Validation of a new noninvasive method (contrast-enhanced transthoracic second harmonic echo Doppler) for the evaluation of coronary flow reserve: comparison with intracoronary Doppler flow wire.
OBJECTIVE
We tested the hypothesis that coronary flow reserve (CFR) in the left anterior descending coronary artery (LAD) as assessed by a new noninvasive method (contrast-enhanced transthoracic second harmonic echo Doppler) is in agreement with CFR measurements assessed by intracoronary Doppler flow wire.


BACKGROUND
Contrast-enhanced transthoracic second harmonic echo Doppler is a novel noninvasive method to detect blood flow velocity and reserve in the LAD. However, it has not yet been validated versus a gold-standard method.


METHODS
Twenty-five patients undergoing CFR assessment in the LAD by Doppler flow wire were also evaluated by contrast-enhanced transthoracic Doppler to record blood flow in the distal LAD at rest and during hyperemia obtained by adenosine i.v. infusion. In five patients CFR was evaluated twice (before and after angioplasty).


RESULTS
As a result of the combined use of i.v. contrast and second harmonic Doppler technology, feasibility in assessing coronary flow reserve equaled 100%. The agreement between the two methods was high. In fact, in all but five patients the maximum difference between the two CFR measurements was 0.38. Overall, the prediction (95%) interval of individual differences was -0.69 to +0.72. Reproducibility of CFR measurements was also high. The limits of the agreement (95%) between the two measurements were -0.32 to +0.32.


CONCLUSIONS
Coronary flow reserve in the LAD as assessed by contrast-enhanced transthoracic echo Doppler along with harmonic mode concurs very closely with Doppler flow wire CFR measurements. This new noninvasive method allows feasible, reliable and reproducible assessment of CFR in the LAD.
Caiati
C
C
Division of Cardiology, S. Maugeri Foundation, IRCCS Medical Center of Rehabilitation, Cassano Murge, Italy. carlo.caiati@teseo.it
Montaldo
C
C
Zedda
N
N
Montisci
R
R
Ruscazio
M
M
Lai
G
G
Cadeddu
M
M
Meloni
L
L
Iliceto
S
S
D000241:Adenosine; D000328:Adult; D000368:Aged; D015906:Angioplasty, Balloon, Coronary; D001783:Blood Flow Velocity / Q000502:physiology; D003287:Contrast Media; D003326:Coronary Circulation / Q000502:physiology*; D003327:Coronary Disease / Q000000981:diagnostic imaging* / Q000503:physiopathology / Q000628:therapy; D015150:Echocardiography, Doppler / Q000295:instrumentation*; D005240:Feasibility Studies; D005260:Female; D005583:Fourier Analysis; D006801:Humans; D007089:Image Enhancement / Q000295:instrumentation*; D007091:Image Processing, Computer-Assisted / Q000295:instrumentation*; D008297:Male; D008875:Middle Aged; D011134:Polysaccharides; D015203:Reproducibility of Results
D003287:Contrast Media; D011134:Polysaccharides; C059891:SHU 508; D000241:Adenosine