Determinants and Prognostic Significance of Periprocedural Myocardial Injury in Patients With Successful Percutaneous Chronic Total Occlusion Interventions

Objectives This study sought to evaluate the determinants and prognostic implications of periprocedural myocardial injury (PMI) in successful percutaneous coronary intervention (PCI) of chronic total occlusions (CTOs). Background There are limited studies addressing the risk factors and clinical implication of PMI in patients undergoing CTO-PCI. Methods We examined 1,058 consecutive CTO patients who underwent successful drug-eluting stent implantation and serial measurements of creatine kinase-myocardial band (CK-MB) values between March 2003 and August 2014. PMI was defined as elevations of CK-MB >3 times the upper reference limit (URL). Results PMI occurred in 121 patients (11.4%). Multivariable analysis revealed that the presence of renal failure (odds ratio [OR]: 4.25; 95% confidence interval [CI]: 1.59 to 11.35; p = 0.004), attempted retrograde approach (OR: 2.27; 95% CI: 1.34 to 3.84; p = 0.002), concomitant non–target lesion intervention (OR: 1.74; 95% CI: 1.17 to 2.59; p = 0.006), and stent number (OR: 1.38; 95% CI: 1.08 to 1.77; p = 0.011) were predictors associated with PMI. During a median follow-up of 4.4 years, PMI was associated with an increased risk of mortality (adjusted hazard ratio: 1.86; 95% CI: 1.09 to 3.17; p = 0.02). These findings were also consistent when higher CK-MB cutoff was used to define PMI. Although there was a trend toward higher all-cause mortality with increasing peak CK-MB levels, in multivariable analyses, this association was statistically significant only for peak CK-MB levels of >10 times the URL. Conclusions PMI was associated with an increased risk of long-term mortality after successful CTO-PCI. Patients with renal insufficiency, those who require more stents, multiple lesion treatment, and retrograde approach have a higher likelihood of having PMI.