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Evaluation of a comprehensive cardiovascular magnetic resonance protocol in young adults late after the arterial switch operation for d-transposition of the great arteries.

Tobler D, Motwani M, Wald RM, Roche SL, Verocai F, Iwanochko RM, Greenwood JP, Oechslin EN, Crean AM - J Cardiovasc Magn Reson (2014)

Bottom Line: In 24 cases the coronary ostia could conclusively be demonstrated to be normal.The data shows that the asymptomatic and clinically stable adult ASO patient has a low pre-test probability for inducible ischemia.In this situation it is likely that routine evaluation with stress CMR is unnecessary.

View Article: PubMed Central - PubMed

Affiliation: Toronto Congenital Centre for Adults, Peter Munk Cardiac Centre, University Health Network, Toronto General Hospital, 585 University Avenue, 5 N-525, Toronto M5G 2N2, ON, Canada. andrew.crean@uhn.ca.

ABSTRACT

Background: In adults with prior arterial switch operation (ASO) for d-transposition of the great arteries, the need for routine coronary artery assessment and evaluation for silent myocardial ischemia is not well defined. In this observational study we aimed to determine the value of a comprehensive cardiovascular magnetic resonance (CMR) protocol for the detection of coronary problems in adults with prior ASO for d-transposition of the great arteries.

Methods: Adult ASO patients (≥18 years of age) were recruited consecutively. Patients underwent a comprehensive stress perfusion CMR protocol that included measurement of biventricular systolic function, myocardial scar burden, coronary ostial assessment and myocardial perfusion during vasodilator stress by perfusion CMR. Single photon emission computed tomography (SPECT) was performed on the same day as a confirmatory second imaging modality. Stress studies were visually assessed for perfusion defects (qualitative analysis). Additionally, myocardial blood flow was quantitatively analysed from mid-ventricular perfusion CMR images. In unclear cases, CT coronary angiography or conventional angiography was done.

Results: Twenty-seven adult ASO patients (mean age 23 years, 85% male, 67% with a usual coronary pattern; none with a prior coronary artery complication) were included in the study. CMR stress perfusion was normal in all 27 patients with no evidence of inducible perfusion defects. In 24 cases the coronary ostia could conclusively be demonstrated to be normal. There was disagreement between CMR and SPECT for visually-assessed perfusion defects in 54% of patients with most disagreement due to false positive SPECT.

Conclusions: Adult ASO survivors in this study had no CMR evidence of myocardial ischemia, scar or coronary ostial abnormality. Compared to SPECT, CMR provides additional valuable information about the coronary artery anatomy. The data shows that the asymptomatic and clinically stable adult ASO patient has a low pre-test probability for inducible ischemia. In this situation it is likely that routine evaluation with stress CMR is unnecessary.

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Related in: MedlinePlus

Evaluation of a “kinked” right coronary artery. (A) Straight axial image from a whole heart magnetic resonance angiogram demonstrates an apparent “kink” at the right coronary artery origin. (B-D) Subsequent multiplanar and centre line reformats however demonstrate that the ostium is in reality unobstructed. (E) The left coronary origin is also unobstructed. (Fi-iii) Stress perfusion magnetic resonance frames at basal, mid and apical left ventricular level show no evidence of any inducible perfusion defect. Quantitative perfusion measured in the right coronary territory was normal (not shown).
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Fig4: Evaluation of a “kinked” right coronary artery. (A) Straight axial image from a whole heart magnetic resonance angiogram demonstrates an apparent “kink” at the right coronary artery origin. (B-D) Subsequent multiplanar and centre line reformats however demonstrate that the ostium is in reality unobstructed. (E) The left coronary origin is also unobstructed. (Fi-iii) Stress perfusion magnetic resonance frames at basal, mid and apical left ventricular level show no evidence of any inducible perfusion defect. Quantitative perfusion measured in the right coronary territory was normal (not shown).

Mentions: The second case was a patient with possible compression of the right coronary artery on CMR but negative CMR perfusion study (Patient 22). A small SPECT defect was recorded in the LAD territory and was therefore not congruent with the potential right coronary artery anomaly. Subsequent multiplanar reformats of the whole heart data set demonstrated tortuosity rather than obstruction (Figure 4). The patient remains asymptomatic and has declined further investigation by either CT coronary angiography or conventional catheterization.Figure 4


Evaluation of a comprehensive cardiovascular magnetic resonance protocol in young adults late after the arterial switch operation for d-transposition of the great arteries.

