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'Splenic switch-off' to detect adenosine understress; a novel method to improve test sensitivity

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The sensitivity of adenosine perfusion CMR is reduced by false negative scans, with up to 50% resulting from inadequate pharmacological stress... 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... With dobutamine (where only stress images were acquired), splenic perfusion was greater than myocardial (54.1 ± 1 versus 67.6 ± 25.2 au, p = 0.0005), again in contrast to adenosine... Within the CE-MARC cohort, patients with false negative CMR scans had a 36% rate of failed splenic switch-off... By contrast, the true negative group had a 9% rate (p = 0.0027 for difference), Figure 2... Splenic response to adenosine was concordant with haemodynamic response in 81% of subjects... 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.

No MeSH data available.


Splenic perfusion at stress and rest with adenosine (upper panels) and regadenoson (lower panels), showing splenic switch-off with adenosine only.
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Figure 1: Splenic perfusion at stress and rest with adenosine (upper panels) and regadenoson (lower panels), showing splenic switch-off with adenosine only.

Mentions: The spleen was visible in 98.5% of scans and grading of splenic perfusion was concordant between 2 blinded observers, κ = 0.84. Splenic switch-off occurred in 92% of adenosine studies acquired in London, but did not occur either with dobutamine or regadenoson perfusion studies, Figure 1. Measuring perfusion semi-quantitatively using signal intensity, splenic perfusion with adenosine stress was significantly lower than at rest (8.1 ± 9 versus 33.3 ± 19 arbitrary units, p < 0.0001), in contrast to with regadenoson where it increased significantly (123.7 ± 56.7 versus 144.6 ± 59.2 au, p = 0.003). With dobutamine (where only stress images were acquired), splenic perfusion was greater than myocardial (54.1 ± 1 versus 67.6 ± 25.2 au, p = 0.0005), again in contrast to adenosine. Within the CE-MARC cohort, patients with false negative CMR scans had a 36% rate of failed splenic switch-off. By contrast, the true negative group had a 9% rate (p = 0.0027 for difference), Figure 2. Splenic response to adenosine was concordant with haemodynamic response in 81% of subjects.


'Splenic switch-off' to detect adenosine understress; a novel method to improve test sensitivity
Splenic perfusion at stress and rest with adenosine (upper panels) and regadenoson (lower panels), showing splenic switch-off with adenosine only.
© Copyright Policy - open-access
Related In: Results  -  Collection

License 1 - License 2
Show All Figures
getmorefigures.php?uid=PMC4042617&req=5

Figure 1: Splenic perfusion at stress and rest with adenosine (upper panels) and regadenoson (lower panels), showing splenic switch-off with adenosine only.
Mentions: The spleen was visible in 98.5% of scans and grading of splenic perfusion was concordant between 2 blinded observers, κ = 0.84. Splenic switch-off occurred in 92% of adenosine studies acquired in London, but did not occur either with dobutamine or regadenoson perfusion studies, Figure 1. Measuring perfusion semi-quantitatively using signal intensity, splenic perfusion with adenosine stress was significantly lower than at rest (8.1 ± 9 versus 33.3 ± 19 arbitrary units, p < 0.0001), in contrast to with regadenoson where it increased significantly (123.7 ± 56.7 versus 144.6 ± 59.2 au, p = 0.003). With dobutamine (where only stress images were acquired), splenic perfusion was greater than myocardial (54.1 ± 1 versus 67.6 ± 25.2 au, p = 0.0005), again in contrast to adenosine. Within the CE-MARC cohort, patients with false negative CMR scans had a 36% rate of failed splenic switch-off. By contrast, the true negative group had a 9% rate (p = 0.0027 for difference), Figure 2. Splenic response to adenosine was concordant with haemodynamic response in 81% of subjects.

View Article: PubMed Central - HTML

AUTOMATICALLY GENERATED EXCERPT
Please rate it.

The sensitivity of adenosine perfusion CMR is reduced by false negative scans, with up to 50% resulting from inadequate pharmacological stress... 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... With dobutamine (where only stress images were acquired), splenic perfusion was greater than myocardial (54.1 ± 1 versus 67.6 ± 25.2 au, p = 0.0005), again in contrast to adenosine... Within the CE-MARC cohort, patients with false negative CMR scans had a 36% rate of failed splenic switch-off... By contrast, the true negative group had a 9% rate (p = 0.0027 for difference), Figure 2... Splenic response to adenosine was concordant with haemodynamic response in 81% of subjects... 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.

No MeSH data available.