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Comparison of three different principles in the assessment of coronary flow reserve from digital angiograms
R Simon1, G Herrmann, I Amende
1Department of Cardiology, University Hospital of Kiel, FRG.
Insights
Digital angiography can assess coronary flow reserve. The Stewart-Hamilton principle offers advantages over time-dependent methods for evaluating coronary blood flow. This finding aids in diagnosing coronary artery disease.
Area of Science:
- Cardiovascular imaging
- Diagnostic cardiology
- Hemodynamics
Background:
- Assessing coronary flow reserve is crucial for diagnosing coronary artery disease.
- Digital angiography offers a non-invasive method for evaluating coronary hemodynamics.
- Existing methods for coronary flow reserve assessment have limitations.
Purpose of the Study:
- To compare three digital angiography principles for assessing coronary flow reserve.
- To evaluate the efficacy of dipyridamole and papaverine in stimulating coronary blood flow.
- To identify the most advantageous method for coronary flow reserve measurement using digital angiography.
Main Methods:
- Seventy patients without coronary disease underwent diagnostic heart catheterization.
- Digital angiograms were acquired at rest and after dipyridamole or papaverine administration.
- Coronary flow in the LAD area was assessed using densitometry, CMAP, and a modified Stewart-Hamilton principle, compared with thermodilution.
Main Results:
- Drug stimulation increased coronary blood flow up to fivefold compared to resting flow.
- The modified Stewart-Hamilton principle showed strong correlation with thermodilution measurements (r=0.78).
- The Stewart-Hamilton principle, particularly when enhanced with morphometric LAD volume, proved advantageous.
Conclusions:
- The Stewart-Hamilton principle is a potentially advantageous method for assessing coronary flow reserve via digital angiography.
- Time parameter-dependent approaches may be less accurate than the Stewart-Hamilton method.
- This study provides valuable insights for improving non-invasive coronary blood flow assessment.
Abstract:
In 70 patients without coronary disease we have compared three different principles to assess coronary flow reserve during diagnostic heart catheterization. Digital angiograms with ECG-triggered bolus injections of 4 to 8 ml of contrast medium at rest and after stimulation by dipyridamole (0,5 mg/kg i.v.) or papaverine (12,5 mg i.c.) were acquired in a 512 x 512 matrix at 8 bit resolution (ADAC 4100) and stored on a digital disk at 25 frames/sec. or 2 frames/cardiac cycle (PPR-mode). Angiograms were processed by cyclic R-wave-gated mask mode subtraction and coronary flow in the LAD area was assessed by three different approaches: 1. A traditional densitometric principle. 2. The 'CMAP' principle. 3. A modification of the Stewart-Hamilton principle comparing the total amount of contrast medium that enters the coronary circulation to the area of the contrast dilution curve in a fixed portion of the LAD. Flow was measured simultaneously during angiography using the thermodilution technique for coronary sinus/great cardiac vein flow. Drug stimulation resulted in an increased coronary blood flow up to five times of resting flow. Regression analysis revealed the following results for the assessment of the coronary flow reserved by digital angiography (y) when compared to thermodilution (x): [table: see text] Method 2 could be improved by replacing the density factor by morphometrically measured proximal LAD volume (y = 0.77x + 0.55; r = 0.78; SEE = +/- 0.43). In conclusion, our data suggest that the Stewart-Hamilton principle may be advantageous over time parameter-dependent approaches in the assessment of coronary flow reserve by digital angiography.
