizations. The European Society of Cardiology, American College of Cardiology, American Heart Association, and World Heart Federation have jointly developed the Fifth Universal Definition of Myocardial Infarction. This new framework simplifies the classification into three broad clinical settings: primary, secondary, and procedure-related.

Primary MI arises spontaneously from acute coronary artery problems like plaque rupture, dissection, or spasm. Secondary MI occurs due to an oxygen supply-demand imbalance in the heart caused by other conditions, such as high blood pressure or rapid heart rate. Procedure-related MI is defined as an event occurring within 30 days of cardiac procedures or surgeries.

This revised approach emphasizes the underlying reasons for heart muscle injury, moving beyond previous numerical systems that were difficult to apply consistently. Experts note this is crucial for accurate diagnosis and individualized treatment, particularly as women may experience less recognized types of coronary disease, including spontaneous coronary artery dissection (SCAD) which is closely linked to pregnancy.

Heart attack symptoms can vary, and individuals should not solely wait for crushing chest pain. Breathlessness, severe fatigue, nausea, dizziness, or discomfort in the jaw, back, shoulder, or arm can also indicate a cardiac event. Prompt medical attention for new or unexplained symptoms is vital. Regular monitoring of blood pressure, blood sugar, and cholesterol, along with a healthy lifestyle, is essential for prevention.