Abstract 4472: Validation of an Angiography based Algorithm to Calculate the Coronary Flow Reserve
Coronary Flow Reserve (CFR) is defined as the ratio between flow in a coronary vessel at maximum hyperemia and at rest. It is considered as a marker for the integrity of the coronary mircrocirculation. The measurement is typically performed using dedicated Doppler guidewires and pharmacologic stimulation (CFRdoppler). This measurement is costly, time-consuming and potentially harmful since the Doppler wire has to be advanced into the coronary artery. Today a new angiography based algorithm is available using the first pass kinetic of the injected contrast dye to calculate the CFR. The aim of the present study was, to compare this new algorithm with the conventionally Doppler wire technique. CFR measurements were performed during 27 coronary interventions (10 female, mean age 64 ± 11 years). CFRdoppler (Flowire, Volcano corp.) was calculated as the ratio of average peak velocity (APV) during hyperemia (140μg/kg·min −1) and at rest. For calculation of angiographic CFRangio, two angiograms were analised, one at base line flow and one at hyperemia state. CFR was calculated by the ratio between the hyperemia representing numbers of the logarithmic Time Density Curve (TDC) linear slope, multiplied with the coronary cross-sections, and the respective baseline representing numbers. An excellent correlation was found between the CFRdoppler and the CFRangio values: CFRangio = 1× CFRdoppler (r=0.87; p<0.0001). The average absolute difference between both indexes was 0.36±0.31. Angiographic measurement of CFR is a feasible and valid method in daily routine with an excellent correlation to doppler-wire derived measurements and moreover less potential of adverse interventional health effects.