1. Background Methods Results Conclusion
Assessment of LV scar burden cardiac magnetic resonance and
phase analysis gated SPECT and impact on cardiac
resynchronization therapy
Walid Kamel BCCh 1; Wael Samy MD; 1 Osama Tayeh MD 1; Noha Behairy MD 2; Alia Abd el Fattah MD 1
1 Critical care department, Cairo University
2 Radiology department, Cairo University
Background
Cardiac resynchronization therapy (CRT) is an established tool in improving dyssynchrony in chronic heart failure. Scar burden assessment plays an important role in predicting response to CRT implantation.
P <.001
Phase analysis
Area
P value
Cut-off
Sensitivity
specificity
Histogram BW
72.2%
.045
152
72.7%
63.2%
Histogram SD
74.2%
.030 54
81.8%
Histogram Entropy
78.9%
.009
48.5
73.7%
Methods
30 Pts  CRT implantation
Echocardiographic response, defined as relative increase in LVES or decrease in LVEF by ≥15%
CMR: Pre-implantation delayed hyperenhancement cardiac magnetic resonance
- Scar burden
- Lateral wall involvement.
Group A: (0-50% scar thickness)
Segments
Group B: (>50% scar thickness).
Rest 99mTc-MIBI gated SPECT
- LV volumes & EF
- Rest perfusion defects
- Dyssynchrony parameters (Histogram bandwidth BW, Standard deviation SD and entropy)
Echocardiography
CMR
Responder
Non-responder
P value
CMR Scar segments
9.0±3.2
12.2±2.6
0.009
Scarred segment percentage
53±18%
73±15%
0.006
Scar score CMR
20.5±7.5
27.9±5.2
0.008
Scar burden CMR
30±11%
41±8%
CRT non-responder
Area
P value
Cut-off
Sensitivity
Specificity
Summed Rest Score
.641
.204
15.5
72.7%
57.9%
scar burden SPECT
.617
.292
23.0%
scar score (CMR)
.782
.011
25.0
81.8%
68.4%
scar burden (CMR)
.780
.012
38.5%
CMR
Responder
Non-responder
P value
Lat. wall scarred segments
1.5±1.2
2.3±.8
0.08
Lat. wall CMR scar score
6.3±4.1
9.2±2.6
0.024
Results
30 Pts CRT (mean age 58.7±9.0, 24 males).
Echocardiographic response, was documented in 19 patients (63.3%).
There was no statistically significant difference between responders and non-responders for their baseline risk factors, demographics, cardiac imaging data.
P .005
R .238, P .206
R .257, P .170
R .364, P .058
Conclusion
Gated SPECT LV dyssynchrony depends largely on underlying LV scar substrate.
Cardiac Magnetic Resonance could provide an adequate tool to rule out potential CRT non-responders.