Sudden cardiac death (SCD) is one of the most common causes of death in the world. Coronary heart disease (CHD) is the root cause of most patients with SCD, and myocardial infarction (MI) is the main cause of SCD among all types of CHD. Early identification of high-risk patients after an MI, and the application of related prevention strategies and disease-specific treatments will be the key to reduce SCD. The mechanism of SCD after MI varies over time, and the relevant risk prediction indicators are also dynamic and different. In the existing guidelines for MI patients, the static and slightly single stratification of primary (PP) and secondary (SP) prevention has significant room for improvement. The 1.5 primary prevention (1.5PP) is defined as patients with PP who also had the following risk factors: non-sustained ventricular tachycardia (NSVT), frequent premature ventricular contractions (PVCs), severe heart failure (left ventricular ejection fraction, LVEF 25%), and syncope or pre-syncope. The emergence of 1.5PP has provided a new method for the stratification and management of SCD after an MI.