Prognostic and Practical Validation of Current Definitions of Myocardial Infarction Associated With Percutaneous Coronary Intervention.

Objectives: In 13,038 patients with non-ST-segment elevation acute coronary syndrome undergoing index percutaneous coronary intervention (PCI) in the EARLY ACS (Early Glycoprotein IIb/IIIa Inhibition in Non-ST-Segment Elevation Acute Coronary Syndrome) and TRACER (Thrombin Receptor Antagonist for Clinical Event Reduction in Acute Coronary Syndrome) trials, the relationship between PCI-related myocardial infarction (MI) and 1-year mortality was assessed.

Background: The definition of PCI-related MI is controversial. The third universal definition of PCI-related MI requires cardiac troponin >5 times the 99th percentile of the normal reference limit from a stable or falling baseline and PCI-related clinical or angiographic complications. The definition from the Society for Cardiovascular Angiography and Interventions (SCAI) requires creatine kinase-MB elevation >10 times the upper limit of normal (or 5 times if new electrocardiographic Q waves are present). Implications of these definitions on prognosis, prevalence, and implementation are not established.

Methods: In our cohort of patients undergoing PCI, PCI-related MIs were classified using the third universal type 4a MI definition and SCAI criteria. In the subgroup of patients included in the angiographic core laboratory (ACL) substudy of EARLY ACS (n = 1,401) local investigator- versus ACL-reported angiographic complications were compared.

Results: Altogether, 2.0% of patients met third universal definition of PCI-related MI criteria, and 1.2% met SCAI criteria. One-year mortality was 3.3% with the third universal definition (hazard ratio: 1.96; 95% confidence interval: 1.24 to 3.10) and 5.3% with SCAI criteria (hazard ratio: 2.79; 95% confidence interval: 1.69 to 4.58; p < 0.001). Agreement between ACL and local investigators in detecting angiographic complications during PCI was overall moderate (κ = 0.53).

Conclusions: The third universal definition of MI and the SCAI definition were both associated with significant risk for mortality at 1 year. Suboptimal concordance was observed between ACL and local investigators in identifying patients with PCI complications detected on angiography. (Trial to Assess the Effects of Vorapaxar [SCH 530348; MK-5348] in Preventing Heart Attack and Stroke in Participants With Acute Coronary Syndrome [TRA·CER] [Study P04736]; NCT00527943; EARLY ACS: Early Glycoprotein IIb/IIIa Inhibition in Patients With Non-ST-Segment Elevation Acute Coronary Syndrome [Study P03684AM2]; NCT00089895).