Simultaneous intracoronary velocity- and pressure-derived assessment of adenosine-induced collateral hemodynamics in patients with one- to two-vesselcoronary artery disease

OBJECTIVES The purpose of this investigation in patients with poorly and we ll developed coronary collaterals was to assess the influence of collateral and collateral adjacent vascular resistances and, in part, a stenotic lesi on of the collateral supplying vessel on the hemodynamic collateral respons es to adenosine. BACKGROUND In humans, little is known about the functional behavior of the coronary collateral circulation. METHODS In 50 patients with one- and two-vessel coronary artery disease (CA D) undergoing percutaneous transluminal coronary angioplasty (PTCA), collat eral flow index (CFI, no unit) changes and vascular resistance index (R, cm /mm Hg) changes of the collateral (R-coll) and the distal collateral receiv ing (R-4) vessel in response to adenosine (140 mu g/min/kg ITT) were measur ed by intracoronary (i.c.) Doppler and pressure guidewires. The variables w ere determined at baseline and during adenosine in patients with poor (angi ographic collateral degree before PTCA <2 of 0 to 3) and good coronary coll aterals. RESULTS Pressure-derived CFI (CFI,) decreased under adenosine in patients w ith poor collaterals, and it increased in the group with good collaterals. There were inverse correlations between the adenosine-induced change in CFI p and the change in R-coll (r = 0.61, p = 0.0001). In the group with good, but not with poor collaterals, there was also a significant correlation bet ween CFIp increase and the decrease in R-4, between the severity of the con tralateral stenosis and CFIp augmentation and among the left versus right c oronary artery as ipsilateral vessel and CFIp change. CONCLUSIONS Overall, patients with well, versus poorly developed coronary c ollaterals do better regarding the capacity to increase collateral flow in response to adenosine, In patients with good, but not poor, collaterals, an adenosine-induced collateral flow increase depends on the ipsilateral dist al vascular resistance decrease, but is also directly influenced by the sev erity of a contralateral stenosis and probably by the size of the collatera lized vascular bed. (C) 1999 by the American College of Cardiology.