Quantifying the Area at Risk in Reperfused ST-Segment-Elevation Myocardial Infarction Patients Using Hybrid Cardiac Positron Emission Tomography-Magnetic Resonance Imaging.

BACKGROUND: Hybrid positron emission tomography and magnetic resonance allows the advantages of magnetic resonance in tissue characterizing the myocardium to be combined with the unique metabolic insights of positron emission tomography. We hypothesized that the area of reduced myocardial glucose uptake would closely match the area at risk delineated by T2 mapping in ST-segment-elevation myocardial infarction patients. METHODS AND RESULTS: Hybrid positron emission tomography and magnetic resonance using (18)F-fluorodeoxyglucose (FDG) for glucose uptake was performed in 21 ST-segment-elevation myocardial infarction patients at a median of 5 days. Follow-up scans were performed in a subset of patients 12 months later. The area of reduced FDG uptake was significantly larger than the infarct size quantified by late gadolinium enhancement (37.2±11.6% versus 22.3±11.7%; P<0.001) and closely matched the area at risk by T2 mapping (37.2±11.6% versus 36.3±12.2%; P=0.10, R=0.98, bias 0.9±4.4%). On the follow-up scans, the area of reduced FDG uptake was significantly smaller in size when compared with the acute scans (19.5 [6.3%-31.8%] versus 44.0 [21.3%-55.3%]; P=0.002) and closely correlated with the areas of late gadolinium enhancement (R 0.98) with a small bias of 2.0±5.6%. An FDG uptake of ≥45% on the acute scans could predict viable myocardium on the follow-up scan. Both transmural extent of late gadolinium enhancement and FDG uptake on the acute scan performed equally well to predict segmental wall motion recovery. CONCLUSIONS: Hybrid positron emission tomography and magnetic resonance in the reperfused ST-segment-elevation myocardial infarction patients showed reduced myocardial glucose uptake within the area at risk and closely matched the area at risk delineated by T2 mapping. FDG uptake, as well as transmural extent of late gadolinium enhancement, acutely can identify viable myocardial segments.

How long has NICE taken to produce Technology Appraisal guidance? A retrospective study to estimate predictors of time to guidance.

OBJECTIVES: To assess how long the UK's National Institute for Health and Clinical Excellence's (NICE) Technology Appraisal Programme has taken to produce guidance and to determine independent predictors of time to guidance. DESIGN: Retrospective time to event (survival) analysis. SETTING: Technology Appraisal guidance produced by NICE. DATASOURCE: All appraisals referred to NICE by February 2010 were included, except those referred prior to 2001 and a number that were suspended. OUTCOME MEASURE: Duration from the start of an appraisal (when the scope document was released) until publication of guidance. RESULTS: Single Technology Appraisals (STAs) were published significantly faster than Multiple Technology Appraisals (MTAs) with median durations of 48.0 (IQR; 44.3-75.4) and 74.0 (IQR; 60.9-114.0) weeks, respectively (p <0.0001). Median time to publication exceeded published process timelines, even after adjusting for appeals. Results from the modelling suggest that STAs published guidance significantly faster than MTAs after adjusting for other covariates (by 36.2 weeks (95% CI -46.05 to -26.42 weeks)) and that appeals against provisional guidance significantly increased the time to publication (by 42.83 weeks (95% CI 35.50 to 50.17 weeks)). There was no evidence that STAs of cancer-related technologies took longer to complete compared with STAs of other technologies after adjusting for potentially confounding variables and only weak evidence suggesting that the time to produce guidance is increasing each year (by 1.40 weeks (95% CI -0.35 to 2.94 weeks)). CONCLUSIONS: The results from this study suggest that the STA process has resulted in significantly faster guidance compared with the MTA process irrespective of the topic, but that these gains are lost if appeals are made against provisional guidance. While NICE processes continue to evolve over time, a trade-off might be that decisions take longer but at present there is no evidence of a significant increase in duration.