919-11 Plaque Pulverization During Rotablator Atherectomy: Does It Impair Coronary Flow Dynamics?

Abstract

Rotablator atherectomy (MRA) results in pulverization of plaque which is cleared by the microcirculation, but the impact of microembolization on coronary blood flow is unknown. Accordingly, coronary flow dynamics were studied before, immediately after MRA, and after adjunctive PTCA using Doppler Flowires proximal and distal to the stenosis in 15 patients (LAD 8, LCX 3, RCA 4). Stable phasic signals were recorded distally in the same angiographic position and basal average peak velocity (APV) and diastolic to systolic velocity ratio (DSVR) were measured. There were significant decreases (p < 0.007) in diameter stenosis assessed by quantitative angiography from baseline (63 ± 17%) after MRA (49 ± 18%) and after adjunctive PTCA (28 ± 12%). Heart rate and blood pressure did not change at any stage. There were significant increases in basal APV and DSVR after MRA and adjunctive PTCA: 1. Despite tissue pulverization and microembolization, Rotablator atherectomy did not result in detectable impairment in coronary blood flow. 2. Average peak velocity and diastolic/systolic velocity ratio improve after MRA. 3. Adjunctive PTCA significantly contributes to the improvement in distal coronary blood flow after MRA.