Peri-procedural myocardial infarction is all the same?

Peri-procedural MI is one of the important complications after percutaneous coronary intervention (PCI). In general, the incidence of peri-procedural MI was reported as 2% to 30%, which depends on the definitions of peri-procedural MI (1). These definitions use the different types of cardiac marker measured, the different thresholds of these markers for diagnosis, and additional clinical criteria. Although the pathophysiology of peri-procedural MI are not fully understood, distal embolization of thrombus or plaques, and occlusion of small side branch has been well known to contribute to peri-procedural MI (1). The most relevant risk factors are the complexed lesions (i.e., calcified lesion, high SYNTAX score, and large necrotic core), and complex procedures (i.e., multiple lesions and usage of rotational atherectomy) (1). Previous studies showed that other characteristics such as old age, diabetes mellitus (DM), renal dysfunction and left ventricular dysfunction are also associated with peri-procedural MI (1). Additionally, those risk factors interact with each other and contribute to peri-procedural MI. Patients who require rotational atherectomy during the procedure usually have multiple risk factors of peri-procedural MI (2). These patients are more likely to be high age, and have the atherosclerotic risk factors (DM, hypertension and hyperlipidemia) and renal dysfunction (2). The lesions that require rotational atherectomy are frequently associated with calcified plaques, long lesions and multiple lesions (2). Moreover, rotational atherectomy is associated with the higher incidence of slow flow phenomenon (3). The mechanism of this phenomenon has been described as platelet aggregation, micro-vessel obstruction, release of vasoactive substances, atheromatous debris and vasospasm. Slow flow phenomenon results in myocardial hypoperfusion, and secondary to peri-procedural MI (4). Therefore, peri-procedural MI frequently occurred in the patients with rotational atherectomy (4). The decision of how the patients with peri-procedural MI should be treated (i.e., longer hospitalization with monitor, additional medical treatment, and coronary angiography) must be made soon. Therefore, the important first-step is the awareness of peri-procedural MI after PCI so that the patients with peri-procedural MI are properly and promptly treaded after procedure without any delay