Transthoracic coronary flow velocity reserve assessment: comparison between adenosine and dobutamine.

OBJECTIVE: We sought to compare coronary flow velocity reserve (CFVR) with adenosine and dobutamine in patients scheduled for noninvasive evaluation of coronary artery disease.

BACKGROUND: Assessment of CFVR in the distal part of the left anterior descending coronary artery (LAD) by Doppler transthoracic echocardiography (TTE) is usually performed with adenosine in various settings. CFVR can also be determined during dobutamine stress echocardiography (DSE), but it has not been established whether TTE CFVR with dobutamine is equivalent to CFVR with adenosine.

METHODS: In all, 47 consecutive stable patients in sinus rhythm (28 men, 64 +/- 12 years, left ventricular ejection fraction 55 +/- 5%) were prospectively studied. Coronary flow velocity was measured in the distal part of the LAD by TTE, at rest and during continuous infusion of 0.14 mg/kg/min of adenosine over 2 minutes, and during DSE performed immediately after the adenosine test, using a multifrequency transducer, on a modified parasternal view. CFVR with adenosine was calculated as hyperemic to basal peak flow velocity. CFVR with DSE was obtained by calculating peak diastolic flow velocity divided by baseline diastolic flow velocity.

RESULTS: Adequate recording of CFVR with adenosine and dobutamine was possible in 43 (91%) and 41 (87%) patients, respectively. CFVR was 2.5 +/- 0.7 with adenosine compared with 2.4 +/- 0.7 with dobutamine (P = .7). A good linear correlation was observed between the two tests (r = 0.81, P < .0001). In patients with dobutamine-induced wall-motion abnormalities in the LAD territory (n = 8), CFVR was similar during dobutamine and adenosine infusion (1.6 +/- 0.3 vs 1.5 +/- 0.2, respectively, P = .7). Coronary angiography was available in 12 patients (LAD stenosis: 55 +/- 10% quantitative coronary angiography, with a range from 40%-75%). The correlation between CFVR values was also good in this subgroup of patients (r = 0.87, P < .0001).

CONCLUSION: TTE CFVR with dobutamine is comparable to CFVR with adenosine in patients with a wide range of LAD diseases. Dobutamine could be a good alternative to adenosine for TTE CFVR assessment, particularly in patients with a contraindication to adenosine or scheduled for DSE.