Drug-COated Balloon Coronary Angioplasty versus Stenting for Treatment of Disease Adjacent to a Chronic Total Occlusion - The Co-CTO Trial.

Chronic total coronary occlusions (CTO) are documented in approximately 20% of
diagnostic coronary angiograms. New developments such as retrograde approach
and dissection re-entry techniques have resulted in more widespread application
of percutaneous coronary intervention (PCI) of CTOs, and this technique now
serves as a viable alternative to optimal medical therapy alone or coronary
artery bypass surgery. In general, PCI CTO is accompanied by extensive stenting
of the coronary artery beyond the original occlusive segment itself.
Unfortunately, stent length and diameter are directly related to poorer
outcome, which is related to an increased rate of in-stent restenosis and
thrombosis. An alternative to stenting is the application of drug-coated
balloons (DCB). This strategy may prove beneficial, as it could significantly
reduce stent length, among other things. However, data on the use of DCBs in
the context of PCI CTO are currently lacking.

The aim of the study is to investigate the value of DCB treatment in the
residual disease of the coronary artery after successful recanalization and
stenting of the actual CTO body as compared with complete stenting in a
randomized fashion.

This is an investigator-initiated, randomized, single-blind (patients will be
masked), multi-center, non-inferiority clinical trial.
Patients with a CTO who are eligible for PCI will be randomized in a 1:1 ratio
to additional DCB treatment or stenting of residual disease.

After inclusion, patients will be randomized (1:1) to additional DCB treatment
or stenting of residual disease.

All patients included in the trial will have a clinical indication for
percutaneous revascularization. Since there are no randomized controlled trials
which advocate the use of either DES or DCB over one another in this setting,
patients will not be exposed to extra risk due to randomization in the trial.
Contemporary native vessel PCI is associated with low in-hospital events rates,
i.e. in-hospital mortality of 0.9%, vascular complication in 0.7%, procedural
complications in 4.7% and bleeding requiring transfusion in 3.3%.
All patients will undergo coronary angiography after 1 year follow-up and will
thus be exposed to the risks of invasive coronary angiography. Coronary
angiography is characterized by a low complication rate (<0.5%) of e.g.
bleeding, stroke, coronary dissection, myocardial infarction, or death (<0.1%).
Radiation exposure of a repeat coronary angiography is estimated at 5-10 mSv.

Patients participating in the CCTA substudy will be exposed to an effective
dose equivalent ~2.1 mSv. Impact CT Dosimetry software package version 1.04 was
used to calculate the radiation dosage. Furthermore, ionized contrast agents
will be used during CCTA, which can be nefrotoxic and may elicit allergic
reactions.

Expected benefit of this study:
A DCB facilitated minimal stenting strategy for treatment of chronic total
occlusions may significantly reduce stent length, number of used stents, as
well as compression of the distal lumen with undersized stents and consequently
may avoid potential late detrimental complications of a permanent metallic
cage. However, data on the use of DCBs in the context of PCI CTO are currently
lacking. This trial could influence current guidelines on the application of
DCBs in CTO procedures, and facilitate its use in patients with high bleeding
risk.