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Background: We conducted a meta-analysis of observational studies which examined the association between flow-mediated dilatation (FMD) of brachial artery, a noninvasive measure of endothelial function, and future cardiovascular events.Methods: Electronic databases were searched using a predefined search strategy. Data was independently abstracted on study characteristics, study quality, and outcomes by two reviewers. The multivariate relative risks, adjusted for confounding factors, were calculated from individual studies and then pooled using random-effects models. Statistical heterogeneity was evaluated using I2 statistics. Subgroup analyses and meta-regression analyses were conducted to assess the robustness of the meta-analysis. Publication bias was examined with funnel plot analysis and Egger's test.Results: Four population-based cohort studies and ten convenience-cohort studies, involving 5,547 participants, were included in the meta-analysis. The pooled relative risks of cardiovascular events per 1% increase in brachial FMD, adjusted for confounding risk factors, was 0.87 (95% CI, 0.83- 0.91). The significant associations between brachial FMD and cardiovascular events were consistent among all subgroups evaluated, suggesting the robustness of the meta-analysis. However, the presence of heterogeneity in study quality, the remaining confounding factors, and publication bias in the available literature prevent a definitive evaluation of the additional predictive value of brachial FMD beyond traditional cardiovascular risk factors.Conclusions: The meta-analysis of heterogeneous studies with moderate methodological quality suggested that impairment of brachial FMD is significantly associated with future cardiovascular events. Further prospective randomized trials are warranted to confirm the efficacy of the usage of brachial FMD in the management of cardiovascular diseases. [ABSTRACT FROM AUTHOR]

Purpose: Computations of left and right ventricular (LV and RV) gated blood pool SPECT (GBPS) ejection fraction (EF) have been well validated against other imaging modalities. As GBPS images depict the entire extent of both blood pools, it is possible to compute not only global but also regional biventricular function parameters, which have the prospect of being clinically useful for planning cardiac resynchronization therapy. This investigation sought to establish LV and RV count-based GBPS regional functional normal limits and to quantify their reproducibility.Methods and Materials: Count-versus-time curves were fit to third-order Fourier series for each of 17 LV and RV sub-volumes to compute global and regional EF, timing, phase and dyssynchrony parameters. Algorithms were applied to data for 40 normal controls (NLs) and 15 patients with CHF. To assess reproducibility, data were reprocessed a second time, blinded to initial calculations.Results: There were no statistically significant differences between any initial and reprocessed LV or RV parameters for NLs or patients with CHF. Percent of subjects categorized as abnormal were the same for initial and reprocessed parameters (McNemar's differences = 0-7%, P > 0.05 for each parameter). Most parameters were significantly different for patients with CHF versus NLs. Normal limits for the new technique agreed well with the literature for other imaging methods, and RV normal limits closely paralleled LV limits.Conclusion: GBPS global and regional LV and RV normal limits are reproducible, and application of these normal limits to patients with CHF results in reproducible detection of functional abnormalities. [ABSTRACT FROM AUTHOR]

Background: beta-Methyl-p-[(123)I]-iodophenyl-pentadecanoic acid (BMIPP) imaging has been used extensively to detect coronary artery disease (CAD), primarily in Japan. However, the reported sensitivity and specificity vary considerably from study to study. This meta-analysis was conducted to summarize the evidence for the diagnostic accuracy of resting BMIPP imaging in the detection of CAD.Methods and Results: A MEDLINE search of the literature published through the end of 2006 was performed. Seven studies (528 patients) met the inclusion criteria. Using random-effects models, the overall sensitivity and specificity to detect CAD were 78% (95% confidence interval, 73% to 81%) and 84% (95% confidence interval, 77% to 89%), respectively. A significant threshold effect was identified among studies, which was expected given the between-study variability in study methodology. A summary receiver-operating characteristic curve yielded an asymmetric curve with an area under the curve of 0.91 (SE, 0.020), indicating excellent diagnostic performance.Conclusions: Imaging with BMIPP at rest exhibits a moderate sensitivity and high specificity to detect CAD in patients with a high prevalence of CAD. Thus, this tracer may be of great value for patients with acute chest pain and those with relative contraindications to exercise or pharmacologic stress myocardial perfusion imaging (MPI). [ABSTRACT FROM AUTHOR]