Efficacy of ivabradin to reduce heart rate prior to coronary CT angiography: comparison with beta-blocker.

PURPOSE

The objective of our study was to assess the effect of ivabradine on image quality of ECG-gated multidetector computed tomography (MDCT) coronary angiography.

MATERIALS AND METHODS

Computed tomography coronary angiography (CTCA) was performed on two groups. In Group 1 (n=54), an intravenous beta-blocker was administered to patients with a heart rate >70 beats per minute (bpm) just before CTCA. In Group 2 (n=56), oral ivabradine 5 mg was administered twice a day for three days prior to CTCA examination to patients with a heart rate >70 bpm and contraindication to beta-blockers. Images acquired on two different MDCT scanners were scored in terms of image quality of the coronary artery segments using a 5-point grading scale (Grade 1, unreadable; Grade 5, excellent).

RESULTS

The mean heart rates during CTCA were 64 ± 6.7 bpm for Group 1 and 59 ± 4.1 bpm for Group 2 (P < 0.05). Mean heart rate reduction was 9 ± 5% and 14 ± 8% for Groups 1 and 2, respectively (P < 0.001). A total of 880 segments were evaluated in 110 patients. When the best reconstruction interval was used, 89.8% and 95.5% of all the coronary segments showed acceptable image quality in Groups 1 and 2, respectively. Acceptable image quality of the middle right coronary artery was obtained in 78.3% of Group 1 and 92.4% of Group 2. These ratios for the other segments were 88.4% for Group 1 and 95.2% for Group 2.

CONCLUSION

Reduction of heart rates with ivabradine premedication improves the image quality of CTCA. It should be considered as an alternative drug, particularly in patients with contraindications to beta-blockers.