New algorithm for endovascular treatment of chronic coronary total occlusions
Objective. The creation and implementation of a novel tactical algorithm for endovascular treatment of patients with coronary chronic total occlusions (CTO) both de novo and in the previously stented segment. To optimize the procedural results of percutaneous coronary intervention (PCI) during recanalization of CTO based on the developed prediction scale and the results of a comparative assessment of various surgical strategies. Material and methods. The present scientific work on the creation of a tactical algorithm is based on the results of the analysis of several, sequentially conducted studies on the basis of the Meshalkin Center from 2013 to 2020. To develop a predictive model of procedural success, a retrospective analysis of data from 665 patients with CTO was carried out in whom 681 recanalization procedures were performed from 2013 to 2016. To assess the impact of the switching time between recanalization strategies on the procedural success of CTO PCI the time of switching from one recanalization strategy to another was analyzed in 99 patients when both antegrade and retrograde recanalization approaches were used from 2013 to 2016. Further, the procedural success and technical features of recanalization in 109 patients with instent CTO were analyzed for the period from 2013 to 2019. The final stage was the verification of the effectiveness of the developed tactical algorithm for choosing a endovascular strategy for recanalization of CTO in a prospective randomized study including 200 patients from 2019 to 2020. Results. Finally, a tactical algorithm for the recanalization of the CTO was developed based on the analysis of the results of the studies. The developed predictive model includes 5 predictors of procedural failure (calcification, ambiguous stump, bending, lesion in the artery-donor, localization of the CTO in the left circum flex or left anterior descending arteries). It has been demonstrated that the predictive capabilities of the new model are comparable to the standard model (J-CTO) for assessing the complexity of CTO. As a result of the analysis, it was found that in order to preserve the maximum chances of final procedural success, the threshold switching time between CTO recanalization strategies should be observed: no later than 33 minutes of the antegrade attempt of CTO recanalization. The chance of success with early switching was 3.34 times higher (95% CI 1.3-8.6). When choosing a primary strategy for CTO recanalization based on the developed tactical algorithm, the indicators of technical and procedural success were 90% and 88.8%, respectively, and were statistically significantly higher compared to the group of primary antegrade recanalization - 76.3% and 75%, respectively. At the same time, in both groups the frequency of using antegrade and retrograde techniques did not differ significantly. The success rate of the primary recanalization strategy of CTO was higher in the group that selected the recanalization strategy based on the developed algorithm (80% versus 58.8%, p=0.005). Conclusion. The use of the developed tactical algorithm provides higher rate of procedural success than when the traditional approach CTO PCI is being used.