Determinants and prognostic implication of periprocedural myocardial injury after successful recanalization of coronary chronic total occlusion

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.

A contemporary review of clinical significances of percutaneous coronary intervention for chronic total occlusions, with some Japanese insights

The clinical "significance" of percutaneous coronary intervention for coronary chronic total occlusion (CTO-PCI) has been evaluated. In the beginning, the effects on clinical endpoints were investigated by comparisons between cases of success and failure of CTO-PCI, which mostly demonstrated better long-term outcomes in the successful cases. Similarly, improvement of cardiac function or wall motion was proven by serial observational studies. Accordingly, several prospective randomized trials (RCTs), which should confirm such accumulated potential benefits, were recently conducted by comparison with studies of patients that had received optical medical therapy (OMT) alone. While they mostly demonstrated significant improvement of angina symptoms and quality of life (QOL) in the CTO-PCI group, they failed to prove a reduction of clinical events or improvement of left ventricle wall motion, compared with OMT. Concurrent guidelines or consensus documents emphasize that the principal indication for CTO-PCI is to improve symptoms. To determine strategy, the following must be discussed in each individual case: the probability of procedural success, the expectation of long-term patency, and an assessment of the balance between procedure-related complications and overall benefits. In essence, we believe the following facts to be the current sincere appraisal of CTO-PCI: (1) improvements of symptoms and QOL are established, but the others remain inconclusive, and; (2) their margins for improvement are narrowing and numbers of candidates are shrinking. Precision medicine or individualization may be the right directions to take, to enhance the potential of this treatment. This course of action demands discrimination of those candidates who will truly receive benefits from invasive treatment, and that still requires further clinical studies or actions.