CORONARY BLOOD-FLOW VELOCITIES DURING ROTATIONAL ATHERECTOMY

This study was designed to evaluate the alterations in doppler derived coronary blood flow velocities and flow reserve following rotational ablation. Changes in doppler derived coronary blood flow velocity vari ables have been valuable in assessing the physiological outcome follow ing coronary balloon angioplasty. Rotational ablation's mechanism of p laque removal could alter distal vascular bed characteristics, and, as a result, intracoronary blood flow velocities and the coronary flow r eserve. A 12-MHz doppler guidewire recorded intracoronary phasic veloc ities and coronary flow reserve (as assessed by the hyperemic response to adenosine [12-18 meg intracoronary]) in 28 patients, before and af ter rotational ablation of 30 lesions. Adjunctive balloon angioplasty was performed in 27 of 28 patients (96%). Rotational ablation and adju nctive balloon angioplasty successfully reduced the lesion diameter (8 7 +/- 9% to 14 +/- 11%; P < 0.001). A significant increase in the mean distal average peak velocity (25 +/- 13 cm/sec, before; 47 +/- 22 cm/ sec, after; P < 0.001), and decrease in the proximal to distal average peak velocity ratio, (2.1 +/- 1.3; to 1.2 +/- 0.4; P = 0.002) was rec orded. The mean distal diastolic to systolic velocity ratio (before, 1 .4 +/- 0.7; after, 1.6 +/- 0.8; P = 0.44) and the coronary flow reserv e (before, 1.6 +/- 0.6; after, 1.5 +/- 0.5; P = 0.34) did not increase despite increases in distal velocities, following successful interven tion. Doppler derived distal coronary blood flow velocities increased following rotational ablation and adjunctive balloon angioplasty, with resolution of transstenotic velocity gradient. Changes in distal phas ic velocity pattern and coronary flow reserve, immediately after the i ntervention, were not useful in the assessment of the functional outco me and may be related to abnormalities in distal vascular bed vasoreac tivity produced by rotational ablation. (C) 1997 Wiley-Liss, Inc.