Coronary Flow Velocity Reserve After Successful Balloon Angioplasty and Directional Atherectomy

Abstract

Background: To ascertain whether transesophageal echocardiography (TEE) allows for measurement of coronary flow velocity “reserve” in patients with disease of the left anterior descending artery (LAD), and to establish the flow velocity response following angiographically successful angioplasty and atherectomy. Methods: Four groups of patients were studied: normal controls (n = 15) consisted of patients without obstructive coronary artery disease, a LAD stenosis group (n = 15) consisted of patients with > 70% stenosis, an LAD postangiographically successful balloon angioplasty group (n = 12), and an LAD postangiographically successful directional atherectomy group (n = 6). Two‐dimensional horizontal plane TEE was used to image the proximal left coronary arterial system. Pulsed Doppler recordings were made of proximal LAD flow velocities at rest, and following an infusion of 0.56 mg/kg IV dipyridamole. Results: The peak diastolic flow velocity ratio (hyperemic flow/baseline flow) for normal controls was 3.46 ± 0.48 (mean ± standard deviation), for the LAD stenosis group was 1.35 ± 0.26, for the balloon angioplasty group was 2.08 ± 0.45, and for the directional atherectomy group was 2.10 ± 0.82. Conclusions: We conclude that: (1) it is feasible to record with TEE Doppler, flow velocity and flow reserve in normals, in obstructive coronary artery disease, and following revascularization; (2) coronary flow velocity ratio (CFVR) is decreased in patients with LAD stenosis; (3) CFVR remains subnormal in patients with angiographically successful directional atherectomy and balloon angioplasty; and (4) that flow velocity ratios following directional atherectomy were not significantly different from those following balloon angioplasty.