Coronary Steal Via Natural Internal Mammary Artery-To-Coronary Artery Bypasses

NCT02332564 | Completed

• 2 other identifiers: SNCTP0000011382631
• Study Type: observational
• Target: 40
• Locations: 1 country
• Sites: 1

Brief Summary

CORONARY ARTERY DISEASE AND THE BENEFIT OF BYPASSES Despite considerable advances in medicine, cardiovascular diseases remain the number one cause of death globally. In industrialized countries, coronary artery disease (CAD) is the leading cause of death, consequence of myocardial infarction (MI). Artificial - or natural - bypasses 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. In patients with chronic CAD, sufficient coronary collaterals have been shown to confer a significant benefits in terms of overall mortality and cardiovascular events. EXTRACARDIAC-TO-CORONARY COLLATERAL SUPPLY Commonly, coronary collaterals are implicitly understood to exist between coronary artery branches. However, the structural existence of coronary collaterals with an extracardiac connection has been confirmed by anatomical investigations. Pathophysiologically and with regard to a potential for arteriogenic stimulation, the connections from the internal mammary arteries, are of special interest. In a recently published work the investigators have investigated the effect of temporary balloon occlusion of the distal IMA on coronary collateral function. There were equivocal findings for the left circumflex coronary artery: CFI was increased by ipsilateral IMA occlusion, but the level of myocardial ischemia was unchanged. MYOCARDIAL STEAL VIA INTERNAL MAMMARY ARTERIES In the investigators' previous study, the coronary occlusion with simultaneous distal IMA occlusion was always performed first as a conservative measure against false-positive detection of internal-mammary-to-coronary artery connections. Repetitive coronary occlusions per se result in higher collateral flow by collateral recruitment and reduced ischemia by ischemic preconditioning and augmented collateral function. Conversely, the sensitivity of the employed method was reduced and might have contributed to the equivocal findings in case of the left circumflex artery. Moreover, the hypothesize d mechanism of localized pressure augmentation was not investigated. This study aims to further characterize the prevalence and function of natural ipsilateral IMA-to-coronary connections, as well as to investigate the hemodynamic mechanisms of coronary collateral function augmentation by distal IMA occlusion. In the investigators' last study, the increased coronary collateral function in response to manipulation of a potential coronary collateral donor (in this case, the IMA) was taken as indirect evidence for the existence of IMA-to-coronary-artery connections. Thus, the employed distal IMA occlusion served as a positive stimulus. Conceptually, additional evaluation with a negative stimulus could heighten the discriminatory power of the investigation. This could be in the form of a hyperemic stimulus affecting the collateral donor, ie in analogy to myocardial or coronary steal (ie, a reduction in coronary collateral supply to a collateral recipient).

Conditions

Coronary Artery Disease; Ischemia

Keywords

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

Outcome Measures

Primary Outcomes (1)

• Coronary collateral function (CFI)

  Coronary collateral function (CFI)

  Baseline

Secondary Outcomes (3)

• Myocardial ischemia during temporary coronary balloon occlusion

  Baseline

• Proximal IMA pressure immediately before and during (ipsilateral) reactive arm hyperemia.

  Baseline

• Distal IMA CFI

  Baseline

Study Arms (2)

Coronary Artery Disease

Patient with significant coronary artery disease

Other: Coronary Artery Balloon Occlusion for Determination of Collateral Flow Index

No Coronary Artery Disease

Patient without significant coronary artery disease

Other: Coronary Artery Balloon Occlusion for Determination of Collateral Flow Index

Interventions

Coronary Artery Balloon Occlusion for Determination of Collateral Flow Index OTHER

Coronary Artery Balloon Occlusion for Determination of Collateral Flow Index

Coronary Artery Disease; No Coronary Artery Disease

Eligibility Criteria

• Age: 18 Years+
• Sex: all
• Healthy Volunteers: Yes
• Age Groups: Adult (18-64), Older Adult (65+)
• Sampling Method: Probability Sample

Study Population

Patients electively referred for coronary angiography

You may qualify if:

• Age \> 18 years
• Referred for elective coronary angiography
• Written informed consent to participate in the study

You may not qualify if:

• Acute coronary syndrome; unstable cardiopulmonary conditions
• Severe cardiac valve disease
• Congestive heart failure NYHA III-IV
• Prior coronary artery bypass surgery / prior cardiac surgery
• 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
• Pregnancy

Sponsors & Collaborators

• Insel Gruppe AG, University Hospital Bern: lead

Study Sites (1)

Bern University Hospital

Bern, 3010, Switzerland

Location

Related Publications (3)

• 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.

  PMID: 24744276 BACKGROUND

• 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.

  PMID: 13801236 BACKGROUND

• Bigler MR, Buffle E, Stoller M, Grossenbacher R, Tschannen C, Seiler C. Extracardiac coronary steal induced by upper limb hyperemia: a feature of internal mammary artery arteriogenesis. J Appl Physiol (1985). 2021 Sep 1;131(3):905-913. doi: 10.1152/japplphysiol.00082.2021. Epub 2021 Jul 8.

  PMID: 34236245 BACKGROUND

MeSH Terms

Conditions

Coronary Artery Disease; Ischemia

Condition Hierarchy (Ancestors)

Coronary Disease; Myocardial Ischemia; Heart Diseases; Cardiovascular Diseases; Arteriosclerosis; Arterial Occlusive Diseases; Vascular Diseases; Pathologic Processes; Pathological Conditions, Signs and Symptoms

Study Officials

• Christian Seiler, MD, Prof.

  Department of Cardiology, Bern University Hospital

  PRINCIPAL INVESTIGATOR

Study Design

• Study Type: observational
• Observational Model: COHORT
• Time Perspective: PROSPECTIVE
• Sponsor Type: OTHER
• Responsible Party: SPONSOR

Study Record Dates

• First Submitted: January 5, 2015
• First Posted: January 7, 2015
• Study Start: December 1, 2014
• Primary Completion: November 1, 2020
• Study Completion: July 1, 2021
• Last Updated: February 14, 2023

Record last verified: 2023-02

Locations

CH (1)