Periprocedural myocardial injury in chronic total occlusion percutaneous interventions: A systematic cardiac biomarker evaluation study

Objectives This study sought to evaluate the incidence, correlates, and clinical implications of periprocedural myocardial injury (PMI) during percutaneous coronary intervention (PCI) of chronic total occlusions (CTO). Background The risk of PMI during CTO PCI may be underestimated because systematic cardiac biomarker measurement was not performed in published studies. Methods We retrospectively examined PMI among 325 consecutive CTO PCI performed at our institution between 2005 and 2012. Creatine kinase-myocardial band fraction and troponin were measured before PCI and 8 to 12 h and 18 to 24 h after PCI in all patients. PMI was defined as creatine kinase-myocardial band increase ≥3× the upper limit of normal. Major adverse cardiac events during mid-term follow-up were evaluated. Results Mean age was 64 ± 8 years. The retrograde approach was used in 26.8% of all procedures. The technical and procedural success was 77.8% and 76.6%, respectively. PMI occurred in 28 patients (8.6%, 95% confidence intervals: 5.8% to 12.2%), with symptomatic ischemia in 7 of those patients. The incidence of PMI was higher in patients treated with the retrograde than the antegrade approach (13.8% vs. 6.7%, p = 0.04). During a median follow-up of 2.3 years, compared with patients without PMI, those with PMI had a higher incidence of major adverse cardiac events (hazard ratio [HR]: 2.25, p = 0.006). Patients with only asymptomatic PMI also had a higher incidence of major adverse cardiac events on follow-up (HR: 2.26, p = 0.013). Conclusions Systematic measurement of cardiac biomarkers post-CTO PCI demonstrates that PMI occurs in 8.6% of patients, is more common with the retrograde approach, and is associated with worse subsequent clinical outcomes during mid-term follow-up.