Predictors Of Procedural Success Of Chronic Total Occlusion (CTO) Intervention And Its Effects On The Patients’ Prognosis

Part 1 Predictors of Procedural Success of Chronic Total Occlusion(CTO)InterventionObjective:The purpose of this study was to investigate the predictors of procedural outcome of percutaneous coronary intervention(PCI)for chronic total occlusion(CTO).Methods:Patients underwent PCI for CTO were consecutively recruited and divided into procedural success and procedural failure groups.The clinical,coronary lesion and procedural characteristics between the two groups were compared.Variables related to procedural success(P<0.1)in univariate analysis were selected in multivariable logistic regression model to identify predictors of procedural outcome.Results:A total of 147 CTO PCIs performed in 122 patients were finally enrolled in the study.The mean J-CTO score was 2.15.The overall procedural success rate was 70.07%,which increased by year.There were no death,nonfatal myocardial infarction,tamponade(requiring either pericardiocentesis or surgery),stroke,stent thrombosis or emergent target vessel revascularization occurred during hospitalization.Type D coronary dissection developed in 5 patients and no reflow in 3 patients during PCI.The incidence of stumpless lesion(56.82%vs.26.21%,P<0.001),occlusion length>20 mm(63.64%vs.41.75%,P = 0.015),ad hoc PCI(56.82%vs.37.86%,P = 0.034),procedural complication(11.36%vs.2.91%,P =0.052)and Werner’s collateral connection(CC)score of 2(56.82%vs.38.83%,P=0.044)in the failure group was higher than that in the successful group,while the presence of Werner’s CC score of 1(36.36%vs.54.37%,P =0.046)was lower in the failed group.Multivariable logistic regression indicated the independent predictors of CTO-PCI failure were stumpless lesion(odds ratio,[OR]:4.381;95%confidence interval[CI]:1.821-10.452,P = 0.001),occlusion length>20 mm(OR:2.462;95%CI:1.030-5.887,P = 0.043),ad hoc PCI(OR:4.617;95%CI:1.900-11.221,P =0.001)and procedural complication(OR:8.688;95%CI:1.573-47.971,P = 0.013).J-CTO scores could not predict procedural success(area under the receiver operator characteristic[ROC]curve = 0.531;P = 0.548)in our study.Whereas the area under the ROC curve increased to 0.602(P = 0.051)after addition of stumpless lesion to the J-CTO score.Conclusions:Stumpless lesion,occlusion length>20 mm,ad hoc PCI and procedural complication were independent predictors of CTO PCI failure.The addition of stumpless lesion to the J-CTO score improved the predictive value of the model.Use of novel equipment and techniques,increased operator experience were also important factors that would contribute to the procedural success.Part 2 Effects of Percutaneous Coronary Intervention on the Prognosis of Patients with Chronic Total OcclusionObjective:The aim of this study was to evaluate the effects of chronic total occlusion(CTO)intervention on the patients’ clinical outcomes.Methods:Patients who underwent PCI for CTO were consecutively enrolled and stratified according to successful or failed recanalization.For major clinical events(composite endpoint of all-cause mortality,non-fatal myocardial infarction,stroke,and target vessel revascularization[TVR])outcome,survival curves were estimated by means of the Kaplan-Meier method and were compared by means of the log-rank test.Variables displaying relationships with major clinical events(p<0.1)in univariate analysis were included in the Cox’s proportional hazards regression model,which was used to determine the predictors of clinical outcomes.The safety events including bleeding,contrast-induced nephropathy and radiation-induced injury were also observed.Results:A total of 112 patients were finally enrolled.After a median follow-up of 27 months,the cumulative event free survival was significantly higher in patients with successful CTO PCI(98.78%vs.85.45%,Log-rank P = 0.020).Variables entered into the multivariate model were procedural failure(hazard ratio,[HR]:14.847;95%confidence interval,[CI]:1.537-143.424,P = 0.020),triple-vessel disease(HR:0.132;95%CI:0.014-1.274,P = 0.080)and creatinine(HR:1.025;95%CI:0.996-1.055,P = 0.092).After Cox’s regression analysis,failed CTO PCI was the only independent predictor of a higher major adverse event(HR:17.752;95%CI:1.795-175.582,P = 0.014).GUSTO(Global use of strategies to open occluded coronary arteries)mild bleeding occurred in 2 patients(1.79%)and no contrast-induced nephropathy was observed during follow up.Radiation-induced skin injury developed in 5 patients(4.46%)and skin graft was performed in 2 patients(1.79%).Conclusions:Successful PCI decreased the risk of composite endpoint of all-cause mortality,non-fatal myocardial infarction,stroke and TVR in CTO patients.Radiation protection should be strengthened to minimize X-ray exposure during CTO PCI.