Measurement of myocardial fractional flow reserve is a cost-effective way to identify coronary artery lesions of indeterminate severity that warrant revascularisation.

BACKGROUND: The RADI pressure wire may be used in stenotic coronary arteries to calculate myocardial fractional flow reserve (FFR(myo)), the ratio between distal hyperaemic coronary pressure and aortic pressure. A ratio less than 0.75 categorizes lesions of haemodynamic significance for which percutaneous coronary intervention (PCI) or coronary artery bypass surgery (CABG) may be warranted. We undertook this study to evaluate the cost implications of performing these measurements. METHODS: We recorded FFR(myo) using RADI wires in 32 coronary artery lesions of between 30 and 60% diameter stenosis in 31 patients and assessed how this information changed our management. RESULTS: We followed our original "management plan" in only eight patients. PCI or CABG was performed in eight whose lesions were characterised by a FFR(myo) value of 0.76 or less. Myocardial perfusion imaging (MPI) was done in only one of nine for whom this had seemed to be appropriate. Two-thirds of those for whom PCI had appeared to be warranted were treated conservatively and only one quarter of the original "surgical" group underwent CABG. CONCLUSION: Although RADI pressure wires are an additional expense, it is appropriate to use them to assess coronary stenotic lesions of indeterminate severity. When we took into account the savings that arose from changes in management, the additional cost of measuring FFR(myo) was around dollar 580 per study.

Patterns of coronary artery movement and the development of coronary atherosclerosis.

Mechanical stress in coronary arteries has been postulated to cause endothelial injury and atherosclerotic lesions, but the relationship between the pattern of coronary artery movement (CAM) and lesion severity is not known. In the present study CAM was classified into 10 patterns, which were grouped into 3 classes: (1) bend type = coronary artery flexes into a curve; (2) compression type = segmental length is shortened without vertical deviation of the artery; (3) displacement type = location of the coronary artery shifts without change of segmental length or shape. Assessment of CAM was made for 6 segments from the left anterior descending artery and 3-5 segments from the left circumflex artery, and in total 673 segments were analyzed. Coronary arterial segments with the compression type had a significantly higher percent stenosis than those without it (Compression 57.9+/-29.4 % vs Bend 7.9+/-19.0 %, Displacement 4.3+/-13.0 %; p<0.00001). The compression type was seen frequently in the proximal and mid left anterior descending artery, ostial diagonal branch, obtuse marginal branch and mid left circumflex artery. The critical CAM (eg, compression pattern) may be an important mechanical stress inducing coronary atherosclerosis.