Determination of Coronarphysiological Parameters With the Method of Thermodillution

Coronary Artery Stenosis of Unclear Hemodynamic Relevance Clinical Trial

Official title:

Determination of Coronarphysiological Parameters With the Method of Thermodillution

Clinical Trial Details — Status: Completed

Administrative data

• NCT number: NCT03101696
• Other study ID #: 16-024
• Status: Completed
• Start date: February 5, 2017
• Est. completion date: February 28, 2019

Study information

• Verified date: March 2019
• Source: Heinrich-Heine University, Duesseldorf
• Contact: n/a
• Is FDA regulated: No
• Study type: Observational

Clinical Trial Summary

The gold standard to induce coronary hyperemia for measurement of fractional flow reserve (FFR), coronary flow reserve (CFR) and index of microcirculatory resistance (IMR) is adenosine, but it exerts several side effects due to its unspecific action on adenosine receptors. The specific A2a-receptor agonist, regadenoson, has been shown to dilate coronary arteries and enables FFR measurements. The aim of the study was to evaluate whether simultaneous measurement of FFR, CFR and IMR is feasible, safe and effective within regadenoson-induced hyperemia.

Description:

Fractional flow reserve (FFR), coronary flow reserve (CFR) and the index of microcirculatory resistance (IMR) provide significant information on the conductance of coronary macro- and microcirculation.

FFR-based functional assessment of coronary artery disease has proven to be superior to purely morphologic assessment and thereby guides therapy decision. IMR is a pressure-temperature derived parameter for quantifying microcirculatory resistance, which has been proven to be relatively independent of epicardial stenosis severity when taking collateral flow into account. IMR is increased in patients with acute myocardial infarction and microvascular obstruction (MVO) as assessed by contrast-enhanced CMR and predicts left ventricular function and enddiastolic volumes at 6 month independently of initial infarct size.

Most interestingly, even in the absence of obstructive coronary artery disease, IMR is elevated in more than 20% of patients presenting with chest pain. The clinical meaning for this finding has to be elucidated.

FFR, CFR and IMR can only be measured under conditions of minimal coronary resistance with the need for coronary hyperemia. The current "gold standard" to induce hyperemia in the assessment of coronary conductance is adenosine. However, adenosine is known to cause side effects (bronchospasm and disturbances in atrioventricular conduction) due to its unselective action on all adenosine receptors. Besides that, adenosine requires a body weight adapted dosing and continuous infusion. However, alternative routes like intracoronary injection show good correlation compared with the intravenous route and side effects can be reduced. In contrast, regadenoson, a specific A2A receptor agonist, exhibits negligible side effects. It can be administered intravenously as a non-body weight adapted bolus via peripheral vein without the need for transfemoral delivery. Thus, patients with a transradial access for cardiac catheterization might benefit the most from inducing hypermedia via peripheral vein. It has already been shown that regadenoson increases coronary blood flow yielding comparable values for FFR and indexes of perfusion in SPECT. However, the duration and stability of regadenoson-induced hyperemia might be insufficient for a simultaneous measurement of FFR, CFR and IMR, which has not been tested so far.

The aim of the present study is to evaluate whether simultaneous measurement of the parameters FFR, CFR and IMR under regadenoson-induced hyperemia is feasible, safe and effective in patients with stable coronary artery disease undergoing a transradial procedure

Recruitment information / eligibility

• Status: Completed
• Enrollment: 50
• Est. completion date: February 28, 2019
• Est. primary completion date: February 28, 2019
• Gender: All
• Age group: 18 Years and older

Eligibility

Inclusion Criteria:

Coronary angiography with indication of FFR measurement

• angiography without pathological results explaining the patients' symptoms

• intermediate stenosis (50-70%)

Exclusion Criteria:

• <18 years

• Hypersensitivity towards regadenoson

• hemodynamic instability

• severe hypotension

• acute myocardial ischemia

• AV block II-III

Related Conditions & MeSH terms

• Coronary Artery Stenosis of Unclear Hemodynamic Relevance
• Coronary Stenosis

Locations

Country	Name	City	State
Germany	Division of Cardiology, Pulmonary Disease and Vascular Medicine	Dusseldorf

Sponsors (1)

Lead Sponsor	Collaborator
Heinrich-Heine University, Duesseldorf

Country where clinical trial is conducted

Germany, 

Outcome

Type	Measure	Description	Time frame	Safety issue
Primary	fractional flow reserve (FFR)	Description: the proximal aortic (Pa) and distal arterial pressure (Pd) are recorded and RadiAnalyzer Xpress™ control unit automatically calculates FFR as Pd/Pa	Baseline
Secondary	coronary flow reserve	The RadiAnalyzer Xpress™ calculates CFR as Tmnr/Tmnh	Baseline
Secondary	index of microcirculatory resistance	Using the derived Pd and transit mean times under hyperemia (Tmnh), it will be calculated apparent IMR as Pd×Tmnh. All IMR values are also corrected by Yong's formula (IMRcorr=Pa×Tmnh×([1.35×Pd/Pa]-0.32) to adjust for the influence of collateral flow.	Baseline