Correlation between hypotension during dobutamine myocardial perfusion imaging and severity of stress-induced ischemia

Objectives: An accurate non-invasive evaluation of coronary artery disease (CAD) is essential in choosing the right management plan. Dobutamine stress myocardial perfusion imaging (MPI) is a substitute test for patients who cannot exercise. This study aimed to assess the relationship between dobutamine-induced hypotension and risk stratification of annual hard cardiac events evaluated by MPI. Methods: This study is a retrospective study conducted on 1004 patients from October 2015 to august 2019.These patients referred to Rasoul Akram Hospital, because they could not exercise electrocardiography or had contraindications to vasodilator therapy, they were subjected to dobutamine Tc99m-Sestamibi single photon emission tomography (SPECT) protocol. During the protocol, blood pressure was measured with a one-minute interval. From among the participants, 247 patients had decreased blood pressure by more than 20 mmHg during infusion. Then for patients, a gated MPI scan was performed, and MPI with a quantitative and visual interpretation determined the risk stratification of the patients. Multivariable logistic regression model assessed the associations between decrease in blood pressure (above 20 mmHg) and risk stratification. Results: A total of 1004 patients with a mean age of 59.07 years were studied. Of these patients, 247 had > 20mmHg drop in systolic BP from baseline. This study revealed a significant correlation between hypotension during the dobutamine stress test and high-risk scan patterns in myocardial perfusion scan. Moreover, there was a significant correlation between age increase, smoking, diabetes mellitus, transient ischemic dilation (TID), high baseline blood pressure, and history of CABG or angioplasty with a high-risk scan pattern in MPI. Conclusions: This study demonstrated that hypotension during the dobutamine stress test is correlated with high-risk scan patterns in MPI.