NEW ORLEANS - The growing incidence of heart disease in women has lately captured the attention of both the public and the medical community. Eight million women in the U.S. currently have some form of heart disease and it is the leading cause of death, according to the National Coalition for Women with Heart Disease.
But when it comes to the imaging assessment of heart disease, does gender make a difference? A group from the University of Michigan Medical Center in Ann Arbor tested the normal ranges of cardiac functional parameters in women and men.
Lead by Ed Ficaro, Ph.D., the researchers used gated SPECT with a 4D-MSPECT cardiac quantification software, which was co-developed by Ficaro. (The university receives royalties from the sale of this product.)
"Gender-specific differences in normal values of LV (left ventricular) cardiac variables must be taken into account for correct diagnostic interpretation," the group wrote in a poster presentation at the 2003 Society of Nuclear Medicine meeting.
The patient population for this study consisted of 30 males and 30 females all with a pre-test likelihood of having coronary artery disease of less than or equal to 5%. The mean age of the subjects was 47.3 years.
Images were acquired on a 30000XP SPECT system (Philips Medical Systems), 15 minutes after the injection of 1.1 GBq of 99mTC sestamibi during the stress phase. The parameters for the SPECT studies were as follows:
- 360° orbit, 60 step/detector, 16 seconds/step
- 64 x 64 matrix
- 6.3 mm pixel size
- 16 frame/cardiac cycle
"All gated data were reconstructed from 180° projection image orbits…using filtered back projection," they explained.
The processing protocol included reslicing the reconstructed images into LV, short-axis images of the entire ventricular volume. LV 3-D surfaces were automatically rendered using 4D MSPECT and analyzed for perfusion, volumes and cardic outputs.
With these results, the authors then compared the following based on gender:
- Ejection fraction (EF)
- End-diastolic volume index (EDVI)
- End-systolic volume index (ESVI)
- Cardiac index (CI)
- Body surface area (BSA)
According to the mean values ± standard deviation, the mean EF for females was 72.2 ± 5.4. For men, it was 64.4 ± 5.6, for a significant p value of <0.0001. The EDVI was females was 46.3 ± 8.5 and 64.6 ± 14.7 for males (p<0.0001). In term of ESVI, the group reported a value of 13.2 ± 4.4 for women and 23.2 ± 7.4 for men (p<0.0001). The CI was 2.29 ± 0.39 for women and 2.73 ± 0.61 for men (p<0.01). The BSA came in at 1.77 ± 0.18 for women and 2.03 ± 0.16 for men (p<0.0001).
The authors found no significant difference in heart rate between men (66.3 ± 7.7) and women (69.6 ± 10). However, the differences in all other measured variables were noteworthy.
"The higher EFs seen in females appears to be a physiologic response to their smaller ED volumes, as there is a concordant reduction in cardiac indices without corresponding increases in heart rate," the authors concluded.
By Shalmali PalAuntMinnie.com staff writer
June 24, 2003
Related Reading
Nuclear medicine sheds lights on cardiovascular disease in women, October 3, 2002
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