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Optimal visualization of the coronary arteries with Coronary Computed Tomography Angiography (CCTA) requires a low heart rate (HR), generally 65 beats per minute (bpm) or less, to reduce the occurrence of motion artifact. There is no universally accepted protocol to reduce HR for CCTA. We initiated a novel protocol involving high dose oral metoprolol given as 2 doses several hours apart prior to CCTA, with additional intravenous (IV) metoprolol as needed.
We retrospectively analyzed all patients >18 years of age who underwent outpatient CCTA between 1/10 and 3/12. CCTA was performed using a GE Lightspeed VCT 64 Slice CT Scanner. Depending on body mass index, resting HR, and blood pressure, patients are routinely given a prescription for oral metoprolol (dose range of 25 mg to 200 mg) to be taken the night before and morning of the CCTA examination. Patients are instructed to arrive 1 hour prior to the exam; vital signs are measured on arrival and immediately before the scan. Patients whose HR remains >65 bpm are given IV metoprolol. Patients are closely monitored for side effects from excessive beta-blockade.
A total of 215 CCTA patients were included in this analysis; 196 required HR reduction, and 175 were given oral metoprolol. Of these 175 patients, 37 needed additional IV metoprolol. The mean pre-treatment HR was 75 bpm and the average decrease in HR was 17 bpm (standard deviation of 11 bpm) in those who received metoprolol. The average total dose of oral metoprolol was 204 mg. The target HR was achieved in 163 of 175 patients (93%). For only 7 of 215 patients’ (3%) were CCTA results suboptimal for interpretation due to motion artifact; 5 of the 7 patients had a HR >65 bpm at scanning despite receiving IV metoprolol. No side effects from metoprolol were noted.
An outpatient protocol involving the administration of high dose oral metoprolol given as 2 separate doses prior to CCTA with additional IV metoprolol as needed, was safe and effective and permitted high quality, diagnostic CCTA in nearly all patients.
Poster Sessions, Expo North
Saturday, March 09, 2013, 10:00 a.m.-10:45 a.m.
Session Title: Imaging: CT/Multimodality I
Abstract Category: 20. Imaging: CT/Multimodality
Presentation Number: 1140-337
- 2013 American College of Cardiology Foundation