Ejection fractions determined by cardiac computed tomographic angiography and single photon emission computed tomographic myocardial perfusion imaging are not interchangeable: evidence of significant and sex-associated disparities.

PURPOSE: Left ventricular ejection fraction (LVEF) determines patient management and is a standard part of cardiac imaging evaluation. Intermodality comparisons are useful in determining whether modalities are interchangeable. Multidetector Computed tomography (CT) and single photon emission CT (SPECT) myocardial perfusion imaging (MPI) have been compared in only a few cohorts. We compared these modalities in a sex-balanced group. MATERIALS AND METHODS: Sixty outpatients (30 women 30 men) referred for MPI underwent CT on the same day. We calculated LVEF, end-diastolic volume (EDV), and end-systolic volume (ESV) from CT and MPI datasets using a commercially available, semi-automated routine and quantitative gated SPECT (QGS) respectively. Correlations, t-tests and Bland-Altman plots were performed for ESV, EDV, and LVEF. Bivariate and multiple regression analyses for LVEF were performed for both modalities. The subgroups for men and women were analyzed. RESULTS: Computed tomography showed moderate to high correlations with SPECT for LVEF (0.62), EDV (0.70), and ESV (0.63). End-diastolic volume and LVEF were significantly higher on CT as compared to SPECT (P < 0.001 each). Multiple regression analysis showed a significant relationship between sex and LVEF (P < 0.0001) on SPECT but not on CT. In men, there were significantly higher EDV (P = 0.014) and LVEF (P < 0.001) on CT compared with SPECT, but there was no difference in ESV. For women, there were significantly higher EDV and ESV on CT (P < 0.001 each), but no difference in LVEF. CONCLUSIONS: Left ventricular volumes and LVEF differed significantly on CT compared with SPECT and varied according to sex. Therefore, left ventricular volumes and LVEF values on CT and SPECT are not interchangeable.

Burden of asthma in inner-city elementary schoolchildren: do school-based health centers make a difference?

BACKGROUND: About 1400 school-based health centers (SBHCs) provide care to 1.1 million children. However, it is unknown if access to on-site services is associated with a better outcome. OBJECTIVE: To compare outcomes including hospitalizations, emergency department visits, and school absenteeism in elementary schoolchildren with asthma who were grouped according to their enrollment at schools that have or do not have SBHCs. SETTING: Six elementary schools in The Bronx, NY (4 schools with and 2 without SBHCs). PARTICIPANTS: Nine hundred forty-nine inner-city schoolchildren with asthma. DESIGN: To collect baseline data for a longitudinal study, we surveyed parents to identify children with asthma, and to obtain information about symptoms and the use of health services in the last 12 months. Participating schools provided absenteeism information. RESULTS: Of 6433 parents surveyed, 74% completed the questionnaires. The prevalence of asthma was 19.9% and the morbidity was high-during the previous year, 46.2% had been treated for asthma in an emergency department; 12.6% had been hospitalized. Emergency department use was not associated with SBHCs. However, in univariate and multivariate analyses, the rate of hospitalization was higher among children enrolled at schools without an SBHC (rate ratio, 1.5; 95% confidence interval, 1.1-1.9). In addition, schoolchildren with asthma enrolled in the schools without an SBHC missed more days of school than those enrolled in schools with an SBHC (mean [SD], 21.3 [15.4] vs 18.2 [13.0], respectively; P =.02). CONCLUSION: Access to SBHCs was associated with a reduction in the rate of hospitalization and a gain of 3 days of school for schoolchildren who have asthma.