- Oral presentation
- Open Access
'Splenic switch-off' to detect adenosine understress; a novel method to improve test sensitivity
© Manisty et al.; licensee BioMed Central Ltd. 2014
- Published: 16 January 2014
- Pharmacological Stressor
- Adenosine Perfusion
The sensitivity of adenosine perfusion CMR is reduced by false negative scans, with up to 50% resulting from inadequate pharmacological stress. Without a robust physiological marker for adequate myocardial hyperaemia, this false negative rate is difficult to address. We observed that splenic perfusion is markedly attenuated with adenosine - compared both to rest and to myocardial perfusion. In this collaborative multi-center study, we investigate the pharmacology of 'splenic switch-off', and evaluate its potential clinical utility as a marker of inadequate stress in adenosine perfusion imaging.
We assessed splenic perfusion in 4 cohorts acquired in 4 separate CMR units using 3 different pharmacological stressors. This study included: • Verification cohort of 50 adenosine perfusion scans (London, UK); to determine if splenic perfusion is consistently switched-off with adenosine. • 2 comparison cohorts using alternative pharmacological stressors (25 dobutamine scans; Southampton, UK and 25 regadenoson scans; Pittsburgh, USA); to assess whether generic stress (or only adenosine) causes splenic switch-off. • Clinical utility cohort of 100 adenosine scans (35 false and 65 true negative) from the CE-MARC trial (Leeds, UK); to assess whether failure of splenic switch-off could be a useful clinical indicator of inadequate stress.
Splenic switch-off with adenosine is a new observation, and although a drug-specific effect, can be assessed in nearly all scans. Rescanning individuals with failure of splenic switch-off would reduce false negative scans by a third, but it may be that up to 1 in 11 of all adenosine perfusion patients are understressed. Further work is needed on this important sign.
CM is an NIHR Clinical Lecturer.
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