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Coronary collateral quantitation in patients with coronary artery disease using intravascular flow velocity or
C Seiler1, M Fleisch, A Garachemani
1Department of Cardiology, University Hospital, Bern, Switzerland. christian.seiler@insel.ch
Insights
Quantitative measurement of coronary collateral circulation is now possible using intracoronary (IC) blood flow velocity or pressure during percutaneous transluminal coronary angioplasty (PTCA). This accurate method aids in assessing collateral function and guiding therapies.
Area of Science:
- Cardiovascular research
- Interventional cardiology
- Hemodynamics
Background:
- Myocardial necrosis extent is influenced by coronary collateral circulation.
- Current qualitative assessment methods limit research into collateral development therapies.
Purpose of the Study:
- Evaluate quantitative measurement of coronary collaterals using intracoronary (IC) blood flow velocity or pressure.
- Compare these novel methods with conventional assessments.
Main Methods:
- Investigated 51 patients undergoing percutaneous transluminal coronary angioplasty (PTCA).
- Used IC PTCA guidewire-based Doppler and pressure sensors distal to stenosis.
- Calculated collateral flow indices (CFIv and CFIp) from simultaneous pressure and velocity measurements.
Main Results:
- Sufficient collaterals (n=11) showed 46% relative collateral flow; insufficient collaterals (n=40) showed 18%.
- IC Doppler achieved 100% sensitivity and 93% specificity for diagnosing sufficient collaterals (CFI=30%).
- IC pressure measurements showed 75% sensitivity and 92% specificity; good agreement between Doppler and pressure (r=0.80).
Conclusions:
- Intracoronary flow velocity and pressure measurements during PTCA provide accurate, quantitative assessment of human coronary collateral circulation.
- These methods offer a significant advancement over qualitative assessments.
- Enables further research and therapeutic development for collateral circulation.
Objectives:
This study evaluated two methods for the quantitative measurement of collaterals using intracoronary (IC) blood flow velocity or pressure measurements.
Background:
The extent of myocardial necrosis after coronary artery occlusion is substantially influenced by the collateral circulation. So far, qualitative methods have been available to assess the human coronary collateral circulation, thus restraining the conclusive investigation of, for example, therapies to promote collateral development.
Methods:
Fifty-one patients with a coronary artery stenosis to be treated by percutaneous transluminal coronary angioplasty (PTCA) were investigated using IC PTCA guidewire-based Doppler and pressure sensors positioned distal to the stenosis. Simultaneous measurements of aortic pressure, IC velocity and pressure distal to the stenosis during and after PTCA provided the variables for calculating collateral flow indices (CFIv and CFIp) that express collateral flow as a fraction of flow via the patent vessel. Both CFIv and CFIp were compared with conventional methods for collateral assessment, among them ST-segment changes >1 mm on IC and surface electrocardiogram (ECG) at PTCA. Also, CFIv and CFIp were compared with each other.
Results:
In 11 patients without ECG signs of ischemia during PTCA (sufficient collaterals), relative collateral flow amounted to 46% as determined by Doppler and pressure wire. Patients with insufficient collaterals (n=40) had relative collateral flow values of 18%. Using a threshold of CFI=30%, sufficient and insufficient collaterals could be diagnosed with 100% sensitivity and 93% specificity by IC Doppler, and 75% sensitivity and 92% specificity by IC pressure measurements. The agreement between Doppler and pressure measurements was good: CFIv=0.08 + 0.8 CFIp, r=0.80, p=0.0001.
Conclusions:
Intracoronary flow velocity or pressure measurements during routine PTCA represent an accurate and, at last, quantitative method for assessing the coronary collateral circulation in humans.