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.