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. 2022 Oct 1;95(1139):20220422.
doi: 10.1259/bjr.20220422. Epub 2022 Sep 26.

Assessing splenic switch-off in Adenosine stress CMR for patients with atrial fibrillation: a propensity-matched study

Adam Barrishi  1 , John Graby  1 , Ali Khavandi  2 , Amardeep Dastidar  3 , Jonathan Cl Rodrigues  1
Affiliations

Assessing splenic switch-off in Adenosine stress CMR for patients with atrial fibrillation: a propensity-matched study

Adam Barrishi et al. Br J Radiol. .

Abstract

Objectives: Splenic switch-off (SSO) is a validated indicator of adequate vasodilator stress unique to adenosine stress cardiac MR (CMR). Patients in atrial fibrillation (AF) may have a reduced adenosine response due to lower hyperaemic coronary flow reserve and may achieve SSO less frequently versus sinus rhythm (SR).

Methods: 1100 stress CMR studies were identified from a clinical CMR database (2016-2021). 70 patients in AF were propensity score matched to a SR group for age, sex, and body mass index. The adenosine dose administered, symptoms, heart-rate change and scan result were recorded. SSO was evaluated subjectively and semi-quantitatively via changes in splenic and myocardial signal intensity (SI) from rest to stress.

Results: SSO occurred significantly less frequently in AF than SR (34/70 [49%] vs 53/70 [76%], p = 0.003). Semi-quantitative assessment supported this, with a smaller splenic SI difference between stress and rest in AF vs SR (median splenic stress:rest peak SI ratio 0.92 [IQR:0.61-1.11] vs 0.56 [IQR:0.45-0.75], p < 0.001). A heart-rate increase >10 bpm predicted visual SSO in SR but not AF. Fewer patients in AF than SR had inducible ischaemia (9/70 [13%] vs 17/69 [25%], p = 0.058). This difference was not driven by inducible ischaemia rates in patients who did not achieve SSO (6/36 [17%] AF vs 4/17 [24%] SR, p = 0.403).

Conclusions: SSO occurs significantly less frequently with AF. This may risk the under diagnosis of inducible ischaemia and requires further assessment.

Advances in knowledge: SSO, a validated marker of adequate stress in CMR, occurs significantly less frequently in the presence of AF, risking a suboptimal functional assessment of coronary disease.

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Conflict of interest statement

Competing interests: Dr Rodrigues reports personal fees from NHSX outside of the submitted work and Dr Rodrigues and Dr Graby report personal fees from Sanofi outside of the submitted work. No other conflicts to disclose.

Figures

Figure 1.
Figure 1.
Study Flowchart. * Patients with greater than one scan during the study period. ** Breakdown of reasons for no scan: Claustrophobic (4), recent steroids (1), recent caffeine (4), abandoned (3), hypotensive (3), unable to tolerate symptoms (10), cancelled (1), low eGFR (2), asthma (1), body habitus (2), CMR not required (1), tachycardic (4), admitted for CP (1), bradycardic (2), dropped oxygen saturations (1), ECG rhythm (3), pacemaker (1), incorrectly coded (1), no reason given (18).
Figure 2.
Figure 2.
Splenic Switch-Off on Stress CMR. (A-D) Stress CMR images showing splenic switch-off in a 75-year-old male in sinus rhythm. Splenic signal intensity (SI) is clearly visually reduced at stress. This is confirmed in the corresponding graphical representation of tissue SI against time. Red line indicates splenic SI. Other lines each represent SI of a myocardial segment. (A) Rest image B) Stress image C) Rest graph D) Stress graph. (E-F) Stress CMR images showing failed splenic-switch off in a 68-year-old male with AF. (E) Rest maximum splenic SI F) Stress maximum splenic SI. (G-H) Graphical representation of tissue perfusion on stress CMR showing failed splenic switch-off in a 72-year-old male with AF. (G) Rest H) Stress.
Figure 3.
Figure 3.
Inducible Ischaemia Frequency in Splenic Switch-Off. * Percutaneous coronary intervention.
See this image and copyright information in PMC

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References

    1. Knuuti J, Wijns W, Saraste A, Capodanno D, Barbato E, Funck-Brentano C, et al. . 2019 ESC guidelines for the diagnosis and management of chronic coronary syndromes. Eur Heart J 2020; 41: 407–77. doi: 10.1093/eurheartj/ehz425 - DOI - PubMed
    1. Recent-onset chest pain of suspected cardiac origin: assessment and diagnosis. London: National Institute for Health and. 2016. Available from: https://www.nice.org.uk/guidance/cg95/chapter/Recommendations - PubMed
    1. Greenwood JP, Ripley DP, Berry C, McCann GP, Plein S, Bucciarelli-Ducci C, et al. . CE-MARC 2 Investigators. In: Effect of Care Guided by Cardiovascular Magnetic Resonance, Myocardial Perfusion Scintigraphy, or NICE Guidelines on Subsequent Unnecessary Angiography Rates: The CE-MARC 2 Randomized Clinical Trial. JAMA. ; September 2016., pp. 1051–60. doi: 10.1001/jama.2016.12680 - DOI - PubMed
    1. Einstein A, Fisher D, Gregory S, Hansen C, Messana S. Pharmacologic and Exercise Stress Tests. 2011. Available from: https://www.asnc.org/practicepoints
    1. Brown LAE, Saunderson CED, Das A, Craven T, Levelt E, Knott KD, et al. . A comparison of standard and high dose adenosine protocols in routine vasodilator stress cardiovascular magnetic resonance: dosage affects hyperaemic myocardial blood flow in patients with severe left ventricular systolic impairment. J Cardiovasc Magn Reson 2021; 23: 37. doi: 10.1186/s12968-021-00714-7 - DOI - PMC - PubMed