Impact of diabetes mellitus on worsening of the left ventricular ejection fraction in exercise-gated 201Tl myocardial single photon emission computed tomography in patients with coronary artery disease

Gender differences in myocardial perfusion defect in asymptomatic postmenopausal women and men with and without diabetes mellitus

BACKGROUND

To compare the results of myocardial perfusion imaging (MPI) of asymptomatic postmenopausal women and age-matched men and to investigate the effect of diabetes mellitus (DM) on gender differences and the risk estimation of coronary heart disease (CHD).

METHODS

Sixty-seven postmenopausal women and 27 men low in Framingham Global Risk Score (FGRS) were recruited from year 2008 to 2009 in northern Taiwan. Each subject underwent blood tests, a cardiopulmonary exercise test, an electrocardiograph (ECG), and MPI.

RESULTS

Women had similar percentages of predicted oxygen consumption and ECG changes at peak exercise, but lower oxygen pulse and rate-pressure product. They also had significantly higher summed stress score (SSS), summed rest score (SRS), and summed difference score (SDS) than men, despite showing much lower scores for the FGRS than men. Women with DM had a lower 10-year risk of CHD assessed by the United Kingdom Prospective Diabetes Study (UKPDS) risk engine, but significantly higher SSS and SDS than men. In the subjects with abnormal MPI, the extent of ischemia was small to moderate in men, whereas in 50% of the women, the extent of ischemia was large.

CONCLUSION

The results of this preliminary study suggest that asymptomatic postmenopausal women had more abnormalities in MPI and those with DM had a higher SSS and SDS than age-matched men. The risk of CAD may still be underestimated by the UKPDS.

Myocardial perfusion image in asymptomatic postmenopausal women with physical inactivity and overweight

OBJECTIVE

This study aimed to investigate whether physical inactivity and overweight deteriorate myocardial perfusion and cardiac function in asymptomatic postmenopausal women.

METHODS

A prospective cross-sectional study design was used. Postmenopausal women recruited in this study were categorized into groups based on activity level and BMI: physically active, normal-weight group (PANw, n = 15, 60.9 ± 6.0 years), physically inactive, normal-weight group (PIANw, n = 13, 57.2 ± 5.0 years) and physically inactive, overweight group (PIAO, n = 26, 58.5 ± 5.8 years). Each subject took cardiopulmonary function tests and ECG-gated exercise (201)Tl myocardial perfusion imaging (MPI). Perfusion abnormalities, cardiac function indices, and (201)Tl lung-to- heart ratio (LHR) were derived.

RESULTS

The PIANw women had lower exercise capacity than PANw women. More subjects in PIANw (46%) or PIAO (48%) groups had worsening in left ventricular ejection fraction (LVEF) by exercise than subjects in PANw (7%) group. The PIAO women exhibited significantly lower exercise capacity and higher rest LHR than PANw women (LHR 0.41 ± 0.05 vs. 0.36 ± 0.06; p = 0.014). Abnormal MPI tended to increase in PIANw (38%) and PIAO (46%) women when compared with the PANw (27%) group.

CONCLUSIONS

Physically inactive, overweight postmenopausal women had higher rest (201)Tl lung uptake and worsening LVEF by exercise and tended to have higher prevalence of inducible ischemia, suggesting higher cardiovascular risks although asymptomatic.

Prediction of Cardiac Events in Patients With Transient Left Ventricle Dilation on Stress Myocardial Perfusion SPECT Images

BACKGROUND

The purpose of this study was to investigate cardiac events in patients with transient left ventricle (LV) dilation on stress myocardial perfusion single-photon emission computed tomography images (MPI).

METHODS AND RESULTS

Consecutive patients (n=53, 31 males, mean age 71 years) with transient LV dilation on thallium-201 stress MPI (treadmill: 21, pharmacologic: 32) were followed for 17 months. Follow-up time was censored at the occurrence of cardiac death, congestive heart failure, acute coronary syndrome, or revascularization. Images were scored and then the summed stress score (SSS), summed rest score, and summed difference score were calculated. Cardiac death occurred in 3 patients, hospitalization occurred in 8 patients, and revascularization occurred in 20 patients. The combined cardiac event rate was 59% (76% for exercise stress vs 47% for pharmacologic stress, p=0.034). Cox regression analysis demonstrated that a combination of higher SSS and slow washout rate was the best predictor of cardiac events (hazard ratio =3.3, p=0.029).

CONCLUSIONS

A high cardiac event rate is associated with transient LV dilation on thallium-201 stress MPI. The event rate is particularly high for exercise stress MPI. Furthermore, a combination of the SSS and thallium-201 slow washout is the best predictor of cardiac events in patients with transient LV dilation.