A preliminary study of dobutamine myocardial flow reserve on Tc-Sestamibi CZT-SPECT.

Background: With improved resolution and sensitivity, the cadmium zinc telluride (CZT) detector measures myocardial blood flow (MBF) and myocardial flow reserve (MFR) via single photon emission computed tomography (SPECT). Recently, many studies have used vasodilator stress to obtain quantitative indexes. However, dobutamine used as a pharmaceutical stress has been rarely used to quantify myocardial perfusion using CZT-SPECT. Our study retrospectively analyzed the blood flow performance of Tc-Sestamibi (Tc -MIBI) CZT-SPECT comparing dobutamine to adenosine.

Purpose: The study aims to explore whether dobutamine stress can be used for the myocardial perfusion quantitative analysis via CZT-SPECT as well as compare dobutamine MBF and MFR to adenosine.

Methods: It was a retrospective study. A total of 68 patients with suspected or known coronary artery disease (CAD) were consecutively enrolled in this study. Thirty-four patients underwent dobutamine stress Tc-MIBI CZT-SPECT. Another thirty-four patients underwent adenosine stress Tc-MIBI CZT-SPECT. Patient characteristics, myocardial perfusion imaging (MPI) results, gated-myocardial perfusion imaging (G-MPI) results and quantitative analysis of MBF and MFR were collected.

Results: In dobutamine stress group, stress MBF was significantly higher than rest MBF (median [interquartile range], 1.63 [1.46-1.94] vs. 0.89 [0.73-1.06], P < 0.001). In adenosine stress group, similar results were observed (median [interquartile range], 2.01 [1.34-2.20] vs. 0.88 [0.75-1.01], P < 0.001). When comparing the dobutamine and adenosine stress group, global MFR showed significant differences (median [interquartile range], the dobutamine group: 1.88 [1.67-2.38] vs. the adenosine group: 2.19 [1.87-2.64], P = 0.037).

Conclusion: MBF and MFR can be measured using dobutamine Tc -MIBI CZT-SPECT. In small sample single-center study, there was a difference in MFR produced by adenosine and dobutamine within the suspected or the known CAD population.