Consensus or Controversy?: Evolution of Criteria for Myocardial Infarction After Percutaneous Coronary Intervention

BACKGROUND The definition and the clinical implications of myocardial infarction (MI) occurring in the setting of percutaneous coronary intervention have been subjects of unresolved controversy. As a result of the use of more sensitive diagnostic tools such as cardiac troponin, the expanding evidence, and the ensuing debate, the definition of procedural MI (pMI) has evolved, leading to several revisions, different proposed definitions, and lack of standardization in randomized clinical trials. CONTENT In this review, we will describe the key clinical data on cardiac biomarkers, creatine kinase isoenzyme MB and cTn, in the setting of percutaneous coronary intervention and the main issues that have lead to various consensus documents with a proposed definition of pMI. We will focus on the rationale of the current “Third Universal Definition of Myocardial Infarction” and of the alternative approach proposed by the Society for Cardiovascular Angiography and Interventions. SUMMARY The definition of pMI is an evolving field where the Third Universal MI definition represents the best attempt to date to incorporate available evidence along with scientific and clinical judgment into criteria to ensure adequate specificity in the diagnosis and the relevant prognostic significance, while trying to maintain sensitivity. Questions on the recommended criteria and their practical implementation remain, but the Third Universal definition document represents an important milestone toward a better standardization and enhanced consensus on the pMI definition.