Myocardial Injury after Percutaneous Coronary Intervention for In-Stent Restenosis Versus de novo Stenosis.

OBJECTIVE Periprocedural myocardial injury (PMI) remains a relatively common complication even after successful procedures. In-stent restenosis (ISR) may be involved in lesion-related factors for PMI. We compared the incidence of PMI between patients with ISR and those with de novo stenosis. METHODS The study population consisted of 121 patients with coronary artery disease who had been treated with statins and subsequently underwent angiographically successful percutaneous coronary intervention (PCI). Blood samples for troponin I were collected 18 to 24 hours after PCI. PMI was defined as an increase in the troponin I levels greater than 0.15 ng/mL. Major PMI was defined as an increase in the troponin I levels greater than 0.75 ng/mL. RESULTS There were 34 patients with ISR and 87 patients with de novo stenosis. The incidence of PMI was similar between the two groups (47.1 % vs. 55.2 %, p=0.42). Among the patients with ISR, the incidences of PMI were 33.3 %, 60.0 % and 66.7 % in patients with focal ISR, diffuse ISR and diffuse proliferative ISR, respectively, although these differences were not statistically significant. The incidence of major PMI was significantly less frequent in patients with ISR than those with de novo stenosis (5.9 % vs. 25.3 %, p=0.03). A multivariate logistic regression analysis showed that ISR [odds ratio (OR) 0.22, 95% confidence interval (CI) 0.03-0.90; p=0.03] and the maximum inflation pressure (OR 1.15, 95% CI 1.04-1.30; p=0.009) were independent predictors of major PMI. CONCLUSION Our results suggest that while PMI occurs in patients with ISR as commonly as those with de novo stenosis, major PMI occurs less frequently in patients with ISR.