Old and new insights into viability:perfusion and Perfusion Reserve R.Senior Professor of Clinical Cardiology Consultant Cardiologist and Director of Echo,Royal Brompton Hospital,London and Northwick Park Hosptal,Harrow
MBF (ml/min/100g) Myocardial Blood Flow (MBF) in LV Dysfunction Meta-analysis of five studies 120 Normal myocardium Mismatch 80 40 0 Mean ± SD P = 0.004 Rahimtoola SH et al. Circulation 1994
MBF (ml/min/100g) MBF in Patients With and Without LV Dysfunction 125 Without LVD With LVD 100 85 50 25 82.7 ± 18 84.8 ± 13.9 95.5 ± 26.7 77.1 ± 24.6 0 Remote collateral (n = 34) Collateral dependent (n = 25) Remote collateral (n = 70) Collateral dependent (n = 52) Vanoverschelde JL et al. Circulation 1993
MBF (ml min -1 g -1 ) % Wall Thickening Relationship Between Wall Thickening and MBF in LAD bed(dog) 40 30 20 10 0 1.80 1.40 1.00 0.60 Epi Trans Endo 0.20 2 (n=12) 5 (n=5) Post-operative days 13 (n=4) 21 (n=5) 42 (n=12) Adapted from Firoozan S et al. Am J Physiol 1999
MBF (ml min -1 g -1 ) % Wall Thickening Relationship Between Wall Thickening and MBF in LCX 40 30 20 10 0 1.80 1.40 1.00 0.60 0.20 2 (n=12) 5 (n=5) Post-operative days 13 (n=4) 21 (n=5) 42 (n=12) Epi Trans Endo Adapted from Firoozan S et al. Am J Physiol 1999
Normal wall motion Improvement of Viable Myocardium after Revascularisation 30 Wall motion score < 2 * 20 * 10 11 days 14 weeks >12 months * P < 0.05 Normal perfusion but dysfunctional Reduced perfusion but dysfunctional Adapted from Haas M et al. J Am Coll Cardiol 2000
Bar graph of ratio of hyperaemic to baseline absolute slow shown as an index of collateral flow reserve Vanoverschelde JL et al. Circulation 1993; 87: 1513-1523
Contrast Echocardiography Tiny microbubbles sized to pass through the smallest capillaries Designed to increase the signal strength of echoes
Risk area and perfusion defect size in a dog with coronary occlusion (6 hrs) Coggins et al, Circ 2001;104:2471-2477 9/9/2010 GBT Workshop 1 10
. MCE and Gad-enhanced MRI after AMI
Mean perfusion score on MCE Relationship between Contrast score and Transmural Extent of Infarction 2 1.8 1.6 1.4 1.2 1 0.8 0.6 0.4 0.2 0 1.8 p < 0.0001 1.3 0.5 0.3 1-25% 26-50% 51-75% 76-100% Transmural extent of infarction on CMR Janardhanan, Moon, Pennell, Senior Am Heart J 2005:149;352-63
Accuracy of resting intravenous MCE and DSE for the prediction of myocardial viability following AMI 09/09/2010 GBT Workshop 1 16
Kaplan Meier Survival curves for MCE Defect Size for the prediction of cardiac death in 95 pts following AMI Dwivedi and Senior J Am Coll.Cardiol2007;50:327-34 9/9/2010 GBT Workshop 1 17
Relationship Between Contrast Intensity and Microvascular and Capillary Densities Shimoni et al Circulation 2003; 106:950-956
Relationship Between Contrast Intensity ß and MBF vs Collagen Shimoni et al Circulation 2003; 106:950-956
Assessment of MBF by MCE compared to PET Vogel et al JACC 2005: 45; 754-762
Patient Characteristics in Ischemic Cadiomyomathy N 27 Previous AMI 24 LVEF 30±10% Dysfunctional segments 79% CABG 21 PCI 6 Recovery of function 74%
MCV (A), MBF(B) AND CFR (β RESERVE) IN NORMAL, HIBERNATING MYOCARDIUM (HM) AND NECROTIC SEGMENT Group 1 Myocardium A(dβ) β(dβ/s) β reserve Normal baseline function(n=35) 8.1±2.1 0.85±0.47 1.68±1.02 Group 2 HM (n=159) 7.2±2.33* 0.67±0.56 1.12±3.3 Group 3 Necrotic (n=55) 4.4±2.3Ŧ 0.43±0.32Ŧ 0.82±3.2 * p<0.05 vs Group 1; p<0.01 vs Group 1; Ŧp<0.01 vs Group 2; p = NS vs Group 2 Hickman and Senior et al Eur.J.Echocardiography 2010
COMPARISON OF MYOCARDIAL CONTRAST ECHOCARDIOGRAPHY (MCE) VS DOBUTAMINE STRESS ECHOCARDIOGRAPHY (DSE) FOR THE PREDICTION OF HM (DYSFUNCTIONAL SEGMENTS) Imaging Modalities Sensitivity Specificity Qualitative MCE 82* 55 Quantitaive MCE 87 67 DSE 67Ŧ 63 p<0.0001 vs DSE; p=0.04 vs qualitative MCE; Ŧ <0.0001 vs quantitative M p<0.03 vs qualitative MCE
Coronary Angiography
Dobutamine Stress Echo-Apical 4 chamber
Apical 4 chamber REST
Left Ventricle 6m after Revascularisation
Characteristics of Dysfunctional But Viable Myocardium in Relation to MBF at Rest MBF reserve Microcirculation Contractile protein and energy Glucose utilisation Structural alteration Recovery of function Normal MBF Reduced Preserved Preserved Normal Normal Immediate complete Reduced MBF Severely reduced Preserved Reduced Increased Moderate - severe Immediate-delayed maybe incomplete