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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

Whole heart coronary magnetic resonance angiography (MRA) at 1×1×1 mm resolution with multiplanar maximum intensity projection reformats to demonstrate the coronary arteries. (A) The right coronary artery (RCA) is seen to have a normal origin and course. (B) Excellent image quality is evident from the depiction of a small RCA marginal branch (arrow). (C) A large conal branch (arrows) takes a pre-pulmonic course and anastomoses with the left coronary system at the apex. (D, E) The left anterior descending (D solid arrow) and left circumflex (D dotted arrow) coronary arteries are shown in their proximal portions. Although the bifurcation of these vessels is clearly depicted, note that the left main coronary artery is not visible and that there is a’gap’ between the aortic root and the LAD/Cx bifurcation even on ultrahigh resolution (0.5 × 0.5 × 0.5 mm) MRA (E arrows). This was misinterpreted as an occlusion of the left main segment as the diagnosis of single coronary artery had not been recognized. RV = right ventricle; LV = left ventricle; nAo = neo-aorta; RA = right atrium; LA = left atrium.
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Fig3: Whole heart coronary magnetic resonance angiography (MRA) at 1×1×1 mm resolution with multiplanar maximum intensity projection reformats to demonstrate the coronary arteries. (A) The right coronary artery (RCA) is seen to have a normal origin and course. (B) Excellent image quality is evident from the depiction of a small RCA marginal branch (arrow). (C) A large conal branch (arrows) takes a pre-pulmonic course and anastomoses with the left coronary system at the apex. (D, E) The left anterior descending (D solid arrow) and left circumflex (D dotted arrow) coronary arteries are shown in their proximal portions. Although the bifurcation of these vessels is clearly depicted, note that the left main coronary artery is not visible and that there is a’gap’ between the aortic root and the LAD/Cx bifurcation even on ultrahigh resolution (0.5 × 0.5 × 0.5 mm) MRA (E arrows). This was misinterpreted as an occlusion of the left main segment as the diagnosis of single coronary artery had not been recognized. RV = right ventricle; LV = left ventricle; nAo = neo-aorta; RA = right atrium; LA = left atrium.

Mentions: In the first of the abnormal cases (Patient 12) the left main coronary artery could not be identified (Figure 3) – however it later transpired that the patient had previously been documented to have a single coronary system arising from the right coronary ostium.Figure 3


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)

Whole heart coronary magnetic resonance angiography (MRA) at 1×1×1 mm resolution with multiplanar maximum intensity projection reformats to demonstrate the coronary arteries. (A) The right coronary artery (RCA) is seen to have a normal origin and course. (B) Excellent image quality is evident from the depiction of a small RCA marginal branch (arrow). (C) A large conal branch (arrows) takes a pre-pulmonic course and anastomoses with the left coronary system at the apex. (D, E) The left anterior descending (D solid arrow) and left circumflex (D dotted arrow) coronary arteries are shown in their proximal portions. Although the bifurcation of these vessels is clearly depicted, note that the left main coronary artery is not visible and that there is a’gap’ between the aortic root and the LAD/Cx bifurcation even on ultrahigh resolution (0.5 × 0.5 × 0.5 mm) MRA (E arrows). This was misinterpreted as an occlusion of the left main segment as the diagnosis of single coronary artery had not been recognized. RV = right ventricle; LV = left ventricle; nAo = neo-aorta; RA = right atrium; LA = left atrium.
© Copyright Policy - open-access
Related In: Results  -  Collection

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

Fig3: Whole heart coronary magnetic resonance angiography (MRA) at 1×1×1 mm resolution with multiplanar maximum intensity projection reformats to demonstrate the coronary arteries. (A) The right coronary artery (RCA) is seen to have a normal origin and course. (B) Excellent image quality is evident from the depiction of a small RCA marginal branch (arrow). (C) A large conal branch (arrows) takes a pre-pulmonic course and anastomoses with the left coronary system at the apex. (D, E) The left anterior descending (D solid arrow) and left circumflex (D dotted arrow) coronary arteries are shown in their proximal portions. Although the bifurcation of these vessels is clearly depicted, note that the left main coronary artery is not visible and that there is a’gap’ between the aortic root and the LAD/Cx bifurcation even on ultrahigh resolution (0.5 × 0.5 × 0.5 mm) MRA (E arrows). This was misinterpreted as an occlusion of the left main segment as the diagnosis of single coronary artery had not been recognized. RV = right ventricle; LV = left ventricle; nAo = neo-aorta; RA = right atrium; LA = left atrium.
Mentions: In the first of the abnormal cases (Patient 12) the left main coronary artery could not be identified (Figure 3) – however it later transpired that the patient had previously been documented to have a single coronary system arising from the right coronary ostium.Figure 3

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