Simultaneous Assessment of FFR and SPECT

The Simultaneous Assessment of Invasive Fractional Flow Reserve and SPECT Myocardial Ischemia Using Regadenoson in the Catheterization Laboratory

The overall purpose of this research study is to identify the disparity in ischemia measurement between fractional flow reserve (FFR) used in the cardiac catheterization laboratory and myocardial perfusion stress- single-photon emission computed tomography (SPECT). This study aims to determine the correlation between simultaneous FFR and SPECT obtained using regadenoson in the catheterization laboratory.

Patients who are previously scheduled for diagnostic coronary angiography will be approached for consent to be part of the study. If the patient is found to have one or two vessel disease and it is planned by the interventional cardiologist that FFR will be used, then the previously consented patient will be deemed appropriate for the study. The standard procedure will be followed for FFR testing using regadenoson. The patient will then receive the standard dose of Tc-99m sestamibi. The interventional cardiologist will proceed with percutaneous coronary intervention (PCI) if appropriate. Patients will proceed to the cardiac catheterization laboratory holding area post procedure. Patients will then be scheduled to be taken to the nuclear cardiology laboratory one to three hours following the coronary angiogram for standard SPECT acquisition. Patients will be monitored for 2-6 hours or overnight as clinically indicated following diagnostic coronary angiography and PCI. Low dose resting myocardial perfusion scanning may be performed the next day if stress myocardial perfusion study was abnormal.

Subjects who have undergone a clinically indicated fractional flow reserve measurement in the cardiac catheterization laboratory will receive standard dose Tc-99m sestamibi and undergo resting SPECT image acquisition within three hours from end of cardiac catheterization procedure.

The concordance will be calculated as the percentage of patients who had an abnormal FFR (<0.8) and an abnormal SPECT (a perfusion defect on the SPECT) PLUS patients who had a normal FFR (≥ 0.8) and a normal SPECT. concordance= patients with abnormal FFR and abnormal SPECT + patients with normal FFR and normal SPECT/ total no. of patients

Inclusion Criteria: Patients undergoing clinically-indicated FFR measurement (to determine the hemodynamic significance of intermediate degrees of stenosis) for single or two -vessel epicardial coronary disease during diagnostic coronary angiography for suspected coronary artery disease. Exclusion Criteria: Patients with 3-vessel disease Prior coronary artery bypass grafting Patients with second or third- degree atrioventricular block, without a functioning pacemaker Patients who have ingested caffeine-containing products within the past 12 hours.