Effect of Periprocedural Myocardial Infarction After Initial Revascularization With Left Main PCI in Patients With Recent Myocardial Infarction

Background: Periprocedural myocardial infarction (PMI) after percutaneous coronary intervention (PCI) for left main coronary artery disease (LMCAD) may be particularly deleterious in patients with recent myocardial infarction (MI). We sought to determine the rates and prognostic relevance of PMI using different definitions and biomarker thresholds after PCI for LMCAD in patients with recent MI. Methods: Between January 2004 and December 2016, 442 patients underwent PCI for LMCAD at a median of 3 days after presentation with MI. A total of 350 patients presented with elevated cardiac biomarker levels (349 with serial creatine kinase–myocardial band [CK-MB] and 219 with serial cardiac troponin I (cTnI) values) that were stable or falling before the PCI. In this cohort, PMI within 48 hours of PCI was adjudicated using Society for Cardiovascular Angiography & Interventions (SCAI), Academic Research Consortium 2 (ARC-2), and fourth Universal Definition of Myocardial Infarction (UDMI) criteria. The primary and secondary end points were 3-year rates of cardiovascular (CV) and all-cause death. Results: An incremental post-PCI rise in CK-MB starting at ≥10× the upper reference limit from baseline was significantly associated with 3-year CV death (adjusted hazard ratio [aHR], 7.96; 95% confidence interval [CI], 2.89-21.90), whereas CV death was not associated with any threshold elevation of cTnI. The frequencies of PMI according to the fourth UDMI, ARC-2, and SCAI definitions were 19.4%, 12.3%, and 8.6%, respectively. PMI by all 3 definitions was significantly associated with 3-year CV death, with the SCAI definition having the strongest relationship (aHR, 6.34; 95% CI, 2.47-16.27) compared with those of ARC-2 (aHR, 2.82; 95% CI, 1.15-6.96) and fourth UDMI (aHR, 2.65; 95% CI, 1.14-6.14). Conclusions: In patients with recent MI undergoing PCI for LMCAD, an incremental elevation in postprocedural CK-MB of ≥10× the upper reference limit as a stand-alone measure was strongly predictive of 3-year CV and all-cause death, whereas no cTnI elevations of any level were prognostic. All 3 contemporary PMI definitions in widespread use were associated with 3-year mortality after PCI in this high-risk cohort, with the SCAI definition having the strongest relationship with subsequent death.