Maximizing the clinical benefit of high-pitch, single-heartbeat CT coronary angiography in clinical practice

Aim: To prospectively analyse the occurrence of right coronary artery (RCA) artefact and assess its relationship with patient heart rate (HR) and HR variability (HRV) in order to determine the most appropriate parameters for high-pitch cardiovascular computed tomography (CT) acquisition, minimize the likelihood of artefact, and maximize the clinical benefit in consecutive clinical high-pitch CT coronary angiography (CA) examinations.

Materials and methods: One hundred and seventy-three patients undergoing high-pitch CTCA were prospectively assessed for the presence of RCA artefact. Median and maximum HR and the difference in predicted and actual acquisition HR (HR difference, HRD) were correlated from the electrocardiograms recorded at the time of acquisition.

Results: Sixty-six percent of the cohort was male, with a median age of 54 (range 16-84 years). There were 53 cases of RCA artefact (30.6%); 26 (49.1%) of these required further imaging to fully delineate the RCA. Of the 53 cases with artefact, 81.1% affected the distal RCA and 18.9% were more proximal. Gender was not associated with an increased likelihood of the artefact (p = 0.14). RCA artefact decreased by 2% with each year of increasing age (p = 0.04). When compared with a reference HR of >70 beats/min, univariate analysis demonstrated RCA artefact significantly increased with both increasing median and maximum HR, whilst the incidence of RCA artefact increased for all HRD >1, with a greater likelihood of artefact with increasing HRD.

Conclusion: The present results highlight the importance of optimizing patient HR in order to reduce the likelihood of RCA artefact. In addition to aggressive HR control to a median HR of ≤60 beats/min, the present results suggest limiting high-pitch acquisition to patients with HR variability of <3 beats/min. Therefore, use of beta-blockers is of crucial importance to both reduce HR and HR variability to optimize use of high-pitch single-heartbeat CTCA.