Usefulness of myocardial parametric imaging to evaluate myocardial viability in experimental and in clinical studies.
OBJECTIVE
To evaluate whether myocardial parametric imaging (MPI) is superior to visual assessment for the evaluation of myocardial viability.


RESULTS
Myocardial contrast echocardiography (MCE) was assessed in 11 pigs before, during, and after left anterior descending coronary artery occlusion and in 32 patients with ischaemic heart disease by using intravenous SonoVue administration. In experimental studies perfusion defect area assessment by MPI was compared with visually guided perfusion defect planimetry. Histological assessment of necrotic tissue was the standard reference. In clinical studies viability was assessed on a segmental level by (1) visual analysis of myocardial opacification; (2) quantitative estimation of myocardial blood flow in regions of interest; and (3) MPI. Functional recovery between three and six months after revascularisation was the standard reference. In experimental studies, compared with visually guided perfusion defect planimetry, planimetric assessment of infarct size by MPI correlated more significantly with histology (r2 = 0.92 versus r2 = 0.56) and had a lower intraobserver variability (4% v 15%, p < 0.05). In clinical studies, MPI had higher specificity (66% v 43%, p < 0.05) than visual MCE and good accuracy (81%) for viability detection. It was less time consuming (3.4 (1.6) v 9.2 (2.4) minutes per image, p < 0.05) than quantitative blood flow estimation by regions of interest and increased the agreement between observers interpreting myocardial perfusion (kappa = 0.87 v kappa = 0.75, p < 0.05).


CONCLUSIONS
MPI is useful for the evaluation of myocardial viability both in animals and in patients. It is less time consuming than quantification analysis by regions of interest and less observer dependent than visual analysis. Thus, strategies incorporating this technique may be valuable for the evaluation of myocardial viability in clinical routine.
Korosoglou
G
G
Department of Cardiology, University of Heidelberg, Heidelberg, Germany. Grigorios_Korosoglou@med.uni-heidelberg.de
Hansen
A
A
Bekeredjian
R
R
Filusch
A
A
Hardt
S
S
Wolf
D
D
Schellberg
D
D
Katus
H A
HA
Kuecherer
H
H
D000368:Aged; D000818:Animals; D003326:Coronary Circulation / Q000502:physiology; D023921:Coronary Stenosis / Q000175:diagnosis* / Q000503:physiopathology; D004452:Echocardiography / Q000379:methods; D005260:Female; D006801:Humans; D008297:Male; D017202:Myocardial Ischemia / Q000175:diagnosis* / Q000503:physiopathology; D015588:Observer Variation; D010743:Phospholipids; D012307:Risk Factors; D013459:Sulfur Hexafluoride; D013552:Swine
D010743:Phospholipids; C420843:contrast agent BR1; D013459:Sulfur Hexafluoride