Assessment of internal mammary artery and saphenous vein graft patency and flow reserve using transthoracic Doppler echocardiography.
OBJECTIVE
To investigate transthoracic Doppler echocardiography in the identification of coronary artery bypass graft (CABG) flow for assessing graft patency.


METHODS
The initial study group comprised 45 consecutive patients with previous CABG undergoing elective cardiac catheterisation for recurrent ischaemia. The Doppler variables best correlated with angiographic graft patency were then tested prospectively in a further 84 patients (test group).


METHODS
Three tertiary referral centres.


METHODS
Flow velocities in grafts were recorded at rest and during hyperaemia induced by dipyridamole (0.56 mg/kg/4 min), under the guidance of transthoracic colour Doppler flow mapping. Findings on transthoracic Doppler were compared with angiography.


METHODS
Feasibility of identifying open grafts by Doppler and diagnostic accuracy for Doppler detection of significant (>/= 70%) graft stenosis.


RESULTS
In the test group the identification rate for mammary artery grafts was 100%, for saphenous vein grafts to left anterior descending coronary artery 91%, for vein grafts to right coronary artery 96%, and for vein grafts to circumflex artery 90%. Coronary flow reserve (the ratio between peak diastolic velocity under hyperaemia and at baseline) of < 1.9 (95% confidence interval 1.83 to 2.08) had 100% sensitivity, 98% specificity, 87.5% positive predictive value, and 100% negative predictive value for mammary artery graft stenosis. Coronary flow reserve of < 1.6 (95% CI 1.51 to 1.73) had 91% sensitivity, 87% specificity, 85.4% positive predictive value, and 92.3% negative predictive value for significant vein graft stenosis.


CONCLUSIONS
Transthoracic Doppler can provide non-invasive assessment of CABG patency.
Chirillo
F
F
Department of Cardiology, Regional Hospital Ca' Foncello, 31100 Treviso, Italy. fchirillo@ulss.tv.it
Bruni
A
A
Balestra
G
G
Cavallini
C
C
Olivari
Z
Z
Thomas
J D
JD
Stritoni
P
P
D000704:Analysis of Variance; D001783:Blood Flow Velocity; D001026:Coronary Artery Bypass / Q000379:methods; D003326:Coronary Circulation / Q000502:physiology; D003327:Coronary Disease / Q000503:physiopathology / Q000601:surgery; D003971:Diastole; D018618:Echocardiography, Doppler, Color / Q000379:methods / Q000592:standards; D005260:Female; D006083:Graft Occlusion, Vascular / Q000000981:diagnostic imaging / Q000473:pathology / Q000503:physiopathology*; D006085:Graft Survival / Q000502:physiology*; D006801:Humans; D008297:Male; D008323:Mammary Arteries / Q000502:physiology / Q000637:transplantation; D008875:Middle Aged; D015588:Observer Variation; D012501:Saphenous Vein / Q000502:physiology / Q000637:transplantation; D012680:Sensitivity and Specificity; D013599:Systole; D014654:Vascular Patency / Q000502:physiology*