Intracoronary Doppler guide wire versus stress single-photon emission computed tomographic thallium-201 imaging in assessment of intermediate coronary stenoses.

Objectives: The purpose of this study was to compare measures of coronary flow reserve by an intracoronary Doppler guide wire with results of stress single-photon emission computed tomographic (SPECT) thallium-201 imaging in patients with intermediate coronary artery disease (40% to 70% stenosis).
Background: Visual assessment of the coronary arteriogram as a means of predicting the physiologic significance of intermediate coronary stenoses is inaccurate. Coronary flow reserve is a reliable marker of the functional importance of a coronary lesion. The recent development of an intracoronary Doppler guide wire permits routine assessment of coronary flow reserve distal to coronary artery stenoses.
Methods: We prospectively evaluated coronary flow reserve in 30 subjects with intermediate stenoses using an intracoronary Doppler guide wire during elective coronary angiography. Patients subsequently underwent stress SPECT thallium-201 testing, and the blinded interpretations were correlated. Coronary flow reserve in a control group with normal coronary arteries classified our sample into group 1 (abnormal flow reserve, < 2.0) and group 2 (normal flow reserve, > or = 2.0).
Results: As defined, the coronary flow reserve of 16 vessels in group 1 was diminished in comparison to that of 19 vessels in group 2 (p = 0.0001). Qualitative and quantitative analysis of stress SPECT thallium-201 images confirmed perfusion defects in 15 of 16 vascular territories in group 1 in contrast to 1 of 19 regions in group 2. The sensitivity, specificity and overall predictive accuracy of Doppler-determined coronary flow reserve for stress SPECT thallium-201 results were 94%, 95% and 94%, respectively.
Conclusions: In appropriately selected patients with intermediate coronary artery stenoses, Doppler guide wire determination of lesion significance provides equivalent data to those acquired by stress SPECT thallium-201 imaging.