CTO
Also written as: CTO — Chronic Total Occlusion
Chronic total occlusion, a complete blockage of a coronary artery present for more than three months with TIMI 0 flow.
Full Definition
Chronic total occlusion (CTO) represents a complete blockage of a coronary artery that has been present for at least three months, characterized by TIMI 0 flow (no antegrade flow) and often associated with well-developed collateral circulation. CTO interventions are among the most technically challenging procedures in interventional cardiology, requiring specialized equipment, techniques, and operator expertise. Success rates have improved significantly with the development of dedicated CTO algorithms, microcatheters, specialized guidewires, and retrograde approaches through collateral vessels. Patient selection for CTO intervention depends on symptom severity, ischemic burden, and technical feasibility. These procedures carry higher radiation exposure and contrast usage compared to conventional percutaneous interventions.
Usage
Usage note: Standard abbreviation in interventional cardiology; specify vessel and duration when known in comprehensive reports.
In Context
- "The patient was referred for CTO intervention of the chronically occluded RCA." — Referral indication
- "Successful CTO recanalization was achieved using a retrograde approach via septal collaterals." — Procedure summary