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COronary and MICrocirculatory Measurements in Patients With Aortic Valve Stenosis.

COronary and MICrocirculatory Measurements in Patients With Aortic Valve, the COMIC AS Study.

Status
Completed
Phases
Unknown
Study type
Observational
Source
ClinicalTrials.gov
Registry ID
NCT04420325
Acronym
COMIC-AS
Enrollment
116
Registered
2020-06-09
Start date
2020-06-01
Completion date
2024-10-01
Last updated
2025-09-05

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

Aortic Stenosis, Coronary Artery Disease

Brief summary

Although concomitant coronary artery disease (CAD) is frequent in patients with severe aortic stenosis (AS), hemodynamic assessment of CAD severity in patients undergoing valve replacement for severe AS is challenging. Myocardial hypertrophic remodeling interferes with coronary blood flow and may influence the values of fractional flow reserve (FFR) and nonhyperemic pressure ratios (NHPRs). The aim of the current study is to investigate the effect of the AS and its treatment on current indices used for evaluation of CAD. The investigators will compare intracoronary hemodynamics before, immediately after, and 6 mo after aortic valve replacement (AVR) when it is expected that microvascular function has improved. Furthermore, the investigators will compare FFR and resting full-cycle ratio (RFR) with myocardial perfusion single-photon emission-computed tomography (SPECT) as indicators of myocardial ischemia in patients with AS and CAD. One-hundred consecutive patients with AS and intermediate CAD will be prospectively included. Patients will undergo pre-AVR SPECT and intracoronary hemodynamic assessment at baseline, immediately after valve replacement \[if transcatheter AVR (TAVR) is chosen\], and 6 mo after AVR. The primary end point is the change in FFR 6 mo after AVR. Secondary end points include the acute change of FFR after TAVR, the diagnostic accuracy of FFR versus RFR compared with SPECT for the assessment of ischemia, changes in microvascular function as assessed by the index of microcirculatory resistance (IMR), and the effect of these changes on FFR. The present study will evaluate intracoronary hemodynamic parameters before, immediately after, and 6 mo after AVR in patients with AS and intermediate coronary stenosis. The understanding of the impact of AVR on the assessment of FFR, NHPR, and microvascular function may help guide the need for revascularization in patients with AS and CAD planned for AVR.

Detailed description

https://journals.physiology.org/doi/full/10.1152/ajpheart.00541.2021?rfr\_dat=cr\_pub++0pubmed&url\_ver=Z39.88-2003&rfr\_id=ori%3Arid%3Acrossref.org

Interventions

None listed

Sponsors

AZ Delta
CollaboratorOTHER
University Hospital, Antwerp
CollaboratorOTHER
Universitaire Ziekenhuizen KU Leuven
Lead SponsorOTHER

Study design

Observational model
COHORT
Time perspective
PROSPECTIVE

Eligibility

Sex/Gender
ALL
Age
18 Years to No maximum
Healthy volunteers
No

Inclusion criteria

* 1\. Patient undergoing the procedure is older than 18 years, has severe aortic valve stenosis (according to ESC guidelines) and is planned for cardiac catheterization as part of the pre-operative (SAVR) or pre-percutaneous (TAVI) work up. 2\. The patient has an intermediate (50-90%) coronary lesion that requires further evaluation. 3\. The patient undergoing the procedure is male, or if female, has no childbearing potential or is not pregnant.

Exclusion criteria

1. The procedure is an emergency and/or the patient is unstable. 2. Pregnancy or lactation 3. Haemodynamically unstable patients 4. Killip class III-IV heart failure 5. Previous coronary artery by-pass in the artery being assessed 6. Contra-indications for adenosine administration: severe asthma or pre-existing type 2 AV-block 7. No significant coronary artery disease (\<50% stenosis on angiography). 8. Critical coronary artery disease deemed by the Heart Team to require immediate revascularization 9. Patients will be excluded from the SPECT study (secondary objective) if they have a left main coronary stenosis \>50%, triple vessel disease, previous myocardial infarction in the same coronary artery & tandem lesions (separated by \>10mm) requiring independent evaluation in the same coronary artery since these factors interfere with the SPECT analysis.

