Assessment of the relationship between distal occluded pressure and angiographically evident collateral flow during coronary angioplasty

The relationship between the presence of collateral filling on the baseline coronary angiogram and the distal occluded pressure obtained during balloon inflation was examined in 83 patients undergoing coronary angioplasty. The patients were divided into three groups: Group I (n = 40) had conventional stenoses (80% to 95% luminal diameter narrowing) without angiographically evident collaterals, group II (n = 22) had conventional stenoses with angiographically present collaterals, and group III (n = 21) had total or functional total occlusions (99% to 100% diameter narrowing) with angiographically evident collateral flow. There was no significant difference in age, sex, vessel distribution, clinical class, residual gradient, or residual percent stenosis following successful angioplasty among the three groups. The distal occluded pressure in group I (18 +/- 5 mm Hg) was, however, significantly lower than the distal occluded pressure in either group II (34 +/- 7 mm Hg) or group III (36 +/- 9 mm Hg) (p less than 0.001). This could not be explained by differences in aortic pressure, since there was no correlation between the mean aortic blood pressure and the distal occluded pressure and since the distal occluded pressure/aortic pressure ratio in group I (0.23 +/- 0.07) was significantly lower than that of group II (0.41 +/- 0.09) or group III (0.41 +/- 0.11) (p less than 0.001). These findings indicate a close correlation between the presence of angiographically evident collateral flow and the distal coronary artery pressure during an angioplasty balloon inflation.(ABSTRACT TRUNCATED AT 250 WORDS)