Tobler D, Motwani M, Wald RM, Roche SL, Verocai F, Iwanochko RM, Greenwood JP, Oechslin EN, Crean AM - J Cardiovasc Magn Reson (2014)

Evaluation of a “kinked” right coronary artery. (A) Straight axial image from a whole heart magnetic resonance angiogram demonstrates an apparent “kink” at the right coronary artery origin. (B-D) Subsequent multiplanar and centre line reformats however demonstrate that the ostium is in reality unobstructed. (E) The left coronary origin is also unobstructed. (Fi-iii) Stress perfusion magnetic resonance frames at basal, mid and apical left ventricular level show no evidence of any inducible perfusion defect. Quantitative perfusion measured in the right coronary territory was normal (not shown).
© Copyright Policy - open-access
Related In: Results  -  Collection

License 1 - License 2
Show All Figures
getmorefigures.php?uid=PMC4263214&req=5

Fig4: Evaluation of a “kinked” right coronary artery. (A) Straight axial image from a whole heart magnetic resonance angiogram demonstrates an apparent “kink” at the right coronary artery origin. (B-D) Subsequent multiplanar and centre line reformats however demonstrate that the ostium is in reality unobstructed. (E) The left coronary origin is also unobstructed. (Fi-iii) Stress perfusion magnetic resonance frames at basal, mid and apical left ventricular level show no evidence of any inducible perfusion defect. Quantitative perfusion measured in the right coronary territory was normal (not shown).
Mentions: The second case was a patient with possible compression of the right coronary artery on CMR but negative CMR perfusion study (Patient 22). A small SPECT defect was recorded in the LAD territory and was therefore not congruent with the potential right coronary artery anomaly. Subsequent multiplanar reformats of the whole heart data set demonstrated tortuosity rather than obstruction (Figure 4). The patient remains asymptomatic and has declined further investigation by either CT coronary angiography or conventional catheterization.Figure 4

Bottom Line: In 24 cases the coronary ostia could conclusively be demonstrated to be normal.The data shows that the asymptomatic and clinically stable adult ASO patient has a low pre-test probability for inducible ischemia.In this situation it is likely that routine evaluation with stress CMR is unnecessary.

View Article: PubMed Central - PubMed

Affiliation: Toronto Congenital Centre for Adults, Peter Munk Cardiac Centre, University Health Network, Toronto General Hospital, 585 University Avenue, 5 N-525, Toronto M5G 2N2, ON, Canada. andrew.crean@uhn.ca.

ABSTRACT

Background: In adults with prior arterial switch operation (ASO) for d-transposition of the great arteries, the need for routine coronary artery assessment and evaluation for silent myocardial ischemia is not well defined. In this observational study we aimed to determine the value of a comprehensive cardiovascular magnetic resonance (CMR) protocol for the detection of coronary problems in adults with prior ASO for d-transposition of the great arteries.

Methods: Adult ASO patients (≥18 years of age) were recruited consecutively. Patients underwent a comprehensive stress perfusion CMR protocol that included measurement of biventricular systolic function, myocardial scar burden, coronary ostial assessment and myocardial perfusion during vasodilator stress by perfusion CMR. Single photon emission computed tomography (SPECT) was performed on the same day as a confirmatory second imaging modality. Stress studies were visually assessed for perfusion defects (qualitative analysis). Additionally, myocardial blood flow was quantitatively analysed from mid-ventricular perfusion CMR images. In unclear cases, CT coronary angiography or conventional angiography was done.

Results: Twenty-seven adult ASO patients (mean age 23 years, 85% male, 67% with a usual coronary pattern; none with a prior coronary artery complication) were included in the study. CMR stress perfusion was normal in all 27 patients with no evidence of inducible perfusion defects. In 24 cases the coronary ostia could conclusively be demonstrated to be normal. There was disagreement between CMR and SPECT for visually-assessed perfusion defects in 54% of patients with most disagreement due to false positive SPECT.

Conclusions: Adult ASO survivors in this study had no CMR evidence of myocardial ischemia, scar or coronary ostial abnormality. Compared to SPECT, CMR provides additional valuable information about the coronary artery anatomy. The data shows that the asymptomatic and clinically stable adult ASO patient has a low pre-test probability for inducible ischemia. In this situation it is likely that routine evaluation with stress CMR is unnecessary.

Show MeSH
Related in: MedlinePlus