Remodeling of Distal Coronary Vessel in Chronic Total Occlusions: Prediction Based on Hemodynamic Coronary Parameters (CTO-VR)

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.

Study Overview

• Status: Completed
• Conditions: Fractional Flow Reserve; Absolute Flow Measurement; Optical Coherence Tomography (OCT); Percutaneous Coronary Intervention (PCI); Chronic Total Occlusion (CTO); Quantitative Coronary Analysis

• Study Type: Observational
• Enrollment (Actual): 30

Contacts and Locations

Study Locations

• Netherlands
  • Nijmegen, Netherlands
    • Radboudumc

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Child; Adult; Older Adult
• Accepts Healthy Volunteers: No

• Sampling Method: Non-Probability Sample

Study Population

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

Description

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

Study Plan

How is the study designed?

Number of groups / cohorts

1

Cohorts and Interventions

Group / Cohort

CTO patients undergoing FFR collateral, Absolute flow and OCT measurements; FFR collateral will be measured by measuring the wedge pressure distal from the occlusion, and after stent implantation by creating a balloon-over-the-wire occlusion. MLD will be measured with quantitative coronary analysis (QCA) Absolute flow will be measured by using a rayflow catheter with a pressure wire, and by using the Coroventis system. OCT will be performed during follow-up, using an OCT catheter and perform a pullback through the entire stent trajectory.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Acute FFR collateral change	Changes in collateral function in rest and hyperaemic state, measured before recanalization and after recanalization	30 minutes
Late FFR collateral change	Changes in collateral function in rest and hyperaemic state, measured after recanalization and at 3 months follow-up	3 months
Acute MLD change	Changes in mean lumen diameter of the treated vessel, measured up to 5 mm distal to the occlusion before recanalization and distal to the stent after recanalization	30 minutes
Late MLD change	Changes in mean lumen diameter of the treated vessel, measured up to 5 mm distal to the stent after recanalization and at 3 months follow-up	3 months

Collaborators and Investigators

• Sponsor: Radboud University Medical Center

Study record dates

Study Major Dates

• Study Start (Actual): December 16, 2021
• Primary Completion (Actual): August 28, 2024
• Study Completion (Actual): August 28, 2024

Study Registration Dates

• First Submitted: December 6, 2024
• First Submitted That Met QC Criteria: December 6, 2024
• First Posted (Estimated): December 11, 2024

Study Record Updates

• Last Update Posted (Estimated): December 11, 2024
• Last Update Submitted That Met QC Criteria: December 6, 2024
• Last Verified: December 1, 2024

More Information

Terms related to this study

• Keywords: Percutaneous Coronary Intervention; Chronic Total Occlusion; Optical Coherence Tomography; Absolute flow measurement; Quantitative coronary analysis
• Other Study ID Numbers: 111578

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO
• IPD Plan Description: We have planned to perform additional research on this topic.

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No
• product manufactured in and exported from the U.S.: No