Effect of Permanent Internal Mammary Artery Occlusion on Extracardiac Coronary Collateral Supply

NCT ID: NCT02475408

Last Updated: 2016-05-12

Study Results

Results pending

The study team has not published outcome measurements, participant flow, or safety data for this trial yet. Check back later for updates.

Basic Information

Get a concise snapshot of the trial, including recruitment status, study phase, enrollment targets, and key timeline milestones.

Recruitment Status

COMPLETED

Clinical Phase

PHASE1/PHASE2

Total Enrollment

50 participants

Study Classification

INTERVENTIONAL

Study Start Date

2014-12-31

Study Completion Date

2016-04-30

Brief Summary

Review the sponsor-provided synopsis that highlights what the study is about and why it is being conducted.

Coronary artery disease and the benefit of bypasses:

Despite considerable advances in medicine, cardiovascular diseases remain the number one cause of death globally, primarily consequence of myocardial infarction (MI). Coronary collaterals exert a protective effect by providing an alternative source of blood flow to a myocardial territory potentially affected by an acute coronary occlusion. Coronary collaterals represent pre-existing inter-arterial anastomoses and as such are the natural counter-part of surgically created bypasses. Sufficient coronary collaterals have been shown to confer a significant benefit in terms of overall mortality and cardiovascular events. In this regard, the concept of augmenting coronary collateral function as an alternative treatment strategy to alter the course of CAD, as well as to control symptoms, is attractive.

Durable promotion of coronary collateral circulation:

Before the advent of coronary artery bypass grafting, permanent augmentation of coronary collateral supply by a single structural modification has already been attempted. Bilateral ligation of the internal mammary arteries (IMA) was performed in CAD patients to alleviate angina pectoris and electrocardiographic (ECG) signs of ischemia. The prevalent in vivo function of natural IMA-to-coronary artery bypasses and their anti-ischemic effect has - for the first time - been recently demonstrated by our research group. The acute functional changes observed in response to temporary distal IMA balloon occlusion are expected to result in larger chronic structural adaptations of the IMA-to-coronary-artery connections when the distal IMA is permanently occluded. In contrast to the previously employed arteriogenic approaches in humans, the attractiveness of such an intervention lies in the potential durability of the effect.

In a first step, catheter-based IMA occlusion ought to be conceptually investigated in the setting of the less frequently grafted right IMA among patients with ischemia in the right coronary artery territory.

Detailed Description

Dive into the extended narrative that explains the scientific background, objectives, and procedures in greater depth.

Coronary artery disease and the benefit of bypasses:

Despite considerable advances in medicine, cardiovascular diseases remain the number one cause of death globally, primarily consequence of myocardial infarction (MI). Although widely used in stable CAD, percutaneous coronary intervention (PCI) has not been shown to reduce the incidence of myocardial infarction or death. In contrast, coronary artery bypass grafting (CABG) significantly reduced rates of death and myocardial infarction compared to PCI. Similarly, coronary collaterals exert a protective effect by providing an alternative source of blood flow to a myocardial territory potentially affected by an acute coronary occlusion. Coronary collaterals represent pre-existing inter-arterial anastomoses and as such are the natural counter-part of surgically created bypasses. Sufficient coronary collaterals have been shown to confer a significant benefit in terms of overall mortality and cardiovascular events. In this regard, the concept of augmenting coronary collateral function as an alternative treatment strategy to alter the course of CAD, as well as to control symptoms, is attractive.

Durable promotion of coronary collateral circulation:

While a multitude of interventions has been shown to be effective in collateral growth promotion, so far, the effect of current interventions is only temporary and therefore recurrent application is necessary to sustain the level of collaterals. However, before the advent of coronary artery bypass grafting, permanent augmentation of coronary collateral supply by a single structural modification has already been attempted. Bilateral ligation of the internal mammary arteries (IMA) was performed in CAD patients to alleviate angina pectoris and electrocardiographic (ECG) signs of ischemia. The prevalent in vivo function of natural IMA-to-coronary artery bypasses and their anti-ischemic effect has - for the first time - been recently demonstrated by our research group. Levels of collateral function and myocardial ischemia were determined during two coronary balloon occlusions, the first with, the second without distal IMA balloon occlusion. Coronary collateral function, was consistently increased in the presence vs the absence of distal ipsilateral IMA balloon occlusion. These findings were corroborated by the observed reduction in ischemia. Conversely, with distal contralateral IMA occlusion, collateral function and ECG signs of ischemia remained unchanged. The acute functional changes observed in response to temporary distal IMA balloon occlusion are expected to result in larger chronic structural adaptations of the IMA-to-coronary-artery connections when the distal IMA is permanently occluded. In contrast to the previously employed arteriogenic approaches in humans, the attractiveness of such an intervention lies in the potential durability of the effect.

