A Placebo-controlled Trial of Chronic Total Occlusion Percutaneous Coronary Intervention for the Relief of Stable Angina

Inclusion criteria

ORBITA CTO will enrol patients who meet all 5 of the following criteria:

• Accepted for CTO PCI procedure by a specialist CTO operator.
• Patients with symptoms related to a single vessel CTO (≥3 months duration, or probable CTO where duration is unknown) in a vessel of at least 2.5mm diameter without angiographically significant (LMS ≥50%, LAD/Cx/RCA/Graft ≥70%, ≥2mm diameter) coronary artery stenosis in remaining non-CTO vessels.

Symptoms are:

a) Typical exertional angina defined as: i) constricting discomfort in the front of the chest or in the neck, jaw, shoulder or arm ii) precipitated by physical exertion iii) relieved by rest or nitrates within 5 minutes b) Angina symptoms at rest (including decubitus angina and post-prandial angina).

c) Shortness of breath on exertion considered to be angina equivalent.

• Clinical evidence of ischaemia in CTO territory on dobutamine stress echocardiography, nuclear myocardial perfusion scan, stress perfusion CMR or PET).
• Evidence of viability: If left ventricular angiogram or echocardiogram demonstrates LV impairment or RWMA then viability must be demonstrated.
• J-CTO score ≤ 3.

Exclusion criteria

• Acute coronary syndrome within 4 weeks.
• PCI to non-CTO lesion in prior 4 weeks as part of ACS or elective PCI.
• Non-revascularised clinically important non-CTO vessel.
• Proven ischaemia (invasive or non-invasive) in non-culprit territory.
• Contraindications to PCI or drug-eluting stent (DES) implantation.
• Inability to tolerate or contraindication to DAPT.
• Severe valvular heart disease.
• Severe chronic pulmonary disease (FEV1 <30% of predicted value).
• Severe musculoskeletal disease resulting in immobility.
• Life expectancy <2years.
• Pregnancy.
• Age <18years.
• Inability to consent.