Design outcomes

Primary

MeasureTime frameDescription
FFR 6 Months After SAVR/TAVI.6 monthsAortic valve intervention can potentially result in a change in fractional flow reserve (FFR) 6 months after SAVR/TAVI. FFR is the ratio of two intra-coronary measurements (Distal coronary pressure divided by proximal coronary pressure) and can range from 0.0-1.0. A lower FFR means that the lesion is more severe and therefore a higher FFR is considered better. The threshold to speak about hemodynamic significant of a lesion is 0.80. If the lesion has an FFR of ≤ 0.80 means the lesions is significant and treatment is necessary.

Secondary

MeasureTime frameDescription
IMR 6 Months After SAVR/TAVI.6 monthsMeasurement of IMR in patients with AS prior to intervention and 6 months after TAVI/SAVR. IMR is unitless and gives a description of coronary microvascular resistance, it can range from 0-100. Lower values are considered better as they are related with better microvascular function and health. If the IMR \> 25 we say microvascular dysfunction is present and treatment is considered necessary.
FFR Versus RFR to Determine Ischemia.BaselineComparison of the diagnostic performance of FFR versus RFR compared with SPECT ischemia. The higher the Area under the curve the better. The range is 0.0-1.0. An area under the curve for a ROC model is considered excellent if \> 0.8.

Countries

Belgium

Participant flow

Participants by arm

ArmCount
Entire Study Population
Patients with AS undergoing TAVI or SAVR
116
Total116

Baseline characteristics

CharacteristicEntire Study Population
Age, Categorical
<=18 years
0 Participants
Age, Categorical
>=65 years
110 Participants
Age, Categorical
Between 18 and 65 years
6 Participants
Age, Continuous79.48 years
STANDARD_DEVIATION 8.18
Race/Ethnicity, Customized
White
116 Participants
Region of Enrollment
Belgium
116 Participants
Sex: Female, Male
Female
47 Participants
Sex: Female, Male
Male
69 Participants

Adverse events

Event typeEG000
affected / at risk
deaths
Total, all-cause mortality
0 / 116
other
Total, other adverse events
0 / 116
serious
Total, serious adverse events
0 / 116

Outcome results

Primary

FFR 6 Months After SAVR/TAVI.

Aortic valve intervention can potentially result in a change in fractional flow reserve (FFR) 6 months after SAVR/TAVI. FFR is the ratio of two intra-coronary measurements (Distal coronary pressure divided by proximal coronary pressure) and can range from 0.0-1.0. A lower FFR means that the lesion is more severe and therefore a higher FFR is considered better. The threshold to speak about hemodynamic significant of a lesion is 0.80. If the lesion has an FFR of ≤ 0.80 means the lesions is significant and treatment is necessary.

Time frame: 6 months

ArmMeasureValue (MEAN)Dispersion
Entire Study PopulationFFR 6 Months After SAVR/TAVI.-0.0279 ratioStandard Deviation 0.0368
Secondary

FFR Versus RFR to Determine Ischemia.

Comparison of the diagnostic performance of FFR versus RFR compared with SPECT ischemia. The higher the Area under the curve the better. The range is 0.0-1.0. An area under the curve for a ROC model is considered excellent if \> 0.8.

Time frame: Baseline

ArmMeasureValue (NUMBER)
Entire Study PopulationFFR Versus RFR to Determine Ischemia.0.8719 probability
Secondary

IMR 6 Months After SAVR/TAVI.

Measurement of IMR in patients with AS prior to intervention and 6 months after TAVI/SAVR. IMR is unitless and gives a description of coronary microvascular resistance, it can range from 0-100. Lower values are considered better as they are related with better microvascular function and health. If the IMR \> 25 we say microvascular dysfunction is present and treatment is considered necessary.

Time frame: 6 months

ArmMeasureValue (MEAN)Dispersion
Entire Study PopulationIMR 6 Months After SAVR/TAVI.-2.8150 UnitlessStandard Deviation 12.16

Source: ClinicalTrials.gov · Data processed: Feb 4, 2026