Chronic Total Occlusion (CTO)

Chronic Total Occlusion (CTO) represents a severe form of coronary artery disease where a coronary artery is 100% blocked by atherosclerotic plaque for at least three months, severely limiting blood flow to the heart muscle. This condition often develops silently from progressive atherosclerosis combined with thrombosis, affecting up to 25% of coronary artery disease patients. Compromised perfusion leads to ischemia, manifesting as exertional chest pain (angina), fatigue, dyspnea, or even silent myocardial damage.

This diagram illustrates primary coronary arteries and cross-sections showing plaque buildup in CTO versus normal flow.

Symptoms and Diagnosis

Patients commonly experience stable angina, reduced exercise tolerance, or heart failure symptoms; some remain asymptomatic until complications arise. Diagnosis relies on coronary angiography confirming TIMI 0 flow (no anterograde perfusion) for ?3 months, often supplemented by CT angiography or intravascular imaging.

Treatment Options

Primary interventions include percutaneous coronary intervention (CTO-PCI) using specialized wires, balloons, and stents for revascularization, boasting 80% first-time success rates. For complex cases, coronary artery bypass grafting (CABG) provides durable bypass around blockages. Medical therapy with beta-blockers, statins, antiplatelets, and lifestyle modifications (e.g., diet, exercise) supports symptom relief and risk reduction. Early intervention improves quality of life and prognosis in suitable candidates.