The influence of clinical and acquisition parameters on the interpretability of adenosine stress myocardial computed tomography perfusion

Abstract

Aims: The interpretation of adenosine stress myocardial computed tomography perfusion (CTP) is often hampered by image artefacts caused by cardiac motion, beam hardening, and cone beam. The aim of the present analysis was to assess the influence of the heart-rate response during adenosine infusion, patient characteristics, and medication use on the interpretability of stress myocardial CTP examinations.

Methods and results: Interpretability of stress myocardial CTP examinations was evaluated in 120 patients who underwent sequentially coronary CTA and adenosine stress myocardial CTP (320-row CT scanner, temporal resolution 175 ms) and scored as follows: excellent = absence of any artefact (n = 27, 22%); good = presence of artefacts that do not interfere with the study interpretability (n = 56, 47%); fair = artefacts that do interfere with interpretability (n = 35, 29%); poor = uninterpretable study due to artefacts (n = 2, 2%). 'Fair' and 'poor' were merged into 'reduced' for comparisons. Increasing heart rate during stress myocardial CTP acquisition was related to worse interpretability (excellent: 61.7 ± 13.4 bpm vs. good: 69.8 ± 13.5 bpm vs. reduced: 78.1 ± 17.0 bpm, P < 0.001). Thirteen (11%) of all examinations were considered non-diagnostic. In patients with a heart rate exceeding 85 bpm, 76% of the studies were 'reduced' interpretable. In multivariate analysis, no use of beta blocker (baseline or additional use prior to coronary CTA) (OR: 0.2, P = 0.012), increasing heart rate during coronary CTA (OR: 1.09, P = 0.032), younger age (OR: 0.92, P = 0.021), and the use of calcium antagonist (OR: 6.48, P = 0.017) were independently associated with a heart rate ≥85 bpm during stress myocardial CTP.

Conclusion: Higher heart rate during the acquisition of stress myocardial CTP was related to worse interpretability. Furthermore, increasing heart rate during and no beta blocker use prior to the previously performed coronary CTA, younger age, and the use of calcium antagonist were independently associated with a heart rate ≥85 bpm during stress myocardial CTP acquisition.

Keywords: CT myocardial perfusion; coronary CTA; image quality; imaging.