Comparison of Treatment Methods for Coronary Heart Disease in Patients with Chronic Total Coronary Artery Occlusions. Summary of the Doctoral Thesis
Authors:   ,   Rīga Stradiņš University, Kalniņš Artis 
Published: December 2021

One of the methods for coronary heart disease (CHD) treatment is percutaneous coronary intervention (PCI). After the first successful percutaneous coronary angioplasty, done in 1977, PCI many years were performed only for patients with stable CHD. Since the early 1980s, PCI has also been used for acute myocardial infarction (MI) treatment. The benefits of invasive treatment over thrombolysis in acute MI had became clear already after the first studies (Keeley et al., 2003). Primary percutaneous coronary intervention is now undoubtedly the treatment of choice for the treatment of acute myocardial infarction (Ibanez et al., 2018). The usefulness and effectiveness of PCI in the treatment of chronic coronary heart disease, on the other hand, is constantly being discussed. Several studies have been performed trying to attempt to question the efficacy of PCI in the treatment of stable CHD (COURAGE, ORBITA). However, these studies have had a relatively short follow-up time and have not led to a limitation of PCI as a treatment method for stable CHD. A large proportion of CTO patients are asymptomatic and it is therefore even more difficult to demonstrate the benefits and advantages of invasive treatment for this group of patients. There are very few long-term follow-up studies that would prove efficacy or ineffectiveness of CTO invasive treatment, so the dissertation summarizes data and angioplasty results for 551 patients who underwent CTO PCI over 10 years.The aim of the study is to compare the long-term results of invasive treatment methods for patients with coronary heart disease and chronic total coronary artery occlusions. The dissertation compared the overall survival after successful and unsuccessful CTO PCI procedures, compared the long-term results of antegrade and retrograde percutaneous coronary intervention techniques, evaluated the multifactor effect of chronic total coronary artery occlusion complexity on the outcome of percutaneous coronary intervention and survival. Study also analyses PCI results for different groups of patients: with and without diabetes, before and after the age of 65, men and women, patients with and without a history of coronary artery bypass graft surgery.Comparing the long-term results after successful and unsuccessful CTO PCI procedures, a better survival was found after successful CTO PCI. Also has been found that the use of the retrograde approach improves the results of procedures and does not worsen the prognosis. It is concluded that in cases where successful antegrade CTO PCI is unlikely, the retrograde approach should be used as the primary strategy. It has been confirmed that the complexity of CTO, calculated by the J-CTO, PROGRESS CTO, CL and CASTLE scores, is directly correlated with the outcome of the procedure. The complexity of CTO, assessed by the PROGRESS CTO and CASTLE scales, can affect patient survival due to the complexity criteria included in these scales – quality of collaterals available for retrograde approach, age, and previous CABG.Analyses of different groups of patients have shown that CTO revascularization provides better survival in men than in women, the presence or absence of diabetes does not affect the long-term results of CTO PCI, for patients under and up to 65 years of age long term outcome after CTO PCI is not related to the patients age, but to the success of the procedure, patients with CTO and previous coronary artery bypass grafting should be considered as patients with increased complexity of CTO PCI.The obtained results provide recommendations for the CTO patients assesement and for CTO PCI procedure planning and performance.