In a first step, catheter-based IMA occlusion ought to be conceptually investigated in the setting of the less frequently grafted right IMA among patients with ischemia in the right coronary artery territory.

Conditions

See the medical conditions and disease areas that this research is targeting or investigating.

Circulation, Collateral Coronary Artery Disease Internal Mammary-Coronary Artery Anastomosis Ischemia

Study Design

Understand how the trial is structured, including allocation methods, masking strategies, primary purpose, and other design elements.

Allocation Method

NA

Intervention Model

SINGLE_GROUP

Primary Study Purpose

BASIC_SCIENCE

Blinding Strategy

NONE

Study Groups

Review each arm or cohort in the study, along with the interventions and objectives associated with them.

Interventional Study Arm

In the presence of a significant right coronary artery stenosis, catheter-based occlusion of the right IMA distal to the take-off of the pericardio-phrenic branch is performed at baseline using a dedicated occlusion device (Amplatzer vascular plug).

Group Type EXPERIMENTAL

Amplatzer vascular plug

Intervention Type DEVICE

Interventions

Learn about the drugs, procedures, or behavioral strategies being tested and how they are applied within this trial.

Amplatzer vascular plug

Intervention Type DEVICE

Eligibility Criteria

Check the participation requirements, including inclusion and exclusion rules, age limits, and whether healthy volunteers are accepted.

Inclusion Criteria

* Age \> 18 years
* Referred for elective coronary angiography
* Written informed consent to participate in the study
* Significant stenosis of right coronary artery (FFR ≤0.80)

Exclusion Criteria

* Acute coronary syndrome; unstable cardiopulmonary conditions, unstable angina pectoris
* Collateral flow index of right IMA \<0.25
* Severe cardiac valve disease
* Congestive heart failure NYHA III-IV
* Prior coronary artery bypass surgery / prior cardiac surgery
* Coronary artery disease best treated by coronary artery bypass grafting
* Coronary artery disease unsuitable for intracoronary pressure measurements
* Prior Q-wave myocardial infarction in the vascular territory undergoing collateral function determination
* Severe renal or hepatic failure
* Women of childbearing age
Minimum Eligible Age

18 Years

Eligible Sex

ALL

Accepts Healthy Volunteers

No

Sponsors

Meet the organizations funding or collaborating on the study and learn about their roles.

Insel Gruppe AG, University Hospital Bern

OTHER

Sponsor Role lead

Responsible Party

Identify the individual or organization who holds primary responsibility for the study information submitted to regulators.

Responsibility Role SPONSOR

Principal Investigators

Learn about the lead researchers overseeing the trial and their institutional affiliations.

Seiler Christian, MD, Prof

Role: PRINCIPAL_INVESTIGATOR

Bern University Hospital

Locations

Explore where the study is taking place and check the recruitment status at each participating site.

Bern University Hospital

Bern, , Switzerland

Site Status

Countries

Review the countries where the study has at least one active or historical site.

Switzerland

References

Explore related publications, articles, or registry entries linked to this study.

Stoller M, de Marchi SF, Seiler C. Function of natural internal mammary-to-coronary artery bypasses and its effect on myocardial ischemia. Circulation. 2014 Jun 24;129(25):2645-52. doi: 10.1161/CIRCULATIONAHA.114.008898. Epub 2014 Apr 17.

Reference Type BACKGROUND
PMID: 24744276 (View on PubMed)

Moberg A. Anastomoses between extracardiac vessels and coronary arteries. II. Via internal mammary arteries. Post-mortem angiographic study. Acta Radiol Diagn (Stockh). 1967 May;6(3):263-72. doi: 10.1177/028418516700600306. No abstract available.

Reference Type BACKGROUND
PMID: 6025072 (View on PubMed)

BLAIR CR, ROTH RF, ZINTEL HA. Measurement of coronary artery blood-flow following experimental ligation of the internal mammary artery. Ann Surg. 1960 Aug;152(2):325-9. doi: 10.1097/00000658-196008000-00018. No abstract available.

Reference Type BACKGROUND
PMID: 13801236 (View on PubMed)

Stoller M, Seiler C. Effect of Permanent Right Internal Mammary Artery Closure on Coronary Collateral Function and Myocardial Ischemia. Circ Cardiovasc Interv. 2017 Jun;10(6):e004990. doi: 10.1161/CIRCINTERVENTIONS.116.004990.

Reference Type DERIVED
PMID: 28566292 (View on PubMed)

Other Identifiers

Review additional registry numbers or institutional identifiers associated with this trial.

SNCTP000000901

Identifier Type: -

Identifier Source: org_study_id

More Related Trials

Additional clinical trials that may be relevant based on similarity analysis.