MEASUREMENT OF MYOCARDIAL FRACTIONAL FLOW RESERVE DURING CORONARY ANGIOPLASTY IN PATIENTS WITH OLD MYOCARDIAL-INFARCTION

Although myocardial fractional flow reserve (FFRmyo) has been demonstr ated to be a useful index for determining functional significance of c oronary stenosis, the data in previous studies was derived from a high ly selected group of patients. The aim of this study was to investigat e the value of FFRmyo in a more clinically relevant group of patients, especially in patients who also had resistance vessel dysfunction. We measured FFRmyo in 20 consecutive patients who had undergone elective coronary angioplasty, FFRmyo was calculated by the ratio of Pc/Pa dur ing intracoronary adenosine 5'-triphosphate (ATP; 50 mu g in the left coronary and 20 mu g in the right coronary artery) induced maximal hyp eremia, where Pa represents mean aortic pressure obtained by the guidi ng catheter and Pc represents mean distal coronary pressure measured b y a 2.1 F infusion catheter. In total, 21 vessels were dilated and 14 of them were infarct-related arteries, The percent diameter stenosis s ignificantly decreased from 80 +/- 14% to 27 +/- 17%, and the FFRmyo i ncreased significantly from 0.46 +/- 0.18 to 0.77 +/- 0.15 after angio plasty, There was no significant differences in the FFRmyo between ves sels with previous myocardial infarction and those without, after angi oplasty (0.78 +/- 0.18 vs. 0.76 +/- 0.08). There was a significant cor relation between the percent diameter stenosis and FFRmyo before (r = 0.83, P < 0.001) and after (r = 0.64, P < 0.01) angioplasty. In conclu sion, FFRmyo significantly improved immediately after angioplasty in V essels with myocardial infarction as well as those without. These resu lts led us to suggest the usefulness of FFRmyo in patients who had bot h epicardial stenosis and resistance vessel dysfunction. The significa nt correlation between FFRmyo and quantitative coronary arterial diame ter stenosis would further support the more widespread use of FFRmyo i n the clinical setting. (C) 1997 Wiley-Liss, Inc.