Predictors and prognosis of PCI-related myocardial injury in chronic total occlusion.

Background: Periprocedural myocardial injury (PMI) is associated with major adverse cardiovascular events (MACE) after percutaneous coronary intervention (PCI). However, the incidence predictors and prognosis of PMI in chronic total occlusion (CTO) undergoing PCI remains unclear.

Method: To evaluate the predictors and prognostic impact of PMI following PCI in patients with CTO. We consecutively enrolled 132 individuals and 8 of whom with procedural failure were excluded in this study. Thus, a total of 124 CTO patients successfully received PCI were included in this study. And patients were divided into the PMI group (n = 42) and the non-PMI group (n = 82) according to their c-TnI levels measured after procedure. The baseline and angiographic characteristics of the two groups were compared. The predictors of PMI and the correlation between PMI and MACE were investigated.

Results: Overall, PMI occurred in 42 patients (33.9%). Comparing with control group, PMI group had more diabetes (54.8% vs. 31.7%,P = 0.013) and dyslipidemia (54.8% vs. 13.4%, P＜0.001). Also, there were significant differences between the two groups in left ventricular ejection fraction(43.2 ± 7.2 vs 47.2 ± 8.0, P = 0.027), prior myocardial infarction(54.8%vs43.1%, P = 0.020), prior PCI(57.1% vs 22.0%, P＜0.001) and prior CABG(14.3% vs 2.4%, P = 0.011). Also, patients with PMI had more calcified lesions (52.4% vs 24.4%, P = 0.002) and were more likely to have multivessel disease (71.4% vs 35.4%, P＜0.001). In addition, patients in the PMI group had higher J-CTO scores (3.3 ± 1.0 vs 1.9 ± 0.5, P＜0.001) and were more likely to have wire-crossing difficulties (64.3% vs 37.8%, P = 0.005), require more use of retrograde approach (38.1% vs 7.3%, P＜0.001) and have more procedural complications (19.0% vs 2.4%, P = 0.003). In the multivariate analysis, multivessel artery disease (odd ratio [OR], 4.347;95% confidence interval [CI], 1.601- 11.809;P  = 0.004), retrograde approach (OR, 4.036; 95%CI, 1.162- 14.020;P  = 0.028) and the presence of procedural complications (OR, 16.480;95%CI, 2.515-107.987;P = 0.003) were predictors of PMI.

Conclusion: The incidence of PMI in CTO patients after PCI was 33.9%. Multivessel artery disease, retrograde approach, and the presence of procedural complications were predictors of PMI after CTO-PCI. Patients who develop PMI tend to have a poorer clinical prognosis and more MACE than those who do not develop PMI.