Percutaneous coronary intervention of chronic total occlusions (CTO) is currently indicated for symptom improvement, as studies have inadequate randomization of data which hinders the assessment of hard outcomes. However, patient inclusion in randomized controlled trials has been challenging, especially for highly symptomatic and higher risk patients. This causes a selection bias in randomized studies on CTOs.
The purpose of this meta-analysis was to evaluate the differences between patients with CTOs in the real world vs. those who were included in randomized studies.
Outcomes were evaluated in terms of procedural success, in-hospital mortality, acute myocardial infarction (AMI), major cardiovascular events (MACE), and cardiac tamponade. Procedural success was defined as technical success (<30% residual stenosis with TIMI 3 flow) without MACE.
In this study, the analysis included 6 randomized controlled studies comparing CTA to CTO vs. medical treatment (N = 1047), 10 CTO-dedicated registries (N = 76,467), and 5 national registries (N = 110,349). Most patients in the randomized studies were men and had a trend of lower comorbidities such as diabetes, hypertension, peripheral artery disease, prior AMI, prior CTA, and prior myocardial revascularization surgery. In addition, these patients underwent procedures with longer fluoroscopy time and greater use of contrast material.
Procedural success was significantly lower in the national registries compared with the randomized studies (63.9% vs. 84.5%, relative difference = 24.4%). However, randomized studies had a higher risk of in-hospital events, including death (1.3% vs. 0.6%, relative difference = 52.3%), MACE (7.9% vs. 1.5%, relative difference = 81.0%), AMI (5.9% vs. 1.0%, relative difference = 83.1%), and cardiac tamponade (0.9% vs. 0.3%, relative difference = 66.7%).
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When comparing patients from randomized studies vs. CTO-dedicated registries, patients included in the studies had shorter CTOs and low J-CTO scores (2.0-1.1 vs. 2.3-1.2, relative difference = 13.0%). Although procedural success was similar between both groups (84.5% vs. 81.4%), patients included in the studies presented a higher risk of in-hospital events (death, MACE, AMI, and cardiac tamponade).
Conclusion
Patients included in the randomized studies had less risk profile and less injury complexity than real-world registries. Current evidence from randomized controlled studies may not be representative of real-world patients and should be interpreted with this limitation. Procedures performed by surgeons specialized in CTOs have significantly more success and fewer complications than those performed by surgeons that are not specialized in CTOs.
Dr. Andrés Rodríguez.
Member of the Editorial Board of SOLACI.org.
Original Title: Comparative Analysis of Patient Characteristics in Chronic Total Occlusion Revascularization Studies Trials vs Real-World Registries.
Reference: Michael Megaly, MD et al J Am Coll Cardiol Intv 2022;15:1441–1449.
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