CTO
Also written as: CTO — Chronic Total Occlusion
Complete coronary artery blockage present for at least 3 months, representing complex lesions requiring specialized intervention techniques.
Full Definition
Chronic Total Occlusion (CTO) refers to complete occlusion of a coronary artery with absent antegrade flow (TIMI flow 0) that has been present for at least 3 months duration. CTO lesions represent some of the most challenging cases in interventional cardiology, often requiring specialized techniques, equipment, and operator expertise. In cardiovascular research, CTO intervention studies focus on procedural success rates, safety outcomes, and long-term clinical benefits. Success rates have improved significantly with advanced techniques including retrograde approaches, specialized guidewires, and dedicated CTO devices. Clinical trials evaluating CTO intervention often use procedural success and clinical outcomes as primary endpoints.
Usage
Usage note: Always specify duration (≥3 months) when defining; distinguish from acute/subacute occlusions.
In Context
- "CTO PCI success rates exceeded 85% with contemporary techniques and experienced operators." — interventional cardiology registry
- "The study randomized patients with chronic total occlusions to PCI versus optimal medical therapy." — randomized controlled trial