Background Revascularization of a chronic total occlusion (CTO) has gained popularity last decade. After recanalization there is an acute gain in vessel diameter, as well as a late lumen gain distal to the stent as a result of positive remodeling. The evolution of a recanalized CTO-vessel is however diverse. Several studies are performed to measure distal lumen gain and hemodynamic coronary parameters of a recanalized CTO, including the novel measurement Absolute Flow. Although the results seem promising, an association between those parameters and distal vessel lumen gain has never been found. The aim of this study is to understand the remodeling of the distal coronary vessel in relation with hemodynamic coronary parameters, establishing baseline predictive factors, adding new information about coronary physiology.

Objectives:

To establish baseline predictive factors for acute and late lumen growth after successful opening of chronic total occlusions. Secondary objectives are 1) Identifying the relation between change in absolute microvascular resistance and late change distal lumen diameter at the end of the index procedure and at 3 months follow-up, 2) Identifying the relation between late lumen growth and stent malapposition, assessed using Optical Coherence Tomography (OCT) and 3) Identifying the relation between angina-related symptoms, assessed using the Seattle Angina Questionnaire-7 (SAQ-7), and absolute microvascular resistance.

Hypothesis:

Acute and late lumen growth are dependent on preprocedural distal coronary artery perfusion pressure, decrease in microvascular resistance and growth of absolute antegrade flow. Late lumen growth predisposes for late stent malapposition.

Study design:

A single-center, prospective, observational cohort study. The center performing this study will be the Radboudumc.

Study Population:

30 patients scheduled for an elective revascularization procedure of a CTO and Heart-team consensus for the indication of a CTO treatment.

Inclusion Criteria:

• Scheduled elective revascularization procedure of a CTO, defined as a complete obstruction of a coronary artery with TIMI-0 or TIMI-1 flow and occlusion duration of at least 3 months
• Heart-team consensus for the indication of a CTO treatment, based on viability and ischemia testing (using TTE or MRI)
• Able to give valid, written informed consent

Exclusion Criteria:

• Unsuccessful crossing of the lesion during PCI
• Renal insufficiency defined as eGFR < 30 ml/min
• Contra-indications to intravenous adenosine
• < 18 years of age
• Pregnancy

30 patients scheduled for an elective revascularization procedure of a CTO and Heart-team consensus for the indication of a CTO treatment

We have planned to perform additional research on this topic.